Lightweight method suitable for non-uniform opening of single-extending-position stacking machine stand column

Abstract

The invention relates to the technical field of automatic storage equipment, in particular to a light weight method suitable for non-uniform openings of stand columns of a single-extension-position stacker, which comprises the following steps: step 1, building a complete machine model of the stacker according to structural appearance and size parameters; 2, establishing an equivalent mechanical model of the stand column and verifying the effectiveness of the equivalent mechanical model; 3, sensitivity analysis is conducted on all parameters of the stand column; 4, based on a variable density method, topological optimization is carried out on a stand column wing plate area; 5, non-uniform opening lightweight design is conducted on the stand column structure according to stress distribution, rigidity and topological optimization results; and step 6, carrying out performance checking on the lightweight column model under all working conditions. Through the non-uniform opening lightweight design, on the basis of ensuring the structural safety of the piler stand column, the weight of the stand column is reduced, the dead weight of the whole machine is reduced, the operation energy consumption is reduced, the operation efficiency is improved, the design pertinence is high, and the good engineering feasibility is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of automated warehousing equipment, and in particular to a lightweight method for a non-uniform opening of a stacker column suitable for a single extension position. Background Art

[0002] Stacker cranes are the core handling devices in automated warehouses. Due to their unique operating environment, stacker cranes with one-way extensions are particularly advantageous for storing and sorting goods in lineside warehouses. Reducing the deadweight of stacker cranes and other crane equipment not only reduces manufacturing costs but also energy consumption. Lightweighting a stacker crane isn't simply about increasing or decreasing the thickness of its components. Rather, it's about achieving an optimal, coordinated optimization solution with high efficiency, low energy consumption, and stable power, while maintaining the original device's rigidity and strength.

[0003] As the main load-bearing component of a stacker crane, the column accounts for over 70% of its total mass. The static and dynamic performance of this structure directly impacts the overall performance of the high-rise stacker. Conventional lightweighting methods are often designed for double-reach stackers. The resulting symmetry of the lightweighted structure doesn't align well with the single-deep stacker's single-side retrieval system, thus failing to achieve the desired effect. A lightweight design with asymmetrical openings on both sides of the column structure for a single-reach stacker reduces the stacker's weight, saving materials and improving warehouse efficiency. Summary of the Invention

[0004] The purpose of the present invention is to propose a non-uniform opening lightweighting method for a stacker crane for single-extension storage operations in a line-side warehouse, so as to achieve the effects of reducing dead weight, reducing energy consumption and improving operating efficiency while ensuring structural safety.

[0005] In order to achieve the above object, the technical solution of the present invention provides a method for lightweighting a stacker crane column with non-uniform openings applicable to a single extension position, comprising the following steps:

[0006] Step 1: Build a complete model of the stacker crane according to its structural shape and size parameters;

[0007] Step 2: Considering the single-extension stacker crane operating conditions, establish an equivalent mechanical model of the column and verify its effectiveness;

[0008] Step 3: Conduct sensitivity analysis on the parameters of the column based on the column equivalent mechanical model and response surface optimization method;

[0009] Step 4: Topology optimization of the column wing area based on the variable density method;

[0010] Step 5: Perform non-uniform opening lightweight design on the column structure based on the stress distribution, stiffness and topology optimization results;

[0011] Step 6: Perform performance verification of the lightweight column model under all working conditions.

[0012] Preferably, the column structure of the high-rise stacker is a two-section design, and the main load-bearing structure of each section includes a front wing plate, a straight web plate, a rear wing plate, and an inclined web plate. The two adjacent structures are connected by welding, and the upper and lower sections are bolted together by flange 5.

[0013] Preferably, in step 2, the column equivalent mechanical model established can replace the whole machine model of the stacker crane to achieve lightweight analysis, achieve the effect of simplifying the finite element model, and improve the analysis and calculation efficiency.

[0014] Preferably, in step 3, the finite element simulation software performs a response surface analysis on the column structure of the single-extension stacker; the wing plate thickness has the greatest impact on the column mass and has almost no effect on the stiffness and strength of the column. Therefore, under the premise of meeting the stiffness and strength requirements of the column, the wing plate thickness is used as a lightweight parameter.

