Forklift driving wheel pressurization antiskid device and method

Abstract

The invention relates to the technical field of forklift driving skid resistance, and discloses a forklift driving wheel pressurization skid resistance device and method. The device comprises a main oil cylinder, an auxiliary oil cylinder, a hydraulic pipeline and a suspension force transmission structure, the auxiliary oil cylinder is communicated with the main oil cylinder of a forklift hoisting system through the hydraulic pipeline and arranged at the suspension position of a driving assembly, and the suspension force transmission structure is connected with a forklift frame and the driving assembly. When the forklift works, the hydraulic pressure in the main oil cylinder is transmitted to the auxiliary oil cylinder along with the load change of the pallet fork, and the auxiliary oil cylinder applies additional downward pressure to the driving assembly through the suspension force transmission structure so as to increase the grounding pressure of the driving wheel and the ground adhesive force. According to the device and method, pressurization of the driving wheels can be achieved according to load changes, slipping is reduced, and the trafficability, stability and operation safety of the forklift under the load working condition are improved.

Description

Technical Field

[0001] This invention belongs to the field of forklift engineering technology, specifically relating to a forklift drive wheel pressure anti-slip device and method, which is particularly suitable for improving the traction of forklift drive wheels and preventing slippage under complex working conditions such as uneven roads and slopes. Background Technology

[0002] Forklifts are specialized vehicles widely used in industrial logistics handling operations. In operating environments such as ports, warehouses, and factory workshops, ground conditions are often complex and varied, including uneven surfaces, localized slopes, and areas with water or oil accumulation. When a forklift is fully loaded, its center of gravity shifts forward, reducing the wheel load on the drive wheels (usually located at the rear of the vehicle) and decreasing the normal force between the drive wheels and the ground. This results in insufficient effective friction, making the drive wheels highly susceptible to slippage. Slippage not only causes loss of traction and reduced transport efficiency but also poses significant safety hazards, potentially leading to accidents such as cargo tipping and personal injury.

[0003] In existing technologies, the main solutions to the forklift drive wheel slippage problem are as follows: First, increasing the load on the drive wheels by adding counterweights. However, this solution increases the overall weight of the vehicle, requires higher ground bearing capacity, and the counterweight is fixed and cannot be adjusted, resulting in unnecessary energy loss when unloaded. Second, using differential locks or electronic anti-slip control systems to suppress slippage by limiting wheel speed differences. However, this solution is costly, requires significant modifications to the vehicle's electrical system, and is complex to maintain. Third, using anti-slip tires to improve grip by improving tire tread patterns. However, this still cannot effectively prevent slippage when the ground depression exceeds a certain depth. Fourth, adding an independent hydraulic system to apply downforce to the drive axle. However, this requires an independent hydraulic power source, increasing system complexity and energy consumption.

[0004] In summary, existing technologies all have certain limitations, especially lacking a simple and reliable technical solution that can automatically and synchronously adjust the ground pressure of the drive wheels based on the actual load on the forks. Therefore, it is necessary to provide an adaptive anti-slip device and method that is simple in structure, seamlessly integrated with the existing forklift lifting hydraulic system, and requires no independent control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a forklift drive wheel pressure anti-slip device and method. By directly guiding the hydraulic pressure signal of the fork lifting system to the auxiliary cylinder set on the suspension structure of the drive assembly, the auxiliary cylinder automatically applies additional downward pressure to the drive wheel as the load increases, thereby increasing the friction between the drive wheel and the ground, realizing the adaptive anti-slip function, while also taking into account the driving stability of the forklift when passing through complex road surfaces.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: On one hand, the present invention provides a forklift drive wheel pressure anti-slip device, comprising: The main cylinder is a hydraulic cylinder used in the forklift system to drive the lifting and lowering of the forks. When the forks are under load, the hydraulic pressure in the main cylinder chamber increases synchronously with the increase of the load. The auxiliary cylinder is mounted on the suspension structure of the forklift drive assembly. The auxiliary cylinder is connected to the main cylinder via hydraulic lines. The piston rod of the auxiliary cylinder is arranged vertically downward to apply downward pressure to the drive assembly. Hydraulic lines connect the main cylinder and the auxiliary cylinder, enabling synchronous pressure transmission between them; The suspension structure includes a mounting plate, a pressure rod, and a limiting mechanism. The mounting plate is fixedly connected to the forklift frame. One end of the pressure rod is movably connected to the mounting plate, and the other end is fixedly connected to the drive assembly. The auxiliary hydraulic cylinder is installed between the mounting plate and the drive assembly. The extension and retraction of its piston rod is transmitted to the drive assembly through the pressure rod to achieve additional downward pressure on the drive wheels. Furthermore, the cross-sectional area ratio between the auxiliary cylinder and the main cylinder is designed to match Pascal's law, so that when the forks are fully loaded, the additional downward pressure applied by the auxiliary cylinder to the drive assembly is positively correlated with the load magnitude.

