A special vehicle with a flexible force limiting docking mechanism of an on-board telescopic platform and a docking method

Abstract

This invention relates to the field of special vehicle technology, specifically a special vehicle and docking method with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform. The vehicle includes a fixed platform, a docking platform, an elastic drive component, and an active pull-back assembly. The fixed platform is mounted on the vehicle body, and the docking platform is telescopically mounted relative to the fixed platform, forming an overlap channel with an external target object in its extended state. The elastic drive component connects the fixed platform and the docking platform, and drives the docking platform to extend away from the fixed platform through its own elastic restoring force. The active pull-back assembly connects the fixed platform and the docking platform, and overcomes the elastic restoring force of the elastic drive component to drive the docking platform to retract towards the fixed platform. The maximum thrust exerted by the elastic drive component on the docking platform is less than the contact damage critical force of the external target object. This invention can limit the extension thrust of the docking platform at the mechanical structure level, reducing the risk of crush damage to the external target object and improving the stability and safety of the vehicle-mounted telescopic platform docking process.

Description

Technical Field

[0001] This invention relates to the field of special vehicle technology, and in particular to a special vehicle and docking method having a flexible force-limiting docking mechanism with an on-board telescopic platform. Background Technology

[0002] With the increasing use of special vehicles in logistics transportation, equipment maintenance, personnel access, and emergency response, these vehicles typically require extendable or retractable telescopic platforms to create temporary access routes between the vehicle and external targets. These external targets can be platforms, equipment hatches, building interfaces, mobile cabins, work platforms, or other structures requiring close proximity to the vehicle. The telescopic platform bridges the gap between the vehicle and the external target, enabling the safe transfer of personnel, materials, or equipment between them.

[0003] Existing vehicle-mounted telescopic platforms for special vehicles typically use hydraulic cylinders, electric push rods, or other rigid drive mechanisms to directly extend the platform, and rely on displacement sensors, pressure sensors, or electronically controlled limit devices to determine whether the platform has reached the predetermined position. While this type of structure can achieve the extension and retraction of the platform, in actual use, deviations may occur due to the vehicle's parking position, vehicle posture, the position of external target objects, and the operating environment. During extension, the vehicle-mounted telescopic platform is prone to contact or compression with external target objects.

[0004] Especially in operating environments characterized by low temperature, high humidity, dust, vibration, or frequent start-stop cycles, sensors, control circuits, or actuators are at risk of failure. If the detection device fails to promptly identify the contact state between the vehicle-mounted telescopic platform and the external target object, the rigid drive mechanism may continue to output significant thrust, causing crush damage to the contact surface between the vehicle-mounted telescopic platform and the external target object, or resulting in impact deformation of the platform's own structure, hinged parts, and guide components. Even with protection measures such as improving control precision or increasing the number of sensors, the reliability of the electronic control system remains crucial, making it difficult to limit the contact force through the mechanical structure itself in the event of control failure or misoperation. Summary of the Invention

[0005] In this section, as well as in the abstract and title of this application, some simplifications or omissions may be made to avoid obscuring the purpose of this section, the abstract, and the title of this application, and such simplifications or omissions shall not be used to limit the scope of the invention.

[0006] To address the shortcomings of existing technologies, one objective of this invention is to provide a special vehicle with a flexible force-limiting docking mechanism for an onboard telescopic platform.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform, comprising a fixed platform for mounting on the vehicle body; a docking platform telescopically mounted relative to the fixed platform and used to form an overlap channel with an external target object in the extended state; an elastic drive member connected between the fixed platform and the docking platform, which drives the docking platform to extend away from the fixed platform through its own elastic restoring force; and an active pull-back component connected between the fixed platform and the docking platform, used to overcome the elastic restoring force of the elastic drive member and drive the docking platform to retract towards the fixed platform; wherein the maximum thrust of the elastic drive member acting on the docking platform is less than the contact damage critical force of the external target object.

[0008] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform according to the present invention, the elastic drive component includes gas springs symmetrically arranged on the fixed platform, the fixed end of the gas springs being connected to the fixed platform, and the output end of the gas springs being connected to the docking platform.

[0009] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, the active pull-back assembly includes hydraulic cylinders symmetrically arranged on the fixed platform, and the output end of the hydraulic cylinders is connected to the docking platform via a flexible rigging.

[0010] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, wherein: the elastic drive component and the active pull-back component are both arranged symmetrically with respect to the central axis of the fixed platform.

[0011] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, the maximum thrust of the elastic drive component is set to be between 400N and 1000N.

[0012] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform according to the present invention, the fixed platform includes a plurality of vertical beams and a crossbeam disposed between two adjacent vertical beams; the crossbeam includes a first plate flush with the top surface of the vertical beam and a second plate perpendicularly connected to the first plate; a structural frame disposed on the second plate, the structural frame including support plates disposed parallel to and spaced apart from the second plate; wherein the fixed end of the gas spring is connected to the support plate, and the fixed end of the hydraulic cylinder spans the support plate and the second plate.