[0015] Preferably, in step 3, in order to ensure the consistency of the welding process before and after the lightweight design, the thickness of the wing plate should not be directly reduced, but a design method of the wing plate opening should be adopted to reduce its thickness equivalently.

[0016] Preferably, in step 4, the wing panel close to the cargo is the rear wing panel, and the wing panel away from the cargo is the front wing panel.

[0017] Preferably, in step 4, the single-extension stacker only retrieves goods from one side, so that the stress distribution of the front and rear wing panels is inconsistent, and the structures of the wing panels on both sides of the column after topological optimization are also inconsistent.

[0018] Preferably, in step 5, a lightweighting method of non-uniform openings is performed on both sides of the wing panel according to the stress distribution and the topology optimization result in step 4.

[0019] Preferably, in step 5, the sizes and positions of the openings on the front and rear fenders present an asymmetric structural distribution.

[0020] Preferably, in step 6, numerical analysis is performed on the lightweight column model under normal working conditions and emergency braking conditions respectively to ensure the stability and reliability of the lightweight stacker.

[0021] In summary, the present invention has the following beneficial technical effects:

[0022] This invention utilizes a lightweight, non-uniform opening design to effectively reduce the weight of the stacker's columns while ensuring their structural safety, thereby lowering the overall weight of the stacker. This weight reduction directly contributes to reduced energy consumption during operation, as lighter equipment requires less energy to start, stop, and operate, thereby improving energy efficiency and reducing operating costs.

[0023] The lightweight columns make the stacker crane's overall operation more flexible and efficient, reducing inertial resistance, improving the stacker crane's response speed and operating efficiency, and enhancing the logistics efficiency of the lineside warehouse. Furthermore, through a series of analysis and optimization steps, such as finite element analysis, equivalent mechanical analysis, response surface optimization analysis, and topology optimization, the column structure was refined. While lightweight, it still meets the design requirements for stiffness and strength, ensuring the stacker crane's stability and safety under normal operating conditions and emergency braking.

[0024] Designed specifically for single-reach stackers operating in lineside warehouses, the system fully considers their actual operating conditions and stress characteristics. The asymmetric and uneven opening design makes the column structure more adaptable to the working requirements of single-reach stackers, enhancing the design's relevance and practicality. Finally, during the lightweight design, column size and density were constrained according to engineering manufacturing requirements, ensuring that the optimized design can be implemented in actual manufacturing and has good engineering feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a method for lightweighting an asymmetric opening structure of a variable-section column according to an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of a stacker column structure according to an embodiment of the present invention;

[0027] Figure 3 is another schematic diagram of the stacker column structure according to an embodiment of the present invention;

[0028] Figure 4 A horizontal cross-sectional view of a stacker column structure according to an embodiment of the present invention;

[0029] Figure 5 2. It is a schematic diagram of the front wing panel of the stacker crane after the lightweight design of the column structure according to an embodiment of the present invention;

[0030] Figure 6 Schematic diagram of the rear wing panel of the stacker crane column structure after lightweight design according to an embodiment of the present invention.

[0031] Reference numerals: 1. front wing panel; 2. web (straight); 3. rear wing panel; 4. web (oblique); 5. flange. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] This application proposes a non-uniform opening lightweighting method for stackers used in single-position storage operations in lineside warehouses, which reduces deadweight, reduces energy consumption, and improves operating efficiency while ensuring structural safety. The present invention is carried out in the following steps:

[0034] Step 1: Build a 3D model of the stacker crane based on CAD / CAE technology, and perform finite element analysis on the overall structure of the stacker crane to obtain the stress distribution on the entire model as well as the stiffness and stability of the model.

[0035] Step 2: Based on the actual operating conditions of the stacker crane, an equivalent mechanical analysis of the loads generated by the non-column structure is performed, taking into account bending and torsional effects. This results in an equivalent mechanical model of the column. The 3D model is then converted into a finite element analysis model. Material properties are defined, loads are applied, and the consistency of the column finite element model with the stacker crane finite element model in terms of static characteristics is verified.