[0007] Furthermore, the auxiliary hydraulic cylinder includes a dual-cylinder implementation and a single-cylinder implementation: The dual-cylinder implementation method is as follows: two auxiliary cylinders are symmetrically arranged on the left and right sides of the drive assembly suspension structure, and together apply uniform downforce to the drive assembly to avoid uneven load caused by unilateral force. The single hydraulic cylinder implementation method is as follows: the cylinder core of a single auxiliary hydraulic cylinder adopts a hollow structure. The cylinder core of the auxiliary hydraulic cylinder and the adjusting spring are concentrically mounted on the pressure rod. The adjusting spring is sleeved on the outside of the cylinder core, providing preload to the drive assembly and working together with the hydraulic pressure, which is suitable for forklift models with small installation space.

[0008] Furthermore, the auxiliary cylinder is equipped with upper and lower limit structures, with an upper limit movement distance of 30mm and a lower limit movement distance of 50mm. When the road surface protrusion height is less than 30mm, the drive wheel moves upward to the upper limit and touches the limit stop, and the vehicle body smoothly passes over the protrusion through elastic buffer. When the road surface depression depth is less than 50mm, the drive wheel moves downward to the lower limit, and the auxiliary cylinder continuously applies downward pressure to maintain full contact between the drive wheel and the ground and maintain effective friction.

[0009] Furthermore, the suspension structure also includes an adjusting spring, which is disposed between the auxiliary cylinder and the drive assembly to provide elastic buffer for the drive assembly and assist in resetting after the auxiliary cylinder is depressurized, ensuring the natural ground contact of the drive wheels when driving without load.

[0010] Furthermore, the hydraulic pipeline is located between the main cylinder and the auxiliary cylinder, and the hydraulic pipeline may be equipped with a throttle valve or a one-way throttle valve to adjust the pressure transmission rate and prevent hydraulic shock from damaging the auxiliary cylinder and the suspension structure.

[0011] Furthermore, the pressure rod is connected to the forklift frame via a spline connection. This spline connection allows the pressure rod to slide relative to the frame along the axial direction while transmitting steering torque, ensuring that the forklift's steering function is not affected. The length of the spline mating section between the pressure rod and the frame is not less than the sum of the upper and lower limit movement distances of the limiting mechanism, i.e., not less than 80mm, to ensure that the pressure rod and the mounting plate always maintain a reliable torque transmission connection within the limiting range.

[0012] On the other hand, the present invention also provides a self-pressurizing anti-slip method for forklift drive wheels based on the above-mentioned device, which includes the following steps: Step S1, load detection step: The forklift forks bear the load of the goods, and the hydraulic pressure in the main cylinder of the lifting system increases synchronously with the increase of the load. The hydraulic pressure value is positively correlated with the load of the forks. Step S2, pressure transmission step: The main cylinder transmits hydraulic pressure to the auxiliary cylinder in real time through the hydraulic pipeline. According to Pascal's law, the difference between the piston area of ​​the auxiliary cylinder and the piston area of ​​the main cylinder makes the output thrust of the auxiliary cylinder proportional to the pressure of the main cylinder. Step S3, downward pressure application step: The auxiliary cylinder piston rod extends downward under hydraulic pressure, and applies additional vertical downward pressure to the drive assembly through the connecting rod of the suspension structure. The additional downward pressure changes synchronously with the load on the forks to achieve adaptive adjustment. Step S4, Friction Enhancement Step: Under the action of additional downforce, the normal force of the drive wheel on the ground increases. According to Coulomb's law of friction, the maximum static friction between the drive wheel and the ground increases accordingly, thereby effectively suppressing drive wheel slippage. Step S5, Complex Road Adaptation Step: When the forklift travels on uneven road surfaces, the drive assembly floats freely within the upper and lower limits through the suspension structure (upper limit movement distance 30mm, lower limit movement distance 50mm). The auxiliary cylinder continuously outputs downforce corresponding to the load to ensure that the drive wheels always maintain full contact with the ground when the road surface changes, thus maintaining the anti-slip effect. Step S6, Unloading and Reset Step: After the forklift has finished unloading, the forks are unloaded, the main cylinder is depressurized through the unloading operation, the auxiliary cylinder is depressurized synchronously through the shared hydraulic line, the piston rod retracts automatically with the assistance of the adjusting spring, the drive assembly returns to its natural state, the anti-slip pressurization function is automatically released, and the forklift returns to its normal unloaded driving state.

