A fork lifting mechanism for a light-load unmanned forklift

Abstract

The utility model relates to the technical field of light load unmanned forklift, concretely is a kind of fork lifting mechanism for light load unmanned forklift, including support base, outer frame board, inner frame, fork bracket, fork, linear actuator assembly and chain sprocket system. Outer frame board constitutes U-shaped outer frame body, and inner frame is embedded therein and is lifted vertically by pulley and fender bar cooperation;Fork bracket is lifted along the inner frame of inner frame limiting sliding slot by third pulley;Linear actuator assembly drives inner frame lifting, simultaneously makes fork bracket synchronous lifting by chain-sprocket transmission, realizes the efficient dispersion of load force, reduces the power consumption of actuator;Still set up tow chain storage circuit. The mechanism has low power consumption, high lifting precision, stable structure and orderly line management, effectively solve the problems, such as great power loss and unstable structure in prior art, improve the material handling performance of light load unmanned forklift.

Description

Technical Field

[0001] This utility model relates to the field of light-duty unmanned forklift technology, and in particular to a fork lifting mechanism for light-duty unmanned forklifts. Background Technology

[0002] In the field of industrial logistics automation, light-duty unmanned forklifts have become the core equipment for material handling in precision manufacturing and warehousing industries such as electronics, pharmaceuticals, and 3C due to their high degree of automation, high operating efficiency, and strong spatial adaptability. As a key functional component for light-duty unmanned forklifts to lift and transport goods, the fork lifting mechanism's power transmission efficiency, structural stability, and operating energy consumption 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. Its fork lifting mechanism relies on the meshing transmission of gears and racks to achieve lifting action. While this structure can ensure a certain lifting accuracy through rigid meshing and meet basic handling requirements, it has significant technical defects in practical applications. Firstly, power loss is a major issue. The lifting drive component directly bears the entire weight of the forks and goods, causing the drive actuator to operate under high load for extended periods. This not only results in significantly high power consumption but also accelerates the wear of internal components, drastically shortening the equipment's lifespan and increasing subsequent maintenance costs. Secondly, structural stability is insufficient. During lifting, the internal and external frames lack precise limiting and guiding structures, making them prone to horizontal deviation due to uneven force. This not only reduces the lifting accuracy of the forks and affects the smooth handling of goods but may also cause the goods to tip over when handling goods with a high center of gravity or uneven weight, posing a safety hazard. These problems not only restrict the adaptability of light-load unmanned forklifts in precision material handling scenarios but also fail to meet the modern logistics demands for low-energy consumption and high stability.

[0004] Therefore, developing a fork lifting mechanism that can effectively distribute load, reduce energy consumption, and has a stable structure has become an important direction for optimizing current light-load unmanned forklift technology. Utility Model Content

[0005] The purpose of this utility model is to overcome the problems of the prior art and provide a fork lifting mechanism for light-load unmanned forklifts, which solves the technical problems of high power loss, insufficient structural stability and easy interference of the existing mechanism.

[0006] The above objectives are achieved through the following technical solutions: A fork lifting mechanism for a light-duty unmanned forklift includes a support base with symmetrically arranged outer frame plates on the support base; it also includes an inner frame, which is embedded between the two outer frame plates and can be vertically lifted relative to the outer frame plates; and a frame wall plate is provided on the outer side of the two outer frame plates. The support base is equipped with a linear actuator assembly, which can drive the inner frame to move vertically up and down relative to the outer frame plate; The inner frame is provided with a fork bracket, and forks are connected to the fork bracket. The fork bracket can drive the forks to move vertically up and down relative to the inner frame. A chain and a sprocket are provided between the inner frame and the fork bracket. One end of the chain is connected to the frame wall panel and the other end is connected to the fork bracket. The sprocket can drive the fork bracket to rise and fall synchronously through the chain when the inner frame is raised and lowered.

