Chassis and wheeled vehicle

Abstract

This application discloses a chassis and a wheeled vehicle. The chassis includes a base, a bottom beam mechanism, and an unlocking mechanism. The bottom beam mechanism is rotatably connected to the base; the unlocking mechanism is also rotatably connected to the base. The chassis is configured to have a locked state and an unlocked state, wherein: in the locked state, the base locks the bottom beam mechanism; the unlocking mechanism is used to push the bottom beam mechanism to unlock from the base when transitioning from the locked state to the unlocked state. This structure achieves controllable folding / unfolding conversion, consistent linkage of movements, and highly stable support in the unfolded state, thereby improving ease of use, safety, and durability.

Description

Technical Field

[0001] This application relates to the technical field of chassis, and more particularly to a chassis and wheeled vehicle. Background Technology

[0002] Foldable wheeled vehicles (such as portable trolleys, luggage carts, walkers, and some miniature mobile platforms) generally employ folding mechanisms that can switch between use and storage to balance portability and stability. Existing technologies mostly use circumferentially arranged columns / vertical rods and chassis frames as basic units, and achieve folding through linkages, cables, or manual folding hinges.

[0003] However, existing solutions generally suffer from the following common problems: First, the folding drive path is scattered, relying on the user to unlock and fold sequentially at multiple positions, resulting in poor linkage consistency and the possibility of one side folding first or getting stuck, leading to cumbersome operation steps and requiring considerable force; Second, the unlocking and locking mechanisms are often mixed with the load-bearing frame or positioned by elastic elements, resulting in insufficient locking force or being greatly affected by deformation, causing geometric position drift, shaking, and abnormal noise after unfolding, affecting load-bearing stability and durability; Third, the force transmission chain between the chassis and the outer vertical beam is unclear, and the relative movement of the vertical beam and chassis during folding lacks definite kinematic pair constraints, with common problems including hinge point wear, folding interference, poor synchronization, and difficulty in repeating the extreme position; Fourth, some designs use single-sided locking or rely on indirect limiting by multiple cables, which is complex to maintain, has poor environmental adaptability, and is prone to failure under dust, low temperature, or long-term load.

[0004] Furthermore, if the existing folding structure does not establish a clear "controllable unlocking - restricted unfolding" relationship at the chassis level, it is difficult to ensure high rigidity support after unfolding while ensuring rapid folding. It often requires additional support rods or secondary locking actions, increasing the user's learning cost and the number of potential failure points. Utility Model Content

[0005] One objective of this application is to provide a chassis and wheeled vehicle that establishes clear kinematic constraints and a reliable locking / unlocking mechanism at the chassis level, so that the bottom beam can serve as an effective force transmission and driving component of the vertical beam, and can achieve predictable and low-resistance switching between locking and unlocking conditions.

[0006] The first aspect of this application provides a chassis for a wheeled vehicle, the chassis including: a base, a bottom beam mechanism, and an unlocking mechanism, the bottom beam mechanism being rotatably connected to the base; the unlocking mechanism being rotatably connected to the base; the chassis is configured to have a locked state and an unlocked state, wherein: in the locked state, the base locks the bottom beam mechanism; the unlocking mechanism is used to push the bottom beam mechanism to unlock from the base when transitioning from the locked state to the unlocked state.

[0007] Optionally, the unlocking mechanism includes a pressing component and an activation component. The pressing component is rotatably connected to the base, and the activation component is rotatably connected to the base. When the pressing component is switched from the locked state to the unlocked state, it rotates and drives the activation component to rotate, so that the activation component pushes the bottom beam mechanism to unlock from the base.

[0008] Optionally, the pressing component includes a pressure plate, which is rotatably connected to the base. The first end of the pressure plate is used to receive force applied by the user, and the second end of the pressure plate is used to drive the activation component to rotate.

[0009] Optionally, the distance from the first end of the pressure plate to its pivot is L1, and the distance from the second end of the pressure plate to its pivot is L2, where 1.5 ≤ L1 / L2 ≤ 4.

[0010] Optionally, the pressing assembly further includes a first rod and a second rod, the extension direction of the second rod being parallel to the extension direction of the pressure plate and being arranged opposite to each other; the opposite ends of the first rod are respectively rotatably connected to the second end of the pressure plate and the first end of the second rod, the second end of the second rod being rotatably connected to the base, and the pressure plate is used to drive the activation assembly to rotate through the second rod.

[0011] Optionally, the pressure plate is rotatably connected to the base by a pin, and the pressure plate and the base are in movable contact with each other, with a matching arc groove and arc protrusion at the contact point.

[0012] Optionally, the number of bottom beam mechanisms is at least two, and the at least two bottom beam mechanisms are arranged in a radiating pattern on the base. In the unlocked state, the at least two bottom beam mechanisms retract towards each other, and in the locked state, the at least two bottom beam mechanisms extend away from each other.

[0013] Optionally, the chassis also includes a first limiting mechanism, which is connected to the end of the bottom beam mechanism away from the base, and the first limiting mechanism is connected to two adjacent bottom beam mechanisms. The first limiting mechanism is used to maintain the extended state of the adjacent bottom beam mechanisms when they are in the locked state.

[0014] Optionally, the first limiting mechanism includes at least two first limiting seats, at least one second limiting seat, and at least two rotating rods. Each first limiting seat is connected to the end of the bottom beam mechanism away from the base. Each second limiting seat has a rotating rod rotatably connected to its opposite ends. The end of each rotating rod away from the second limiting seat it is connected to is rotatably connected to either the first limiting seat or the other second limiting seat.

[0015] Optionally, the activation component includes at least two first rotors, which are rotatably connected to the base. The first end of the first rotor is used to receive a push from the pressing component, and the second end of the first rotor is used to push at least two bottom beam mechanisms to unlock from the base. The first ends of adjacent first rotors are interlocked.

[0016] Optionally, the pressing component abuts against the outer peripheral surfaces of at least two of the first rotors.

[0017] Optionally, the activation component includes at least four second rotors, and the base beam mechanism has at least four components. The second rotors are rotatably connected to the base. Each first rotor corresponds to two second rotors, and each second rotor corresponds to one base beam mechanism. The first rotor is used to drive its two corresponding second rotors to rotate, so that the second rotors push the base beam mechanism to unlock from the base.

[0018] Optionally, an inclined pushing surface is provided at the contact point between the second end of the first rotor and the second rotor.

[0019] Optionally, the activation component includes a first rotor, which is rotatably connected to the base. A first end of the first rotor is used to receive a push from the pressing component, and a second end of the first rotor is used to push the bottom beam mechanism to unlock from the base. The distance from the first end of the first rotor to its axis of rotation is L3, and the distance from the second end of the first rotor to its axis of rotation is L4, where 1.5 ≤ L3 / L4 ≤ 4.

[0020] Optionally, the bottom beam mechanism includes a main beam and a blocking component. The main beam is rotatably connected to the base, and the blocking component is slidably connected to the main beam along its axial direction. The blocking component is used to elastically move and abut against the base to limit the rotation of the bottom beam mechanism. The unlocking mechanism is specifically used to push the blocking component to move when changing from the locked state to the unlocked state, so as to push the bottom beam mechanism to unlock from the base.

[0021] Optionally, the blocking assembly includes a pin and a reset member, the reset member being connected to the pin and the main beam respectively, the pin being slidably connected to the main beam along its axial direction, and the reset member being used to drive the pin to elastically move and abut against the base to limit the rotation of the bottom beam mechanism.

[0022] Optionally, the bottom beam mechanism also includes a rotating component, which is connected to the base. The main beam is rotatably connected to the base through the rotating component, and the pin has a buffer groove, in which the rotating component is inserted.

[0023] Optionally, the bottom beam mechanism also includes an auxiliary beam and connecting parts. The auxiliary beam is rotatably connected to the base, and the auxiliary beam is parallel to and spaced apart from the main beam. The connecting parts are rotatably connected to the main beam and the auxiliary beam respectively.

[0024] Optionally, the chassis includes a cover plate, the base has a receiving groove, the activation component is assembled in the receiving groove, the cover plate is detachably connected to the base and covers the receiving groove, and the pressure plate of the pressing component is rotatably connected to the cover plate.

[0025] A second aspect of this application provides a wheeled vehicle comprising: a peripheral vertical beam and a chassis, wherein the peripheral vertical beam is rotatably connected to the end of the chassis away from the base; and the wheeled vehicle is foldable when the chassis is in an unlocked state.