[0013] Furthermore, the method also includes an unload protection step: when the forklift is in an unloaded state, the main cylinder has no hydraulic pressure input, the auxiliary cylinder is in a pressure-free closed state, no additional downforce is applied to the drive assembly, the forklift maintains its original unloaded driving characteristics, and no additional driving resistance is added.

[0014] The calculation relationship of the additional downward pressure in step S3 is as follows: Let the working pressure of the main cylinder be P, and the effective area of ​​the piston of the auxiliary cylinder be A, then the output thrust of the auxiliary cylinder F = P × A; by reasonably designing the ratio of the cross-sectional areas of the pistons of the main and auxiliary cylinders, the additional downward pressure output by the auxiliary cylinder under full load conditions can effectively compensate for the reduction in the load on the drive wheel caused by the load of the fork, and ensure that the ground pressure of the drive wheel under full load is not lower than that under no-load conditions, thereby ensuring the anti-slip effect.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Adaptive linkage, no independent control required. This invention utilizes the existing hydraulic lines of the forklift lifting system to directly drive the auxiliary cylinder, without the need for additional sensors, controllers or independent hydraulic power sources. It has a simple structure, high reliability, and is easy to install and maintain.

[0016] 2. Significant anti-slip effect: Tests have verified that under complex road surface conditions with a depression depth of less than 50mm, this invention can effectively eliminate drive wheel slippage, allowing forklifts to smoothly pass through road surfaces that conventional forklifts cannot pass smoothly under full load, thus significantly improving transportation efficiency.

[0017] 3. Excellent ramp passability: In ramp operation environment, the present invention can automatically adjust the ground pressure of the drive wheel in real time according to the load of the forks, prevent the operation from being stopped due to ramp slippage, and improve the ramp passability of the forklift.

[0018] 4. When unloaded, it does not interfere with normal operation. When unloaded, the auxiliary cylinder has no hydraulic pressure, does not apply additional downward pressure, does not increase the forklift's driving resistance, and has no impact on the forklift's unloaded maneuverability.

[0019] 5. The floating suspension ensures driving stability. The upper and lower limit mechanisms work together with the adjusting springs to ensure that the forklift is stable when passing over uneven surfaces, balancing anti-slip effect with driving comfort and safety.

[0020] 6. The structure is compact and highly adaptable. The dual-cylinder and single-cylinder solutions can be flexibly selected according to the installation space of different forklift models, which has strong versatility and adaptability.

[0021] 7. The impact of driving resistance is within an acceptable range. The increased driving resistance caused by the increased ground pressure of the drive wheel is, according to actual testing, within a reasonable and acceptable range in the industry and does not have a substantial impact on the normal transportation efficiency of the forklift.

[0022] The technical solution of the present invention will be further described in detail below through embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the axonal side of the device of the present invention; Figure 2 This is a front view of the device of the present invention; Figure 3 This is a side view of the device of the present invention; Figure 4 This is a front sectional view of the device of the present invention; Figure 5 This is a front view of the first and second transmission components of the present invention; Figure 6 This is an axonal sectional view of the first and second transmission components of the present invention.

[0024] Figure label: 1. Mounting plate; 2. Auxiliary cylinder (left); 3. Auxiliary cylinder (right); 4. Adjusting spring; 5. First transmission assembly; 501. Plate body; 502. Sleeve; 503. Abutment ring; 6. Second transmission assembly; 601. Bushing; 602. Thrust bearing; 603. Fastening ring; 7. Splined pressure rod; 8. Drive assembly mounting base; 9. Drive motor; 10. Drive wheel. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by those skilled in the art.