[0013] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, wherein: the length of the first fixed section of the hydraulic cylinder is L1, the distance between two adjacent crossbeams is L2, and the net distance between the second plate and the support plate is L3; wherein, the relationship is satisfied: L1+L3=L2.

[0014] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, wherein: the straight-line distance from the support plate to the front edge of the fixed platform is L4, and the length of the second fixed section of the gas spring is L5; wherein, the following relationship is satisfied: L1 <L5<L4。

[0015] As a preferred embodiment of the special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in this invention, wherein: the length of the first extension section of the hydraulic cylinder is L6, the length of the second extension section of the gas spring is L7, and the length of the flexible rigging is L8; wherein, the relationship is satisfied: L7+L5=L8+L6.

[0016] To address the shortcomings of existing technologies, another objective of this invention is to provide a special vehicle.

[0017] The present invention adopts the following technical solution: a special vehicle, including a vehicle body and a special vehicle with a vehicle-mounted telescopic platform flexible force-limiting docking mechanism, a fixed platform is set on the vehicle body, and the docking platform is used to extend relative to the vehicle body and form an overlapping channel with an external target object.

[0018] To address the shortcomings of existing technologies, another objective of this invention is to provide a flexible force-limiting docking method for vehicle-mounted telescopic platforms.

[0019] This invention adopts the following technical solution: a flexible force-limiting docking method for a vehicle-mounted telescopic platform, comprising the following steps: The active pull-back component is controlled to perform a release action at a preset rate, and the elastic drive component continuously outputs elastic restoring force to drive the docking platform to move away from the fixed platform, and keep the flexible rigging taut throughout the entire extension process. The release rate of the active pull-back component is used to limit the extension speed of the docking platform to achieve smooth docking.

[0020] Physical protection of external target objects is achieved by relying on the maximum thrust limited by the elastic drive component. If sensor failure or control failure occurs, the contact force of the elastic drive component acting on the external target object will still remain below the critical contact damage force.

[0021] The active pull-back component is controlled to perform a retraction action. The flexible rigging outputs tension to overcome the elastic restoring force of the elastic drive component, thereby driving the docking platform to retract smoothly towards the fixed platform.

[0022] Based on the second extension section of the gas spring having a length of L7, the second fixed section of the gas spring having a length of L5, the flexible rigging having a length of L8, and the first extension section of the hydraulic cylinder having a length of L6, the geometric constraint established by L7+L5=L8+L6 ensures that the first extension section of the hydraulic cylinder is fully retracted when returning to the initial position, and simultaneously drives the second extension section of the gas spring to retract into the second fixed section.

[0023] The beneficial effects of this invention on a special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform are as follows: By setting an elastic drive member between the fixed platform and the docking platform, the elastic drive member drives the docking platform to extend away from the fixed platform through its own elastic restoring force. Simultaneously, an active pull-back component overcomes the elastic restoring force of the elastic drive member and drives the docking platform to retract. Thus, the extension force of the docking platform is provided by the elastic drive member, while the retraction action is completed by the active pull-back component. Compared with existing structures where a rigid drive member directly pushes the platform to extend, this invention limits the maximum contact thrust of the extension action within the output range of the elastic drive member, thereby limiting the extension thrust of the docking platform at the mechanical structural level.

[0024] Since the maximum thrust of the elastic drive component acting on the docking platform is less than the critical force of contact damage to the external target object, when the docking platform contacts the external target object during the extension process, even if sensor failure, control failure or human error occurs, the contact force acting on the external target object can still be limited to a safe range. This reduces the risk of the external target object's contact surface being squeezed and damaged, and also reduces the possibility of the docking platform itself being deformed, jammed or damaged by rigid impact. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a bottom view of the present invention.

[0027] Figure 2 For the present invention Figure 1 A magnified view of a portion of point A in the middle.

[0028] Figure 3This is a schematic diagram of the overall structure of the present invention.

[0029] Figure 4 This is a schematic diagram showing the layout of the elastic drive component and the active pull-back component of the present invention.

[0030] Figure 5 This is a schematic diagram of the structure of the elastic drive component and the active pull-back assembly of the present invention.

[0031] Figure 6 This is a schematic diagram of the structural frame of the present invention.

[0032] Figure 7 This is a schematic diagram showing the connection between the gas spring and the hydraulic cylinder of the present invention.

[0033] Figure 8 This is a schematic diagram showing the net distance between the second plate and the support plate of the present invention.

[0034] Figure 9 This is a schematic diagram showing the length of the second fixed section of the gas spring of the present invention.

[0035] Figure 10 This is a schematic diagram showing the length of the flexible rigging of the present invention.