[0026] The beneficial effects of this application are as follows: By introducing a controlled rotation and locking relationship between the "base-bottom beam mechanism-unlocking mechanism" in the chassis, the technical problems of unsmooth folding process, inconsistent component linkage, and insufficient stability after unfolding in traditional folding wheeled vehicles are solved. Specifically, when triggered by the user, the unlocking mechanism actively pushes the bottom beam mechanism to unlock from the base, allowing the bottom beam mechanism to rotate smoothly relative to the base. This, in turn, drives the surrounding vertical beams to retract synchronously towards the chassis with a single driving action, significantly simplifying the folding operation and reducing the risk of jamming. In the locked state, the base rigidly limits the bottom beam mechanism, which then transmits the constraint to the surrounding vertical beams through its rotational connection with the vertical beams. This allows the vertical beams to be positioned in a controlled manner in the unfolding direction, improving the structural stability and load-bearing reliability of the entire vehicle after unfolding, and reducing swaying and deformation. Thus, this structure achieves controllable switching between folding and unfolding, consistent linkage of actions, and high stability support in the unfolded state, achieving the technical effects of improving ease of use, safety, and durability. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the chassis in the locked state provided in the embodiments of this application;

[0029] Figure 2 This is a schematic diagram of the chassis with the base hidden in the locked state, provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the chassis in the unlocked state provided in the embodiments of this application;

[0031] Figure 4 This is provided by the embodiments of this application. Figure 1 A magnified view of a portion of the area along the IV-IV direction;

[0032] Figure 5 This is provided by the embodiments of this application. Figure 3 A magnified view of a portion of the VV direction;

[0033] Figure 6 This is provided by the embodiments of this application. Figure 1 A magnified view of a portion of the diagram along the VI-VI direction;

[0034] Figure 7 This is provided by the embodiments of this application. Figure 1A partially enlarged schematic diagram of the locked state in the VII-VII direction;

[0035] Figure 8 This is provided by the embodiments of this application. Figure 1 A magnified view of the unlocked state along the VII-VII direction;

[0036] Figure 9 This is a schematic diagram of the structure of the base provided in the embodiment of this application.

[0037] Explanation of icon numbers:

[0038] 100 Chassis, 10 Base, 101 Arc Groove, 20 Bottom Beam Mechanism, 21 Main Beam, 22 Blocking Assembly, 23 Pin

[0039] 24 Reset component, 25 Rotating component, 26 Buffer groove, 27 Auxiliary beam, 28 Connecting component, 30 Unlocking mechanism, 31 Pressing assembly

[0040] 311 Pressure plate, 312 First rod, 313 Second rod, 314 Arc protrusion, 32 Activation component, 321 First rotor, 323 Push surface, 324 Second rotor, 325 Connector, 40 First limiting mechanism, 41 First limiting seat, 42 Second limiting seat

[0041] 43 Rotating rod, 50 Cover plate, 102 Receiving groove. Detailed Implementation

[0042] The embodiments of this application will be described in detail below with reference to the accompanying drawings, clearly and comprehensively demonstrating the technical solutions. It should be noted that the listed embodiments are only a part of this application, and not all possible implementations. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0043] Please see Figures 1 to 5 As shown, Figure 1 This is a schematic diagram of the chassis 100 in the locked state according to an embodiment of this application. Figure 2 This is a schematic diagram of the chassis 100 with the base 10 hidden in the locked state, according to an embodiment of this application. Figure 3 This is a schematic diagram of the chassis 100 in the unlocked state according to an embodiment of this application. Figure 4 This is provided by the embodiments of this application. Figure 1 A magnified view of a portion of the middle IV-IV direction. Figure 5 This is provided by the embodiments of this application. Figure 1 A magnified view of a portion of the VV direction.

[0044] In some embodiments, a foldable wheeled vehicle structure is provided, comprising a circumferential vertical beam disposed at the circumferential boundary of the wheeled vehicle structure and a chassis 100. The circumferential vertical beam is rotatably connected to a bottom beam mechanism 20 at the end away from the base 10 via a pivot or hinge-like rotating joint, allowing the vertical beam to be folded and unfolded relative to the chassis 100 around the rotating joint. The chassis 100 includes a base 10, a bottom beam mechanism 20, and an unlocking mechanism 30. The bottom beam mechanism 20 is rotatably connected to the base 10 via a hinge or rotating joint, and the unlocking mechanism 30 is rotatably mounted on the base 10. The chassis 100 is configured to operate in two stable states: a locked state and an unlocked state. When transitioning from the locked state to the unlocked state, the unlocking mechanism 30 releases the limiting lock relationship between the bottom beam mechanism 20 and the base 10 through torque or thrust stroke, allowing the bottom beam mechanism 20 to rotate relative to the base 10. This drives the connected peripheral vertical beams towards the chassis 100, achieving circumferential folding. When transitioning from the unlocked state to the locked state, the base 10 locks and limits the bottom beam mechanism 20, allowing it to remain constrained at its maximum unfolding position. This causes the peripheral vertical beams to unfold away from the chassis 100 and maintain their unfolded shape. Through this arrangement, the bottom beam mechanism 20 serves both as a driving force transmission component for the vertical beams and as a controllable locking / unlocking relationship with the base 10. The unlocking mechanism 30 can be a lever, a cam, or a clamping wedge, etc., to achieve reliable switching from locked to unlocked.

[0045] In some embodiments, by introducing a controlled rotation and locking relationship between the "base 10—bottom beam mechanism 20—unlocking mechanism 30" in the chassis 100, the technical problems of unsmooth folding process, inconsistent component linkage, and insufficient stability after unfolding in traditional folding wheeled vehicles are solved. Specifically, when triggered by the user, the unlocking mechanism 30 actively pushes the bottom beam mechanism 20 to unlock from the base 10, allowing the bottom beam mechanism 20 to rotate smoothly relative to the base 10. This, in turn, drives the peripheral vertical beams to retract synchronously towards the chassis 100 with a single driving action, significantly simplifying the folding operation and reducing the risk of jamming. In the locked state, the base 10 rigidly limits the bottom beam mechanism 20, which then transmits the constraint to the peripheral vertical beams through its rotational connection with the vertical beams. This allows the vertical beams to be positioned in a controlled manner in the unfolding direction, improving the structural stability and load-bearing reliability of the entire vehicle after unfolding and reducing swaying and deformation. Thus, this structure achieves controllable switching between folding and unfolding, consistent linkage of actions, and high stability support in the unfolded state, achieving the technical effects of improving ease of use, safety, and durability.

[0046] Please see Figures 1 to 6 As shown, Figure 6 This is provided by the embodiments of this application. Figure 1 A magnified view of a section along the VI-VI direction.

[0047] In some embodiments, an unlocking mechanism 30 for a wheeled vehicle chassis 100 is provided. The unlocking mechanism 30 comprises a pressing component 31 and an activation component 32, which are rotatably mounted on a base 10 and form a force and displacement transmission chain with a bottom beam mechanism 20. During the process of switching the vehicle from a locked state to an unlocked state, the user applies force to the pressing component 31, causing the pressing component 31 to rotate relative to the base 10. The pressing component 31 engages or abuts with the activation component 32 through its transmission interface (e.g., a fork, a connecting rod end, or a cam profile), driving the activation component 32 to rotate synchronously. During the rotation of the activation component 32, its working end (e.g., a pusher, a roller, or a wedge-shaped end) applies a pushing or disengaging action to the locking part (e.g., a locking tongue, a pin hole, or a locking tooth) on the bottom beam mechanism 20, thereby releasing the original locking fit between the bottom beam mechanism 20 and the base 10, allowing the bottom beam mechanism 20 to rotate freely relative to the base 10. Through the above structure, the pressing component 31 undertakes the functions of human-machine input and primary torque amplification, while the activation component 32 undertakes the functions of action guidance and fixed-point unlocking. The rotational cooperation between the two ensures that the action chain from force application and transmission to unlocking is clear and reliable.