[0026] The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0027] Example 1: See Figures 1-6 This embodiment provides a detailed description of the dual auxiliary cylinder device. The device mainly consists of a mounting plate 1, a left auxiliary cylinder 2, a right auxiliary cylinder 3, an adjusting spring 4, a first transmission assembly 5, a second transmission assembly 6, a spline pressure rod 7, a drive assembly mounting base 8, a drive motor 9, and a drive wheel 10. It is connected to the main cylinder of the forklift lifting system through a hydraulic pipeline interface, and the whole is fixed to the forklift frame through an L-shaped mounting bracket.

[0028] First, there is the mounting plate and the L-shaped mounting bracket. The mounting plate 1 serves as the top support foundation for the entire suspension structure. It is rigidly connected to the forklift frame via the L-shaped mounting bracket to ensure reliable installation of the entire device and prevent relative displacement. The mounting plate 1 is equipped with cylinder seats and hydraulic line interfaces for mounting auxiliary cylinders 2 and 3. The hydraulic line interfaces are connected to the hydraulic lines of the forklift lifting system, introducing the hydraulic pressure signal of the main cylinder.

[0029] The vertical section of the L-shaped mounting bracket is fixed to the forklift frame, and the horizontal section is fixedly connected to the mounting plate 1 by bolts to form a stable mounting frame. At the same time, it ensures that the extension and retraction direction of the auxiliary cylinder piston rod is strictly in the vertical direction, ensuring the accuracy of the downward pressure direction.

[0030] Secondly, regarding the auxiliary cylinders, this embodiment adopts a dual auxiliary cylinder scheme. The left auxiliary cylinder 2 and the right auxiliary cylinder 3 are symmetrically arranged on the left and right sides of the mounting plate 1 (the left and right are relative to the drive assembly or tires). Their cylinder bodies are fixedly connected to the mounting plate 1, and the piston rods extend downward to generate downward pressure. The two auxiliary cylinders are simultaneously connected to the main cylinder through hydraulic pipeline interfaces to receive the same hydraulic pressure, ensuring uniform force distribution and avoiding uneven load distribution.

[0031] The working principle of the auxiliary cylinder is based on Pascal's law. The working pressure P of the main cylinder is transmitted to the auxiliary cylinder through the hydraulic pipeline. The effective piston area of ​​the auxiliary cylinder is A. Then, the output thrust of each auxiliary cylinder is F = P × A, and the total output thrust of the two auxiliary cylinders is 2F = 2P × A. By reasonably designing the piston area A of the auxiliary cylinder, the total output thrust can effectively compensate for the wheel load loss of the drive wheel due to the forward shift of the fork's center of gravity under full load conditions, ensuring that the ground pressure of the drive wheel is not lower than the rated value.

[0032] As an alternative implementation, in the single-cylinder scheme, the auxiliary cylinder core adopts a hollow structure design, with the adjusting spring 4 sleeved on the outside of the hollow cylinder core. Both are concentrically mounted on the splined pressure rod 7, resulting in a more compact overall structure suitable for forklift models with limited installation space. The hydraulic connection method is the same for both the single-cylinder and double-cylinder schemes, and the anti-slip technology effect is completely identical.

