Light-load unmanned forklift truck

Abstract

The utility model relates to unmanned forklift technical field, concretely is a kind of light load unmanned forklift, including walking mechanism of supporting leg subassembly, elastic rudder wheel subassembly, universal wheel subassembly, main body frame, pallet fork lifting mechanism and cover shell;In walking mechanism, elastic rudder wheel subassembly is damped by spring buffer and realizes shock absorption, universal wheel adopts hidden design of recessed groove and cooperates arc bottom plate to enclose, rudder wheel module integrated motor realizes accurate drive steering;Pallet fork lifting mechanism drives inner frame lifting by linear actuator, load is dispersed by chain-sprocket transmission, and supporting leg groove is equipped on pallet fork bottom surface, can be connected with supporting leg sleeve to realize lowest position feeding;Cover shell and arc bottom plate form protective space, and tow chain stores circuit.This light load unmanned forklift is stable in walking, low in consumption in lifting, convenient in feeding, comprehensive in protection, and is suitable for the scene of narrow storage and precision material handling in electronic, pharmaceutical and other industries.It can effectively solve the problems that the wheel train of existing equipment walking mechanism is easily disturbed, steering accuracy is low, and lifting mechanism power consumption is high.

Description

Technical Field

[0001] This utility model relates to the field of unmanned forklift technology, and in particular to a light-load unmanned forklift. Background Technology

[0002] In the field of industrial logistics automation, light-duty unmanned forklifts have become core equipment for material handling in industries such as electronics, pharmaceuticals, and 3C due to their high degree of automation and flexible operation. The operational stability of their walking mechanism, the rationality of their structural layout, and the power transmission efficiency of their fork lifting mechanism directly determine the overall operating performance and service life of the equipment.

[0003] Patent CN 111847323 A discloses a self-driven rack and pinion forklift, which can achieve basic movement and cargo lifting functions, but has obvious technical defects in the core design of the walking mechanism and the fork lifting mechanism: Firstly, the walking mechanism lacks a dedicated shock absorption design, making it prone to severe vibrations when traversing uneven surfaces or encountering small obstacles. This not only affects the stability of cargo handling but also accelerates the wear and tear on components. Secondly, the wheel system layout of the walking mechanism is unreasonable, and most of the components such as the casters are exposed, making them highly susceptible to interference from external obstacles, which can lead to operational failures. Third, the driving and steering precision of the walking mechanism is insufficient, relying on manual or simple mechanical transmission, which makes it difficult to meet the needs of high-precision material handling. Fourth, the walking mechanism has poor spatial adaptability and a relatively bulky structure, resulting in poor flexibility in narrow storage environments. Fifth, the forklift mechanism relies on a single gear and rack transmission without a load-distribution design. The drive component must directly bear the entire weight of the forks and goods, leading to high power consumption and prolonged high-load operation. This accelerates wear on internal gears, motors, and other components, significantly shortening the lifespan of the lifting mechanism. Furthermore, the rigid contact of the gear and rack transmission is prone to transmission jamming due to force fluctuations, affecting lifting accuracy. These problems severely restrict the adaptability of light-duty unmanned forklifts in scenarios such as precision material handling and narrow warehouse operations, making it difficult to meet the modern logistics demands for low vibration, anti-interference, high precision, and high flexibility. Therefore, developing a light-duty unmanned forklift with a shock-absorbing walking mechanism, optimized wheel layout, precise drive steering, and a load-distribution forklift mechanism has become a key direction for technological optimization in the industry. Utility Model Content

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a light-load unmanned forklift to solve the technical problems of existing light-load unmanned forklifts, such as the lack of shock absorption in the walking mechanism, easy disturbance of the wheel system, low steering accuracy, poor space adaptability, high power consumption and short life of the fork lifting mechanism.

[0005] The above objectives are achieved through the following technical solutions: A light-duty unmanned forklift includes a walking mechanism, a main frame, and a fork lifting mechanism; The walking mechanism includes a support leg assembly, a flexible steering wheel assembly, and a caster wheel assembly. In the ground-penetrating state, the drive wheel of the flexible steering wheel assembly, the caster wheel of the caster wheel assembly, and the bottom of the roller at the front end of the support leg assembly are horizontal. The main frame consists of two outer frame plates symmetrically arranged on the support leg assembly, with wall panels on their outer sides. The fork lifting mechanism is located within the main frame and includes an inner frame, a fork bracket, forks, and a linear actuator assembly. The linear actuator assembly is connected to the support leg assembly, and its piston end is connected to the inner frame. The bottom surface of the forks has support leg grooves that can engage with the support legs of the support leg assembly, and the forks have through grooves for the rollers to extend from them. The linear actuator assembly can drive the fork bracket to vertically lift the forks relative to the inner frame, and the inner frame to synchronously vertically lift relative to the main frame.