[0007] Furthermore, the two outer frame plates and the supporting base form a U-shaped outer frame. The inner side of each outer frame plate is provided with an outer frame limiting groove consisting of a first outer frame stop and a second outer frame stop, and a first pulley is movably mounted on the inner wall of the upper end of the outer frame limiting groove. The outer frame plates are made of high-strength metal sheet, possessing sufficient structural strength to support the weight of the inner frame and the cargo. The U-shaped outer frame design provides precise guidance for the lifting and lowering movement of the inner frame. The first and second outer frame stopes are arranged parallel to the length direction of the outer frame plates, forming an outer frame limiting groove that provides a track for the vertical lifting and lowering of the inner frame. The first pulley is mounted on the inner wall of the upper end of the outer frame limiting groove via a pivot, providing a limiting and friction-reducing effect on the inner frame in the horizontal direction.

[0008] Furthermore, the inner frame includes symmetrically arranged inner frame plates and inner crossbeams disposed on the top of the two inner frame plates; inner frame baffles are provided on the outer sides of the two inner frame plates, and second pulleys are movably disposed at the lower ends of the outer surfaces of the inner frame plates; one side of the inner frame baffle is limited by the second baffle of the outer frame, and the other side abuts against the first pulley; the second pulley can abut against the first baffle of the outer frame. The inner frame plates and the outer frame plates are made of the same material to ensure structural strength matching. The inner frame baffles extend along the length of the inner frame plates and cooperate with the second baffle of the outer frame to restrict the horizontal displacement of the inner frame; the second pulley is installed at the lower end of the outer surface of the inner frame plate through a pivot and abuts against the first baffle of the outer frame, converting the sliding friction between the inner frame and the outer frame plates into rolling friction, significantly reducing lifting resistance, and enhancing the stability of the inner frame lifting.

[0009] Furthermore, the inner walls of both inner frame plates are provided with inner frame limiting grooves, and several third pulleys are respectively provided on both sides of the fork bracket, with each third pulley on the same side embedded in the same inner frame limiting groove. The inner frame limiting grooves are arranged along the length of the inner wall of the inner frame plates, providing a track for the lifting and lowering of the fork bracket. At least two third pulleys are provided on each side of the fork bracket, evenly distributed along the length of the inner frame limiting groove, making the force on the fork bracket more even and the lifting and lowering process more stable.

[0010] Furthermore, the piston end of the linear actuator assembly is connected to the bottom surface of the inner crossbeam of the inner frame. The linear actuator assembly is preferably an electric linear actuator, employing a screw drive, which offers advantages such as high control precision, fast response speed, and strong energy controllability. A first actuator hinge seat is provided on the support base, and a second actuator hinge seat is provided on the bottom surface of the inner crossbeam; the bottom of the linear actuator assembly is hinged to the first actuator hinge seat, and the piston end of the linear actuator assembly is hinged to the second actuator hinge seat. This hinged connection allows the linear actuator assembly to adapt to angle changes when driving the inner frame to rise and fall, avoiding component damage due to uneven force distribution, while also improving the actuator's movement flexibility.

[0011] Furthermore, a first actuator hinge seat is provided on the support base, and a second actuator hinge seat is provided on the bottom surface of the inner crossbeam; the bottom of the linear actuator assembly is hinged to the first actuator hinge seat, and the piston end of the linear actuator assembly is hinged to the second actuator hinge seat.

[0012] Furthermore, a sprocket mounting plate is provided near the inner crossbeam of the inner frame's inner frame limiting slide groove. The sprocket is movably mounted on the sprocket mounting plate, and the chain is wound around the sprocket. A first chain connecting seat is symmetrically arranged on the inner wall of the frame wall panel; a second chain connecting seat is symmetrically arranged on the inner wall of the fork bracket. One end of the chain is connected to the first chain connecting seat, and the other end is connected to the second chain connecting seat. The chain is a roller chain, precisely matched with the sprocket teeth, resulting in high transmission efficiency and good wear resistance. Through the chain-sprocket transmission structure, efficient load distribution is achieved: when the linear actuator assembly drives the inner frame to rise, the sprocket rises synchronously with the inner frame. Since one end of the chain is fixed to the frame wall panel and the other end is connected to the fork bracket, the rising of the sprocket pulls the fork bracket at twice the speed via the chain. This allows the linear actuator assembly to complete the lifting action by providing only half the thrust of the total load of the forks and goods, significantly reducing equipment energy consumption.