[0033] Next is the crucial transmission component, which mainly consists of four parts responsible for transmitting the downward pressure generated by the auxiliary cylinders to the drive assembly. In the transmission sequence, they are: the first transmission assembly 5, the adjusting spring 4, the second transmission assembly 6, and the splined pressure rod 7. The first transmission assembly 5 mainly includes a plate 501, a sleeve 502, and a contact ring 503. The plate 501 is horizontally arranged and synchronously fixedly connected to the telescopic rods of the two auxiliary cylinders 2 and 3. A through hole is provided in the middle of the plate 501 through which the splined pressure rod 7 and the adjusting spring 4 pass. The sleeve 502 is coaxially arranged with this through hole and fixedly installed above the plate 501. The contact ring 503 is coaxially arranged with the sleeve 502 and fixedly installed on the upper end face of the sleeve 502. The annular surface of the contact ring 503 extends radially inward and beyond the inner wall of the sleeve 502. The excess portion is used to abut against the upper end of the adjusting spring 4. The sleeve 502 is coaxially arranged at the upper end and abuts against the abutment ring 503. The first stage of transmission is completed according to the above structure. When the telescopic rods of the auxiliary oil cylinders 2 and 3 press down, the force is transmitted to the plate 501. The plate 501 drives the sleeve 502 and the abutment ring 503 on it to abut against the upper end of the adjusting spring 4, thus completing the pressure on the adjusting spring 4. The lower end of the adjusting spring 4 is connected to the spline pressure rod 7 through the second transmission assembly 6. The second transmission assembly 6 mainly includes a bushing 601, a thrust bearing 602, and several fastening rings 603. The bushing 601, the thrust bearing 602, and several fastening rings 603 are sequentially sleeved on the outer wall of the spline pressure rod 7 from top to bottom. The upper and lower end faces of the bushing 601 are opened with annular grooves. The upper end is used to assemble the lower end of the adjusting spring 4, and the lower end is used to cooperate with the thrust bearing 602. The lower end of the thrust bearing 602 abuts against several fastening rings 603. After the upper end of the adjusting spring 4 is compressed, under the action of elastic potential energy, its lower end transmits the pressure to the spline pressure rod 7 through the second transmission assembly 6. Using the adjusting spring 4 as an intermediate transmission structure has the following advantages: First, it provides preload. The adjusting spring 4 is in a pre-compressed state in the initial installation state, applying a continuous elastic downward pressure to the drive assembly mounting seat 8, ensuring that the drive wheel 10 can maintain reliable contact with the ground even when unloaded.

[0034] Second, elastic cushioning. When the forklift travels on uneven roads, the drive wheel 10 moves up and down with the undulations of the ground. The adjusting spring 4 absorbs the impact of the road surface through elastic deformation, reducing the impact load on the vehicle body and drive system, and improving the ride smoothness.

[0035] Third, auxiliary reset. After the forks are unloaded and the auxiliary cylinder is depressurized, the elastic restoring force of the adjusting spring 4 assists the drive assembly mounting base 8 to return to the neutral position, which, together with the upper and lower limit mechanisms, ensures reliable system reset.

[0036] In addition, the spline section on the spline pressure rod 7 cooperates with the frame of the forklift through conventional spline transmission components such as spline sleeves and bearings, allowing the spline pressure rod 7 to slide up and down relative to the mounting plate 1 along the axial direction. This achieves the degree of freedom of movement within the upper and lower limit range, while the circumferential constraint of the spline ensures the reliable transmission of steering torque and ensures that the steering function of the forklift is not affected.

[0037] Further optimization of the technical solution involved adding upper and lower limit structures within the auxiliary cylinder 2.3 to restrict the vertical movement of the drive assembly relative to the mounting plate 1. The basis for setting these limit distances and the impact of their adjustment are supplemented below: The upper and lower limit movement distances are designed with the forklift's ability to smoothly traverse complex road surfaces as the core design principle. Through testing, the specific parameters were determined to be: upper limit movement distance 30mm, lower limit movement distance 50mm. These parameters are suitable for the forklift's passage requirements on locally uneven road surfaces. Specifically, when the road surface protrusion height is <30mm and the depression depth is <50mm, the forklift can maintain stability through the buffering effect of the limit structure, while simultaneously ensuring the effective pressurization function of the auxiliary cylinder. Adjusting the movement distance of the upper and lower limit switches will directly change the forklift's road adaptability: reducing the upper limit distance will prevent the forklift from smoothly passing through road surfaces with a protrusion height of ≥30mm, and may damage the limit structure; reducing the lower limit distance will reduce the forklift's stability on road surfaces with a depression depth of ≥50mm, and may even prevent the auxiliary cylinder from applying additional pressure normally, causing the anti-slip function to fail; increasing the limit distance will affect the vehicle's stability and increase driving safety hazards.

[0038] The above limit parameters have been verified through testing and are suitable for typical uneven road conditions encountered by forklifts in conventional warehousing, port, and factory environments. For special operating environments, the upper and lower limit distance parameters can be adjusted during the design phase based on actual road conditions, but the impact on vehicle stability must be assessed simultaneously.

[0039] Additionally, it should be noted that, in order to match the values ​​of the limit structure, the spline engagement length of the spline pressure rod 7 is not less than 80mm, which is the sum of the upper and lower limit movement distances, to ensure that the spline always maintains reliable engagement throughout the entire stroke range, preventing the safety hazard of steering failure due to spline disengagement.