[0006] Furthermore, the outrigger assembly includes a connecting plate, support legs symmetrically arranged on the outside of the connecting plate, and an outer plate symmetrically arranged on the outside of the support legs; the outer frame plate of the main frame is perpendicularly connected to the outer plate; a roller bracket is provided at the front end of the support leg, the roller is movably arranged in the roller bracket, and the roller can extend out from the roller through slot of the fork.

[0007] Furthermore, the outrigger groove is a U-shaped groove adapted to the shape of the outrigger. In the initial state, the outrigger is embedded in the outrigger groove, so that the fork and the outrigger assembly overlap and the fork is in the lowest position.

[0008] Furthermore, the inner side of the outer frame plate of the main frame is provided with an outer frame limiting slide groove, which is composed of an outer frame first stop bar and an outer frame second stop bar, and a first pulley is movably provided on the inner wall of the upper end of the outer frame limiting slide groove.

[0009] Furthermore, the inner frame includes symmetrically arranged inner frame plates and inner crossbeams located on the top of the two inner frame plates; the outer side of the inner frame plate is provided with an inner frame stop strip, and the lower end of the outer side is movably provided with a second pulley; one side of the inner frame stop strip is limited by the second stop strip of the outer frame, and the other side abuts against the first pulley, and the second pulley abuts against the first stop strip of the outer frame; the fork bracket is provided with third pulleys on both sides, and the third pulleys are embedded in the inner frame limiting grooves on the inner wall of the inner frame plate of the inner frame.

[0010] Furthermore, the fork lifting mechanism also includes a chain and a sprocket; the bottom of the linear actuator assembly is hinged to the connecting plate of the outrigger assembly, and the piston end is hinged to the inner crossbeam of the inner frame; the sprocket is located on the inner wall of the inner frame plate of the inner frame, one end of the chain is connected to the wall plate, and the other end is connected to the fork bracket, and the sprocket drives the fork bracket to lift synchronously through the chain; the linear actuator assembly is an electric linear actuator, which adopts screw drive.

[0011] Furthermore, the elastic steering wheel assembly is disposed on the outer side of the wall panel, including an upper beam plate, a lower beam plate, a spring shaft, a spring, and a slider arranged in parallel; the upper beam plate and the lower beam plate are connected by the spring shaft, the spring and the slider are connected in series on the spring shaft, the top end of the spring abuts against the bottom surface of the upper beam plate, the bottom end abuts against the slider, and the bottom surface of the slider abuts against the surface of the lower beam plate.

[0012] Furthermore, the outer side of the slider is provided with an L-shaped mounting base, and a steering wheel module is mounted on the mounting base. The steering wheel module includes a travel motor and a steering motor. The travel motor is driven by a reduction gearbox, and one side of the reduction gearbox is driven by a drive wheel. The reduction gearbox is provided with a rotary gear, and the shaft of the steering motor is connected to the steering gear, which meshes with the rotary gear. The steering wheel module described in this embodiment is a known technology in the art, and its internal structure, connection relationship, and transmission principle are also common knowledge in the art, so they will not be described in detail here.

[0013] Furthermore, the caster assembly includes a short caster side plate, a long caster side plate, and a caster fixing plate. The short caster side plate and the long caster side plate are fixedly connected to the outer frame plate of the main frame and the outer side plate of the support leg assembly. The caster fixing plate is located on the top of the short caster side plate and the long caster side plate, and the caster is movably connected to the caster fixing plate.

[0014] Furthermore, the main frame is provided with a cover on the outside, the support leg assembly is provided with an arc-shaped base plate on the outside, and the bottom of the cover is connected to the arc-shaped base plate; the cover is a semi-enclosed structure, covering the outside of the main frame, and is made of high-strength plastic or metal sheet.

[0015] This utility model provides a light-duty unmanned forklift with a walking mechanism that includes shock-absorbing components to buffer vibrations, protect the wheel system, and provide precise steering, making it suitable for narrow spaces. The fork lifting mechanism uses a chain and sprocket to distribute the load, reducing power consumption and wear. The casing and cable chain protect core components, comprehensively improving the equipment's stability, reliability, and operational efficiency, making it suitable for precision material handling scenarios. Specific beneficial effects are as follows: 1. The walking mechanism integrates outrigger components and adds a spring buffer structure to the elastic steering wheel components, which can effectively absorb vibrations caused by uneven road surfaces or obstacles, prevent cargo from shifting, and reduce component wear, thus solving the defect of existing equipment without shock absorption; the wheel system adopts a hidden groove design and an arc-shaped bottom plate enclosure, which greatly reduces the interference of external obstacles on components such as swivel wheels, reduces operational failures, and the compact layout significantly improves the adaptability of the vehicle space, allowing it to move flexibly in narrow warehouse environments.

[0016] 2. The steering wheel module of the walking mechanism integrates the walking and steering motors, and achieves precise driving and steering through gear meshing transmission. It has a rapid response and high control accuracy, meeting the needs of high-precision material handling.

