A middle trough middle plate of gradient lattice interlayer and biomimetic wear-resistant integrated scraper conveyor and a forming method thereof

Abstract

The application discloses a middle plate of a gradient crystal lattice sandwich and biomimetic wear-resistant integrated scraper conveyor middle trough, and relates to the technical field of coal mine conveying equipment. The middle plate is integrally composed of an upper bearing entity layer, a biomimetic non-smooth structure, a gradient crystal lattice filling layer and a bottom supporting entity layer. The upper bearing entity layer and the biomimetic structure are used for bearing impact load and reducing abrasive wear; the gradient crystal lattice filling layer is designed in a Face-Centered Cubic (FCC) lattice density gradient with different diameters according to the stress distribution of the middle plate, so that material optimization configuration and structure lightweight are realized; and the bottom supporting entity layer improves the overall stability. The integrally formed multi-layer structure is realized through laser additive manufacturing, the self-weight is reduced while the bearing performance is ensured. The surface hemispherical array pit structure can store abrasive particles, reduce the friction contact area and improve the wear resistance life. The application has the advantages of lightweight, high impact resistance and excellent wear resistance, and is suitable for high load and strong wear working conditions in coal mines.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mine machinery and bulk material conveying equipment, and particularly relates to a middle trough plate and forming method of a gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor. Background Technology

[0002] Scraper conveyors are the core conveying equipment in fully mechanized mining faces, and the center plate in the central trough is a key load-bearing component for coal transport. Traditional center plates are mostly made of homogeneous thick steel plates, resulting in high weight and low material utilization, which is not conducive to the lightweight development requirements of equipment in the trend of coal industry development towards deep-well mining. At the same time, the center plate is subjected to long-term cyclic impact and abrasive wear from coal, scrapers, and chains, making it prone to wear failure, shortening equipment life, reducing fully mechanized mining efficiency, and increasing operation and maintenance costs. Therefore, it is urgent to simultaneously solve the two major technical challenges of lightweight design and surface wear-resistant strengthening of the center plate.

[0003] Existing research on lightweighting of medium-density plates mainly focuses on material substitution, with relatively few studies based on structural optimization. Crystallographic structures possess mechanical properties such as high specific strength, lightweight, impact resistance, and energy absorption. Designing lattice density gradient filling structures with differentiated designs for stress-bearing regions can achieve weight reduction while meeting structural mechanical performance requirements, representing an effective approach to lightweight design.

[0004] Existing methods for improving wear resistance include material modification, surface strengthening, and wear-resistant coatings. While these methods can increase surface hardness, they also increase material brittleness, making them unsuitable for heavy-load impact conditions. Biomimetic concave non-smooth structures offer advantages in friction reduction and wear resistance, and applying them to the surface of medium-plates can compensate for the shortcomings of traditional wear-resistant processes.

[0005] Traditional machining processes cannot integrally form complex metal structures with lattices and biomimetic composites. However, laser additive manufacturing breaks through the forming limitations and can integrally prepare composite plates containing solid load-bearing layers, gradient lattice filling layers, and biomimetic non-smooth wear-resistant surfaces, providing process support for the forming of the plate structure of this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor trough plate in the middle section to solve some of the problems mentioned in the background art.

[0007] Another objective of this invention is to provide a method for forming the above-mentioned central groove plate, which integrates the upper supporting solid layer, the biomimetic non-smooth structure, the gradient lattice filling layer, and the bottom supporting solid layer.

[0008] To achieve the above-mentioned objectives, the technical solution of the present invention is: a middle trough plate of a gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor, comprising an upper bearing solid layer, a biomimetic non-smooth structure, a gradient lattice filling layer, and a bottom supporting solid layer; the gradient lattice filling layer is sandwiched between the upper bearing solid layer and the bottom supporting solid layer, and the biomimetic non-smooth structure is disposed on the outer surface of the upper bearing solid layer.

[0009] The gradient lattice filling layer adopts a face-centered cubic (FCC) lattice structure, composed of multiple regularly arranged and periodically arranged lattice units. The gradient lattice filling layer is divided into multi-density zones along the direction perpendicular to the transport direction (lateral direction), with the zone boundaries matching the actual load distribution characteristics of the middle plate. The lattice density is controlled by changing the diameter of the lattice rods in each zone: large-diameter lattice rods are used in high-load areas to improve structural stiffness and deformation resistance; small-diameter lattice rods are used in low-load areas to reduce material usage; and medium-diameter lattice rods are used for loads between high and low loads. This reduces the overall weight while ensuring mechanical performance, achieving a precise match between structural mechanical performance and operating load.

[0010] The biomimetic non-smooth structure adopts a hemispherical pit structure, and multiple hemispherical pits are distributed in an array on the surface of the upper supporting entity layer according to a preset longitudinal and transverse spacing.

