A fork guide mechanism

Abstract

This utility model discloses a fork guide mechanism, relating to the technical field of forklift components. It includes a fork slot in the chassis and symmetrically arranged fork slot guide surfaces. A guide block is provided at the opening of the fork slot guide surface, and the guide surface of the guide block protrudes from the fork slot guide surface. The chassis fork slot is adapted to the fork. Linear slide rails are provided on both sides of the fork, slidingly engaging with the fork slot guide surfaces. A protruding nylon slider is provided at the end of each linear slide rail, and the nylon slider engages with the guide block for limiting. This utility model provides a fork guide mechanism that solves the problem of the fork not being able to accurately retract into the chassis fork slot, ensuring that the fork can accurately extend and retract within the chassis fork slot.

Description

Technical Field

[0001] This utility model relates to the technical field of forklift components, specifically to a fork guide mechanism. Background Technology

[0002] During the operation of a stealth forklift (such as a stealth AGV), the fork assembly needs to frequently extend from the fork slots inside the vehicle body to pick up and place goods, and then accurately retract into the slots after the operation. However, when the vehicle is traveling or parked on uneven ground, the vehicle body may tilt or twist, causing the relative position of the fork slots and forks on the vehicle body to shift. In this case, when the extended forks attempt to retract, their ends may not accurately align and smoothly enter the narrow fork slot entrance, easily leading to jamming, scraping, or even damage to the forks or vehicle body structure. This problem of inaccurate fork retraction positioning caused by uneven ground not only affects operational efficiency and the continuity of automated processes, but also increases equipment maintenance costs and operational risks. Therefore, it is urgent to design a reliable guiding mechanism to ensure that the forks can be smoothly and accurately guided and retracted into the fork slots of the vehicle body under various working conditions, especially on uneven ground, ensuring the stability and reliability of the stealth forklift operation. Utility Model Content

[0003] Technical problem to be solved by the utility model

[0004] The technical problem to be solved by this utility model is to provide a fork guide mechanism, which solves the problem that the forks cannot be accurately retracted into the fork slot of the vehicle body, and ensures that the forks can accurately extend and retract in the fork slot of the vehicle body.

[0005] Technical solution

[0006] To solve the above problems, the technical solution provided by this utility model is as follows:

[0007] A fork guiding mechanism includes a fork slot in a vehicle frame and fork slot guide surfaces arranged symmetrically. A guide block is provided at the slot opening of the fork slot guide surface, and the guide surface of the guide block protrudes from the fork slot guide surface. The fork slot in the vehicle frame is adapted to the fork. Linear slide rails are provided on both sides of the fork and slide in cooperation with the fork slot guide surface. A protruding nylon slider is provided at the end of the linear slide rail, and the nylon slider is limited in cooperation with the guide block.

[0008] High-tolerance initial positioning: The key role of the guide block is to provide strong fault tolerance at the initial moment of fork retraction. Its design, which protrudes from the slotted guide surface, significantly increases the effective guiding area. Like a "funnel," it can capture and correct large initial position deviations at the fork ends (nylon sliders), solving the misalignment problem caused by vehicle body deformation.

[0009] Forced correction and path guidance: The cooperation between the guide block and the nylon slider is not just about positioning, but also a dynamic correction process. Through the contact and relative sliding between the two, a forced lateral force is generated, which actively and in real time guides the slightly misaligned forks back to the correct retraction path.

[0010] Stable and precise linear guidance: The sliding fit between the linear guide rail and the guide surface of the fork slot ensures that after the correction is initiated, the fork body maintains extremely high linear motion accuracy and stability throughout the entire retraction stroke, preventing deviation or swaying during long-distance retraction.

[0011] Cushioning and wear resistance: The nylon slider is designed with a dual function:

[0012] Cushioning and shock absorption: Nylon material has good elasticity and shock absorption properties, which can absorb the impact when it first contacts the guide block, reducing noise and potential damage from hard collisions.

[0013] Wear-resistant and drag-reducing: Nylon material has excellent wear resistance and a low coefficient of friction. When sliding with guide blocks and guide surfaces, it can ensure service life and reduce movement resistance, making the extension and retraction movements smoother.

[0014] Ensuring Reliability and Efficiency: Combining the above functions, this mechanism fundamentally solves the problem of forks not retracting accurately on uneven ground, significantly improving the operational reliability of the forklift under various working conditions, avoiding the risks of jamming, scratching, and equipment damage, thereby ensuring the continuity of automated processes and operational efficiency, and reducing maintenance costs.