[0017] 3. The forklift mechanism adopts a chain-sprocket drive structure, which achieves efficient load distribution, so that the linear actuator only needs to bear half of the load thrust, which greatly reduces power consumption, reduces mechanical wear of the actuator, and extends service life; the pulley-slide groove cooperation between the inner frame and the main frame further ensures the smoothness and accuracy of lifting.

[0018] 4. The enclosure and the curved base plate form a closed protective space, protecting the core components from impact and dust corrosion. The cable chain stores the cables to prevent tangling and wear, thus improving the overall reliability and ease of maintenance of the equipment. It is suitable for precision handling scenarios in industries such as electronics and pharmaceuticals. Attached Figure Description

[0019] Figure 1 This is a first-view structural diagram of a lightweight unmanned forklift according to the present invention; Figure 2 This is a second-view structural diagram of a lightweight unmanned forklift according to the present invention; Figure 3 This is a schematic diagram of the internal structure of a light-duty unmanned forklift after the cover is removed, taken from a first-view perspective. Figure 4 This is a schematic diagram of the internal structure of a light-duty unmanned forklift after the cover is removed, taken from a second perspective. Figure 5 This is a schematic diagram of the walking mechanism in a light-duty unmanned forklift according to the present invention; Figure 6 This is a first-view structural diagram of the elastic steering wheel assembly in a light-load unmanned forklift according to the present invention; Figure 7 This is a second-view structural diagram of the elastic steering wheel assembly in a light-load unmanned forklift according to the present invention; Figure 8 This is a first-view structural diagram of the fork lifting mechanism in a light-duty unmanned forklift according to the present invention; Figure 9This is a second-view structural diagram of the fork lifting mechanism in a light-duty unmanned forklift according to the present invention; Figure 10 This is a schematic diagram of the fork lifting mechanism structure of a light-duty unmanned forklift according to the present invention after removing the main frame.

[0020] Illustration markings: 1-Main frame, 101-Outer frame plate, 102-Outer frame limiting slide groove, 103-Outer frame first stop bar, 104-Outer frame second stop bar, 105-First pulley, 106-First chain connecting seat, 107-First drag chain connecting seat, 108-Wall panel; 2-Outer leg assembly, 201-Support leg, 202-Connecting plate, 203-Outer side plate, 204-Roller bracket, 205-Roller; 3-Inner frame, 301-Inner frame plate, 302-Inner crossbeam, 303-Second pulley, 304-Inner frame retaining strip, 305-Inner frame limiting slide groove, 306-Sprocket hanging plate, 307-Sprocket, 308-Drag chain wheel; 4-Elastic steering wheel assembly, 401-Drive wheel, 402-Upper beam plate, 403-Lower beam plate, 404-Spring shaft, 405-Spring, 406-Slider, 407-Mounting base, 408-Steering wheel module, 409-Walking motor, 410-Steering motor, 411-Reduction gearbox, 412-Rotating gear, 413-Steering gear; 5-Fork support, 501-Third pulley, 502-Second chain connector, 503-Second cable chain connector; 6-Wheel assembly, 601-Wheel, 602-Short side plate of wheel, 603-Long side plate of wheel, 604-Wheel fixing plate; 7-Forks, 701-Outrigger grooves, 702-Roller through grooves; 8-Arc-shaped base plate; 9-Linear actuator assembly; 10-Chain; 11-Drag chain; 12-Casing; 13-First actuator hinge seat; 14-Second actuator hinge seat; 15-Radar. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. The described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] like Figure 1 and Figure 2 As shown, this solution provides a light-duty unmanned forklift, including a walking mechanism, a main frame 1, a fork lifting mechanism, and a cover 12. The components work together to achieve stable walking, low-position loading, precise lifting, and safety protection functions.

[0023] The walking mechanism is the core of the vehicle's movement and includes outrigger assembly 2, elastic steering wheel assembly 4, and swivel wheel assembly 6. The non-walking mechanism is located below the outrigger assembly to ensure reasonable structural stress and stable movement, and to avoid stress concentration or operational failure caused by incorrect component subordination.

[0024] like Figures 3-5 As shown, the outrigger assembly 2 in this embodiment is the basic support component of the walking mechanism, including a connecting plate 202, support legs 201 symmetrically welded to the outside of the connecting plate 202, and an outer plate 203 symmetrically welded to the outside of the support legs 201. The support legs 201 are made of high-strength square steel and have sufficient load-bearing capacity to stably support the weight of the entire vehicle and cargo. Each support leg 201 has a roller bracket 204 mounted on its front end via a pivot. Two symmetrically distributed rollers 205 are movably arranged inside the roller bracket 204. The rollers 205 are made of wear-resistant rubber and together with the drive wheel 401 and the caster wheel 601, they form a multi-wheel support structure. When in contact with the ground, the bottom of each wheel remains horizontal, ensuring that the vehicle does not tilt during travel and improving operational stability.