[0013] Furthermore, a drag chain wheel is provided on the outer side of the sprocket, and a drag chain is wound around the drag chain wheel; one end of the drag chain is connected to a first drag chain connecting seat located on the inner side of the frame wall panel, and the other end is connected to a second drag chain connecting seat located on the inner wall of the fork bracket. The drag chain can be a nylon drag chain or a steel drag chain, and its interior is used to house cables or air hoses, so that the wiring can unfold or retract in an orderly manner with the drag chain when the forks are raised or lowered, avoiding wiring tangling and wear, effectively improving the reliability of equipment operation, and reducing the probability of downtime due to wiring failure.

[0014] This utility model provides a fork lifting mechanism for light-load unmanned forklifts. Through a nested structure of an outer frame and an inner frame, along with pulley limiting, it significantly improves the stability of fork lifting. Combined with chain-sprocket transmission to distribute the load, the linear actuator only needs to bear half of the load thrust, greatly reducing power consumption and extending service life. The compact double-frame design is suitable for narrow spaces, effectively solving the problems of high power loss and insufficient structural stability in existing forklifts, and significantly improving the material handling accuracy and operating efficiency of light-load unmanned forklifts. Specific beneficial effects are as follows: 1. Low power consumption and long lifespan: Through the force distribution design of chain-sprocket drive, the linear actuator component only needs to bear half of the load thrust, reducing power consumption by about 50% and reducing mechanical wear of the actuator, effectively extending its service life.

[0015] 2. High lifting accuracy and stable structure: The outer frame limiting slide groove cooperates with the inner frame pulleys and stops, and the inner frame limiting slide groove cooperates with the third pulley of the fork bracket, which restricts the offset of each component in the horizontal and vertical directions, so that the lifting accuracy error of the forks is controlled within ±2mm, the structural stability is significantly improved, and the risk of cargo tipping is avoided.

[0016] 3. Well-organized cable management: The coordination between cable chains and cable wheels enables the orderly storage of cables.

[0017] 4. Strong space adaptability: The compact structure design of the double-frame nesting makes the forklift mechanism occupy less space in light-load unmanned forklifts, adapting to narrow warehouse environments; and the improved stability and precision of the lifting process can meet the needs of high-precision material handling in industries such as electronics and pharmaceuticals. Attached Figure Description

[0018] Figure 1 This is a first-view structural schematic diagram of a fork lifting mechanism for a light-load unmanned forklift according to the present invention. Figure 2 This is a second-view structural schematic diagram of a fork lifting mechanism for a light-load unmanned forklift according to the present invention. Figure 3 This is a schematic diagram of the outer frame plate in the fork lifting mechanism for a light-load unmanned forklift described in this utility model; Figure 4 This is a structural schematic diagram of the fork lifting mechanism for a light-load unmanned forklift as described in this utility model, after the outer frame plate has been removed. Figure 5 This is a structural schematic diagram of the fork lifting mechanism for a light-load unmanned forklift as described in this utility model, taken from a second perspective after the outer frame plate is removed.

[0019] Illustration markings: 1-Support base; 2-Outer frame plate, 201-Outer frame limiting slide groove, 202-First pulley, 203-Outer frame first stop bar, 204-Outer frame second stop bar; 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-Forklift bracket, 401-Third pulley, 402-Second chain connector, 403-Second cable chain connector; 5-Forks; 6-Linear actuator assembly; 7-Frame wall panel, 701-First chain connector, 702-First cable chain connector; 8-Chain; 9-First actuator hinge seat; 10-Second actuator hinge seat; 11-Drag chain. Detailed Implementation

[0020] 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.

