The optimization of the main structure of the heavy-tonnage cubic diamond press primarily focused on improving the equipment’s centering, synchronization, and pressure-keeping performance. Based on the analysis of existing hinged cubic press structures, the following key optimization measures were implemented.

I. Main Body Structural Design Optimization

1. Adoption of the Pocket Bottom Structure: The hinge beams and working cylinders utilized the pocket bottom structure. Physical testing indicates that this structure possesses superior structural rigidity compared to the traditional flange support structure.

2. Live-Bottom Working Cylinder Design: The working cylinder was designed as a live-bottom structure. This structural approach separates the cylinder barrel and the cylinder bottom, improving material utilization, reducing raw material consumption, and greatly enhancing the process performance related to forging, machining, and heat treatment.

3. Working Cylinder Wall Thinning and Reduced Fit Clearance: While ensuring that mechanical processing requirements are met, the design sought to minimize the wall thickness of the working cylinder barrel and reduce the cooperation clearance between the barrel’s outer diameter and the hinge beam’s inner bore. This optimization improves the centering ability of the press. When the barrel is subjected to ultra-high hydraulic pressure, it undergoes slight elastic deformation and presses against the inner wall of the hinge beam, improving the stress conditions and extending the barrel’s service life.

4. Shortening of Key Component Lengths: While maintaining component strength, the length of the working cylinder and hinge beam was shortened, thereby reducing steel consumption and manufacturing costs.

5. Optimization of Hinge Beam Lug Shape: The shape of the hinge beam lugs was rationally designed. By keeping the extension surfaces of adjacent lugs parallel and ensuring that the traditional hinge beam lugs project appropriately higher than the outer diameter of the barrel, the strength of the dangerous bottom cross-section was effectively enhanced, and the rigidity of the equipment was increased.

II. Piston and Connection Optimization

1. Installation of Bronze Wear Strips on Pistons: To resolve the common "scoring" (cylinder scratching) problem during press use and enhance centering, bronze wear strips were installed on the pistons. This measure reduced the fit clearance between the piston and the working cylinder to 0.01 mm, which greatly improved the press's centering and completely solved the "scoring" issue, preventing subsequent synchronization problems or component scrapping.

2. Rearward Shift of Piston Center of Gravity: To reduce the downward deflection of the six horizontal anvils when they advance, the design required the piston's center of gravity to be shifted backward to eliminate deflection caused by the weight of the piston in the horizontal direction.

3. Use of Elastic Gap-Free Pin Connection: Elastic gap-free pin connections were used between the hinge beams. This novel pin design eliminates the clearance between the hinge beams, creating an interference fit, thereby significantly improving the equipment's centering, synchronization, and pressure-keeping performance. Eliminating clearance also helps enhance the coordination of the equipment's inherent deformation.