[0025] like Figure 6 and Figure 7 As shown, in this embodiment, the elastic steering wheel assembly 4 is disposed on the outer side of the wall panel 108 and is the core of the power and steering of the traveling mechanism. It includes a drive wheel 401, an elastic component, and a steering wheel module 408. The elastic component includes an upper beam plate 402 and a lower beam plate 403 arranged in parallel, a pair of spring shafts 404, a spring 405, and a slider 406. The upper beam plate 402 and the lower beam plate 403 are bolted together by the spring shafts 404, which is a firm connection and facilitates later disassembly and maintenance, and is fixed to the wall panel 108. The spring 405 and the slider 406 are connected in series on the spring shafts 404. The top end of the spring 405 abuts against the bottom surface of the upper beam plate 402, and the bottom end abuts against the slider 406. The bottom surface of the slider 406 abuts against the surface of the lower beam plate 403, forming a longitudinal elastic support structure for the steering wheel module 408. When the forklift passes over uneven roads or encounters small obstacles, the spring 405 can buffer vibration through compression and rebound, preventing the goods from shifting or being damaged due to vibration, and ensuring the stability of handling.

[0026] An L-shaped mounting base 407 is welded to the outer side of the slider 406. A steering wheel module 408 is fixed to the mounting base 407 by bolts. The steering wheel module 408 integrates walking and steering functions and includes a walking motor 409 and a steering motor 410. The walking motor 409 is connected to the reduction gearbox 411 below the mounting base 407 via a coupling. One side of the reduction gearbox 411 is connected to the drive wheel 401 via a key. The speed and torque can be adjusted by the gear set inside the reduction gearbox 411 to adapt to the walking requirements under different loads. A rotary gear 412 is fixed to the reduction gearbox 411 by bolts. The shaft of the steering motor 410 is connected to the steering gear 413 via a key. The steering gear 413 meshes with the rotary gear 412. When the walking motor 409 drives the drive wheel 401 to rotate in both directions, the forklift can move forward or backward. When the steering motor 410 drives the steering gear 413 to rotate the slewing gear 412, the drive wheel 401 can be flexibly steered. The response is fast and the control precision is high, which is suitable for multi-directional operation needs in warehousing scenarios.

[0027] like Figure 3 and Figure 4 As shown, in this embodiment, the omnidirectional wheel assembly 6 is symmetrically arranged around the elastic steering wheel assembly 4, assisting the walking mechanism to achieve smooth movement and steering. It includes an omnidirectional wheel 601, a short side plate 602, a long side plate 603, and a fixing plate 604. The short side plate 602 and the long side plate 603 are welded and fixed to the outer side plate 203 of the support leg assembly 2, resulting in high connection strength and resistance to breakage. The fixing plate 604 is bolted to the top, and the three components together form a concealed space for the omnidirectional wheel. The omnidirectional wheel 601 is movably connected to the fixing plate 604 via a pivot.

[0028] The rear ends of the two casters 601 do not extend beyond the rear end of the drive wheel 401. The three landing points form an isosceles triangle support structure. On the one hand, this can reduce the interference of external obstacles on the casters 601 and reduce the risk of failure. On the other hand, it can make the whole vehicle structure lighter and thinner, and improve the flexibility of maneuvering in narrow storage environments.

[0029] like Figure 3 and Figure 4 As shown, in this embodiment, an arc-shaped base plate 8 is also bolted to the outer side of the outer side plate 203 of the outrigger assembly 2. The arc-shaped base plate 8 is made of bent steel plate, which has high structural strength and is not easily deformed. It is welded to the outer ends of the short side plate 602 and the long side plate 603 of the universal wheel, which can provide full protection for the drive wheel 401 and the universal wheel 601, preventing ground gravel, weeds and other debris from being rolled into the wheel body. At the same time, it avoids external obstacles such as the corners of the shelf from directly hitting the wheel system, effectively protecting the core components of the walking mechanism and extending its service life.

[0030] The upper surface of the universal wheel fixing plate 604 can be bolted with a radar 15, which scans the surrounding environment in real time to provide path optimization data for the walking mechanism and improve the efficiency of the vehicle's automated operation.

[0031] like Figure 1 and Figure 2 As shown, the housing 12 is the core of the vehicle's protection, adopting a semi-enclosed structure. It can be made of high-strength plastic or metal sheet, and features impact resistance, dustproofing, and waterproofing, effectively protecting the main frame 1 and the core components of the forklift mechanism. The housing 12 covers the outside of the main frame 1, its outline matching the shape of the main frame 1 and the outrigger assembly 2. The bottom is fixedly connected to the arc-shaped base plate 8 with bolts, forming a closed protective space to prevent components from being damaged by external impacts, dust accumulation, or water stains, extending the equipment's service life and reducing maintenance frequency.