[0036] In the diagram: Fixed platform - 100; Vertical beam - 101; Horizontal beam - 102; First plate - 102a; Second plate - 102b; Structural frame - 103; Support plate - 103a; Docking platform - 200; Elastic drive component - 300; Gas spring - 301; Second fixed section - 301a; Second extension section - 301b; Active pull-back assembly - 400; Hydraulic cylinder - 401; First fixed section - 401a; First extension section - 401b; Flexible rigging - 402; Central axis - M; Length of the first fixed section - L1; Spacing between two adjacent horizontal beams - L2; Clear distance between the second plate and the support plate - L3; Straight-line distance from the support plate to the front edge of the fixed platform - L4; Length of the second fixed section - L5; Length of the first extension section - L6; Length of the second extension section - L7; Length of the flexible rigging - L8. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0038] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0039] Example 1

[0040] Reference Figures 1-3 This embodiment provides a special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform, including a fixed platform 100, a docking platform 200, an elastic drive component 300, and an active pull-back component 400.

[0041] The docking platform 200 is telescopic relative to the fixed platform 100. An elastic drive member 300 is connected between the fixed platform 100 and the docking platform 200, and uses its own elastic restoring force to drive the docking platform 200 to extend away from the fixed platform 100. An active pull-back component 400 is connected between the fixed platform 100 and the docking platform 200, and is used to overcome the elastic restoring force of the elastic drive member 300 to drive the docking platform 200 to retract towards the fixed platform 100.

[0042] Specifically, the fixed platform 100 serves as a reference support structure and is used to be installed on the vehicle body or vehicle platform frame; the docking platform 200 is movably connected to the fixed platform 100 through a guiding mechanism and is able to perform telescopic movements relative to the fixed platform 100 toward or away from external target objects.

[0043] The elastic drive element 300 is positioned between the fixed platform 100 and the docking platform 200. In this embodiment, the elastic drive element 300 is in a pre-compressed or pre-tensioned state, and the elastic restoring force it generates always tends to push the docking platform 200 outward (i.e., away from the fixed platform 100). The active pull-back component 400 is also connected between the fixed platform 100 and the docking platform 200. Its main function is to overcome the restoring force of the elastic drive element 300 by outputting an active pulling force, thereby driving the docking platform 200 to retract inward (i.e., closer to the fixed platform 100).

[0044] When docking is required, the active pull-back assembly 400 receives a control command and begins controlled release (e.g., a hydraulic cylinder slowly extends). At this time, the elastic drive component 300 uses its accumulated elastic potential energy to push the docking platform 200 outward. During this process, because the thrust of the elastic drive component 300 is always present, it keeps the transmission components (e.g., steel wire ropes) in the active pull-back assembly 400 taut. The moving speed of the docking platform 200 is controlled by the release speed of the active pull-back assembly 400, thus achieving smooth docking.

[0045] After the docking task is completed, the active pull-back component 400 is activated, outputting a pulling force to overcome the elastic restoring force, pulling the docking platform 200 back to its initial position, while the elastic drive component 300 re-accumulates energy to prepare for the next docking.

[0046] Among them, the maximum thrust of the elastic drive component 300 is less than the critical force for contact damage to the external target object.

[0047] Specifically, in this embodiment, the "extending" action of the docking platform 200 is not directly driven by a traditional rigid thrust device, but is completed by the elastic drive component 300 "releasing" energy.

[0048] According to the configuration of this embodiment, the maximum thrust of the elastic drive member 300 in its fully extended state is strictly limited to be less than the contact damage critical force of the external target object. For example, by selecting a gas spring or spring combination with a specific stiffness coefficient, the resultant thrust is limited to between 400N and 1000N (e.g., 800N). Finite element analysis verifies that at this thrust level, when the flexible buffer layer at the front end of the docking platform 200 acts on the external target object, the stress generated is lower than the yield strength of the contact surface material of the external target object, thereby ensuring that even in extreme cases where sensor failure or human error causes the mechanism to extend continuously, no structural damage will be caused to the external target object.

[0049] Example 2

[0050] Reference Figure 4 and Figure 5 Based on Example 1, this embodiment further optimizes the specific structural form and spatial layout relationship of the elastic drive component 300 and the active pull-back component 400 to achieve better mechanical balance and operational stability.

[0051] The elastic drive element 300 is used to provide safe thrust, and its implementation includes, but is not limited to: The gas spring 301 utilizes the compression and release of high-pressure gas within a sealed cylinder to provide thrust.

[0052] Mechanical helical springs store elastic potential energy through the compression or stretching deformation of metal materials.

[0053] Rubber elastomers utilize the restoring force of special rubber materials after being compressed to provide power.

[0054] A constant pressure cylinder is a pneumatic transmission component that maintains a constant back pressure through a precision pressure regulating valve.

[0055] The active pull-back component 400 serves as a device for overcoming elastic forces and controlling speed, and its implementation includes, but is not limited to: Hydraulic cylinder 401 drives the piston rod to reciprocate through hydraulic oil pressure.

[0056] The electric winch assembly uses a motor to drive the drum to wind up and unwind flexible rigging.

[0057] A gear and rack mechanism is a device in which a motor drives a gear to crawl on a fixed rack to achieve displacement.

[0058] Electric linear actuator, an integrated linear electric drive actuator.