[0048] The unlocking mechanism 30 solves the technical problems of traditional folding vehicles, such as laborious operation, incomplete unlocking, and mechanism jamming, through a step-by-step rotational force transmission path of "pressing component 31 - activation component 32 - bottom beam mechanism 20". Specifically, the pressing component 31 provides a clear human-machine interface, and the user only needs to apply force in one direction to trigger the rotation; the activation component 32 pushes away the locking part of the bottom beam mechanism 20 in a directional manner, so that the unlocking action is completed within a limited stroke, avoiding inconsistencies and failures caused by simultaneous unlocking at multiple points. Thus, on the one hand, it reduces the user's operating load and improves the smoothness and repeatability of unlocking; on the other hand, it ensures that the bottom beam mechanism 20 and the base 10 form a clear mechanical separation at the moment of unlocking, so that the bottom beam mechanism 20 can rotate smoothly to drive the folding / unfolding of the surrounding vertical beams, reducing jamming and wear, and improving the safety and durability of the whole machine. At the same time, the structure scheme with the rotating joint as the main component is easy to manufacture and assemble. Different mechanical gains and stroke matching can be achieved by changing the length of the pressing arm, the cam profile, or the stroke of the push block, thereby achieving higher adaptability and stable technical effects.

[0049] In some embodiments, a human-machine interface pressing force transmission structure for the unlocking mechanism 30 of the chassis 100 is proposed, using a pressure plate 311 rotatably connected to the base 10 as an input lever. The pressure plate 311 is provided with a first end and a second end opposite to each other, wherein the first end constitutes the user's force application end, used to receive external forces such as fingers or feet; the second end serves as the output end, forming a transmission engagement with the activation component 32 to drive its rotation. Further, to obtain reasonable force amplification and stroke matching, the distance between the two ends of the pressure plate 311 relative to its axis of rotation is set as follows: the distance from the first end to the axis of rotation is L1, and the distance from the second end to the axis of rotation is L2, satisfying 1.5≤L1 / L2≤4, for example 1.5, 2, 2.5, 3, 3.5, 4, etc. This ratio limit allows the pressure plate 311 to take into account both torque amplification and angular displacement output, which can help to achieve effective driving of the activation component 32 with a small human-machine input, and avoid insufficient stroke at the output end due to an excessively large transmission ratio or excessive force from the user due to an excessively small transmission ratio. In practice, the second end of the pressure plate 311 can engage or abut with the activation component 32 through a structure such as a shift fork, roller cam or connecting pin. When the user presses the first end, the pressure plate 311 rotates around its axis and drives the activation component 32 to rotate at a predetermined angle through the displacement and torque output of the second end, thereby completing the unlocking trigger of the bottom beam mechanism 20.

[0050] By limiting the geometric lever ratio L1 / L2 of the pressure plate 311 to the range of 1.5 to 4, two common technical problems in traditional unlocking mechanisms 30 are solved: first, the user's operation is laborious and the unlocking trigger is difficult; second, the unlocking stroke is insufficient and the output angular displacement is insufficient, resulting in incomplete unlocking. Specifically, the lever ratio within the specified range provides the user with effective torque amplification, making the pressing action easy and repeatable, while ensuring that the second end outputs sufficient displacement and thrust to the activation component 32, so that the activation component 32 can reliably disengage or push back the locking element within the limited stroke, avoiding jamming and partial unlocking. As a result, the smoothness and stability of the unlocking process are significantly improved, and the user experience and operational safety are enhanced; at the same time, reasonable mechanical matching reduces the overload and wear of components, improves the life and durability of the mechanism, and facilitates the adaptation of different spring preloads or locking structure tolerances by fine-tuning L1 and L2, thereby achieving higher universality and engineering implementation reliability.

[0051] In some embodiments, based on the rotational connection between the pressure plate 311 and the base 10, a multi-bar pressing assembly 31 consisting of a first rod 312 and a second rod 313 is introduced to achieve a smoother and more controlled drive transmission to the activation assembly 32. Specifically, the two ends of the first rod 312 are respectively connected to the second end of the pressure plate 311 and the first end of the second rod 313 by a revolute joint, and the second end of the second rod 313 is connected to the base 10 by a revolute joint, thus forming a three-stage rotational force transmission chain together with the pressure plate 311. The first and second ends of the second rod 313 are located at opposite ends along the length of the second rod 313. When the user applies force to the first end of the pressure plate 311, the pressure plate 311 rotates around its axis of rotation, and its second end, as an input pivot, transmits displacement and torque to the second rod 313 through the first rod 312. The second rod 313 swings in a controlled manner around the axis of rotation of the base 10 and applies its output to the activation assembly 32 arranged on the same side, thereby driving the activation assembly 32 to generate a predetermined angular displacement to trigger the unlocking. Since the pressure plate 311, the first rod 312, and the second rod 313 are sequentially connected in the plane and arranged around the base 10, they form a semi-enclosed transmission mechanism layout that conforms to the outline of the base 10. This layout retains the necessary hinge clearance and motion diversity while maximizing the fit to the shape of the base 10 without interfering with other chassis 100 components, thereby improving the overall space utilization and assembly compatibility. According to specific design requirements, the lengths, hinge point positions, and included angles of the first rod 312 and the second rod 313 can be optimized to achieve comprehensive adjustment of the output displacement curve, mechanical gain, and dead-point avoidance.

[0052] By transmitting the output of the pressure plate 311 to the activation component 32 in stages via the first rod 312 and the second rod 313, and adopting a semi-enclosed layout, an effective solution is provided for the technical problems of traditional direct-drive systems, such as limited space, difficulty in balancing stroke, and unsatisfactory force transmission direction. First, the multi-rod transmission introduces an adjustable equivalent transmission ratio, achieving a balance between low operating force and sufficient output stroke, avoiding incomplete unlocking or the need for excessive pressure. Second, the second rod 313 uses the base 10 as a rotation fulcrum, optimizing the force transmission direction within a limited space, ensuring that the activation component 32's force direction aligns with the disengagement direction of the bottom beam mechanism 20, reducing friction and the probability of jamming, and improving the smoothness and reliability of unlocking. Third, the semi-enclosed transmission mechanism maximizes fit within the overall space of the base 10, freeing up critical installation areas in the middle or outer regions, facilitating parallel arrangement with electrical components, spring preload components, or guide components, thereby achieving a compact design and modular assembly, reducing manufacturing and maintenance costs. In summary, this solution improves the force transmission efficiency, spatial adaptability, and durability of the unlocking mechanism 30 without increasing complexity, enabling the structure to maintain stable unlocking performance under tolerance fluctuations and long-term wear conditions.

[0053] In some embodiments, the spatial orientation of each component in the pressing assembly 31 is defined such that the extension direction of the second rod 313 is parallel to the extension direction of the pressure plate 311, and the two are arranged opposite to each other on the base 10. Specifically, the pressure plate 311 serves as an input lever, and its length direction is defined as the extension direction of the pressure plate 311; the second rod 313 serves as a swing arm on the output side, and its length direction is defined as the extension direction of the second rod 313. By designing the two to be arranged parallel and opposite to each other, the hinge point between the second end of the pressure plate 311 and the first rod 312, and the hinge point between the first rod 312 and the second rod 313, can form a displacement transmission link in the plane that is substantially in the same direction, reducing unnecessary lateral force components and torsional coupling, and improving the linearity and predictability of force transmission. At the assembly level, the parallel and opposite layout facilitates the formation of symmetrical or mirrored mounting positions on both sides or the same side of the base 10. By adjusting the distance between the two and the hinge height, interference is avoided throughout the entire stroke, and a continuous and regular arrangement channel is reserved for other parts.

[0054] The structure, employing a parallel and opposite arrangement of the second lever 313 and the pressure plate 311, provides an effective solution to common technical problems in traditional multi-bar mechanisms, such as space congestion, transmission ratio fluctuations caused by drastic changes in the angle between levers, and jamming and increased wear due to lateral loads. First, the parallel orientation makes the force flow path straighter, reducing lateral forces and fulcrum loads, thereby reducing wear and clearance accumulation at the hinges and improving the mechanism's durability and long-term stability. Second, due to the stable relative orientation of the levers, the rate of angle change during movement is slowed, resulting in a smoother equivalent transmission ratio. This allows for maintaining a relatively constant mechanical gain and output displacement throughout the entire stroke, avoiding problems such as excessive stiffness in the initial unlocking stage or insufficient stroke in the final stage, thus improving unlocking smoothness and success rate. Third, the parallel layout optimizes the occupancy envelope, forming a regular linear mounting band, making parallel integration of other parts easier, significantly improving the space utilization and assembly accessibility of the base 10, and reducing manufacturing and maintenance costs. Therefore, it achieves a simultaneous improvement in force transmission efficiency, motion stability, and structural compactness, thereby improving the user's pressing feel and unlocking reliability.