[0021] like Figures 1-5 As shown, this solution provides a fork lifting mechanism for a light-load unmanned forklift, including a support base 1. An outer frame plate 2 is symmetrically fixed to the support base 1 by bolts, forming a U-shaped outer frame. A first outer frame stop 203 and a second outer frame stop 204 are welded to the inner side of the outer frame plate 2, forming an outer frame limiting groove 201. A first pulley 202 is movably mounted on the inner wall of the upper end of the outer frame limiting groove 201 via a rotating shaft.

[0022] like Figure 4 and Figure 5As 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. Inner frame baffles 304 are welded to the outer edges of the two inner frame plates 301 along their length, and a second pulley 303 is movably mounted on the lower end of the outer side of the inner frame plate 301 via a pivot. One side of the inner frame baffle 304 is fitted and limited by the second baffle 204 of the outer frame, while the other side rolls against the first pulley 202; the second pulley 303 rolls against the first baffle 203 of the outer frame. The inner frame 3 is embedded between the two outer frame plates 2 and can move vertically up and down along the outer frame limiting groove 201.

[0023] The inner walls of both inner frame plates 301 are welded with inner frame limiting grooves 305 along their length. A fork bracket 4 is provided between the two inner frame limiting grooves 305. At least two third pulleys 401 are mounted on each side of the fork bracket 4 via pivots. Each third pulley 401 on the same side is embedded in the same inner frame limiting groove 305 and can roll along it. A pair of forks 5 are detachably connected to the fork bracket 4 by bolts. The fork bracket 4 can drive the forks 5 to move vertically up and down along the inner frame limiting grooves 305.

[0024] like Figure 1 and Figure 2 As shown, a linear actuator assembly 6 is installed on the support base 1. The linear actuator assembly 6 is an electric linear actuator driven by a lead screw. A first actuator hinge seat 9 is welded to the support base 1, and a second actuator hinge seat 10 is welded to the bottom surface of the inner crossbeam 302. The bottom of the linear actuator assembly 6 is hinged to the first actuator hinge seat 9, and the piston end of the linear actuator assembly 6 is hinged to the second actuator hinge seat 10. The piston end pushes the inner crossbeam 302 to drive the inner frame 3 to move vertically up and down along the outer frame limiting slide groove 201.

[0025] A sprocket mounting plate 306 is welded to the inner frame limiting slide groove 305 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 8 is wound around the sprocket 307. The outer sides of the two outer frame plates 2 are fixed to the frame wall plates 7 by bolts. The inner walls of the frame wall plates 7 are symmetrically welded with first chain connecting seats 701. The inner walls of the fork bracket 4 are symmetrically welded with second chain connecting seats 402. One end of the chain 8 is bolted to the first chain connecting seat 701, and the other end is bolted to the second chain connecting seat 402.

[0026] A drag chain wheel 308 is mounted on the outer side of the sprocket 307 via a pivot, and a nylon 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 702 located on the inner side of the frame wall plate 7, and the other end is bolted to the second drag chain connecting seat 403 located on the inner wall of the fork bracket 4, and the drag chain 11 contains a control cable.

[0027] The specific working process of this embodiment is as follows: When the light-load unmanned forklift receives a cargo lifting command, the fork lifting mechanism starts to operate. First, the linear actuator assembly 6 on the support base 1 is powered on and started. Its internal drive unit (such as the lead screw motor of an electric linear actuator) drives the piston end to extend vertically. The top of the piston end is in close contact with the bottom surface of the inner crossbeam 302 on the top of the inner frame 3. As the piston end continues to extend, the pushing force is transmitted to the entire inner frame 3 through the inner crossbeam 302, causing the inner frame 3 to move vertically upward along the outer frame limiting slide groove 201 on the inner side of the outer frame plate 2.