[0036] Step 3: Use the dimensional parameters at the cross section of the column as the input parameters of the response surface optimization analysis, and mass, deformation, stress, and natural frequency as the output parameters to perform sensitivity analysis of each dimension.

[0037] Step 4: Using the maximum allowable deformation of the column under actual conditions (refer to the crane design specification GB / T3811-2008) as a constraint, perform topology optimization on the column wing area based on the variable density method.

[0038] Step 5: Referring to the results of topological optimization and stress distribution, a structural design of an opening method is performed on the left and right side fenders of the column, and the size or density of the optimized column is constrained according to engineering manufacturing. After the lightweight design, the opening positions of the two side fenders are asymmetrically distributed, and the opening size of the single-side fender is unevenly distributed. The opening size of the upper end of the front fender 1 is small and the opening position is far away from the guide rail side. The openings at the lower end are relatively dense, and the opening size shows an increasing trend. The opening positions of the rear fender 3 are mainly concentrated at the upper end, and the opening size is small. The position distribution is sparser than that of the front fender 1.

[0039] Step 6: Perform finite element analysis of the column under normal operating conditions and emergency braking conditions to confirm that the stiffness and strength indicators of the lightweight column meet the design requirements.

[0040] In this embodiment, the main structure of the column includes a front wing panel 1, a web (straight) 2, a rear wing panel 3, a web (oblique) 4, and a flange 5. The rear wing panel 3 is located on the side close to the cargo, and the front wing panel 1 is located on the side away from the cargo. In step 1, a three-dimensional model of the stacker is built in the three-dimensional modeling software according to the actual size, and imported into the finite element simulation software for pre-processing, including: defining material properties, setting contact, dividing the finite element mesh, setting constraints, etc., to obtain the stress distribution on the whole machine model and the stiffness and stability of the model.

[0041] In step 2, the entire stacker is subjected to a force analysis, and the loads generated by the components of the stacker except the columns are subjected to an equivalent mechanical analysis. This specifically includes the calculation of four equivalent forces: 1. The vertical force balance and the moment balance on the guide rails are used to obtain the pressure P on the positive roller of the column. x 2. The moment balance at the center line of the column is obtained to obtain the pressure P of the side roller on the column. z 3. The pressure P on the top of the column, which includes the lifting force F of the cargo o , rolling friction F at the pulley f The tension F of the lifting rope s 4. Acceleration a and column vibration coefficient S during horizontal movement of the stacker w The lateral force P on the column is obtained H . Establish an equivalent mechanical model of the column and verify the consistency of the column model with the whole machine model in terms of stiffness and stability to achieve the effect of simplifying the finite element analysis model.

[0042] Further, in step 3, sensitivity analysis of each dimension was performed using the dimensional parameters of the column cross section as input parameters for the response surface optimization, and mass, deformation, stress, and natural frequency as output parameters. Specifically, the thickness of the web (oblique) 4 (p6), the thickness of the web (straight) 2 (p1), the thickness of the front wing panel 1 (p5), the wing panel width (upper) (p3), and the wing panel width (lower) (p4) were used as input parameters for the response surface optimization analysis, and the maximum deformation, maximum stress, frequency, and natural frequency of the column component were used as output parameters. The sensitivity relationship between the input and output parameters was obtained.

[0043] By setting step 3, it is found that the thickness of the wing plate has the greatest impact on the mass of the column, and has almost no effect on the stiffness and strength of the column. Then, step 4 is performed to set the objective function of topology optimization: minF(x) = V(x)·ρ, and the constraint condition is the maximum deformation of the column: f max≤(1+5%)mm, with unit density as the design variable and the column wing as the topology optimization area, the optimization goal is to reduce the original mass of the wing by 25%, and the material parameters, loads and constraints are set according to the static analysis to solve the model. P5 (wing thickness) has the greatest impact on the mass of the column and has almost no effect on the stiffness and strength of the column. Therefore, under the premise of meeting the stiffness and strength requirements of the column, the wing thickness is used as a lightweight parameter. In particular, in order to ensure the consistency of the welding process before and after the lightweight design, the wing thickness should not be reduced directly. It is better to adopt the design method of the wing opening to reduce its thickness equivalently.