[0055] In some embodiments, a rotating engagement structure is provided between a pressure plate 311 and a base 10: the pressure plate 311 is rotatably connected to the base 10 via a pin, and a mutually engaging arcuate groove 101 and an arcuate protrusion 314 are arranged in the active contact area between the pressure plate 311 and the base 10. Specifically, the arcuate protrusion 314 is disposed on the surface of one side (such as the base 10), and the arcuate groove 101 is disposed at a corresponding position on the other side (such as the pressure plate 311). The center positions of the two are designed to have a predetermined relative relationship with the axis of rotation of the pressure plate 311 (the axis of the pin), so that during the rotation of the pressure plate 311 around the pin, the arcuate protrusion 314 can be restricted to a rolling-sliding engagement within the arcuate groove 101, thereby achieving geometric guidance of the movement trajectory of the pressure plate 311. Meanwhile, the normal contact surfaces of the arc groove 101 and the arc protrusion 314 provide radial and partial axial reaction force bearing, forming a parallel support path for the pin shaft, thus jointly bearing lateral force and bending moment when the pressure plate 311 is subjected to pressing load or eccentric load. To improve matching accuracy and durability, the radius of curvature, wrap angle, and contact width of the arc groove 101 / protrusion can be optimized according to stroke and load requirements; the contact surfaces can be designed with surface hardening, low-friction coating, or insert materials to reduce wear and adhesion and improve guiding stability.

[0056] The aforementioned structure provides an effective solution to the technical problems of unstable guidance, large lateral sway, easy wear of pin holes, and easy jamming under eccentric / overload conditions caused by traditional single-point rotational bearings relying on pins. By introducing mutually cooperating arc grooves 101 and arc protrusions 314 at the contact points, firstly, it provides deterministic curved guidance in kinematics, restricts the lateral degree of freedom of the pressure plate 311, reduces runout and deviation, and makes the rotation of the pressure plate 311 smoother and more repeatable; secondly, it forms a distributed support for the pin in mechanics, transforming the concentrated bearing pressure of the pin-hole wall into a distributed bearing of surface contact, significantly reducing the unit contact stress and wear rate, and extending the service life of the mechanism; thirdly, the combined design of guidance and support improves the resistance to eccentric loads and interference, avoids jamming and abnormal noise caused by assembly tolerances or external impacts, and improves the pressing feel and rebound consistency; at the same time, the regular arc fit facilitates the arrangement of lubrication and dustproof structures, and improves manufacturing and assembly tolerance. This achieves a synergistic improvement in guiding accuracy, load-bearing capacity, and durability, thereby enhancing the reliability and service life of the overall unlocking mechanism 30.

[0057] In some embodiments, a deformable chassis 100 layout with multiple bottom beam mechanisms 20 is provided. The number of bottom beam mechanisms 20 is at least two, and these two mechanisms are arranged in a radiating pattern around the base 10. Specifically, the root of each bottom beam is hinged or slidably connected to the base 10, and its free end points radially outwards, forming a radial distribution. The at least two bottom beam mechanisms 20 can switch between locked and unlocked states: in the unlocked state, the at least two bottom beams synchronously retract along a direction of mutual approach, causing the connected peripheral vertical beams to converge towards the center of the base 10, thereby reducing the overall machine profile; in the locked state, the at least two bottom beams extend along a direction of mutual distance, causing the support wheel spacing and grounding point distribution to expand outwards, forming a larger support polygon.

[0058] The aforementioned radiating multi-beam variable geometry structure provides an effective solution to the technical problems of traditional fixed-track chassis 100, such as excessive size during transportation, passage through narrow passages, and storage, and insufficient rollover margin due to limited support polygons in the working state. When unlocked and retracted, the bottom beams move inward, significantly reducing the overall dimensions of the wheeled vehicle, lowering the risk of collisions when handling and passing through bottleneck spaces, and improving the convenience of loading, unloading, and storage. When locked and extended, the bottom beams expand outward, creating a larger support polygon and a wider track, effectively increasing the anti-rollover moment and anti-overturning margin, homogenizing the distribution of ground reaction forces, reducing local subsidence and vibration, thereby improving the overall stability and load-bearing capacity of the machine. Simultaneously, it achieves precise positioning and reliable holding in both locked and unlocked states, avoiding positional drift and abnormal noises during movement, improving durability and safety. Thus, it achieves a balance between adjustable size and enhanced stability, significantly improving the overall performance of the equipment in both transportation / storage and operational scenarios.

[0059] Please see Figures 1 to 8 As shown, Figure 7 This is provided by the embodiments of this application. Figure 1 A partially enlarged schematic diagram of the locked state in the VII-VII direction. Figure 8 This is provided by the embodiments of this application. Figure 1 A magnified view of the unlocked state in the VII-VII direction.

[0060] In some embodiments, an activation component 32 structure for the coordinated unlocking / locking of a multi-beam mechanism 20 is provided. The activation component 32 includes at least two first rotors 321, each first rotor 321 being rotatably connected to the base 10 with its axis and capable of angular displacement about its respective pivot. Each first rotor 321 has a first end and a second end that are distinct from each other: the first end faces the pressing component 31 and forms a force-receiving interface with it, used to convert linear thrust into torque of the first rotor 321 when the user presses or the driving mechanism applies displacement; the second end faces the unlocking contact of the base beam mechanism 20, used to transmit the rotor angular displacement to at least two base beam mechanisms 20 through structures such as a fork, cam surface, push block or pull rod, so that the base beam mechanism 20 and the locking member (such as a locking pin, snap ring, wedge block) of the base 10 move relative to each other to complete unlocking or reverse locking. The first ends of adjacent first rotors 321 are interlocked, which can be finger-shaped, dovetail, or boss-slot type interlocking, so as to achieve equal distribution of force and displacement and mutual limiting when pressed, thereby ensuring synchronous start-up and phase consistency of multiple rotors. Through the above-mentioned interlocking parallel arrangement, a single pressing component 31 (such as a center button, pedal, or electric push rod) can simultaneously drive at least two first rotors 321 to work together, thereby acting simultaneously on at least four circumferentially distributed bottom beam mechanisms 20 on the mechanical transmission chain, realizing rapid unlocking of the whole machine.

[0061] The aforementioned activation component 32, through a mechanical coupling design of "multiple first rotors 321 + adjacent ends interlocking," provides a centralized drive and synchronous linkage solution to address the technical problems of uneven force transmission, asynchronous unlocking of bottom beams in different orientations, low efficiency due to multiple independent operations, and high risk of misoperation inherent in traditional single-point drives. The force exerted by the pressing component 31 is automatically distributed and phase-corrected among the multiple first rotors 321 via the first end of the interlocking connection, ensuring that at least four bottom beam mechanisms 20 obtain sufficient and consistent unlocking strokes at the same time, avoiding jamming and off-center loading caused by incomplete unlocking of individual bottom beam mechanisms 20; the multi-contact output of the second end of the first rotor 321 converts the rotational torque into surface or line contact drive for at least two bottom beam mechanisms 20, reducing single-point stress and wear, and improving unlocking reliability and lifespan; the interlocking structure also acts as mutual limit and position guide, reducing phase deviation caused by the accumulation of assembly tolerances, making the locking / unlocking stroke boundaries clear and highly repeatable. This enables simultaneous unlocking and rapid reset of the multi-beam mechanism 20 under a single pressing action, improving operational convenience and safety, shortening conversion time, and enhancing overall stability and durability through uniform force application and synchronous unfolding / retraction.

[0062] The pressing component 31 abuts against the outer peripheral surfaces of at least two first rotors 321. In some embodiments, the pressing component 31 is adapted to the outer peripheral surfaces of at least two first rotors 321. During assembly, the abutting surface of the pressing component 31 directly adheres to the outer circumferential walls of the two first rotors 321, and the pressing component 31 is entirely located in the outer space of the first rotors 321, without any protrusions or pin structures inserted into the interior of the first rotors 321 (such as rotor shaft holes, outer peripheral grooves, etc.). When it is necessary to drive the first rotors 321 to move upward, the pressing component 31 applies a force through an external driving force (such as manual pressing). This force is transmitted to the outer peripheral surfaces of at least two first rotors 321 through the abutting surface, causing at least two first rotors 321 to move synchronously without affecting the normal rotation of the first rotors 321 around their own axes. During this process, the pressing component 31 always maintains close contact with the outer peripheral surface of the first rotor 321 without any insertable connection structure, ensuring that there is surface contact between the outer peripheral surface and the pressing component 31 when the first rotor 321 rotates, rather than frictional interference from the inserted part.