[0059] In a preferred embodiment of the present invention, the elastic drive component 300 is preferably a gas spring 301, and the active pull-back component 400 is preferably a hydraulic cylinder 401. The advantage of choosing a gas spring 301 is that its elastic force output curve is relatively smooth, and it can achieve a constant force limit at the physical level without external energy support. The advantage of choosing a hydraulic cylinder 401 is that it has high power density, smooth operation, and can be highly integrated with the vehicle's existing hydraulic system to achieve high-precision speed control.

[0060] In this preferred embodiment, in order to further improve the operational stability of the mechanism, the present invention adopts a symmetrical mechanical structure.

[0061] The elastic drive component 300 includes gas springs 301 symmetrically arranged on the fixed platform 100. The fixed end of the gas spring 301 is connected to the fixed platform 100, and the output end of the gas spring 301 is connected to the docking platform 200.

[0062] The active pull-back assembly 400 includes hydraulic cylinders 401 symmetrically arranged on the fixed platform 100. The output end of the hydraulic cylinders 401 is connected to the docking platform 200 through a flexible rigging 402 (preferably a high-strength steel wire rope in this embodiment).

[0063] In actual docking operations, the hydraulic cylinder 401 extends in a controlled manner to release the flexible rigging 402. The gas spring 301 uses its elastic force to push the docking platform 200 to extend synchronously, keeping the flexible rigging 402 taut at all times. In retraction operations, the hydraulic cylinder 401 retracts actively, pulling the docking platform 200 back through the flexible rigging 402. During this process, the gas spring 301 is forcibly compressed to store energy for the next cycle.

[0064] Example 3

[0065] Reference Figure 4 Both the elastic drive component 300 and the active pull-back component 400 are arranged symmetrically with respect to the central axis M of the fixed platform 100.

[0066] The center line of the resultant force generated by the two sets of elastic drive components 300 and the center line of the tension generated by the two sets of active pull-back components 400 both coincide with the central axis M of the fixed platform 100. This ensures that the driving force on the docking platform 200 during the extension and retraction process is balanced, and no additional rotational torque is generated due to the offset of the power source position.

[0067] Considering that the docking platform 200 is typically supported by multiple hinge components, after long-term use, the hinges on different sides may experience varying rotational resistance due to wear or different levels of lubrication. By adopting a symmetrical arrangement, when the resistance on one side increases, causing the platform to exhibit a slight tendency to tilt, the force output by the active pull-back component 400 (such as a hydraulic cylinder) has strong rigid constraints. The symmetrical pulling force can forcibly correct the platform's trajectory, effectively offsetting the effects of uneven resistance, thereby significantly improving the consistency of the extension amount at both ends of the docking platform 200.

[0068] Through the aforementioned symmetrical arrangement, this mechanism achieves the functional requirement of automatic leveling. It ensures that the front end of the docking platform 200 always maintains a state of conformity with the contact surface of the external target object, avoiding docking angle deviations caused by one side contacting the external target object first. The balanced force distribution reduces the lateral shear force on the hinge components and guide rails, effectively mitigating abnormal wear of the mechanical structure and extending the overall service life of the machine. The symmetrical thrust and pull forces, combined with the cushioning characteristics of the gas spring, make the extension and retraction movements of the platform smoother, avoiding the jamming or vibration that may occur with unilateral drive.

[0069] Example 4

[0070] Reference Figure 5 The maximum thrust of the elastic drive component 300 is set to 400N to 1000N.

[0071] In this embodiment, the maximum thrust exerted by the elastic drive member 300 on the docking platform 200 in its fully extended state is set to 400N to 1000N. This range was selected considering the following two dimensions: Overcoming the lower limit of resistance (400N), the docking platform 200 is affected by hinge rotation friction, its own weight, and guide rail resistance during the extension and retraction process. Calculations show that a thrust of 400N is sufficient to drive the platform smoothly to overcome static friction under normal maintenance conditions, ensuring the continuity of the docking operation.

[0072] The upper limit of the critical force for contact damage (1000N) is based on the strength analysis of the material of the external target object. When the front end of the docking platform 200 is equipped with a rubber buffer layer of specified hardness, the surface contact pressure after the concentrated load within 1000N is lower than the critical value for permanent deformation of the contact surface of the external target object.

[0073] Example 5

[0074] Reference Figures 6-8 The fixed platform 100 includes several vertical beams 101 and a horizontal beam 102 disposed between two adjacent vertical beams 101.

[0075] The crossbeam 102 includes a first plate 102a that is flush with the top surface of the vertical beam 101, and a second plate 102b that is perpendicularly connected to the first plate 102a.

[0076] Specifically, the frame of the fixed platform 100 consists of multiple longitudinally extending vertical beams 101 and transverse beams 102 arranged between adjacent vertical beams. The transverse beams 102 adopt a reinforced structure of multi-plate welding or integral molding. The top surface of the first plate 102a is flush with the top surface of the vertical beams 101, forming a flat platform reference surface for supporting the upper covering. The second plate 102b is perpendicularly connected to the first plate 102a and extends downward to form the main web of the transverse beam, providing extremely high bending stiffness.