[0032] like Figure 5 , 8 As shown in Figure 9, the main frame 1 in this embodiment serves as the mounting base for the fork lifting mechanism. It consists of two outer frame plates 101 symmetrically arranged on the outer side plate 203 of the support leg assembly 2, forming a U-shaped structure. The outer frame plates 101 are made of high-strength steel plates, possessing sufficient strength to bear the weight of the fork lifting mechanism and the cargo, thus preventing deformation during long-term use. Wherein: The inner side of the outer frame plate 101 of the main frame 1 is welded with a first outer frame stop 103 and a second outer frame stop 104 along the length direction, forming an outer frame limiting groove 102, which provides precise guidance for the lifting and lowering of the inner frame 3 and avoids horizontal deviation during the lifting and lowering process of the inner frame 3. The upper inner wall of the outer frame limiting groove 102 is movably mounted with a first pulley 105 via a pivot. The outer side of the inner frame plate 301 of the inner frame 3 is welded with an inner frame stop 304 along the length direction, and the lower end of the outer side is movably mounted with a second pulley 303 via a pivot. One side of the inner frame stop 304 fits and limits the outer frame second stop 104, and the other side rolls against the first pulley 105. The second pulley 303 rolls against the outer frame first stop 103, converting the sliding friction between the inner frame 3 and the main frame 1 into rolling friction, significantly reducing the lifting resistance and making the lifting process smoother.

[0033] like Figure 10 As shown, the inner frame 3 includes symmetrically arranged inner frame plates 301 and inner crossbeams 302 fixed to the top of the two inner frame plates 301 by bolts. The inner wall of the inner frame plate 301 is welded with an inner frame limiting groove 305 along the length direction. The third pulley 501 of the fork bracket 5 is embedded in the inner frame limiting groove 305 and can roll along it, so that the fork bracket 5 is evenly stressed and the lifting process is smooth and without shaking, ensuring the accuracy of cargo handling.

[0034] like Figures 8-10As shown, the power core of the fork lifting mechanism in this embodiment is the linear actuator assembly 9, preferably an electric linear actuator, which adopts a screw drive method. It has the advantages of high control precision and strong energy controllability, and can accurately control the lifting height of the forks 7. The connecting plate 202 of the outrigger assembly 2 is provided with a first actuator hinge seat 13, and the bottom surface of the inner crossbeam 302 of the inner frame 3 is welded with a second actuator hinge seat 14. The bottom of the linear actuator assembly 9 is hinged to the first actuator hinge seat 13 by a pin, and the piston end is hinged to the second actuator hinge seat 14 by a pin. This connection method can adapt to the small angle changes of the inner frame 3 during the lifting process, avoid component damage caused by uneven force, and extend the service life of the linear actuator assembly 9.

[0035] A sprocket mounting plate 306 is welded to the inner frame limiting slide groove 305 of the inner frame 3 near the inner crossbeam 302. A sprocket 307 is movably mounted on the sprocket mounting plate 306 via a rotating shaft, and a roller chain 10 is wound around the sprocket 307. A first chain connecting seat 106 is symmetrically welded to the inner wall of the outer frame plate 101 of the main frame 1, and a second chain connecting seat 502 is symmetrically welded to the inner wall of the fork bracket 5. One end of the chain 10 is fixed to the first chain connecting seat 106 by bolts, and the other end is fixed to the second chain connecting seat 502 by bolts. The chain-sprocket transmission structure enables efficient load distribution: when the linear actuator assembly 9 drives the inner frame 3 to rise, the sprocket 307 rises synchronously, pulling the fork bracket 5 synchronously through the chain 10. Moreover, the rising speed of the fork 7 is twice that of the inner frame 3, so that the linear actuator only needs to bear half of the total load of the goods and forks, which greatly reduces power consumption and reduces mechanical wear of the linear actuator assembly 9.

[0036] A drag chain wheel 308 is mounted on the outer side of the sprocket 307 via a rotating shaft, and a drag chain 11 is wound around the drag chain wheel 308. One end of the drag chain 11 is bolted to the first drag chain connecting seat 107 on the inner side of the outer frame plate 101 of the main frame 1, and the other end is bolted to the second drag chain connecting seat 503 on the inner wall of the fork bracket 5. The drag chain 11 houses cables such as fork position sensors and motor control lines, preventing cables from getting tangled or rubbing against other components when the forks 7 are raised or lowered, ensuring stable wiring connections, and reducing the probability of equipment downtime due to wiring faults.

[0037] like Figure 4 , 5As shown in Figure 10, the fork 7 in this embodiment is the core component for carrying goods. Its bottom surface has a U-shaped support leg groove 701 that is adapted to the shape of the support leg 201 of the support leg assembly 2. In the initial state, the support leg 201 can be embedded in the support leg groove 701, realizing the overlapping of the fork 7 and the support leg assembly 2, so that the fork 7 is in the lowest position, which is convenient for docking with low-level loading devices such as conveyor belts and bottom shelves. Loading can be completed without additional lifting of goods, significantly improving work efficiency and saving storage space.

[0038] Meanwhile, the fork 7 is provided with a roller through groove 702 at the position corresponding to the roller 205, so that when the fork 7 is attached to the support leg, the roller 205 can extend out from the roller through groove 702 without affecting the normal movement of the walking mechanism, and avoid walking failure caused by interference between the fork 7 and the roller 205.