[0063] This technical solution effectively solves the friction and jamming problem caused by traditional insertion-type pressing structures by designing the pressing component 31 to abut against the outer peripheral surface of the first rotor 321 without being inserted into the first rotor 321. In traditional structures, the insertion part (such as a pin or protrusion) of the pressing component 31 penetrates deep into the internal structure of the first rotor 321. When the rotor rotates, radial friction occurs between the insertion part and the internal hole wall or slot of the rotor. With increased use, this friction leads to wear of the components, resulting in problems such as rotation jamming and abnormal noise. In this solution, the pressing component 31 contacts the outer peripheral surface of the first rotor 321, and there is no radial friction from the insertion part, which significantly reduces the friction during the rotation of the first rotor 321. At the same time, the abutment method of the outer peripheral surface ensures that the upward pushing force of the pressing component 31 on the first rotor 321 is stably transmitted, avoiding pushing failure caused by loose insertion structure. Ultimately, the first rotor 321 can move upward stably while maintaining smooth rotation, completely avoiding jamming.

[0064] In some embodiments, an activation component 32 structure for synchronous unlocking of a multi-point locking mechanism is provided. The activation component 32 includes at least four second rotors 324 and at least four base beam mechanisms 20. Each second rotor 324 is rotatably connected to the base 10 along its axis of rotation and forms a force transmission relationship with the unlocking contacts (such as blocking components 22, push blocks, shift forks, cam surfaces, or pull rod ends) of the corresponding base beam mechanism 20. The system includes at least one first rotor 321, and each first rotor 321 corresponds to two second rotors 324 arranged in parallel on its output side. The angular displacement of each first rotor 321 is synchronously transmitted to the two second rotors 324; each second rotor 324 corresponds to and drives one base beam mechanism 20. During operation, the user drives the first rotor 321 to generate a controlled angular displacement by pressing the component 31 (or the electric push rod). The first rotor 321 drives its paired two second rotors 324 to rotate. Subsequently, the actuator of each second rotor 324 moves relative to the locking components (such as the blocking component 22, locking pin, locking block, wedge block) of the bottom beam mechanism 20, thereby unlocking the bottom beam mechanism 20 relative to the base 10. Through the allocation strategy of "each first rotor 321 corresponds to two second rotors 324, and each second rotor 324 corresponds to one bottom beam", a parallel transmission chain topology from a single drive source to at least four unlocking points is achieved, ensuring that the multiple bottom beam mechanisms 20 are evenly distributed in space and synchronized in time.

[0065] The above structure addresses the technical problems of uneven force transmission, delayed response, asynchronous unlocking, and localized wear and jamming caused by excessive concentrated loads in traditional single-point or series transmission unlocking schemes. It proposes a solution of "two-way distribution of the first rotor 321 + parallel execution of at least four second rotors 324". Its technical effects are reflected in: First, improved synchronization—the first rotor 321 equally distributes the driving force to two second rotors 324, further expanding to at least four second rotors 324 working in parallel, significantly reducing the phase difference between bottom beams in different orientations and avoiding obstruction and off-center loading caused by incomplete unlocking of some bottom beams; Second, balanced force transmission and improved efficiency—each second rotor 324 outputs to one bottom beam mechanism 20, reducing single-point loads, dispersing friction and wear, and making the unlocking stroke smoother, thereby shortening the unlocking time and reducing driving peaks; Third, enhanced fault tolerance and reliability—multi-channel parallel execution can maintain the overall unlocking stroke meeting standards even when there is wear on local components, changes in clearance, or manufacturing tolerances, reducing dependence on a single connecting rod or rotor. Therefore, the activation component 32 can achieve simultaneous unlocking of at least four bottom beam mechanisms 20 on the base 10 in a single drive operation, significantly improving the ease of operation and safety of the whole machine.

[0066] In some embodiments, a rotor coupling structure based on inclined plane force transmission is provided. Specifically, an inclined push surface 323 (which can be a cam inclined surface, wedge, or roller contact ramp) is provided at the relative contact position between the second end of the first rotor 321 and the second rotor 324. When the first rotor 321 is driven and generates angular displacement, the push surface 323 at its second end applies a normal component force to the force-bearing part (such as a lever, roller pin, or driven flange) of the second rotor 324 along a predetermined inclination angle and curvature profile, decomposing it into a tangential driving torque, thereby driving the second rotor 324 to rotate around its axis. The inclination angle, profile curve, and surface treatment of the push surface 323 can be optimized according to the required output torque, stroke characteristics, and contact load. For example, a segmented variable slope surface can be used to achieve the kinematic characteristics of slow start-fast drive-slow return, or rollers can be arranged on the push surface 323 to reduce friction and wear. To ensure contact stability and suppress lateral sway, a limiting shoulder or guide groove can be provided on the second rotor 324.

[0067] The aforementioned inclined push surface 323 structure addresses the technical problems of large starting impact, high friction loss, low force transmission efficiency, and difficulty in precise phase control in traditional planar pushing or indirect linkage transmissions by providing an adjustable slope surface contact force transmission path. Its technical effects are reflected in: firstly, smooth and controllable starting force—by setting the inclination angle and profile of the push surface 323, a gradual force / displacement curve from small to large is achieved, reducing the instantaneous peak value at startup and avoiding jamming and knocking; secondly, improved transmission efficiency and lifespan—the rolling / low-friction inclined surface contact reduces tangential friction and lateral pressure, reducing wear and heat generation, and extending the lifespan of the contact pair; thirdly, customizable output characteristics—the variable slope push surface 323 can achieve torque shaping and angular velocity shaping within a limited angular stroke, meeting the unlocking curve requirements of different bottom beam mechanisms 20 or load conditions. Therefore, this structure effectively solves the problems of starting impact and asynchrony during the unlocking process, achieving reliable driving and smooth rotation of the second rotor 324 while reducing drive power requirements, thereby improving the synchronization, reliability, and durability of the overall unlocking / locking action.

[0068] In some embodiments, an activation component 32 with lever gain control is provided. This component includes a first rotor 321 pivotally connected to a base 10 along a rotation axis. The first rotor 321 has a first end and a second end spaced apart from each other: the first end faces a pressing component 31 and is used to receive input thrust under user pressure or the action of an electric push rod; the second end faces a bottom beam mechanism 20 and is used to transmit the angular displacement and output force of the first rotor 321 to the bottom beam mechanism 20 to unlock it relative to the base 10. To obtain a stable and predictable force-displacement relationship, the lever arm length from the first end to the rotation axis is defined as L3, and the lever arm length from the second end to the rotation axis is defined as L4, and the ratio of the two is set within the range of 1.5 ≤ L3 / L4 ≤ 4, for example, 1.5, 2, 2.5, 3, 3.5, 4, etc. Through the above geometric parameter constraints, when the first rotor 321 receives the linear thrust of the pressing component 31, it converts the input torque into the output torque acting on the bottom beam mechanism 20 with a predetermined lever arm ratio, while ensuring that the stroke and angle response at the output end are within a reasonable range, avoiding insufficient force transmission caused by an excessively small lever arm or insufficient stroke and interference risk caused by an excessively large lever arm.

[0069] The aforementioned lever arm ratio range addresses two common technical problems in existing unlocking mechanisms 30: First, if the lever arm ratio between the input and output ends is too small, it is difficult to obtain sufficient output torque under limited human-machine pressing force or small electric thrust, resulting in incomplete unlocking, jamming, and decreased reliability of the bottom beam mechanism 20. Second, if the lever arm ratio is too large, although a higher output force can be obtained, the angular displacement and linear stroke of the output end are limited, easily leading to insufficient stroke, interference of mating parts, difficulty in reaching the end position, and sensitivity to manufacturing and assembly tolerances. By controlling L3 / L4 between 1.5 and 4, a balance can be achieved between the driving force requirement and the output stroke: on the one hand, the input of the pressing component 31 is effectively amplified, enabling the bottom beam mechanism 20 to reliably disengage under conditions such as full-life wear and low temperature and high resistance; on the other hand, sufficient output stroke is retained to ensure the stroke margin and end position reachability during the unlocking process, reducing sensitivity to tolerances and friction fluctuations. The resulting technical effects include: improved unlocking reliability, reduced user pressure or motor power requirements, reduced risk of structural interference and jamming, more even wear distribution on components, and enhanced reset consistency, thereby improving the overall synchronization, durability, and safety of the activation component 32.