[0077] The fixed platform 100 also includes a structural frame 103.

[0078] The structural frame 103 is disposed on the second plate 102b, and the structural frame 103 includes a support plate 103a disposed parallel to and spaced apart from the second plate 102b.

[0079] Specifically, to provide support points for the active pull-back assembly 400 and the elastic drive component 300, a structural frame 103 is further provided on the second plate 102b. The structural frame 103 includes a support plate 103a that is parallel to the second plate 102b and maintains a specific distance from it. The support plate 103a is fixed to the second plate 102b by reinforcing ribs or connecting blocks.

[0080] The fixed end of the gas spring 301 is connected to the support plate 103a, and the fixed end of the hydraulic cylinder 401 spans the support plate 103a and the second plate 102b.

[0081] In this embodiment, the crossbeam 102 of the fixed platform 100 serves as the main load-bearing and stress-bearing component. Its first plate 102a and second plate 102b are typically integrally formed from high-strength steel (such as channel steel or I-beam structure). Since the second plate 102b is an inherent main structure of the fixed platform 100, it has a large thickness and hardness. Directly drilling or cutting holes in the second plate would significantly reduce the local strength of the crossbeam and would be extremely difficult to process.

[0082] To this end, the present invention designs a specialized structural frame 103 to achieve non-destructive installation and length compensation of the gas spring 301 and the hydraulic cylinder 401. The structural frame 103 serves as an independent mounting interface fixed to the second plate 102b (e.g., through a small number of welding points or pre-drilled positions). The structural frame 103 includes support plates 103a arranged parallel to and spaced apart from the second plate 102b. The fixed ends of both the gas spring 301 and the hydraulic cylinder 401 are connected to the support plate 103a. By using the support plate 103a as an intermediary, large-scale machining on the second plate 102b is avoided, protecting the original structural strength and torsional resistance of the beam 102.

[0083] In the existing platform frame of the vehicle body, the distance L2 between two adjacent crossbeams 102 is preset and fixed. Since the length L1 (cylinder length) of the first fixed section of the hydraulic cylinder 401 is often smaller than the crossbeam spacing L2, direct installation would result in the cylinder being unable to be fixed across the beams. This invention sets up a structural frame 103 to create a specific clear distance L3 between the support plate 103a and the second plate 102b. By setting the position of the support plate 103a, the relationship L1 + L3 = L2 is satisfied. At this time, the structural frame 103 acts as a length compensation block, allowing the cylinder of length L1 to be fixed within the geometric space formed by the support plate 103a and the adjacent crossbeams.

[0084] Example 6

[0085] Reference Figure 8 The length of the first fixed section 401a of the hydraulic cylinder 401 is L1, the distance between two adjacent crossbeams 102 is L2, and the net distance between the second plate 102b and the support plate 103a is L3. The following relationship is satisfied: L1+L3=L2.

[0086] Specifically, in the frame system of the fixed platform 100, the distance between two adjacent crossbeams 102 is L2. Since the crossbeams 102 are the main load-bearing structures, their positions are usually determined by the mechanical structure of the vehicle platform frame and belong to an immovable, inherent space. In this embodiment, a standard model hydraulic cylinder 401 is preferably used, with the length of its first fixed section 401a (i.e., the cylinder barrel part) being L1. In actual engineering design, L1 is usually smaller than the crossbeam spacing L2, causing the cylinder to be unable to be directly fixed between the two crossbeams 102. To solve the problem of the aforementioned mismatch in installation dimensions, and to avoid destructive processing of the high-strength second plate 102b, this invention compensates for this spacing difference by setting up a structural frame 103. The structural frame 103 is fixed to the second plate 102b of one of the crossbeams, and a specific gap is formed between its support plate 103a and the second plate 102b, the horizontal net distance of which is defined as L3. During assembly, by adjusting the welding or fixing position of the support plate 103a on the structural frame 103, the distance between the support plate 103a and the adjacent crossbeam 102 is exactly equal to the length L1 of the first fixed section 401a. That is, the geometric equation L1 + L3 = L2 is satisfied.

[0087] When L1 + L3 = L2, one end of the hydraulic cylinder 401 of length L1 can be tightly attached to the support plate 103a, and the other end can cross the gap of L3 and be directly or through a connector anchored to the crossbeam 102 on the other side. This allows the structural frame 103 to not only provide support but also act as an extension arm for force transmission. In this way, the structural frame 103 successfully transforms the fixed space of L2 into an installation space that adapts to L1. That is, L3, as an adjustable compensation variable, ensures that even if different models (different L1 lengths) of hydraulic cylinder 401 are replaced, only the L3 dimension of the structural frame 103 needs to be adjusted, without changing the crossbeam 102 of the fixed platform.