[0015] Optionally, the guide block has a buffer block at one inward end, and the buffer block is made of a flexible material.

[0016] Core function: Collision protection and shock absorption

[0017] Protective guide block: As the "soft armor" inside the rigid guide block, it directly withstands accidental impacts, preventing the nylon slider or other fork components from deforming, cracking or loosening due to strong collisions, thus significantly extending the service life of the guide block.

[0018] Protecting the forks / nylon sliders: The flexible contact also protects the nylon sliders or related structures at the fork ends from breakage or excessive wear in hard impacts.

[0019] Protecting the vehicle body structure: By absorbing impact energy, it significantly reduces the impact load transmitted to the fork slots of the frame and the connection parts of the vehicle body, preventing these critical structures from developing micro-deformation, fatigue damage or connection failure due to repeated impact accumulation.

[0020] Improve operational smoothness and reliability:

[0021] Reduce the risk of jamming: The flexible rebound after impact helps guide the impacted part back to the correct path, avoiding instantaneous jamming or serious deviation of the movement trajectory due to violent collision, and increasing the possibility that the forks can still retract successfully in the event of extreme deviation.

[0022] Noise and vibration reduction: Flexible materials can effectively suppress harsh noises generated by collisions and harmful vibrations transmitted to the vehicle body, improving the working environment and enhancing the quality of equipment operation.

[0023] Enhance system fault tolerance:

[0024] Building upon the guide block's guidance and correction function, a final "safety net" is added. Even if the correction process experiences a brief loss of control or an excessive initial deviation, the buffer block provides crucial secondary fault tolerance and damage control capabilities, enhancing the robustness of the entire guiding mechanism under non-ideal operating conditions.

[0025] Optionally, the buffer block is provided with a vertical groove, and the guide block has an inward end provided with a protrusion that engages with the groove.

[0026] Core function: Reliable fixation and impact-resistant separation.

[0027] Preventing the buffer block from falling off: This is the most direct and important function. The rigid mechanical engagement of the groove and the protrusion fundamentally solves the problem of flexible buffer blocks easily detaching, shifting, or even flying off the guide block under repeated high-intensity impacts. Traditional methods relying solely on adhesive bonding or simple press-fitting are unreliable under high-impact and vibration environments.

[0028] Ensuring functional continuity: Only when the buffer block is firmly fixed in its designed position can its collision protection and energy absorption functions continue to operate reliably. This structure ensures that the buffer block remains in the correct working position throughout its entire service life.

[0029] Precisely maintain position and orientation:

[0030] Radial positioning: The groove-protrusion fit determines the precise position and orientation of the buffer block relative to the guide block at the moment of installation, without the need for additional adjustment steps, ensuring that its working surface (the impact-bearing surface) can be accurately aligned with the expected impact direction (i.e. the direction in which the nylon slider may impact when the forks retract).

[0031] Preventing torsional displacement: The fit between the vertical groove and the protrusion (usually a non-circular cross section, such as rectangular or keyway) can effectively resist the circumferential rotation of the buffer block under impact torque or vibration, maintaining its designed posture.

[0032] Enhance overall structural stability and lifespan:

[0033] Distributing impact loads: The groove-protrusion mating surface provides a larger load-bearing contact area, which transmits the impact force borne by the buffer block more evenly to the rigid base of the guide block, avoiding stress concentration that could lead to localized damage.

[0034] Reduced fretting wear: By eliminating radial and circumferential movement of the buffer block relative to the guide block, wear caused by minute relative motion (fretting) is greatly reduced, extending the service life of the connection between the buffer block and the guide block.

[0035] Simplified installation and maintenance:

[0036] Easy installation: This structure typically allows the buffer block to be installed and positioned simply by vertical insertion, making the operation quick and easy.

[0037] Replaceability: When the flexible buffer block needs to be replaced due to wear or aging from long-term use, it is usually only necessary to pull out the old block vertically and insert the new block (possibly with a small amount of fixing agent). Maintenance is simple and does not require disassembling the entire guide block or complicated tools.

[0038] Optionally, the guide block has a chamfered edge.