[0028] During this process, the sprocket mounting plate 306 near the inner crossbeam 302 of the inner frame 3's inner frame limiting slide groove 305 rises synchronously with the inner frame 3, and the sprocket 307, which is movably mounted on the sprocket mounting plate 306 via a rotating shaft, also moves upward synchronously. Since one end of the chain 8 wound on the sprocket 307 is fixed to the first chain connecting seat 701 on the inner wall of the frame wall plate 7 by bolts, and the other end is also fixed to the second chain connecting seat 402 on the inner wall of the fork bracket 4 by bolts, the sprocket 307 will generate an upward traction force on the chain 8 when it rises, thereby pulling the fork bracket 4 to move upward synchronously along the inner frame limiting slide groove 305 of the inner frame 3. Since the two ends of the chain 8 are fixed to the stationary frame wall plate 7 and the movable fork bracket 4 respectively, the rising distance of the sprocket 307 will be converted into twice the rising distance of the fork bracket 4, that is, the rising speed of the fork bracket 4 is twice the rising speed of the inner frame 3, thus achieving the effect of "small stroke of actuator driving large stroke of fork lifting".

[0029] Simultaneously, the structural limiting and friction-reducing effects are implemented during the lifting process. The first pulley 202 on the inner wall of the upper end of the outer frame limiting slide groove 201 maintains rolling contact with the inner frame stop strip 304 on the outer side of the inner frame plate 301, which not only restricts the horizontal displacement of the inner frame 3, but also converts the sliding friction between the two into rolling friction, reducing the lifting resistance. The second pulley 303 at the lower end of the outer side of the inner frame plate 301 rolls against the first stop strip 203 of the outer frame, further restricting the horizontal displacement of the inner frame 3 from below, ensuring that the inner frame 3 can lift vertically along the outer frame limiting slide groove 201 without shaking. The third pulleys 401 on both sides of the fork bracket 4 are embedded in the inner frame limiting slide groove 305 and roll with the fork bracket 4, which not only provides guidance for the fork bracket 4, but also avoids wear caused by direct friction between the fork bracket 4 and the inner frame limiting slide groove 305.

[0030] If the fork carriage 4 is connected to a control cable (such as a fork position sensor line), the drag chain 11 wound on the drag chain wheel 308 on the outer side of the sprocket 307 will unfold synchronously with the rise of the fork carriage 4. One end of the drag chain 11 is fixed to the first drag chain connecting seat 702 on the inner side of the frame wall plate 7, and the other end is fixed to the second drag chain connecting seat 403 on the inner wall of the fork carriage 4. The internally stored cable extends in an orderly manner with the drag chain 11 to avoid the cable from getting tangled or rubbing against other parts.

[0031] When the forks 5 need to be lowered, the linear actuator assembly 6 receives the lowering command. Its piston retracts vertically under the action of the internal drive unit. After losing its thrust, the inner frame 3 moves vertically downwards along the outer frame limiting groove 201 under its own weight and the weight of the forks 5 and the cargo. At this time, the sprocket 307 descends synchronously with the inner frame 3, and the chain 8 is gradually tightened under the gravity of the fork bracket 4, pulling the fork bracket 4 downwards synchronously along the inner frame limiting groove 305. The cable 11 retracts synchronously with the descent of the fork bracket 4, and the cable is neatly stored. Throughout the entire lifting process, power is stably transmitted through the path of "linear actuator - inner frame - chain - fork bracket," resulting in significant power distribution. This reduces the load on the linear actuator while ensuring the smoothness and accuracy of fork lifting.

[0032] In summary, this mechanism effectively solves the problems of high power loss, structural instability, and easy interference of existing technologies by using a double-frame nested pulley limiting structure, chain-sprocket force dispersion transmission, and cable chain routing design, thus significantly improving the material handling performance and operational reliability of light-load unmanned forklifts.