[0088] Example 7

[0089] Reference Figure 9 The straight-line distance from the support plate 103a to the front edge of the fixed platform 100 is L4, and the length of the second fixed section 301a of the gas spring 301 is L5. The following relationship is satisfied: L1 <L5<L4。

[0090] Specifically, the support plate 103a of the structural frame 103 serves as the fixing reference for the gas spring 301. To objectively describe its relative position within the fixed platform 100, the spatial straight-line distance from the support plate 103a to the front edge of the fixed platform 100 is defined as L4. Meanwhile, the length of the second fixed section of the gas spring 301 is defined as L5, which mainly corresponds to the cylinder portion of the gas spring 301.

[0091] This embodiment requires that the relational expression L5<L4 is satisfied. The setting of this constraint ensures that the cylinder barrel part of the gas spring 301 can be completely accommodated in the internal space of the fixed platform 100 without protruding beyond the front edge of the platform. This is crucial in actual operation, because when a special vehicle is moving or docking, the edge of the platform is very prone to collision. If the cylinder barrel of the gas spring protrudes from the edge, it is very susceptible to external mechanical damage, resulting in air leakage and failure. At the same time, it ensures that when the docking platform 200 is retracted to the end of the fixed platform 100, no damage will be caused to the end of the gas spring cylinder barrel.

[0092] On the basis of satisfying the above protection logic, the present invention further defines the ratio between the fixed segment length L1 of the hydraulic cylinder 401 and the fixed segment length L5 of the gas spring 301, that is, the condition L1<L5 is satisfied. Since the gas spring 301 needs to provide a larger effective extension margin than the hydraulic cylinder 401 (to ensure that after the hydraulic cylinder is fully extended, the gas spring still exerts residual thrust on the docking platform and keeps the flexible sling 402 taut), the cylinder barrel length L5 of the gas spring often needs to be designed to be longer than the cylinder barrel length L1 of the hydraulic cylinder. Moreover, when the active retraction assembly 400 drives the docking platform 200 to perform the retraction action, if the retraction margin of the gas spring 301 is insufficient, a hard impact inside the cylinder barrel is very likely to occur before the hydraulic cylinder 401 is completely reset, resulting in damage to the gas spring 301 or sealing failure.

[0093] Embodiment 8

[0094] With reference to Figure 10 , the length of the first extension section 401b of the hydraulic cylinder 401 is L6, the length of the second extension section 301b of the gas spring 301 is L7, and the length of the flexible sling 402 is L8, wherein the relational expression L7+L5=L8+L6 is satisfied.

[0095] Specifically, L6, which is the length of the first extension section 401b of the hydraulic cylinder 401, refers to the real-time physical length of the piston rod of the hydraulic cylinder 401 extending out of its cylinder barrel. This length dynamically changes with the displacement of the docking platform 200. When the docking platform 200 is fully retracted, L6 is the residual length of the piston rod extending out of the cylinder barrel; when the docking platform 200 extends outward, L6 increases accordingly.

[0096] L7, which is the length of the second extension section 301b of the gas spring 301, refers to the real-time physical length of the piston rod of the gas spring 301 extending out of its cylinder barrel. Similarly, L7 is also a dynamic value that changes with the movement of the docking platform 200.

[0097] L8 is the total physical length of the flexible sling 402.

[0098] L5 is the length of the second fixed section 301a of the gas spring 301, that is, the total physical length of the cylinder barrel of the gas spring 301.

[0099] In any operating state of the mechanism (including during full retraction, extension, and full extension docking), the entire power transmission chain must satisfy the equation L7+L5=L8+L6.

[0100] The left side of the equation, L7+L5, represents the total physical length of the gas spring 301 in its current position (cylinder barrel plus piston rod extension). The right side of the equation, L8+L6, represents the sum of the real-time extension length of the hydraulic cylinder 401 and the length of the flexible rigging 402.

[0101] When returning to the initial position, based on this equation, when the hydraulic cylinder 401 reaches its fully retracted physical dead point (at which point L6 is the minimum residual length), the piston rod extension length L7 of the gas spring 301 still retains a preset redundancy, thereby preventing the internal piston of the gas spring from hitting the bottom of the cylinder and achieving the aforementioned retraction anti-collision protection.

[0102] Example 9

[0103] Reference Figures 5-10 This embodiment provides a flexible force-limiting docking method for a vehicle-mounted telescopic platform, including the following steps: The active pull-back component 400 is controlled to perform a release action at a preset rate. The elastic drive component 300 continuously outputs elastic restoring force, driving the docking platform 200 to move away from the fixed platform 100, and keeping the flexible rigging 402 taut throughout the entire extension process. The release rate of the active pull-back component 400 is used to limit the extension speed of the docking platform 200 to achieve smooth docking. Physical protection of external target objects is achieved by relying on the maximum thrust limited by the elastic drive element 300. If sensor failure or control failure occurs, the contact force of the elastic drive element 300 on the external target object will still remain below the critical contact damage force. The active pull-back component 400 is controlled to perform the retraction action. The flexible rigging 402 outputs tension to overcome the elastic restoring force of the elastic drive component 300, thereby driving the docking platform 200 to retract smoothly towards the fixed platform 100. Based on the length of the second extension 301b of the gas spring 301 being L7, the length of the second fixed section 301a of the gas spring 301 being L5, the length of the flexible rigging 402 being L8, and the length of the first extension 401b of the hydraulic cylinder 401 being L6, the geometric constraint established by L7+L5=L8+L6 ensures that the first extension 401b of the hydraulic cylinder 401 is fully retracted when returning to the initial position, and simultaneously drives the second extension 301b of the gas spring 301 to retract into the second fixed section 301a.