[0039] The fork bracket 5 is detachably connected to the fork 7 by bolts, which facilitates the replacement of forks 7 of different specifications according to the size of the goods, thereby improving the versatility of the equipment. At least two third pulleys 501 are installed on both sides of the fork bracket 5 via a pivot. The third pulleys 501 use deep groove ball bearings, which have a low coefficient of friction and can reduce the resistance when the fork bracket 5 is raised or lowered.

[0040] As a specific embodiment of this solution, this embodiment provides a light-duty unmanned forklift, including a walking mechanism (including outrigger assembly 2, flexible steering wheel assembly 4, and swivel wheel assembly 6), a main frame 1, a fork lifting mechanism (including inner frame 3, fork bracket 5, fork 7, linear actuator assembly 9, chain 10, and sprocket 307), and a cover 12. The two outer frame plates 101 of the main frame 1 are vertically connected to the outer side plate 203 of the outrigger assembly 2 by bolts or welding, and the connection is firm with no relative displacement; the flexible steering wheel assembly 4 and swivel wheel assembly 6 of the walking mechanism are set on the outrigger assembly 2, together forming the walking system; the fork 7 is sleeved with the support leg 201 through the outrigger groove 701, and the roller 205 extends from the roller through groove 702 to ensure that the fork 7 is in the lowest position in the initial state; the cover 12 is placed on the outside of the main frame 1, and the bottom is bolted to the arc-shaped base plate 8 to form a closed protective space.

[0041] The support leg groove 701 of the fork 7 is a U-shaped groove, which is adapted to the shape of the support leg 201. In the initial state, the support leg 201 is completely embedded in the support leg groove 701, realizing the overlapping of the fork 7 and the support leg assembly 2. At this time, the fork 7 is in the lowest position and can be directly connected to the low-position feeding device. The position of the roller through groove 702 corresponds to the roller 205, ensuring that the roller 205 can be fully extended without interfering with the fork 7, thus ensuring the normal movement of the walking mechanism.

[0042] The specific workflow of the forklift mechanism is as follows: When the light-load unmanned forklift receives a cargo lifting command, the fork lifting mechanism starts operating: First, the linear actuator assembly 9 installed on the outrigger assembly connecting plate is powered on and started. Its internal drive unit (such as a lead screw motor) drives the piston end to extend smoothly in the vertical direction. The top of the piston end is in close contact with the bottom surface of the inner crossbeam at the top of the inner frame 3. As the piston end continues to extend, the thrust is evenly transmitted to the entire inner frame 3 through the inner crossbeam, causing the inner frame 3 to move vertically upward along the outer frame limiting slide groove 102 on the inner side of the outer frame plate of the main frame 1. During this process, the second pulleys on the outer sides of the inner frame plates on both sides of the inner frame 3 roll against the first stop bar of the outer frame limiting slide groove 102. The inner frame stop bar and the second stop bar of the outer frame are in close contact and rolling contact with the first pulley at the top of the outer frame limiting slide groove 102, which not only restricts the horizontal displacement of the inner frame 3, but also converts sliding friction into rolling friction, reducing lifting resistance.

[0043] As the inner frame 3 rises, the sprocket mounting plate near the inner crossbeam on its inner frame limiting slide groove rises synchronously, driving the sprocket 307, which is movably mounted on the mounting plate via a rotating shaft, to move upwards simultaneously. Since one end of the roller chain 10 wound around the sprocket 307 is fixed to the first chain connecting seat 106 on the inner wall of the outer frame plate of the main frame 1 (relatively stationary) by bolts, and the other end is fixed to the second chain connecting seat 502 on the inner wall of the fork bracket 5 by bolts, the rising sprocket 307 generates an upward traction force on the chain 10, thereby pulling the fork bracket 5 upwards synchronously along the inner frame limiting slide groove 305 of the inner frame 3. During this transmission process, because the two ends of the chain 10 are connected to the stationary component (main frame 1) and the moving component (fork bracket 5) respectively, the rising distance of the sprocket 307 is converted into twice the rising distance of the fork bracket 5, meaning the rising speed of the fork bracket 5 is twice that of the inner frame 3, achieving the effect of "small stroke actuator driving large stroke fork lifting". More importantly, the total load of the forks 7 and the cargo is transmitted to the chain 10 through the fork bracket 5, and then distributed to the inner frame 3 via the sprocket 307, and finally borne by the linear actuator assembly 9. At this time, the linear actuator assembly 9 only needs to bear half of the thrust of the total load to drive the forks 7 to rise. Compared with the traditional non-distributed structure, the power consumption is significantly reduced, and the mechanical wear caused by the actuator bearing the full load for a long time is avoided, effectively extending its service life.