[0070] In some embodiments, a base beam mechanism 20 with elastic limiting and controllable unlocking characteristics is provided. The base beam mechanism 20 includes a main beam 21 pivotally connected to a base 10, and a blocking assembly 22 slidably engaged with the main beam 21 along its axial direction. The blocking assembly 22 is reciprocating along the axial direction of the main beam 21 and is configured with an elastic element (such as a compression spring, elastic pad, or wave spring) to achieve elastic pre-tension, allowing it to actively extend towards the base 10 in its default state and reliably abut against the corresponding abutment surface of the base 10 (such as a limiting block, shoulder, or positioning hole / groove), thereby restricting the rotation of the main beam 21 and achieving the function of locking or limiting. To achieve unlocking, an unlocking mechanism 30 (e.g., a push rod, cam, or swing arm drive) is configured to contact the blocking assembly 22 when transitioning from a locked state to an unlocked state. By applying a pushing force to the blocking assembly 22 along the axial direction of the main beam 21, the blocking assembly 22 overcomes the pre-tension of the elastic element and retracts, disengaging from the abutment position of the base 10, thereby releasing the restriction on the rotation of the main beam 21.

[0071] The above structure addresses the technical problems of unreliable locking, large unlocking impact, rapid wear, and sensitivity to assembly tolerances in traditional bottom beam locking mechanisms by providing a clear division of mechanical and kinematic functions: the blocking component 22, which slides along the axial direction, undertakes the locking contact and elastic pre-tightening, while the main beam 21 undertakes the rotational output. The technical benefits are as follows: First, the axial resistance with elastic pre-tightening forms a stable self-holding locking force, which can limit the rotation of the main beam 21 without continuous external holding force, reducing energy consumption and improving locking reliability. Second, the unlocking mechanism 30 only needs to overcome the pre-tightening force along the axial direction to push the blocking component 22 back, which can quickly release the resistance, decoupling the contradiction between "locking force requirement" and "main beam 21 rotation stroke", reducing the peak driving force required for unlocking and reducing impact and noise. Third, the axial sliding pair and guide structure reduce lateral force and uneven wear, stabilize friction, increase lifespan, reduce sensitivity to manufacturing and assembly tolerances, and maintain a consistent locking / unlocking end position even after long-term use. Fourth, the geometric optimization (bevel / rounded corner) of the blocking end and the return characteristics of the elastic element work together to achieve smooth contact and smooth reset, avoiding jamming and seizing. In summary, this technical solution achieves reliable locking and low-resistance unlocking of the bottom beam mechanism 20 through the combination of elastic pre-tightening axial blocking and controllable unlocking drive, improving the overall safety, durability, and user experience of the machine.

[0072] In some embodiments, the blocking assembly 22 consists of a pin 23 and a reset member 24, wherein the reset member 24 is fixedly or detachably connected to the pin 23 and the main beam 21, respectively. The pin 23 is disposed within the main beam 21 or within a guide hole / guide sleeve arranged along the axis of the main beam 21, forming a sliding pair with the main beam 21 that allows axial reciprocating motion, thereby ensuring that the pin 23 does not wobble when subjected to force. The reset member 24 is preferably a compression spring, a torsion spring with a connecting rod, an elastic sheet, or a rubber elastic element, etc., one end of which is connected to the fixed seat of the main beam 21, and the other end is connected to the shoulder or connecting lug of the pin 23, providing an elastic preload along the axis of the main beam 21. In the initial state after assembly, the reset member 24 pushes the pin 23 to extend toward the base 10, so that the end of the pin 23 abuts against the corresponding abutment position (such as a limiting hole, a stop, or a positioning groove) on the base 10, thereby restricting the rotation of the bottom beam mechanism 20 (the main beam 21 relative to the base 10). When unlocking is required, the unlocking mechanism 30 applies a reverse thrust to the pin 23 along the axis of the main beam 21, overcoming the elasticity of the reset member 24 and causing the pin 23 to retract, releasing the contact with the base 10. The main beam 21 can then rotate freely around its axis. To reduce wear and friction, the pin 23 may have a hardened layer on its outer circumference or be fitted with a low-friction bushing (such as a copper bushing / engineering plastic bushing). The end of the pin 23 may be designed with a guide chamfer or rounded arc to facilitate smooth engagement and disengagement with the base 10.

[0073] This structure addresses the problems of unstable locking, difficult unlocking, increased clearance due to long-term wear, and sensitivity to assembly tolerances inherent in traditional bottom beam mechanisms 20. It provides an elastic locking solution centered on an axial pin 23. Specifically, the axial preload applied to the pin 23 by the reset component 24 ensures that the pin 23 reliably abuts against the base 10 under both static and dynamic loads, achieving continuous self-holding locking and avoiding mis-locking caused by vibration or clearance accumulation. The axial sliding guide between the pin 23 and the main beam 21 aligns the direction of the locking / unlocking force with the direction of movement, significantly reducing lateral friction and jamming risks, decreasing the peak force required for drive, and reducing noise and impact. The chamfered end of the pin 23 and its low-friction fit improve the tolerance for insertion and withdrawal, reducing the structure's sensitivity to manufacturing and assembly tolerances, thermal expansion and contraction, and wear, thus extending its service life. Through stroke limiting and hardening / bushing fit, localized wear and plastic deformation are suppressed, maintaining consistent positioning accuracy over a long period. Therefore, this technical solution achieves reliable locking and smooth unlocking under low driving force conditions, improving the safety, durability and operation experience of the bottom beam mechanism 20.

[0074] A rotating component 25 is added to the bottom beam mechanism 20 as a rotational hub between the main beam 21 and the base 10. Specifically, the rotating component 25 is connected to the base 10 by a support method, and can be fixed to the base 10 by bearing seats, bushings, or shoulders to form a stable rotation axis. The main beam 21 is rotatably connected to the base 10 through the rotating component 25, allowing the main beam 21 to swing or flip around the axis of the rotating component 25. To optimize the force and alignment during locking and unlocking, the pin 23 is provided with a buffer groove 26 for buffering and guiding. Part of the outer shape of the rotating component 25 is inserted into the buffer groove 26 to form a controlled gap or limiting fit. The buffer groove 26 can be annular, arc-shaped, or U-shaped, with a rounded corner transition at the bottom. The groove wall can be provided with a wear-resistant bushing or a low-friction coating to reduce friction and edge stress concentration. The outer surface of the rotating component 25 is preferably hardened or coated to improve contact durability.

[0075] This structure addresses the problems of traditional bottom beam mechanisms 20, such as large impact at the moment of locking, poor unlocking alignment, easy lateral deviation during the initial rotation of the main beam 21, and unstable repeated positioning due to long-term wear. It achieves a combined function of buffering, limiting, and guiding through the coordinated insertion of the "rotating component 25—buffer groove 26". Specifically, after the rotating component 25 enters the buffer groove 26 of the pin 23, it transforms the original point / end-face rigid collision into a progressive contact along the groove surface, dispersing the impact load, reducing peak impact and noise, and mitigating indentation and jamming at the source. The buffer groove 26's envelopment and guidance of the rotating component 25 allows the rotation trajectory of the main beam 21 and the axial movement of the pin 23 to achieve self-alignment, suppressing lateral forces and uneven wear, and improving unlocking smoothness and tolerance tolerance. The cooperation between the groove wall bushing or low-friction coating and the hardened layer of the rotating component 25 significantly reduces the wear rate, maintaining long-term clearance stability and torsional stiffness. Simultaneously, the stable axial constraint between the rotating component 25 and the base 10 reduces axial movement of the main beam 21, improving the repeatability of the locking position. Therefore, this technical solution achieves a comprehensive improvement in buffering and impact resistance, guiding and anti-jamming, and durability without significantly increasing structural complexity, thereby improving the safety, reliability, and service life of the bottom beam mechanism 20.

