The load-bearing stability of the iron pipe pallet is closely related to its structural design, and this correlation is reflected in multiple dimensions such as mechanical conduction, material distribution, and spatial layout. In essence, the structural design of the pallet needs to transfer the external load to the support system through a reasonable path, while avoiding deformation or fracture caused by stress concentration. For example, when the goods are placed on the surface of the pallet, the load will first act on the panel structure, and then be transferred to the support feet or base through the longitudinal beams and cross beams. In this process, the structural design of each level will affect the overall stability. Therefore, the core goal of optimizing the structural design is to build a balanced mechanical conduction system so that the various components of the pallet are subjected to force in coordination when bearing loads, rather than a single component bearing pressure independently.
The structural design of the pallet panel is a basic link that affects the load-bearing stability. As the part that directly contacts the goods, the strength and stiffness of the panel determine the initial distribution efficiency of the load. Common iron pipe pallet panels have two structures: flat and grid. Flat panels provide uniform support through continuous metal plates and are suitable for carrying regular-shaped goods, such as boxed or bagged items. The advantage is that the load is evenly distributed and it is not easy for the panel to sag due to excessive local pressure. The grid panel is a hollow structure formed by iron pipes staggered horizontally and vertically. This design can reduce the weight while improving the overall strength through the rigid support of the iron pipes. It is especially suitable for carrying pallets or barreled goods with fork holes at the bottom, but attention should be paid to the contact area between the goods and the grid to avoid load concentration due to too few contact points. In addition, the thickness of the panel and the spacing between the iron pipes are also key parameters. Thicker panels and smaller iron pipe spacing can provide stronger support, but will increase weight and cost; conversely, thinner panels and larger spacing may deform under heavy load.
The layout of longitudinal beams and cross beams is the core mechanical structure that determines the load stability. The longitudinal beams are usually arranged along the length of the pallet and are the main force-transmitting components connecting the panel and the support feet. Their number, spacing and cross-sectional shape directly affect the bending resistance of the pallet. For example, increasing the number of longitudinal beams can shorten the load transfer path and reduce the span deformation of the panel, but it will increase the material consumption; reasonable adjustment of the longitudinal beam spacing (such as optimization according to the distribution of the center of gravity of the cargo) can make the load more evenly transferred to the support feet. The cross beams are arranged along the width direction, and their main function is to connect the longitudinal beams, enhance the torsional rigidity of the pallet, and prevent distortion caused by uneven force. In heavy iron pipe pallets, a "日"-shaped or "目"-shaped cross beam layout is often used. Through multi-layer cross beams, a truss-like structure is formed. This design can significantly improve the stability of the pallet under complex loads, especially for scenes that are subjected to impact loads during transportation.
The structural design of the support foot plays a decisive role in the stability of the pallet. As the fulcrum for the pallet to contact the ground or shelf, the number, shape and distribution of the support foot directly affect the pallet's anti-overturning ability and bottom surface bearing strength. Common support legs include single-tube, multi-tube and combined types. Single-tube support legs are composed of a single thick iron pipe, which has a simple structure but a small bearing area and is suitable for light-load scenarios. Multi-tube support legs use multiple thin iron pipes arranged side by side or in a ring to increase the bottom contact area, disperse the ground pressure, and improve stability. They are often used for heavy-load pallets. Combined support legs combine iron pipes of different diameters and are connected by internal reinforcement ribs to ensure strength and reduce weight. In addition, the height consistency of the support legs is crucial. If the height deviation of the support legs exceeds the allowable range, the pallet will be unevenly stressed and even tilted when placed, seriously affecting the bearing stability. Therefore, precision machining is required in production to ensure that the height tolerance of the support legs is controlled within the millimeter range.
The reliability of the structural connection method directly affects the stability of the pallet under dynamic loads. The components of the iron pipe pallet are usually fixed by welding, bolting or snap-on structures, and the mechanical properties of different connection methods vary significantly. Welding is the most commonly used connection method. It forms a metallurgical bond between iron pipes through high-temperature melting, which can provide high-strength connection performance. However, the welding quality is greatly affected by the process level. Defects such as cold welding, leaking welding or weld nodules may cause stress concentration and reduce stability. Bolt connection has the advantages of being removable and easy to repair, but the bolt holes may weaken the cross-sectional strength of the iron pipe, and the bolts are easy to loosen during frequent handling, so they need to be checked and tightened regularly. The snap-on structure can be quickly assembled through prefabricated slots and protrusions, which is suitable for modular production, but the connection stiffness is relatively low and is mainly used for light load or temporary use scenarios. In the design, key stress-bearing parts (such as the connection between the longitudinal beam and the support foot) are usually double-sided welded or reinforced plates are added to improve the connection strength and avoid breakage during load.
The overall geometric design of the pallet will also affect stability. The aspect ratio is an important parameter: when the length of the pallet is much greater than the width, its longitudinal bending stiffness is strong, but its lateral anti-overturning ability is weak, and it is easy to roll over when carrying goods with a lopsided center of gravity; on the contrary, a pallet that is close to a square has more balanced stability in all directions, but may not be suitable for stacking long goods. In addition, the height of the pallet (that is, the sum of the height of the support leg and the thickness of the panel) will affect the position of its center of gravity - the higher the height, the higher the center of gravity, and the easier it is to shake due to inertia when stacking or transporting. Therefore, when designing a high-support-leg pallet, it is necessary to lower the center of gravity by adding a bottom beam or using a counterweight structure. For iron pipe pallets that need to be used on shelves, the position and size of the fork hole must also be considered. If the fork hole is too narrow or too shallow, it will be difficult to insert the forklift fork, and even damage the pallet structure due to uneven force, affecting stability.
In actual applications, the optimization of structural design needs to be adjusted in a targeted manner in combination with specific usage scenarios. For example, the iron pipe pallet used in automated warehousing systems needs to consider compatibility with conveyor belts, stackers and other equipment. Its structural design should avoid bumps or depressions that are prone to jamming, and at the same time, improve the impact resistance during dynamic handling by reinforcing ribs; pallets used for open-air storage need to add drainage holes or inclined panels in the structural design to prevent rainwater accumulation from causing rust, which indirectly affects the stability of the structure. In addition, with the development of new materials and new processes, lightweight structural design has become a trend. By adopting high-strength steel and optimizing the cross-sectional shape of iron pipes (such as using hollow square tubes instead of round tubes), the amount of materials can be reduced without reducing the load-bearing stability, which not only reduces costs but also improves handling efficiency. In short, the structural design of the iron pipe pallet is a systematic project that integrates mechanical principles, material properties and application requirements. Only through precise parameter matching and detail control can the optimal balance between load-bearing stability and comprehensive performance be achieved.