[0044] When the fork 7 needs to be lowered, the linear actuator assembly 9 receives the lowering command. The piston end, under the action of the internal drive unit, slowly retracts vertically. After the inner frame 3 loses its pushing force, it moves smoothly and vertically downwards along the outer frame limiting groove 102 under its own weight and the combined weight of the fork 7 and the cargo. At this time, the sprocket 307 descends synchronously with the inner frame 3, and the chain 10 is gradually tightened under the gravity of the fork bracket 5, pulling the fork bracket 5 downwards synchronously along the inner frame limiting groove 305. The fork 7 slowly falls back down with the fork bracket 5 until the support leg groove on the bottom of the fork 7 is fully engaged with the support leg of the support leg assembly, and the fork 7 returns to its initial lowest position. Throughout the entire lifting process, the chain-sprocket transmission structure always achieves efficient load distribution. The linear actuator assembly 9 does not need to bear the entire load, which significantly reduces power consumption and mechanical wear of the actuator, ensuring long-term stable operation of the mechanism.

[0045] The detailed working process of the walking mechanism is as follows: When the light-load unmanned forklift receives the handling path instruction, the walking mechanism starts to operate, first entering the driving walking stage: in the steering wheel module 408 of the elastic steering wheel assembly 4, the walking motor 409 is powered on and started. Its output shaft transmits power to the reduction gearbox 411 below through a coupling. After the reduction gearbox 411 adjusts the speed and torque through the internal gear set, it drives the drive wheel 401 on one side to rotate. If the walking motor 409 rotates clockwise, the drive wheel 401 rotates clockwise synchronously, and the friction between the wheel and the ground propels the whole vehicle forward; if the walking motor 409 rotates counterclockwise, the drive wheel 401 rotates counterclockwise accordingly, realizing the whole vehicle moving backward. The power transmission is stable throughout the driving process, and the driving speed can be flexibly adjusted according to the instructions to adapt to different working scenarios.

[0046] When the driving direction needs to be adjusted, the steering motor 410 is activated, and its shaft drives the steering gear 413 at the end to rotate. Since the steering gear 413 is precisely meshed with the rotary gear 412 on the reduction gearbox 411, the rotation of the steering gear 413 will drive the rotary gear 412 to rotate synchronously, thereby causing the reduction gearbox 411 and the drive wheel 401 connected to it to deflect as a whole. When the steering motor 410 rotates forward, the drive wheel 401 deflects to the left, guiding the whole vehicle to turn left; when the steering motor 410 rotates in reverse, the drive wheel 401 deflects to the right, completing the right turn. The steering process is responsive and the angle control is precise, which can realize small-radius steering and adapt to the steering needs of narrow passages in warehouse scenarios.

[0047] During the vehicle's movement, the caster assembly 6 and the outrigger assembly 2 work together to provide auxiliary support and guidance: the caster 601 of the caster assembly 6 is always in contact with the ground, rolling synchronously with the drive wheel 401 to help the vehicle maintain straight-line stability or adjust its direction in conjunction with the steering of the drive wheel 401; on the other hand, the roller 205 in the roller bracket 204 at the front end of the outrigger assembly 2's support leg 201 rolls synchronously, forming a multi-point support structure together with the drive wheel 401 and the caster 601, distributing the weight of the vehicle and cargo, and preventing tilting caused by the shift of the center of gravity during driving.

[0048] When traveling on uneven surfaces or encountering small obstacles (such as ground bumps or small stones), the shock absorption function of the elastic steering wheel assembly 4 is activated: the drive wheel 401 is subjected to an upward impact force, which is transmitted to the slider 406 through the reduction gearbox 411 and mounting base 407, causing the slider 406 to slide upward along the spring shaft 404 and compress the spring 405; the spring 405 is compressed and undergoes elastic deformation, converting part of the impact force into elastic potential energy, effectively buffering the transmission of vibration and preventing the vibration from causing the goods to shift or be damaged; after passing over the obstacle, the spring 405 releases its elastic potential energy, pushing the slider 406 to return to its original position along the spring shaft 404, and the drive wheel 401 resumes stable contact with the ground. At the same time, the arc-shaped base plate 8 on the outside of the outrigger assembly 2 always surrounds the drive wheel 401 and the caster wheel 601, which can prevent ground debris, weeds and other debris from being rolled into the wheel body, or prevent external obstacles such as the corners of the shelves from directly hitting the wheel system, further ensuring the reliability of the walking mechanism and ensuring the stable operation of the whole vehicle in complex warehouse environments.

[0049] The above description is only for illustrating the embodiments of this utility model and is not intended to limit this utility model. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A light-duty unmanned forklift, characterized in that, It includes a traveling mechanism, a main frame (1), and a fork lifting mechanism; The walking mechanism includes a support leg assembly (2), an elastic steering wheel assembly (4), and a swivel wheel assembly (6). When the vehicle is on the ground, the drive wheel (401) of the elastic steering wheel assembly (4), the swivel wheel (601) of the swivel wheel assembly (6), and the roller (205) at the front end of the support leg assembly (2) are horizontal at the bottom. The main frame (1) is composed of two outer frame plates (101) symmetrically arranged on the leg assembly (2), and a wall panel (108) is provided on its outer side. The fork lifting mechanism is located inside the main frame (1) and includes an inner frame (3), a fork bracket (5), forks (7) and a linear actuator assembly (9). The linear actuator assembly (9) is connected to the support leg assembly (2), and its piston end is connected to the inner frame (3). The linear actuator assembly (9) can drive the fork bracket (5) to move the forks (7) vertically relative to the inner frame (3), and the inner frame (3) can move vertically relative to the main frame (1) synchronously.

