Method and device for laser shock processing of fastening holes

Abstract

The invention discloses a method and a device for laser shock processing of fastening holes, and relates to the field of processing and manufacturing of the fastening holes. An energy absorbing rod (6) is placed at a proper position in a fastening hole, laser pulse (2) acts on a bevel of a head of the energy absorbing rod (6) to induce the explosion of a plasma (6) to generate a shock wave to act on an inner wall of the fastening hole, so that the fastening hole is processed; and the device comprises a laser, a concentrating system (1), a laser head (4), the energy absorbing rod (6), a feed mechanism A (7), a feed mechanism B (9), a fixture (8) and a workbench (10). The explosive force of the plasma (12) induced by the laser in the fastening hole acts on the inner wall of the hole to make the inner wall of the hole generate certain plastic deformation, so that the residual stress larger than that generated by the common processing is introduced, and the fatigue life of the fastening hole is effectively improved.

Description

technical field [0001] The invention relates to the field of fastening hole processing and manufacturing, in particular to a method and device for laser shock strengthening of fastening holes, and is especially suitable for strengthening the inner surface of small-diameter fastening holes with severe stress concentration. technical background [0002] Fastening holes are typical stress concentration details on aircraft components, which are prone to fatigue cracks under the action of alternating loads, which will greatly reduce the safety, reliability and service life of the whole machine. Therefore, in design, material selection and manufacturing, how to reduce the influence of stress concentration in fastening holes as much as possible, improve the fatigue resistance of aircraft structures, prolong the service life, and ensure the reliability and safety of aircraft structures is an important aspect of design and material research. important research topics for researchers....

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Problems solved by technology

People such as Peter A. Simeone and Apostolos P. karafillis of U.S. General Company declared that the patent No. is the U.S. patent of US 6189356 B1, and the name is called shot peening method and device (Method and Apparatus for Peening), and this patent will be the cone surface The splitter rod extends into one end of the fastening hole, and the pellets are sprayed into the other end of the fastening hole. The inner wall of the fastening hole is shot peened by the conical reflection of the splitter rod, but it leads to an increase in the surface roughness of the material. Will offset the contribution of residual stress to prolong fatigue life to some extent

The Chinese patent No. 200610096476.5 declared by Zhang Yongkang, Zhang Xingquan and others is a method and device for strengthening the hole wall based on laser shock wave technology. The patent uses laser shock waves to strengthen the inner wall of the hole. On the other hand, due to the small fastening hole, the diameter of the laser pulse spot is also very small, and the focused laser pulse is very easy to act on the tip of the cone. The impact force is small, and the strengthening effect is not ideal

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