Methods for Repairing Surface Defects on Cylinder Tube Surfaces Cylinder tubes often have many pockmarks on their surfaces before processing, which is a significant factor affecting the quality of the cylinder tubes. To obtain hydraulic cylinder tubes after honing, these pockmarks need to be repaired. So, what are the methods for repairing surface defects on hydraulic cylinder tubes? 1. Increase Cold Drawing Deformation Increasing the number of cold drawing deformation passes and the total deformation can achieve the purpose of reducing the depth of pockmarks and decreasing the stock allowance for honing. 2. Optimize Hot Rolling Billets All pockmark defects in cold drawn tubes are caused by hot rolling tubes. Therefore, by selecting hot rolling tubes with less rust and uniform wall thickness, pockmark defects can be reduced, and the yield rate of cylinder tubes can be improved. 3. Cleaning Internal Defects of Hot Rolling Tubes Quality is the premise of products and the foundation of serving customers. Therefore, the meticulous repair of surface defects on hydraulic cylinder tubes is a significant commitment to our customers. Key Advantages of Cylinder Tubes: 1. Improve surface roughness, with a roughness of Ra≤0.08μm. 2. Correct roundness, with ellipticity ≤0.01mm. 3. Enhance surface hardness, eliminating stress deformation, with hardness HV≥4°. 4. Post-processing residual stress layer increases fatigue strength by 30%. 5. Improve fit quality, reduce wear, extend part lifespan, but lower processing costs. Cylinder Tube Surface: The surface is cross-hatched, which is beneficial for the storage of lubricating oil and the maintenance of oil films. It has a high surface support rate (the actual contact area between the hole and shaft compared to the mating area), thus able to bear greater loads and reduce wear, thereby extending the product's lifespan. Honing speed is low (a fraction of the grinding speed), and the abrasive stone is in face contact with the hole, resulting in a small average abrasive pressure for each abrasive particle. This makes the workpiece's heat generation minimal during honing, with almost no thermal damage or transformation layer on the surface, and minimal deformation. Honing processing surfaces are almost free of embedded sand and hardening layers. Cylinder Tube Production Specifications: Inner diameter: 30mm—300mm, wall thickness: 2mm—40mm. Technical conditions: inner hole accuracy H5—H10, inner hole roughness Ra≤0.63μm, straightness ≤0.3mm/m. Steel grades: 20#, 45#, 16Mn, 27SiMn, and some low-alloy steels. Standard GB8713-88. Honing Production Main Equipment: 350-ton full-hydraulic prestress cold drawing machine and 150-ton machines each, with a larger stroke of 12 meters and a larger drawing force of 350 tons. There are also 2 vertical honing machines and 2 horizontal honing machines.
Welded tube, joining methods, mechanical fitting devices, and cylinder assembly manufacturing techniques
An inventive method is provided for joining two components with high strength and integrity using plastic deformation. The method involves fitting the end of a screw-like part with a female mold section to a piston rod having three rows of annular grooves in its front section (male mold section) that can interlock with the female mold section. In this state, the side walls of the female mold section are radially pressed into the annular grooves of the piston rod through mechanical interlocking. At this point, the interlocked section formed by the pressing ensures that adjacent annular grooves (21) are configured in an interlaced manner, providing the desired joining strength while inhibiting material elongation and preventing separation at the junction of the screw-like part with the cylinder tube (piston rod).
Welded pipe applications
Honed tubes processed by honing machines, manufactured using precision drawing, finishing, and polishing techniques, are suitable for use in oil and gas cylinder piston rods, and find applications in textile, mining, glass, plastic machinery, loaders, cranes, and various automotive industries. Cold drawn honing tubes are used for hydraulic and pneumatic cylinders in construction machinery and ships. To enhance the performance of steel pipes, galvanizing is applied to standard pipes. Galvanized pipes are available in hot-dipped and electro-galvanized types, with hot-dipped having thicker zinc coating and electro-galvanized being more cost-effective but less smooth. Oxygen blowing pipes: Used for steelmaking oxygen blowing, typically in small-diameter welded steel pipes, with specifications ranging from 3/8 to 2 inches. Made from steel strips of grades 08, 10, 15, 20, or 195-Q235, they are treated with aluminum diffusion to prevent corrosion.
The processing of honed tubes is affected by the working pressure of the honing machine.
Honoring tubes are precision-ground using a honing head composed of 46 abrasive sticks to finish the internal bore. Honing is not only productive but also offers high precision, typically achieving IT5-IT6 size accuracy and surface roughness of 0.8-0.1μm, while correcting geometric shape deviations of the bore. To further enhance honing productivity, the honing process has evolved towards high-force honing, automatic size control honing, electrolytic honing, and ultrasonic honing. The working pressure of the honing oil stone significantly impacts the honing cutting performance, directly affecting cutting efficiency, the wear rate of the honing oil stone, and the workpiece's precision and roughness. When the honing working pressure is high, both the cutting volume and the wear rate of the honing oil stone are greater, resulting in lower precision and surface roughness. Conversely, with lower honing working pressure, both the cutting volume and the wear rate of the honing oil stone are reduced, leading to better precision and surface roughness.
Knitted Tube Features
1. Fine DrawnHigh efficiency, saving material and labor loss during mechanical processing.
2. Various specifications, wide application range.
3. Cold drawn honing tubes offer high finished precision and good straightness.
4.缸管 performance is superior, with denser metal.