[0044] In this example, the column wing has a large slenderness ratio, and it is difficult to obtain a clear and periodic topological structure through topological optimization. In step 5, the result after topological optimization is combined with the stress distribution of the static structure when the stacker forks the goods on one side in step 2 for a joint optimization, and a lightweight design of an open structure is performed on the wing, and the size of the column is constrained according to engineering manufacturing. After lightweighting, the opening positions of the two side wing panels are asymmetrically distributed, and the opening size of the single-side wing panel is unevenly distributed. The opening size of the upper end of the front wing panel 1 is small and the opening position is far away from the guide rail side. The openings at the lower end are relatively dense, and the opening size shows an increasing trend. The opening position of the rear wing panel 3 is mainly concentrated at the upper end, and the opening size is small. The position distribution is relatively sparse compared to the front wing panel 1.

[0045] The lightweight column structure is analyzed under static and emergency braking conditions. The static structural analysis is consistent with step 2. Inertial force is applied to the column to verify the stiffness and strength of the column under emergency braking conditions. This embodiment is a lightweight method for the non-uniform opening of the stacker column suitable for single extension position. While ensuring structural safety, it can achieve the effect of reducing dead weight, reducing energy consumption, and improving transportation efficiency. The lightweight rate of the stacker is 5%-15%.

[0046] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lightweight method for the non-uniform opening of a stacker column suitable for single extension position, characterized in that: The following steps are involved: Step 1: Build a complete model of the stacker crane according to its structural shape and size parameters; Step 2: Considering the single-extension stacker crane operating conditions, establish an equivalent mechanical model of the column and verify its effectiveness; Step 3: Conduct sensitivity analysis on the parameters of the column based on the column equivalent mechanical model and response surface optimization method; Step 4: Topology optimization of the column wing area based on the variable density method; Step 5: Perform non-uniform opening lightweight design on the column structure based on the stress distribution, stiffness and topology optimization results; Step 6: Perform performance verification of the lightweight column model under all working conditions.

2. The method for lightweighting a stacker column with non-uniform openings suitable for a single extension position according to claim 1, characterized in that: The column structure of the high-rise stacker is designed in two sections. The main load-bearing structure of each section includes the front wing plate, straight web plate, rear wing plate, and inclined web plate. The two adjacent structures are connected by welding, and the upper and lower sections are bolted together by flanges.

3. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 1, characterized in that: In step 2, the column equivalent mechanical model established can replace the stacker crane model to achieve lightweight analysis, achieve the effect of simplifying the finite element model, and improve the analysis and calculation efficiency.

4. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 1, characterized in that: In step 3, finite element simulation software performs a response surface analysis on the column structure of the single-extension stacker. The wing plate thickness has the greatest impact on the column mass and has almost no effect on the column stiffness and strength. Therefore, under the premise of meeting the column stiffness and strength requirements, the wing plate thickness is used as a lightweight parameter.

5. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 4, characterized in that: In step 3, in order to ensure the consistency of welding process before and after lightweight design, the thickness of the wing panel should not be reduced directly. Instead, a design method of wing panel opening should be adopted to reduce its thickness equivalently.

6. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 2, characterized in that: In step 4, the wing panel closer to the cargo is the rear wing panel, and the wing panel farther from the cargo is the front wing panel.

7. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 6, characterized in that: In step 4, the single-reach stacker crane retrieves goods from only one side, resulting in inconsistent stress distribution on the front and rear fenders, and inconsistent structures of the fenders on both sides of the column after topological optimization.

8. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 2, characterized in that: In step 5, a lightweight method with non-uniform openings is performed on both sides of the wing panel based on the stress distribution and the topology optimization results in step 4.

9. The method for lightweighting a stacker column with non-uniform openings applicable to a single extension position according to claim 8, characterized in that: In step 5, the sizes and positions of the openings on the front and rear fenders are distributed in an asymmetric structure.

10. The method for lightweighting a stacker crane column with non-uniform openings applicable to a single extension position according to claim 1, characterized in that: In step 6, numerical analysis is performed on the lightweight column model under normal operating conditions and emergency braking conditions to ensure the stability and reliability of the lightweight stacker.

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