[0076] An auxiliary beam 27 and a connecting member 28 are introduced to form a spatial four-bar linkage bottom beam mechanism 20 based on the main beam 21 and the base 10. Specifically, the auxiliary beam 27 is rotatably connected to the base 10 through an auxiliary bearing point, and its axis is arranged parallel to the rotation axis of the main beam 21. The auxiliary beam 27 and the main beam 21 are parallel to each other and maintain a preset distance to reduce structural interference and form a stable configuration constraint. The connecting member 28 is located between the main beam 21 and the auxiliary beam 27, and its two ends are rotatably connected to the main beam 21 and the auxiliary beam 27 respectively through pivot pins or spherical pairs, thereby establishing a kinematic coupling relationship between the main beam 21 and the auxiliary beam 27. To ensure motion accuracy and durability, the rotational connection between the main beam 21, the auxiliary beam 27, and the connecting piece 28 preferably adopts the form of needle roller bearings / copper sleeves + hardened pins, and coaxiality and surface runout tolerances are set in the connection holes. The length of the connecting piece 28 and the hinge center distance between the main beam 21, the auxiliary beam 27, and the base 10 can be calibrated according to the desired motion trajectory, so that when the main beam 21 rotates, the connecting piece 28 synchronously pulls the auxiliary beam 27 to move in coordination, suppressing lateral swaying and torsion at the end of the main beam 21.

[0077] The above structure addresses the problems that the single beam bottom beam mechanism 20 is prone to when under load, such as large torsional deformation, end swaying, poor repeatability of locking position, and motion crosstalk caused by hinge wear after long-term use. It provides a parallel constraint and load diversion scheme composed of auxiliary beam 27 and connecting member 28. By setting the auxiliary beam 27 parallel to the main beam 21 at intervals, the connecting piece 28 synchronously couples the angular displacements of the two beams, so that the rotation of the main beam 21 is jointly borne by the double hinge channels, thereby significantly improving the overall torsional stiffness and lateral stability, and reducing the positioning error caused by end runout and cumulative clearance. The load is distributed between the main beam 21 and the auxiliary beam 27, reducing the contact stress and wear rate of the single-point bearing and pin, extending the service life of the mechanism and maintaining long-term motion consistency. The limiting and coaxial control of the connecting piece 28 reduces the sensitivity of assembly tolerances to the motion trajectory, and improves the repeatability and smoothness of locking / unlocking or positioning actions. Overall, the four-bar kinematic constraint ensures the travel and rotation angle requirements while achieving stable mechanical path transmission, so that the bottom beam mechanism 20 can still maintain a reliable, low-wear and low-noise working state under vibration, impact and temperature difference conditions, improving the safety and user experience of the whole machine.

[0078] A first limiting mechanism 40 is provided on the chassis 100. The first limiting mechanism 40 is located at the end of the bottom beam mechanism 20 away from the base 10 and bridges two adjacent bottom beam mechanisms 20 in a one-to-one manner. Specifically, both ends of each first limiting mechanism 40 are connected to the free ends of two adjacent bottom beam mechanisms 20, respectively. The connection can be rotatable or slightly telescopic by means of hinged trunnions, ball joints, or groove-pins, thereby providing geometric limits and attitude constraints when the bottom beam mechanism 20 is deployed to the locked state relative to the base 10. The first limiting mechanism 40 can be a rigid link, a damped link with preload, or an adjustable rod with a telescopic buffer section. Its length or effective stroke matches the deployment angle of the adjacent bottom beam mechanism 20. When necessary, a length fine-tuning structure (such as an eccentric sleeve or threaded sleeve) can be provided at the end of the link for synchronous correction after assembly to ensure that each bottom beam mechanism 20 reaches a consistent deployment position when locked.

[0079] By introducing a first limiting mechanism 40 between the free ends of adjacent bottom beam mechanisms 20, a cross-beam constraint can be formed on the unfolding angle and relative position of the bottom beam mechanism 20 when it enters the locked state, solving problems such as slight angle drift, lateral sway, and poor synchronization that easily occur after a single beam is locked. Compared to relying on individual locking with the base 10, the cross-connecting limiting mechanism forms a closed force loop between adjacent bottom beam mechanisms 20, distributing external disturbances and loads between the two beams, reducing local stress and deformation at the ends of a single beam, thereby maintaining the flatness and geometric stability of the overall unfolding surface. The first limiting mechanism 40 acts as a geometric stop when locked, avoiding inconsistencies in unfolding caused by the superposition of manufacturing and assembly tolerances, and improving the consistency and repeatability of the locking posture. Thus, the first limiting mechanism 40 achieves the maintenance and balance of the unfolding state of adjacent bottom beam mechanisms 20, improving the structural stability, load uniformity, and long-term durability of the chassis 100 in the locked state.

[0080] In some embodiments, the first limiting mechanism 40 includes at least two first limiting seats 41, at least one second limiting seat 42, and at least two rotating rods 43. Each first limiting seat 41 is fixedly disposed at one end of the bottom beam mechanism 20 away from the base 10, serving as a connection base point between the first limiting mechanism 40 and a single bottom beam; each of the two opposite ends of each second limiting seat 42 is rotatably connected to a rotating rod 43 via a pivot or pin, forming a double hinged fulcrum with the second limiting seat 42 as the central pivot. One end of each rotating rod 43 away from the second limiting seat 42 to which it is connected is rotatably connected to either the first limiting seat 41 or the other second limiting seat 42. Specifically, when there is one first limiting seat 42, the other end of each rotating rod 43 (the end furthest from the second limiting seat 42) is rotatably connected to the first limiting seat 41, thereby forming a four-bar / multi-hinge structure closed between the free ends of adjacent bottom beam mechanisms 20, consisting of "first limiting seat 41—rotating rod 43—second limiting seat 42—rotating rod 43—first limiting seat 41". When there are at least two first limiting seats 42, the ends of the first and last rotating rods 43 furthest from their connected second limiting seats 42 are rotatably connected to the first limiting seat 41, and the end of the middle rotating rod 43 furthest from its connected second limiting seat 42 is rotatably connected to another second limiting seat 42. This structure geometrically allows the bottom beam mechanism 20 to expand and retract around its rotation with the base 10, while achieving position self-correction and angle limitation through the arrangement of rod lengths and hinge points when expanded to the locked posture. To accommodate assembly tolerances and thermal expansion and contraction, the rotating rod 43 can be a rigid rod of equal length, with a spherical bearing or a bushed universal joint at the end to provide angle compensation; if necessary, a fine-tuning component (such as a threaded adjustment end or an eccentric sleeve) can be set on one side of the rotating rod 43 to achieve synchronous calibration of the unfolding endpoint.

[0081] The aforementioned first limiting mechanism 40, via a double-sided rotating rod 43 centered on the second limiting seat 42, bridging adjacent bottom beam mechanisms 20, forms a geometric closed-loop constraint in the locked state, solving problems such as inconsistent deployment endpoints, end swaying, and load offset that are prone to occur with traditional single-sided limiting mechanisms. Specifically, the four-bar linkage exhibits a kinematic stiffening effect when approaching the locked position. The feedback of small displacement disturbances by the linkage system causes the free ends of the two bottom beams to restrain each other, achieving self-alignment of angle and position, thereby improving deployment consistency and repeatability accuracy. The double-sided rotating rod 43 distributes and diverts external impacts and working loads between adjacent bottom beams, reducing local stress at the ends of single beams and wear at hinge points, extending service life. At the same time, fine-tuning structural compensation manufacturing ensures synchronization and flatness of the locked posture. Thus, the first limiting mechanism 40, without significantly increasing volume and complexity, achieves stable maintenance of the deployment state of adjacent bottom beams, load balance, and improved durability, significantly improving the structural stability and reliability of the chassis 100 in the locked state.

[0082] Please see Figures 1 to 9As shown, Figure 9 This is a schematic diagram of the structure of the base provided in the embodiment of this application.