[0039] The chamfer creates a funnel-shaped guide ramp at what might otherwise be a sharp, rigid edge, significantly widening the "effective entry area" for the nylon slider to successfully contact and begin the induction process. Even if the slider's initial position deviates slightly from the ideal centerline, the chamfer can "catch" it. The chamfer eliminates right-angled edges that could lead to a "hard-on-hard" impact, greatly reducing the risk of the nylon slider getting stuck at the edge during initial contact or requiring significant force to overcome it, thus increasing the system's tolerance to initial position deviations. The chamfered contact generates less frictional resistance than right-angled edge contact, making the slider slide more easily and avoiding momentary jamming or sluggish movement caused by localized high friction. The chamfered contact also produces less localized impact stress on the nylon slider than a direct impact with a right-angled edge, effectively reducing the risk of wear, deformation, or even breakage at the slider's end.

[0040] Optionally, the linear slide rail has a through hole at its end, and a slider fixing block is provided opposite the nylon slider. The nylon slider and the slider fixing block are connected by screws, which pass through the through hole and fasten the nylon slider.

[0041] High-strength fixing: By passing screws through the slide rail through the holes and fastening them to the slider fixing block, a firm mechanical connection is achieved between the nylon slider and the end of the linear slide rail. This can reliably transmit complex loads (thrust, lateral force, impact force) generated by the forks during guiding, correction, and impact processes, preventing the nylon slider from loosening, falling off, or shifting during use.

[0042] Resistance to separation force: When the nylon slider is subjected to an impact force from the guide block or buffer block (attempting to push it away from the slide rail), the slider fixing block is located on the other side of the slide rail and forms a "clamping" effect through screws, effectively resisting the force that separates the slider from the slide rail.

[0043] Independent Replacement of Wear Parts: The nylon slider, as a component directly involved in friction and impact, is a wear part. The separate design (slider + fixing block) allows for easy replacement of the nylon slider when it wears or is damaged; simply loosen the screws connecting it. This eliminates the need to disassemble the entire slider fixing block, screws, or compromise the linear guide rail. This significantly reduces maintenance costs and downtime.

[0044] Material optimization: The slider fixing block is usually made of metal (such as steel or aluminum alloy) to provide high strength and stable threaded connection; nylon sliders utilize their wear-resistant, friction-reducing, and cushioning material properties. The split design allows for the selection of the optimal material according to functional requirements.

[0045] Optionally, the slider fixing blocks are symmetrically arranged, and each block has a screw hole at its top. A connecting plate is fixed between the slider fixing blocks through the screw hole and screws.

[0046] Core function: Enhance structural rigidity and stability.

[0047] Resisting Torsional Deformation: During the extension and retraction of the forks, especially when the guide blocks are correcting their alignment or when a lateral impact occurs, the nylon sliders on both sides may be subjected to asymmetrical lateral forces, attempting to cause relative torsional or lateral bending deformation of the two slider fixing blocks (along with the side rails). The connecting plate, by rigidly connecting the slider fixing blocks on both sides, significantly improves the torsional stiffness of the entire fork end structure, effectively resisting this torsional tendency and maintaining the parallelism and relative positional accuracy of the side rails.

[0048] Suppressing lateral bending: When the forks are subjected to lateral loads (such as accidental collisions), the connecting plate acts as a "beam" to constrain the relative lateral displacement between the two slider fixing blocks, preventing them from opening outward or bending inward, which greatly enhances the overall lateral stability of the fork ends.

[0049] Ensuring guidance accuracy and synchronization:

[0050] Maintaining parallelism: The connecting plate forcibly locks the relative position and orientation of the tops of the two slider fixing blocks, thereby indirectly ensuring that the ends of the linear guide rails (and the nylon sliders) fixed below them always maintain a precise parallel relationship. This is crucial for the forks to slide smoothly and without jamming synchronously along the guide surfaces of the fork slots on both sides.

[0051] Improved Synchronization: When the forks extend or retract, the linear guide rails on both sides must move synchronously. The rigid frame formed by the connecting plate reduces the possibility of slight asynchrony caused by uneven force on both sides or manufacturing / assembly errors, ensuring the smoothness of the fork movement.

[0052] Distributed load and protective components:

[0053] Load sharing function: When one side is subjected to a large impact load (such as a single nylon slider violently hitting the guide block or buffer block), the connecting plate can transfer part of the load to the slider fixing block and slide rail on the other side, avoiding overload damage to the single-sided structure.

[0054] Reduced local stress: By forming an integral frame, the bending stress and torsional load on individual slider fixing blocks and their connection points (screws) are reduced, improving the reliability and lifespan of these connection points.