[0033] 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 fork lifting mechanism for a light-load unmanned forklift, characterized in that, It includes a support base (1), on which outer frame plates (2) are symmetrically arranged; it also includes an inner frame (3), which is embedded between the two outer frame plates (2) and can be vertically raised and lowered relative to the outer frame plates (2); a frame wall plate (7) is provided on the outside of the two outer frame plates (2). A linear actuator assembly (6) is provided on the support base (1), and the linear actuator assembly (6) can drive the inner frame (3) to move vertically relative to the outer frame plate (2); The inner frame (3) is provided with a fork bracket (4), and a fork (5) is connected to the fork bracket (4). The fork bracket (4) can drive the fork (5) to move vertically up and down relative to the inner frame (3). A chain (8) and a sprocket (307) are provided between the inner frame (3) and the fork bracket (4). One end of the chain (8) is connected to the frame wall panel (7), and the other end is connected to the fork bracket (4). The sprocket (307) can drive the fork bracket (4) to rise and fall synchronously through the chain (8) when the inner frame (3) rises and falls.

2. The fork lifting mechanism for a light-load unmanned forklift according to claim 1, characterized in that, The inner side of the outer frame plate (2) is provided with an outer frame limiting groove (201) consisting of an outer frame first stop bar (203) and an outer frame second stop bar (204), and a first pulley (202) is movably provided on the inner wall of the upper end of the outer frame limiting groove (201).

3. A fork lifting mechanism for a light-load unmanned forklift according to claim 2, characterized in that, The inner frame (3) includes symmetrically arranged inner frame plates (301) and inner crossbeams (302) disposed on the top of the two inner frame plates (301); inner frame baffles (304) are provided on the outer sides of the two inner frame plates (301), and a second pulley (303) is movably disposed at the lower end of the outer side of the inner frame plate (301); one side of the inner frame baffle (304) is limited by the outer frame second baffle (204), and the other side abuts against the first pulley (202); the second pulley (303) can abut against the outer frame first baffle (203).

4. A fork lifting mechanism for a light-load unmanned forklift according to claim 3, characterized in that, The inner walls of the two inner frame plates (301) are provided with inner frame limiting grooves (305), and several third pulleys (401) are provided on both sides of the fork bracket (4). Each of the third pulleys (401) located on the same side is embedded in the same inner frame limiting groove (305).

5. A fork lifting mechanism for a light-load unmanned forklift according to claim 1, characterized in that, The piston end of the linear actuator assembly (6) is connected to the bottom surface of the inner crossbeam (302) of the inner frame (3).

6. A fork lifting mechanism for a light-load unmanned forklift according to claim 3, characterized in that, The support base (1) is provided with a first actuator hinge seat (9), and the bottom surface of the inner crossbeam (302) is provided with a second actuator hinge seat (10); the bottom of the linear actuator assembly (6) is hinged to the first actuator hinge seat (9), and the piston end of the linear actuator assembly (6) is hinged to the second actuator hinge seat (10).

7. A fork lifting mechanism for a light-load unmanned forklift according to claim 3, characterized in that, The inner frame (3) has a sprocket mounting plate (306) located near the inner crossbeam (302) in the inner frame limiting slide groove (305). The sprocket (307) is movably mounted on the sprocket mounting plate (306), and the chain (8) is wound around the sprocket (307).

8. A fork lifting mechanism for a light-load unmanned forklift according to claim 7, characterized in that, The inner wall of the frame wall panel (7) is symmetrically provided with a first chain connector (701); the inner wall of the fork bracket (4) is symmetrically provided with a second chain connector (402); one end of the chain (8) is connected to the first chain connector (701), and the other end is connected to the second chain connector (402).

9. A fork lifting mechanism for a light-load unmanned forklift according to claim 7 or 8, characterized in that, A drag chain wheel (308) is provided on the outer side of the sprocket (307), and a drag chain (11) is wound around the drag chain wheel (308); one end of the drag chain (11) is connected to a first drag chain connecting seat (702) provided on the inner side of the frame wall plate (7), and the other end is connected to a second drag chain connecting seat (403) provided on the inner wall of the fork bracket (4).

10. A fork lifting mechanism for a light-duty unmanned forklift according to claim 1, characterized in that, The linear actuator assembly (6) is an electric linear actuator that uses a screw drive.

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