[0104] During the release action of the active pull-back assembly 400, the extension speed of the piston rod of the hydraulic cylinder 401 is precisely controlled by a proportional relief valve or a speed control valve. Since the elastic restoring force provided by the gas spring 301 is aligned with the extension direction of the docking platform 200, this elastic force is not only the sole power source driving the displacement of the docking platform 200, but also acts as a preload force on the flexible rigging 402. This driving mode overcomes the drawback of thrust fluctuations with load in traditional rigid drives, making the flexible rigging 402 function like a constant tension damper, ensuring that the docking platform 200 does not vibrate or jerk during startup, constant speed phases, or deceleration docking.

[0105] During the active power retraction process, the hydraulic cylinder 401 applies reverse pressure, and the resulting tension is directly transmitted to the docking platform 200 via the flexible rigging 402. At this time, the hydraulic system not only needs to overcome the operating resistance of the docking platform 200, but also simultaneously overcome the compression resistance of the gas spring 301. Through this "forced reset" method, the gas spring 301 is passively compressed and re-accumulates potential energy. Since the tension is directly controlled by the hydraulic system, the risk of "instantaneous ejection" of the flexible rigging 402 due to platform jamming during the retraction process can be effectively avoided.

[0106] The equation L7 + L5 = L8 + L6 is used. During the installation and commissioning phase, the threaded adjustment joint at the end of the flexible rigging 402 is adjusted to ensure that the mechanism strictly matches this equation at the initial zero position. In actual operation, this equation ensures that when the first extension section 401b of the hydraulic cylinder 401 retracts to the minimum residual length L6, the piston rod of the gas spring 301 (i.e., the second extension section 301b) is pressed back to the preset position L7, at which point L7 is greater than the mechanical dead point distance inside the gas spring. This design not only ensures that the physical reference point of the docking platform 200 is completely consistent after each retraction, but also utilizes the dynamic margin of L7 to absorb the inertial impact when the hydraulic system stops, avoiding rigid impact between the piston rod and the bottom of the cylinder, thereby extending the service life of the precision pneumatic components. At the same time, this constraint relationship also simplifies the inspection standards for ground maintenance: only the tension of the rigging in the retracted state needs to be observed to determine whether the geometric positional relationship inside the mechanism has shifted or loosened.

[0107] Example 10

[0108] Reference Figure 1The vehicle body is used to support the flexible force-limiting docking mechanism of the vehicle-mounted telescopic platform. The vehicle body may include a frame, a support platform mounted on the frame, and a support structure for supporting the support platform. A fixed platform 100 is mounted on the vehicle body and serves as the mounting base for the telescopic movement of the docking platform 200. In one embodiment, the fixed platform 100 may be fixedly connected to the front end, side end, or rear end of the support platform of the vehicle body, allowing the docking platform 200 to extend outward according to the relative position between the vehicle and the external target object.

[0109] The docking platform 200 is telescopically mounted relative to the fixed platform 100 and can extend or retract relative to the vehicle body. When the special vehicle moves to the vicinity of the external target object, the docking platform 200 extends away from the vehicle body under the elastic restoring force of the elastic drive member 300, so that the outer end of the docking platform 200 approaches the external target object, forming an overlapping channel with the external target object in the extended state. This overlapping channel can be used for personnel passage, material transfer, tool handling, or equipment maintenance operations.

[0110] During the extension of the docking platform 200, the active pull-back component 400 performs a release action at a preset rate, limiting the extension speed of the docking platform 200 and preventing it from rapidly ejecting due to the elastic restoring force of the elastic drive component 300. Since the maximum thrust exerted by the elastic drive component 300 on the docking platform 200 is less than the critical force for contact damage to the external target object, the contact force can be limited within a safe range when the outer end of the docking platform 200 contacts the external target object, thereby reducing the risk of the contact surface of the external target object being crushed and damaged.

[0111] When it is necessary to disengage the docking channel, the active pull-back component 400 performs a retraction action, outputting a pulling force to the docking platform 200 through the flexible rigging 402, overcoming the elastic restoring force of the elastic drive component 300, causing the docking platform 200 to retract towards the vehicle body. After the docking platform 200 retracts, the elastic drive component 300 returns to an energy storage state to prepare for the next extension and docking.