[0055] Optionally, the fork slot guide surface is provided with a rounded corner structure at its end.

[0056] The rounded corners completely eliminate the "hard edge" at the entrance of the guide surface, making the transition of the nylon slider from the guide area (guide block / bevel) to the main sliding area of ​​the guide surface extremely smooth and seamless, without any noticeable "steps" or "thresholds," greatly reducing the risk of entry jamming. Even if the slider contacts the entrance at a certain speed or slight angle, the rounded corners can effectively absorb impact energy, significantly reducing impact noise and vibration at the moment of contact.

[0057] Optionally, the spacing between the nylon sliders that are arranged opposite each other is greater than the spacing between the guide blocks that are arranged opposite each other.

[0058] Physically preventing the forks from retracting beyond their maximum design travel avoids the following serious consequences:

[0059] Fork / rail impact on vehicle body internal structure: to prevent the fork tip or the rear end of the rail from violently impacting the bottom of the fork slot, drive mechanism or other internal vehicle body components, causing damage.

[0060] Overload damage to drive mechanism: Prevent drive mechanisms (such as motors, chains, and lead screws) from overloading, stalling, or even being damaged when attempting to push the forks beyond their physical limits.

[0061] Derailment or misalignment of the guide system: Prevents the linear guide rail from accidentally detaching from the fork slot guide surface due to excessive retraction, causing misalignment, jamming, or damage to the mechanism.

[0062] Beneficial effects

[0063] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0064] The technical solution provided by this utility model achieves the goal of high precision and smooth retraction of the forks even when the vehicle body is deformed due to uneven ground through a three-level action mechanism of "protruding guide block guiding end slider - slider forced correction - slide rail precise rail setting". Attached Figure Description

[0065] Figure 1 A top view of a fork guide mechanism proposed in an embodiment of this utility model;

[0066] Figure 2 A schematic diagram of the cooperative structure of a fork guide mechanism proposed for an embodiment of this utility model;

[0067] Figure 3 An exploded view of the guide block of a fork guiding mechanism according to an embodiment of this utility model;

[0068] Figure 4 A schematic diagram of the structure of the fork of a fork guiding mechanism proposed in an embodiment of this utility model;

[0069] Figure 5 An exploded view of the forks of a fork guiding mechanism proposed in an embodiment of this utility model;

[0070] 1. Linear guide rail; 2. Nylon slider; 3. Slider fixing block; 4. Connecting plate; 5. Guide block; 6. Block guide surface; 7. Frame fork slot; 8. Fork slot guide surface. Detailed Implementation

[0071] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0072] Example

[0073] Combined with appendix Figure 1 , 2 A fork guide mechanism includes a frame fork slot 7 and fork slot guide surfaces 8 arranged symmetrically. A guide block 5 is provided at the slot opening of the fork slot guide surface 8. The guide surface 51 of the guide block 5 protrudes from the fork slot guide surface 8. The frame fork slot 7 is adapted to the fork. Linear slide rails 1 are provided on both sides of the fork and slide in cooperation with the fork slot guide surface 8. A protruding nylon slider 2 is provided at the end of the linear slide rail 1 and the nylon slider 2 is limited in cooperation with the guide block 5.

[0074] Initial guidance stage: The protruding nylon slider 2 at the end of the fork first contacts the guide block 5 protruding from the slot of the fork groove 7 on the frame. Since the guide block 5 protrudes from the guide surface 8 of the fork groove, its guide surface 51 forms a wider and more accessible "trumpet" shaped guide entrance.

[0075] Correction and introduction stage: Even if the vehicle body deforms due to uneven ground, or there is a certain positional deviation between the fork end and the fork slot inlet, when the nylon slider 2 contacts the guide surface 51 of the guide block 5, under the pushing force of the fork continuing to retract, the nylon slider 2 will slide along the inclined or curved surface of the guide block 5. This sliding process forcibly pushes and guides the nylon slider 2 (along with the entire fork) step by step to a position directly opposite the guide surface 8 of the fork slot.

[0076] Precise Guiding and Limiting Stage: Once the nylon slider 2 is guided into the range defined by the guide block 5, the guide block 5 and the nylon slider 2 form a tight limiting engagement. At this time, the linear guide rails 1 on both sides of the fork are precisely aligned with the fork slot guide surface 8 of the fork slot 7 of the frame. As the fork continues to retract, the linear guide rails 1 slide stably along the fork slot guide surface 8, ensuring that the entire fork retracts accurately and smoothly to the predetermined position inside the vehicle body along a straight path.

