Large journey low-temperature extension hydraulic cylinder manufacture method

Abstract

The invention relates to the technology for manufacturing a hydraulic cylinder, in particular to a method for manufacturing a large-stroke low temperature stretching hydraulic cylinder. The large-stroke low temperature stretching hydraulic cylinder is used on an oil well rig or a service machine working in cold areas and is used for stretching of a nesting headframe. In the technological process of the invention, low temperature resistant alloy structural steel is selected to be blanked and machined into components; the components are conventionally heated; a low temperature process is adopted to weld, connect and assemble the components; low temperature resistant sealing elements are arranged in the four sealed grooves of a piston. In this way, the large-stroke low temperature stretching hydraulic cylinder is manufactured. The large-stroke low temperature stretching hydraulic cylinder manufactured through the method has good low temperature property; the performance of the welds and the heat-affected zones of the cylinder tube and a piston rod reaches the following indices: Sigma b is more than or equal to 410MPa; Delta s is more than or equal to 20 percent; Akv (-45 DEG C) is more than or equal to 27J; the large-stroke low temperature stretching hydraulic cylinder can meet the requirements for intensity, toughness, rigidity and elasticity under low temperature (-45 DEG C), and works reliably with high sealing performance.

Description

technical field [0001] The invention relates to a hydraulic cylinder manufacturing technology, in particular to a manufacturing method of a large-stroke low-temperature telescopic hydraulic cylinder. The large-stroke low-temperature telescopic hydraulic cylinder is matched with oil drilling rigs or workover rigs operating in cold regions, and is used for the telescopic expansion and contraction of the packaged derrick. Background technique [0002] In the prior art, conventional large-stroke telescopic hydraulic cylinders for derrick telescoping are only suitable for ambient temperatures ranging from -18 to 40°C. If used at low temperatures (-45°C), the hydraulic cylinders may leak oil or break. The reasons are as follows: On the one hand, the derrick telescopic hydraulic cylinder cannot meet the strength and toughness required at low temperature (-45°C) due to the material of the cylinder barrel and cylinder rod and the butt joint welding process of the cylinder barrel and ...

AI Technical Summary

Problems solved by technology

On the other hand, the working temperature of the derrick telescopic hydraulic cylinder seal is -30~+100°C. If it is used at the ambient temperature of -45°C, the hardness, modulus and intramolecular friction will increase due to the rapid slowdown of the relaxation process. Significant reduction in elasticity, resulting in a reduction in the ability of the seal to work, resulting in hydraulic cylinder leakage

However, the length of the large-stroke telescopic hydraulic cylinder is about 30 meters when the derrick is extended, which makes it very time-consuming and labor-intensive to replace the hydraulic cylinder seal.

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