[0040] Example 2: This embodiment provides the overall working process of the machine, that is, the method of applying pressure and preventing slippage through the device of Embodiment 1. When the forklift picks up goods and travels fully loaded, the forks bear the load, and the hydraulic pressure in the main cylinder of the lifting system increases synchronously with the increase in load. This hydraulic pressure is transmitted to the auxiliary cylinders 2 and 3 through hydraulic lines, driving the piston rod of the auxiliary cylinder to extend downwards. Through a series of transmissions, an additional downward force F is applied to the drive wheel 10 through the drive assembly mounting seat 8, increasing the normal force between the drive wheel 10 and the ground from N to N+F. According to Coulomb's law of friction, the maximum static friction force of the drive wheel is f=μ(N+F) (μ is the coefficient of friction between the tire and the ground). The increase in friction force raises the upper limit of traction force, effectively suppressing the slippage of the drive wheel when traveling fully loaded.

[0041] When the forklift encounters a road bump (height < 30mm), the drive wheel 10 moves upward under the support of the bump, the drive assembly mounting seat 8 moves upward relative to the mounting plate 1, the adjusting spring 4 is compressed, and the piston rod of the auxiliary cylinder retracts accordingly. A small amount of hydraulic oil flows back to the main cylinder through the hydraulic pipeline. After passing the bump, the adjusting spring 4 releases its elastic potential energy, and the auxiliary drive assembly returns to its original position. Throughout the process, the auxiliary cylinder maintains hydraulic pressure and does not interrupt the downward pressure output.

[0042] When the forklift encounters a road surface depression (depth < 50mm), the drive wheel 10 moves downward with the depression, the drive assembly mounting seat 8 moves downward relative to the mounting plate 1, and the auxiliary cylinder piston rod extends further, continuously increasing the downward pressure on the ground to ensure that the drive wheel 10 maintains full contact with the ground and does not slip in the depression. When the downward movement reaches the lower limit distance of 50mm, the lower limit stop 6 engages to prevent overtravel.

[0043] After the forklift completes the handling task, the forks lower to unload the cargo, and the driver operates the hydraulic control valve to depressurize the main cylinder. Since the auxiliary cylinder shares the same hydraulic line as the main cylinder, it depressurizes synchronously. The piston rod automatically retracts with the assistance of the elastic restoring force of the adjusting spring 4, and the drive assembly mounting seat 8 returns to the neutral position. The anti-slip pressurization function is automatically deactivated. Afterward, the forklift enters an unloaded state; neither the main nor auxiliary cylinders have hydraulic pressure, and the system is in its initial closed state, causing no interference to the forklift's unloaded operation.

[0044] According to the results of the comparative test, when a conventional forklift passes through a road surface with a depression depth greater than 10mm, the drive wheels are prone to slippage, resulting in a significant loss of traction and a reduction in traffic efficiency. After adopting the technical solution of this invention, under the working condition of a road surface with a depression depth of less than 50mm, the auxiliary cylinder automatically applies additional downward pressure according to the load change, the forklift maintains sufficient traction, and can pass through the above-mentioned road surface smoothly. The slippage phenomenon is effectively eliminated, and the transportation efficiency is significantly improved.

[0045] In sloping operating environments, the device of this invention automatically adjusts the additional downward pressure on the drive wheels based on the dynamic changes in fork load, effectively improving the forklift's ramp passability and preventing operational stagnation caused by ramp slippage. Simultaneously, the increased friction on the forklift's movement resistance has been tested and found to be within a reasonable and acceptable range for the industry, without substantially affecting the forklift's normal transport efficiency, thus balancing anti-slip effect with operational efficiency.

[0046] Example 3: Those skilled in the art will understand that, without departing from the concept of the present invention, several modifications and improvements can be made to the above embodiments, for example: 1. Throttling valves or proportional relief valves can be added to the hydraulic lines to achieve more precise adjustment of the pressure of the auxiliary cylinder and adapt to the anti-slip requirements of different load gradients. 2. A pressure sensor can be added to the hydraulic line to connect the real-time pressure data to the forklift's onboard control system, enabling real-time monitoring and alarm of the anti-slip condition; 3. The number of auxiliary hydraulic cylinders can be adjusted according to the specific drive axle structure of the forklift, and is not limited to the two in this embodiment; there can be one or more. 4. The upper and lower limit distance parameters can be adaptively adjusted according to the road conditions of the specific working environment, but the impact on vehicle stability must be checked at the same time; 5. This invention is also applicable to various forklift types such as four-wheel counterbalance forklifts, three-wheel electric forklifts, and reach trucks, and has wide applicability.