[0077] Combined with appendix Figure 3 The guide block 5 has a buffer block 6 at one of its inward ends, and the buffer block 6 is made of flexible material.

[0078] Impact occurs: During the initial guidance stage or forced correction stage of the fork retraction process, when the nylon slider 2 (or other components) at the end of the fork fails to slide smoothly into the guide block 5 according to the block guide surface 51 due to excessive positional deviation or excessive movement speed, and instead directly impacts the inner root area of ​​the guide block 5 itself, the impact force first acts on the buffer block 6 located at the inward end of the guide block 5 (i.e., facing the inside of the fork slot, close to the vehicle body).

[0079] Energy absorption and conversion: Because the buffer block 6 is made of flexible materials (such as polyurethane, rubber and other highly elastic polymer materials), its material will undergo significant elastic or viscoelastic deformation when it is impacted. This deformation process effectively absorbs and dissipates the kinetic energy generated by the impact, converting it into heat energy or other forms of energy within the material.

[0080] Force transmission mitigation: After absorbing most of the impact energy, the buffer block 6 greatly reduces the impact force and peak load transmitted to the rigid guide block 5 itself and its mounting base (frame fork slot 7 / vehicle body). At the same time, the recovery properties of the flexible material help to gently push the impacted object (nylon slider 2 / fork) away from or guide it to the correct path, rather than producing rigid rebound or violent vibration.

[0081] The buffer block 6 has a vertical groove, and the guide block 5 has an inward end with a protrusion that engages with the groove.

[0082] Installation Positioning and Initial Constraints: During assembly, the buffer block 6 (with a vertical groove) is vertically fitted onto the corresponding protrusion at the inward end of the guide block 5. The protrusion is embedded in the groove, which first achieves rapid and accurate radial positioning, ensuring that the buffer block 6 will not move or rotate relative to the guide block 5 in the horizontal plane (X / Y direction).

[0083] Axial limiting and anti-pull-out: The fit between the vertical groove and the protrusion, with its depth and shape design, provides axial (Z-direction) constraint. When the buffer block 6 is subjected to an impact force from the nylon slider 2 or the fork (this force is mainly along the fork retraction direction, i.e., perpendicular to the mounting surface of the buffer block 6), the impact force will attempt to press the buffer block 6 against the base of the guide block 5. At this time, the inner wall of the groove (especially the bottom and side walls) is in close contact with the corresponding surface of the protrusion, forming a mechanical barrier, effectively preventing the buffer block 6 from being pushed away or pulled out along the axial direction of the protrusion (i.e., towards the interior of the vehicle body) due to impact force or vibration.

[0084] Self-reinforcing fixation with flexible material: Since the buffer block 6 itself is made of flexible material, when it deforms under impact force, the material in its groove area will wrap around and tightly adhere to the raised surface, generating additional friction and wrapping force. This "adaptive clamping" effect of the flexible material further enhances the stability of the groove-raised fit, especially when subjected to impact loads.

[0085] The guide block 5 has a chamfered edge. Contact point optimization: When the nylon slider 2 at the end of the fork retracts and does not completely align with the center area of ​​the guide surface 51 of the guide block 5 due to initial position deviation or imperfect movement trajectory, but instead contacts the edge area, the nylon slider 2 will first contact the chamfered bevel of the edge of the guide block 5.

[0086] Angled Sliding and Force Guidance: The chamfered bevel provides a smooth-transition contact surface. As the forks continue to retract, the friction generated by the nylon slider 2 contacting the chamfered bevel is no longer a rigid barrier perpendicular to the contact surface, but rather along the tangential direction of the bevel. This friction (and possibly a normal force component) generates a lateral force component.

[0087] Automatic guide correction: This lateral force propels the nylon slider 2 along the chamfered bevel, moving it from the edge towards the center of the block guide surface 51. This process is an automatic, low-resistance fine-tuning process that gently guides the nylon slider 2 into the effective working area of ​​the block guide surface 51, preparing it for subsequent precise sliding into the fork slot guide surface 8. Simultaneously, the beveled contact significantly reduces the abruptness of the impact.