[0011] The forming method of the gradient lattice sandwich layer and the middle trough plate of the biomimetic wear-resistant integrated scraper conveyor specifically includes the following steps: First, a three-dimensional model of the central trough plate of the integrated gradient lattice sandwich and biomimetic wear-resistant scraper conveyor is established using three-dimensional modeling software, and the thickness of each solid layer, the gradient parameters of the lattice rod diameter, and the size of the biomimetic pit array are precisely defined. Second, slice the 3D model to obtain laser additive manufacturing path data; Third, relying on Laser Metal Direct Forming (LMDF), based on the layered slicing data of the three-dimensional model, the laser melts the metal powder and deposits it layer by layer, completing the integrated forming of the upper and lower solid layers, the middle gradient lattice filling layer and the biomimetic non-smooth structure in one go. After forming, only sandblasting is required for cleaning, without the need for component splicing or secondary assembly.

[0012] Compared with the prior art, the present invention has the following beneficial effects: Firstly, it combines lightweight and high specific strength. This invention adopts a face-centered cubic (FCC) gradient lattice sandwich structure. The diameter of the lattice rods is adjusted according to the different load distribution across the entire middle plate. High-strength lattice structures are concentrated in high-stress areas, while smaller rod diameter lattices are used in low-stress areas. While ensuring the strength and stiffness of key load-bearing areas, it effectively reduces the amount of material used in non-critical areas and the overall structural weight. This avoids the problems of heavy weight, low material utilization, and localized damage and deformation that exist in traditional homogeneous solid middle plates, and achieves a synergistic improvement in the lightweight and specific strength of the middle plate. Secondly, it improves wear resistance and extends service life. This invention features an array of hemispherical, biomimetic, non-smooth pits on the working surface of the medium plate. By altering the contact state between the material and the medium plate surface, it reduces the frictional contact area, weakens the abrasive effect of coal and rock particles on the surface, and simultaneously utilizes the pit structure to accommodate and fill abrasive particles, reducing secondary wear caused by hard particles. This effectively improves the wear resistance of the medium plate surface, reduces the wear rate, and extends the equipment's service life. Third, it achieves integrated forming of complex structures, improving structural reliability. This invention employs a Laser Metal Direct Forming (LMDF) system for additive manufacturing, enabling the integrated forming of the upper load-bearing solid layer, the biomimetic non-smooth structure, the gradient lattice filling layer, and the bottom supporting solid layer. The interfaces between these structures are continuous, smooth, and seamless, eliminating the risks of interlayer delamination and connection failure associated with traditional separate welding and composite spraying, thus improving overall structural stability. Simultaneously, this forming method enables high-precision manufacturing of complex gradient lattices and biomimetic structures, providing a reliable technical approach for the fabrication of high-performance, wear-resistant, and lightweight central slot plates. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view and a partially enlarged schematic diagram of the gradient lattice filling layer in the middle plate of the groove in this invention;

[0014] Figure 2 This is a schematic diagram showing the biomimetic non-smooth structure on the surface of the upper supporting solid layer of the present invention and a partially enlarged view.

[0015] Figure 3 This is a schematic diagram showing the overall cross-section and a partial enlarged view of the integrated gradient lattice sandwich and biomimetic wear-resistant plate of the present invention;

[0016] Figure reference numerals: 1-Upper supporting solid layer, 2-Bionic non-smooth structure, 3-Gradient lattice filling layer, 4-Bottom supporting solid layer;

[0017] The gradient lattice filling layer is divided into: large-diameter lattice rods, medium-diameter lattice rods, and small-diameter lattice rods;

[0018] Biomimetic non-smooth structural parameters: pit diameter, longitudinal spacing, and transverse spacing. Detailed Implementation

[0019] The following describes in detail, with reference to the accompanying drawings and specific embodiments, a middle trough plate of a gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor and its forming method, which are involved in the present invention.

[0020] Example 1: Gradient lattice sandwich structure design.

[0021] like Figure 1 As shown, in this embodiment, the gradient lattice filling layer 3 is formed by periodically arranging face-centered cubic (FCC) lattice units, each of which includes multiple interconnected rod-like structures. The FCC lattice has high specific stiffness and good load-bearing capacity. Its rods mainly bear loads in a tensile manner, which can reduce local stress concentration and improve the impact resistance of the structure.

[0022] First, a simplified 3D model of the central groove was established. The load spectrum of the working surface of the central plate was extracted using EDEM discrete element method software. Then, the load spectrum was imported into ANSYS finite element method software. The global stress distribution of the central plate under actual working conditions was obtained through Discrete Element Method (DEM)-Finite Element Method (FEM) coupling. The load on the central plate along the conveying direction is basically consistent; the load difference mainly lies in the direction perpendicular to the conveying direction (lateral). Based on topology optimization, the gradient lattice filling layer 3 was divided into three lattice density regions along the direction perpendicular to the conveying direction (lateral). 1) Scraper chain operating area: high stress and high load area, equipped with large diameter lattice rods and high density lattice arrangement; 2) Middle region of the middle plate: medium load area, configured with medium diameter lattice rods, medium density lattice arrangement; 3) Edge areas on both sides of the scraper chain: low stress and low load areas, equipped with small diameter lattice rods and low density lattice arrangement.

[0023] By using differentiated rod diameters to achieve a lattice density gradient distribution, materials are concentrated in high-load areas while reducing the use of materials in low-load areas, significantly improving the overall utilization rate of metallic materials.