2. The light-duty unmanned forklift according to claim 1, characterized in that, The support leg assembly (2) includes a connecting plate (202), a support leg (201) symmetrically arranged on the outside of the connecting plate (202), and an outer plate (203) symmetrically arranged on the outside of the support leg (201); the outer frame plate (101) of the main frame (1) is vertically connected to the outer plate (203); the front end of the support leg (201) is provided with a roller bracket (204), and the roller (205) is movably arranged in the roller bracket (204).

3. The light-duty unmanned forklift according to claim 2, characterized in that, The bottom surface of the fork (7) is provided with a support leg groove (701). The support leg groove (701) is a U-shaped groove that is adapted to the shape of the support leg (201). In the initial state, the support leg (201) is embedded in the support leg groove (701), so that the fork (7) and the support leg assembly (2) are sleeved and overlapped, and the fork (7) is in the lowest position.

4. The light-duty unmanned forklift according to claim 1, characterized in that, The outer frame plate (101) of the main frame (1) is provided with an outer frame limiting slide groove (102) on the inner side. The outer frame limiting slide groove (102) is composed of an outer frame first stop bar (103) and an outer frame second stop bar (104). A first pulley (105) is movably provided on the inner wall of the upper end of the outer frame limiting slide groove (102).

5. A light-duty unmanned forklift according to claim 4, characterized in that, The inner frame (3) includes symmetrically arranged inner frame plates (301) and inner crossbeams (302) located on the top of the two inner frame plates (301); the outer side of the inner frame plate (301) is provided with an inner frame baffle (304), and the lower end of the outer side is provided with a second pulley (303); one side of the inner frame baffle (304) is limited by the outer frame second baffle (104), and the other side abuts against the first pulley (105), and the second pulley (303) abuts against the outer frame first baffle (103); the fork bracket (5) is provided with a third pulley (501) on both sides, and the third pulley (501) is embedded in the inner frame limiting groove (305) of the inner frame plate (301) of the inner frame (3).

6. A light-duty unmanned forklift according to claim 5, characterized in that, The fork lifting mechanism also includes a chain (10) and a sprocket (306); the bottom of the linear actuator assembly (9) is hinged to the connecting plate (202) of the outrigger assembly (2), and the piston end is hinged to the inner crossbeam (302) of the inner frame (3); the sprocket (306) is located on the inner wall of the inner frame plate (301) of the inner frame (3), one end of the chain (10) is connected to the wall plate (108), and the other end is connected to the fork bracket (5). The sprocket (306) drives the fork bracket (5) to lift synchronously through the chain (10).

7. A light-duty unmanned forklift according to claim 1, characterized in that, The elastic steering wheel assembly (4) is disposed on the outer side of the wall panel (108) and includes an upper beam plate (402), a lower beam plate (403), a spring shaft (404), a spring (405), and a slider (406) arranged in parallel. The upper beam plate (402) and the lower beam plate (403) are connected by the spring shaft (404). The spring (405) and the slider (406) are connected in series on the spring shaft (404). The top end of the spring (405) abuts against the bottom surface of the upper beam plate (402), and the bottom end abuts against the slider (406). The bottom surface of the slider (406) abuts against the surface of the lower beam plate (403).

8. A light-duty unmanned forklift according to claim 7, characterized in that, The slider (406) has an L-shaped mounting base (407) on its outer side, and a steering wheel module (408) is provided on the mounting base (407); the steering wheel module (408) includes a travel motor (409) and a steering motor (410), the travel motor (409) is connected to a reduction gearbox (411) for transmission, and one side of the reduction gearbox (411) is connected to a drive wheel (401) for transmission; the reduction gearbox (411) is provided with a rotary gear (412), and the shaft of the steering motor (410) is connected to a steering gear (413), and the steering gear (413) meshes with the rotary gear (412).

9. A light-duty unmanned forklift according to claim 1, characterized in that, The caster assembly (6) includes a short caster side plate (602), a long caster side plate (603), and a caster fixing plate (604). The short caster side plate (602) and the long caster side plate (603) are fixedly connected to the outer frame plate (101) of the main frame (1) and the outer side plate (203) of the support leg assembly (2). The caster fixing plate (604) is located on the top of the short caster side plate (602) and the long caster side plate (603). The caster (601) is movably connected to the caster fixing plate (604).

10. A light-duty unmanned forklift according to claim 1, characterized in that, The main frame (1) is provided with a cover (12) on the outside, and the leg assembly (2) is provided with an arc-shaped base plate (8) on the outside. The bottom of the cover (12) is connected to the arc-shaped base plate (8).

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