[0083] The chassis 100 includes a cover plate 50, the base 10 has a receiving groove 102, the activation component 32 is assembled in the receiving groove 102, the cover plate 50 is detachably connected to the base 10 and covers the receiving groove 102, and the pressure plate 311 of the pressing component 31 is rotatably connected to the cover plate 50. In some embodiments, the upper surface of the base 10 is recessed inward to form an accommodating groove 102 with an opening. During assembly, the activation component 32 is placed entirely into the accommodating groove 102, so that the groove wall of the accommodating groove 102 forms a surrounding wrapping structure for the activation component 32 from all sides and the bottom. The edge of the cover plate 50 is fixed to the edge of the opening of the base 10 by means of detachable connection such as bolt connection or snap connection. After the cover plate 50 and the base 10 are assembled, the lower surface of the cover plate 50 fits against the end face of the opening of the base 10, completely sealing the opening of the accommodating groove 102, so that the activation component 32 is in the closed space formed by the accommodating groove 102 and the cover plate 50. At the same time, the pressure plate 311 of the pressing component 31 is rotatably connected to the preset mounting hole of the cover plate 50 through a rotating shaft. The rotating shaft is set in the horizontal direction, and the pressure plate 311 can rotate around the rotating shaft. During the rotation, it will not interfere with the accommodating groove 102 and the activation component 32 inside, ensuring that the operation function of the pressing component 31 is realized normally.

[0084] This technical solution effectively solves the technical problems of insufficient protection for the activation component 32, inconvenient assembly and maintenance, and poor rotational stability of the pressing component 31 by using a design in which "the accommodating groove 102 encloses the activation component 32, the cover plate 50 detachably seals the accommodating groove 102, and the pressure plate 311 of the pressing component 31 is rotatably connected to the cover plate 50". In traditional structures, the activation component 32 is often exposed and easily damaged by dust and impacts; however, in this solution, the accommodating groove 102 provides enclosed protection for the activation component 32, isolating it from external impurities and impacts, and protecting the structural integrity and functional stability of the activation component 32; the detachable connection between the cover plate 50 and the base 10 facilitates opening the accommodating groove 102 for inspection and replacement of the activation component 32 when needed, reducing maintenance difficulty.

[0085] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0086] Furthermore, when an element is referred to as 'fixed to' or 'set on' another element, it may be directly attached to that element, or there may be other intervening elements between them. When an element is referred to as 'connected to' another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element.

[0087] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, the use of terms such as "first" and "second" to denote features can explicitly express or imply the presence of at least one such feature. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0088] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the content of the specification and drawings of this application under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A chassis for a wheeled vehicle, characterized in that, The chassis includes: Base; The bottom beam mechanism is rotatably connected to the base; and The unlocking mechanism is rotatably connected to the base; The chassis is configured to have a locked state and an unlocked state, wherein: In the locked state, the base locks the bottom beam mechanism; The unlocking mechanism is used to push the bottom beam mechanism to unlock from the base when transitioning from the locked state to the unlocked state.

2. The chassis according to claim 1, characterized in that, The unlocking mechanism includes a pressing component and an activation component, wherein the pressing component is rotatably connected to the base, and the activation component is rotatably connected to the base; The pressing component is used to rotate and drive the activation component to rotate when the state changes from the locked state to the unlocked state, so that the activation component pushes the bottom beam mechanism to unlock from the base.

3. The chassis according to claim 2, characterized in that, The pressing component includes a pressure plate, which is rotatably connected to the base. The first end of the pressure plate is used to receive force applied by the user, and the second end of the pressure plate is used to drive the activation component to rotate.

4. The chassis according to claim 3, characterized in that, The distance from the first end of the pressure plate to its pivot is L1, and the distance from the second end of the pressure plate to its pivot is L2, where 1.5 ≤ L1 / L2 ≤ 4.

5. The chassis according to claim 3, characterized in that, The pressing assembly further includes a first rod and a second rod. The extension direction of the second rod is parallel to the extension direction of the pressure plate and they are arranged opposite to each other. The two ends of the first rod are respectively rotatably connected to the second end of the pressure plate and the first end of the second rod. The second end of the second rod is rotatably connected to the base. The pressure plate is used to drive the activation assembly to rotate through the second rod.

6. The chassis according to any one of claims 3 to 5, characterized in that, The pressure plate is rotatably connected to the base by a pin. The pressure plate and the base are in movable contact and are provided with mutually matching arc grooves and arc protrusions at the contact point.

7. The chassis according to claim 2, characterized in that, The number of the bottom beam mechanisms is at least two, and the at least two bottom beam mechanisms are arranged in a radiating pattern on the base. In the unlocked state, the at least two bottom beam mechanisms retract towards each other, and in the locked state, the at least two bottom beam mechanisms extend away from each other.

8. The chassis according to claim 7, characterized in that, The chassis also includes a first limiting mechanism, which is connected to the end of the bottom beam mechanism away from the base, and the first limiting mechanism is connected to two adjacent bottom beam mechanisms. The first limiting mechanism is used to maintain the extended state of the adjacent bottom beam mechanisms when they are in the locked state.

9. The chassis according to claim 8, characterized in that, The first limiting mechanism includes at least two first limiting seats, at least one second limiting seat, and at least two rotating rods. Each first limiting seat is connected to the end of the bottom beam mechanism away from the base. Each second limiting seat has a rotating rod rotatably connected to its opposite ends. The end of each rotating rod away from the second limiting seat it is connected to is rotatably connected to either the first limiting seat or the other second limiting seat.

10. The chassis according to any one of claims 7 to 9, characterized in that, The activation component includes at least two first rotors, which are rotatably connected to the base. The first end of the first rotor is used to receive the push of the pressing component, and the second end of the first rotor is used to push at least two of the bottom beam mechanisms to unlock from the base. The first ends of adjacent first rotors are interlocked.

11. The chassis according to claim 10, characterized in that, The pressing component abuts against at least two of the outer peripheral surfaces of the first rotor.

12. The chassis according to claim 10, characterized in that, The activation component includes at least four second rotors, and the bottom beam mechanism includes at least four. The second rotors are rotatably connected to the base. Each first rotor corresponds to two second rotors, and each second rotor corresponds to one bottom beam mechanism. The first rotor is used to drive the two corresponding second rotors to rotate, so that the second rotors push the bottom beam mechanism to unlock from the base.

13. The chassis according to claim 12, characterized in that, An inclined pushing surface is provided at the contact point between the second end of the first rotor and the second rotor.

14. The chassis according to any one of claims 2 to 5, characterized in that, The activation component includes a first rotor, which is rotatably connected to the base. A first end of the first rotor is used to receive the push of the pressing component, and a second end of the first rotor is used to push the bottom beam mechanism to unlock from the base. The distance from the first end of the first rotor to its axis of rotation is L3, and the distance from the second end of the first rotor to its axis of rotation is L4, where 1.5 ≤ L3 / L4 ≤ 4.

15. The chassis according to any one of claims 1 to 5, characterized in that, The bottom beam mechanism includes a main beam and a blocking assembly. The main beam is rotatably connected to the base, and the blocking assembly is slidably connected to the main beam along its axial direction. The blocking assembly is used to elastically move and abut against the base to restrict the rotation of the bottom beam mechanism. The unlocking mechanism is specifically used to push the blocking assembly to move when the locked state is switched to the unlocked state, so as to push the bottom beam mechanism to unlock from the base.

16. The chassis according to claim 15, characterized in that, The blocking assembly includes a pin and a reset member. The reset member is connected to the pin and the main beam respectively. The pin is slidably connected to the main beam along its axial direction. The reset member is used to drive the pin to elastically move and abut against the base to limit the rotation of the bottom beam mechanism.

17. The chassis according to claim 16, characterized in that, The bottom beam mechanism also includes a rotating component, which is connected to the base. The main beam is rotatably connected to the base through the rotating component. The pin has a buffer groove, and the rotating component is inserted into the buffer groove.

18. The chassis according to claim 15, characterized in that, The bottom beam mechanism also includes an auxiliary beam and a connecting member. The auxiliary beam is rotatably connected to the base. The auxiliary beam is parallel to and spaced apart from the main beam. The connecting member is rotatably connected to the main beam and the auxiliary beam respectively.

19. The chassis according to any one of claims 2 to 5, characterized in that, The chassis includes a cover plate, the base has a receiving groove, the activation component is assembled in the receiving groove, the cover plate is detachably connected to the base and at least partially covers the receiving groove, and the pressure plate of the pressing component is rotatably connected to the cover plate.

20. A wheeled vehicle, characterized in that, The wheeled vehicle includes: a peripheral vertical beam and a chassis as described in any one of claims 1 to 19, wherein the peripheral vertical beam is rotatably connected to the end of the bottom beam mechanism away from the base; and the wheeled vehicle is foldable when the chassis is in an unlocked state.

Images