[0024] Example 2: Biomimetic wear-resistant surface structure design.

[0025] In this embodiment, the biomimetic non-smooth structure 2 adopts a hemispherical pit structure, the morphology of which simulates the non-smooth morphology of wear-resistant biological surfaces in nature.

[0026] like Figure 2As shown, hemispherical pits are arranged in an array on the surface of the upper supporting solid layer 1. Multiple hemispherical pits are evenly distributed in an array along the coal conveying direction (longitudinal) and perpendicular to the conveying direction (transverse). Using the pit diameter, longitudinal spacing, and transverse spacing as design variables, and the average wear depth of the working face as the response index, the optimal combination of dimensional parameters is obtained through response surface methodology.

[0027] During underground transport operations, hard coal and rock particles fall into the hemispherical pit and are stored, reducing the continuous plowing friction between the particles and the steel plate, transforming continuous sliding wear into intermittent wear, reducing the amount of steel plate matrix material removed, and significantly improving the wear resistance of the medium plate.

[0028] Example 3: Integrated mid-plate structure and laser additive manufacturing process.

[0029] In this embodiment, the upper supporting solid layer 1, the biomimetic non-smooth structure 2, the gradient lattice filling layer 3, and the bottom supporting solid layer 4 are integrally formed by laser additive manufacturing, and the interfaces of each layer are continuous without splicing gaps.

[0030] The specific forming method includes the following steps: First, 3D modeling. Using 3D modeling software, a complete integrated 3D model of the middle plate is created, including the upper load-bearing solid layer 1, the biomimetic non-smooth structure 2, the gradient lattice filling layer 3, and the bottom support solid layer 4. Second, model slicing preprocessing. The 3D model is imported into the Laser Metal Direct Forming (LMDF) system, the model is sliced ​​into layers, the printing reference is set as the bottom surface of the middle plate, the bearing working surface is arranged upwards, and the corresponding laser scanning path data is generated; Third, laser layer-by-layer deposition forming. Using Laser Metal Direct Forming (LMDF) equipment, metal powder is used as the forming material. A high-energy laser beam melts the metal powder, and it is deposited layer by layer according to a predetermined scanning path to form a complete composite mid-plate in one step. Fourth, post-processing. After forming, the workpiece is cleaned of surface dust and then sandblasted to reduce the original printing roughness of the workpiece surface and improve the wear resistance of the working surface.

Claims

1. A gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor trough plate, characterized in that, It includes an upper supporting solid layer (1), a biomimetic non-smooth structure (2), a gradient lattice filling layer (3), and a bottom supporting solid layer (4). The biomimetic non-smooth structure (2) is arranged on the outer surface of the upper supporting solid layer (1), and the gradient lattice filling layer (3) is sandwiched between the upper supporting solid layer (1) and the bottom supporting solid layer (4).

2. The gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor trough plate according to claim 1, characterized in that: The gradient lattice filling layer (3) adopts a face-centered cubic (FCC) lattice structure. The FCC lattice structure is composed of multiple regularly arranged lattice units. It is divided into multiple lattice density gradient filling regions along the middle plate perpendicular to the conveying direction (lateral direction). The density distribution matches the stress distribution characteristics of the entire middle plate. The lattice density gradient is configured with lattice rods of different diameters according to the load requirements of different regions. Larger diameter lattice rods are configured in high load regions, and smaller diameter lattice rods are configured in low load regions.

3. The gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor with central trough plate as described in claim 1, characterized in that: The biomimetic non-smooth structure (2) adopts a dry hemispherical pit structure, and multiple hemispherical pits are evenly distributed in an array along the longitudinal and transverse directions at a set interval on the working surface of the upper supporting solid layer (1).

4. The gradient lattice sandwich and biomimetic wear-resistant integrated scraper conveyor trough plate according to claim 1, characterized in that: The upper supporting solid layer (1), the biomimetic non-smooth structure (2), the gradient lattice filling layer (3) and the bottom supporting solid layer (4) are integrally formed by laser additive manufacturing, and the connection interfaces of each structure are continuous without splicing gaps.

5. A forming method for preparing the gradient lattice sandwich layer and the biomimetic wear-resistant integrated scraper conveyor trough plate according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Establish an integrated three-dimensional model of the middle plate, including the upper load-bearing solid layer (1), the biomimetic non-smooth structure (2), the gradient lattice filling layer (3), and the bottom support solid layer (4); 2) Perform layered slicing based on the three-dimensional model to obtain laser additive manufacturing path data; 3) Using a laser metal direct forming (LMDF) device, metal powder is used as raw material to manufacture the middle plate of the tank layer by laser melting and deposition, so as to realize the integrated forming of the upper load-bearing solid layer (1), the biomimetic non-smooth structure (2), the gradient lattice filling layer (3), and the bottom support solid layer (4); 4) After manufacturing using the Laser Metal Direct Forming (LMDF) method, the workpiece is surface cleaned and sandblasted to reduce surface roughness and improve the quality of the working surface.

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