[0047] Finally, it should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents; that is, 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.

Claims

1. A pressure-adjusting anti-slip device for forklift drive wheels, characterized in that, Includes main cylinder, auxiliary cylinder, hydraulic lines and suspension force transmission structure; The main cylinder is a hydraulic cylinder used in the forklift system to drive the lifting and lowering of the forks; The auxiliary cylinder is mounted on the suspension of the forklift drive assembly and is connected to the main cylinder via the hydraulic lines. The suspension force transmission structure is connected between the forklift frame and the drive assembly. It is used to transmit the force output by the auxiliary cylinder to the drive assembly to apply additional downforce to the drive wheel, so that the ground pressure of the drive wheel increases with the load of the forks.

2. The forklift drive wheel pressure anti-slip device according to claim 1, characterized in that, The suspension force transmission structure includes a mounting plate and a pressure rod. The mounting plate is fixedly connected to the forklift frame. One end of the pressure rod is movably connected to the mounting plate, and the other end is connected to the drive assembly. The auxiliary hydraulic cylinder is located between the mounting plate and the drive assembly. The extension and retraction movement of the auxiliary hydraulic cylinder piston rod is transmitted to the drive assembly via the pressure rod.

3. The forklift drive wheel pressure anti-slip device according to claim 1 or 2, characterized in that, There are two auxiliary cylinders, which are symmetrically arranged on the left and right sides of the drive assembly to jointly apply downward pressure to the drive assembly.

4. The forklift drive wheel pressure anti-slip device according to claim 1 or 2, characterized in that, The auxiliary cylinder is a single cylinder, and the cylinder core of the auxiliary cylinder adopts a hollow structure, with an adjusting spring concentrically sleeved on the outside of the hollow structure.

5. The forklift drive wheel pressure anti-slip device according to claim 1, characterized in that, The suspension force transmission structure also includes an adjusting spring, which is disposed between the auxiliary cylinder and the drive assembly to provide elastic buffering and / or assist the drive assembly in resetting after the auxiliary cylinder is depressurized.

6. The forklift drive wheel pressure anti-slip device according to claim 1, characterized in that, The auxiliary cylinder is equipped with upper and lower limit structures to limit the vertical floating stroke of the drive assembly relative to the vehicle frame.

7. The forklift drive wheel pressure anti-slip device according to claim 2, characterized in that, The pressure bar is connected to the forklift frame via a spline to allow the pressure bar to slide relative to the forklift frame along the axial direction and transmit steering torque.

8. A self-pressurizing anti-slip method for forklift drive wheels, characterized in that, The forklift drive wheel pressure anti-slip device according to any one of claims 1 to 7 comprises: When the forks are under load, the hydraulic pressure in the main cylinder increases as the load increases; The hydraulic pressure is transmitted to the auxiliary cylinder via hydraulic lines; The auxiliary cylinder outputs force, which is then applied to the drive assembly via the suspension force transmission structure to exert additional downforce. This increases the ground pressure on the drive wheels, thereby increasing the friction between the drive wheels and the ground and suppressing slippage.

9. The self-pressurizing anti-slip method for forklift drive wheels according to claim 8, characterized in that, It also includes a complex road surface adaptation process: the drive assembly floats up and down relative to the frame within the range defined by the upper and lower limit structures, and the auxiliary cylinder continuously applies downforce corresponding to the load to the drive assembly during the floating process to maintain the contact between the drive wheels and the ground.

10. The self-pressurizing anti-slip method for forklift drive wheels according to claim 8 or 9, characterized in that, It also includes the unloading and reset process: after the forks are unloaded, the main cylinder is depressurized, the auxiliary cylinder is depressurized synchronously through the hydraulic line, the piston rod of the auxiliary cylinder returns to its original position under the action of the adjusting spring, and the drive assembly returns to its natural state.

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