Assembling and welding technique of ship water-jet propulsion flow-passage grid

Abstract

The invention discloses a welding process used for a marine water-jet propulsion chute grate. The process comprises the following steps: firstly, grate components are processed well and the margins are pre-preserved; the actual mounting is carried out to define the actual mounting positions and the final sizes of the components; the components are pre-fixed through spot welding; and after checked and passed, the components are welded in the ship chute to form a complete grate. The proper sequence and process parameters are adopted in the welding so as to reduce the internal stress as much as possible; after welding, the whole grate is demounted to repair welding seams and carry out aging treatment and then the grate is remounted so as to further enhance the strength of the grate and reduce internal stress. The invention can better satisfy the technical requirement and precision requirement of manufacturing, mounting and welding the chute grate so as to avoid the cracks or breaking of grate strips caused by the wearing of the grate structure due to ship vibration.

Description

technical field [0001] The invention belongs to the field of ship hull construction technology, and more specifically relates to a process for installing a welded flow channel grid in the water inlet flow channel during the construction of a ship using a water jet propeller. Background technique [0002] As a special ship propulsion device, water jet propulsion has strong anti-cavitation ability, small attachment resistance, good protection performance, low noise, simple transmission mechanism, strong ability to adapt to variable working conditions, good ship maneuvering and dynamic positioning performance And other features, and the capabilities of stranded self-rescue, turning, reversing, etc. are all unmatched by conventional propellers. Waterjet propulsion occupies a dominant position in the field of high-speed boats, and is also used on tugboats with variable working conditions and military ships that require high maneuverability. [0003] At present, the water inlet c...

AI Technical Summary

Problems solved by technology

[0005] The line shape of the hull at the runner grid is relatively complex and the structure is strong. Due to the assembly error of the hull, shrinkage and deformation after welding and other factors, the theoretical size and shape of the lofting will have different deviations from the actual ship, so it cannot meet the requirements. For the production of movable models or sample boxes, the production of the flow channel grille can only be made by directly using the completed hull flow channel structure as the sample box for the manufacture of the flow channel grille on the actual ship.

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