Machining method for grinding short holes by large-length-diameter-ratio weak-rigidity grinding rods

Abstract

The invention discloses a machining method for grinding short holes by large-length-diameter-ratio weak-rigidity grinding rods, and belongs to the technical field of precise grinding. The machining method comprises the following steps: (S1) apertures of orifices, middle points and bottoms of machined hole sections are measured; (S2) the efficient cutting and grinding are performed; (S3) the efficient-grinded apertures are judged if reaching a set diameter range; (S4) the small-cutting-depth reciprocating grinding is performed; (S5) the precise-grinded apertures are judged if meeting the size requirements; (S6) the morphology of a grinding wheel is finished; (S7) a motion trajectory of the grinding wheel is determined; and an interpolation method is used for grinding; and (S8) the interpolation method is applied to polish the apertures until the size requirements are met. The machining method realizes efficient removal of materials by normal grinding pretightening force between the grinding wheel and workpieces during grinding through adjustment of prebending deformation of the grinding rods during grinding, realizes high-quality and high-efficiency precise grinding of the short holes of large-length-diameter-ratio parts through the morphology change of the grinding wheel, and improves the machining precision and quality and the production efficiency of the short holes.

Description

technical field [0001] The invention belongs to the technical field of precision grinding, and relates to a processing method for grinding short holes with a large length-to-diameter ratio weak rigidity grinding rod. Background technique [0002] Aircraft landing gear is an important part of the aircraft, and it is also a key component to ensure the safe flight of the aircraft. Thin-walled parts (L / D ≥ 12, and hole depth L ≥ 1000mm) with a large depth-to-diameter ratio are important parts of the aircraft landing gear. In order to meet its high-performance requirements, the blank parts It is formed by forging high-strength steel, and then a large amount of material is removed through multiple machining processes (the material removal rate is higher than 87%), and processed into thin-walled tube parts, which belong to the key precision hydraulic components or pneumatic components of the landing gear. , has the characteristics of complex internal structure including multiple s...

AI Technical Summary

Problems solved by technology

However, due to the poor rigidity of the slender grinding rod (length ≥ 1000mm, diameter ≤ 50mm), the grinding wheel causes serious deformation of the knife during grinding. When the length of the inner hole of the grinding section is similar to the width of the grinding wheel, the grinding wheel reciprocates. , the material removal at the bottom of the hole is less, resulting in a large inner hole opening and a small hole bottom, and it is difficult for the parts to meet the machining accuracy requirements

At present, for the precision machining of short holes of such parts with large depth-to-diameter ratio, since the length of the inner hole is equivalent to the width of the grinding wheel, it cannot be trimmed by ordinary interpolation processing. Experienced operators usually adjust the deflection angle of the machine tool pallet to achieve "Slight adjustment" to compensate for the inconsistency of material removal at the hole opening and the bottom of the hole caused by the deformation of the knife due to the weak rigid grinding rod during grinding, and meet the machining accuracy requirements of such short holes, but the adjustment process is extremely complicated and It is cumbersome and prone to over-compensation or under-compensation. Repeated adjustments are required for under-compensation, but once over-compensation occurs, it will directly lead to the scrapping of parts, resulting in huge economic losses, and the process requires high technical requirements for operators. , high labor intensity, time-consuming and labor-intensive, low production efficiency, difficult to realize automatic processing

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