[0112] By installing the flexible force-limiting docking mechanism of the vehicle-mounted telescopic platform on the vehicle body, the special vehicle in this embodiment can form a temporary docking channel through the docking platform 200 when there are certain deviations in the vehicle parking position, the position of the external target object, or the vehicle posture. The elastic drive component 300 realizes mechanical limit protection of the contact force, thereby improving the safety, stability, and adaptability of the docking process between the special vehicle and the external target object.

[0113] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A special vehicle with a flexible force-limiting docking mechanism for an onboard telescopic platform, characterized in that, include: A fixed platform (100) is mounted on the vehicle body; The docking platform (200) is telescopically configured relative to the fixed platform (100) and is used to form an overlapping channel with an external target object in the extended state; An elastic drive component (300) is connected between the fixed platform (100) and the docking platform (200), and drives the docking platform (200) to extend away from the fixed platform (100) through its own elastic restoring force; An active pull-back component (400) is connected between the fixed platform (100) and the docking platform (200) to overcome the elastic restoring force of the elastic drive component (300) and drive the docking platform (200) to retract towards the fixed platform (100); Wherein, the maximum thrust of the elastic drive member (300) acting on the docking platform (200) is less than the contact damage critical force of the external target object; The elastic drive component (300) includes gas springs (301) symmetrically arranged on the fixed platform (100); The active pull-back assembly (400) includes hydraulic cylinders (401) symmetrically arranged on the fixed platform (100); The fixed platform (100) includes a plurality of vertical beams (101) and a horizontal beam (102) disposed between two adjacent vertical beams (101). The crossbeam (102) includes a first plate (102a) flush with the top surface of the vertical beam (101), a second plate (102b) perpendicularly connected to the first plate (102a), and a structural frame (103) disposed on the second plate (102b). The structural frame (103) includes a support plate (103a) disposed parallel to and spaced apart from the second plate (102b). The fixed end of the gas spring (301) is connected to the support plate (103a), and the fixed end of the hydraulic cylinder (401) spans the support plate (103a) and the second plate (102b). The length of the first fixed section (401a) of the hydraulic cylinder (401) is L1, the distance between two adjacent crossbeams (102) is L2, and the net distance between the second plate (102b) and the support plate (103a) is L3. Among them, the following relationship is satisfied: L1 + L3 = L2; The straight-line distance from the support plate (103a) to the front edge of the fixed platform (100) is L4, and the length of the second fixed section (301a) of the gas spring (301) is L5; Wherein, the relation L1 is satisfied. <L5<L4。 2. The special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in claim 1, characterized in that: The fixed end of the gas spring (301) is connected to the fixed platform (100), and the output end of the gas spring (301) is connected to the docking platform (200).

3. The special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in claim 1 or 2, characterized in that: The output end of the hydraulic cylinder (401) is connected to the docking platform (200) via a flexible rigging (402).

4. The special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in claim 1 or 2, characterized in that: Both the elastic drive element (300) and the active pull-back assembly (400) are arranged symmetrically with respect to the central axis of the fixed platform (100).

5. The special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in claim 1 or 2, characterized in that: The maximum thrust of the elastic drive (300) is set to 400N to 1000N.

6. The special vehicle with a flexible force-limiting docking mechanism for a vehicle-mounted telescopic platform as described in claim 3, characterized in that: The length of the first extension (401b) of the hydraulic cylinder (401) is L6, the length of the second extension (301b) of the gas spring (301) is L7, and the length of the flexible rigging (402) is L8. Among them, the following relationship is satisfied: L7+L5=L8+L6.

7. A flexible force-limiting docking method for a vehicle-mounted telescopic platform, characterized in that, The application to the special vehicle with the flexible force-limiting docking mechanism of the vehicle-mounted telescopic platform as described in claim 6 further includes the following steps: The active pull-back component (400) is controlled to perform a release action at a preset rate. The elastic drive component (300) continuously outputs elastic restoring force, driving the docking platform (200) to move away from the fixed platform (100) and keeping the flexible rigging (402) taut throughout the entire extension process. The release rate of the active pull-back component (400) is used to limit the extension speed of the docking platform (200) to achieve smooth docking. Physical protection of external target objects is achieved by relying on the maximum thrust limited by the elastic drive member (300). If sensor failure or control failure occurs, the contact force of the elastic drive member (300) acting on the external target object will still remain below the critical force for contact damage. The active pull-back component (400) is controlled to perform a retraction action. The flexible rigging (402) outputs a pulling force to overcome the elastic restoring force of the elastic drive component (300), thereby driving the docking platform (200) to retract smoothly towards the fixed platform (100). Based on the second extension section (301b) of the gas spring (301) having a length of L7, the second fixed section (301a) of the gas spring (301) having a length of L5, the flexible rigging (402) having a length of L8, and the first extension section (401b) of the hydraulic cylinder (401) having a length of L6, the geometric constraint established by L7+L5=L8+L6 ensures that the first extension section (401b) of the hydraulic cylinder (401) is fully retracted when retracted to the initial position, and simultaneously drives the second extension section (301b) of the gas spring (301) to retract into the second fixed section (301a).

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