[0088] Combined with appendix Figure 4 , 5The linear guide rail 1 has a through hole at its end, and a slider fixing block 3 is provided opposite the nylon slider 2. The nylon slider 2 and the slider fixing block 3 are connected by screws. The screws pass through the through hole and tighten the assembly positioning and pre-assembly: the nylon slider 2 and the slider fixing block 3 are two independent parts, pre-connected together by screws. The screws pass through the nylon slider 2 (or its embedded part) and screw into the threaded hole of the slider fixing block 3, tightly pulling and fixing the two together to form a rigid assembly.

[0089] Connection of the assembly to the slide rail: Place the above assembly (nylon slider 2 + slider fixing block 3) at the preset position at the end of the linear slide rail 1, ensuring that the slider fixing block 3 is located "opposite" to the linear slide rail 1 (i.e., on the other side opposite to the nylon slider 2). At this time, the through hole at the end of the linear slide rail 1 is aligned with the screw through hole (or threaded hole) on the slider fixing block 3.

[0090] Screw fastening forms a rigid connection: Another screw (or the same screw, depending on the design) is passed through the through hole at the end of the linear guide rail 1 and screwed into the corresponding threaded hole in the slider fixing block 3. Tightening this screw generates a strong axial tensile force, tightly clamping and fixing the slider fixing block 3, the linear guide rail 1 (clamped in the middle), and the nylon slider 2 together. The through hole provides a passage for the screw to pass through, while allowing for a gap between the screw shank and the hole wall (for easy installation) or a tight fit (for increased stability). Nylon slider 2.

[0091] The slider fixing blocks 3 are symmetrically arranged, and each has a screw hole on its top. The connecting plate 4 is fixed between the slider fixing blocks 3 through the screw holes and screws.

[0092] Symmetrical positioning and independent installation: The two slider fixing blocks 3 are first symmetrically installed and fixed at the ends of the linear guide rails 1 on both sides of the fork (usually one on the left and one on the right). At this time, each slider fixing block 3 is independently supported and operates.

[0093] The connecting plate 4 is aligned with the screw holes: The connecting plate 4 (usually a long strip of metal) is placed across the top of the two symmetrically arranged slider fixing blocks 3. The connecting plate 4 has through holes or countersunk holes at both ends, which are precisely aligned with the screw holes (threaded holes) on the top of the two slider fixing blocks 3.

[0094] Screw fastening forms the integral frame: Screws are passed through the holes on the connecting plate 4 and screwed into the screw holes on the top of the slider fixing blocks 3. After tightening the screws, the connecting plate 4 is rigidly stretched and pressed against the top plane of the two slider fixing blocks 3. The strong clamping force generated by the screws firmly connects the two originally independent slider fixing blocks 3 into a rigid integral frame structure through the connecting plate 4.

[0095] The fork slot guide surface 8 has a rounded corner structure at its end. Inlet guidance stage: When the nylon slider 2 at the end of the fork is initially guided or corrected by the guide block 5 and is about to enter the main sliding area of ​​the fork slot guide surface 8, the nylon slider 2 first contacts the rounded corner at the end of the guide surface.

[0096] Surface Contact and Progressive Constraints: A fillet is a smooth, circularly transitioned surface. Compared to right angles or small chamfers, fillets offer a larger radius of curvature and a smoother contact surface. When the nylon slider 2 contacts a fillet, the contact point moves along the circular arc surface.

[0097] Low-resistance introduction and stress optimization: Under the thrust of the forks continuing to retract:

[0098] Low sliding resistance: The rounded curved surface makes the change in the direction of the normal force at the contact point smoother, effectively reducing the sliding friction resistance, and the nylon slider 2 can slide into the guide surface more easily.

[0099] Stress distribution optimization: Rounded corners eliminate sharp edges, avoiding stress concentration. Contact pressure is distributed evenly over a larger contact area (even if initially line contact or small-area contact) and a smoother surface, significantly reducing peak contact stress at the contact point.

[0100] Natural transition to linear guidance: As the slider moves deeper along the rounded curved surface, its trajectory is smoothly and gradually guided to a state that is completely parallel and aligned with the main straight part of the fork slot guide surface 8, laying the foundation for stable, low-resistance linear sliding on the guide surface.

[0101] The spacing between the nylon sliders 2 and the guide blocks 5 is greater than the spacing between the guide blocks 5.

[0102] Size difference preset: In the structural design, the center distance (A) between the two nylon sliders 2 installed at the ends of the linear slide rails 1 on both sides of the fork is preset to be greater than the center distance (B) between the two guide blocks 5 installed at the entrance of the fork slot on the vehicle body, that is, A>B.

[0103] Extension and retraction process: During the normal extension and retraction of the forks, the forks (along with the linear guide rail 1 and nylon slider 2) move under the action of the drive mechanism. When the forks extend, the nylon slider 2 moves out of the vehicle body along the guide rail, away from the area of ​​guide block 5. At this time, the dimensional difference (A>B) will not have any effect.

[0104] Extreme position interference: When the forks retract to near their maximum stroke (i.e., the linear guide rail 1 is about to fully retract into the fork slot of the vehicle body), the two nylon sliders 2 will simultaneously move into the area between the two guide blocks 5. Since A > B (the distance between the nylon sliders 2 > the distance between the guide blocks 5), at this time:

[0105] The inner sides (opposite surfaces) of the two nylon sliders 2 will simultaneously contact and abut against the outer sides (opposite surfaces) of the two guide blocks 5.

[0106] Rigid blocking limit: The guide block 5 is a structure rigidly fixed to the frame. When the inner side of the nylon slider 2 comes into contact with the outer side of the guide block 5, a physical rigid block is formed. The driving force for the forks to continue retracting is transmitted to the guide block 5 through the nylon slider 2, but since the guide block 5 is firmly installed on the vehicle body and cannot move, this force directly prevents the forks (along with the linear guide 1 and the nylon slider 2) from further retracting, thus precisely limiting the maximum retraction distance of the linear guide 1 (i.e., the maximum retraction stroke of the forks).

[0107] Working principle:

[0108] Through multi-level collaborative guidance and mechanical constraint mechanisms, the forks can be precisely extended and retracted under vehicle body deformation conditions.

[0109] Initial correction guidance: When the forks retract, the nylon slider 2 protruding at the end first contacts the chamfer or protruding guide surface 51 of the guide block 5, and uses the inclined plane force to automatically correct the forks to align with the fork slot inlet.

[0110] Buffer and anti-collision protection: If there is residual deviation, the nylon slider 2 will impact the flexible buffer block 6 inside the guide block 5, and absorb the impact energy through material deformation to avoid rigid collision damage.

[0111] Precise railing and sliding: The corrected forks slide closely against the guide surface 8 of the fork slot through the linear slide rails 1 on both sides (with rounded corners at the ends for smooth transition), ensuring the accuracy of linear motion throughout the entire process;

[0112] Rigid linkage reinforcement: The symmetrical nylon sliders 2 are rigidly connected by the connecting plate 4 to enhance torsional rigidity and ensure the synchronization of the slide rails on both sides;

[0113] Travel mechanical limit: The spacing of the nylon slider 2 is preset to be greater than the spacing of the guide block 5, which forms physical interference at the maximum retraction position to prevent the forks from overtraveling.

[0114] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A guide mechanism for a fork, characterized in that, The device includes a fork slot in the chassis and symmetrically arranged fork slot guide surfaces. A guide block is provided at the slot opening of the fork slot guide surface. The guide surface of the guide block protrudes from the fork slot guide surface. The fork slot in the chassis is adapted to the fork. Linear slide rails that slide in cooperation with the fork slot guide surface are provided on both sides of the fork. A protruding nylon slider is provided at the end of the linear slide rail. The nylon slider is limited in cooperation with the guide block.

2. A fork guide mechanism according to claim 1, wherein The guide block has a buffer block at one inward end, and the buffer block is made of flexible material.

3. A fork guide mechanism according to claim 2, wherein The buffer block has a vertical groove, and the guide block has an inward end with a protrusion that engages with the groove.

4. The fork guide mechanism of claim 1, wherein, The guide block has a chamfered edge.

5. The fork guide mechanism of claim 1, wherein, The linear slide rail has a through hole at its end, and a slider fixing block is provided opposite the nylon slider. The nylon slider and the slider fixing block are connected by screws, which pass through the through hole and fasten the nylon slider.

6. A fork guide mechanism according to claim 5, wherein, The slider fixing blocks are symmetrically arranged, and each block has a screw hole at its top. A connecting plate is fixed between the slider fixing blocks through the screw hole and screws.

7. A fork guide mechanism according to claim 1 wherein, The fork slot guide surface has a rounded corner structure at its end.

8. A fork guide mechanism according to claim 1, wherein The spacing between the nylon sliders that are positioned opposite each other is greater than the spacing between the guide blocks that are positioned opposite each other.

Images