JPH033178Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to improving the corrosion resistance of steel structural materials such as steel fish reefs. (Prior art and its problems) Currently, steel reefs assembled by joining steel plates with bolts and nuts are provided and widely used. Due to residual machining distortion, the corrosion was more pronounced than in other parts, causing problems such as the steel reef becoming disconnected from the nut and falling off, causing the steel reef to disintegrate and no longer function as a reef. There is. Therefore, in order to suppress seawater corrosion of bolt joints, it has been proposed to manufacture bolts and nuts using materials with excellent corrosion resistance. When attempting to ensure sufficient strength to withstand joining of steel structures, there is a problem with manufacturing costs, making it difficult to use as a general-purpose product. On the other hand, if stainless steel is used, the manufacturing cost problem mentioned above will be reduced and it seems possible to implement it, but contact with steel structural materials will cause electrolytic corrosion between dissimilar metals to accelerate corrosion of bolt holes. It was discovered that the bolts fell off and became virtually unusable. (Problem for the invention) The present invention aims to effectively utilize the corrosion resistance of stainless steel bolts and nuts, which have fewer manufacturing cost problems, and thereby improve the corrosion resistance of joints of underwater steel structures such as steel fish reefs. The task is to achieve this goal. (Summary of the invention) The present invention aims to improve the corrosion resistance of joints of underwater steel structures by preventing electrolytic corrosion caused by contact with constituent structural materials when stainless steel bolts and nuts are used. A pair of insulating washers consisting of a cylindrical projection protruding from the center position of the flange portion are inserted into the bolt hole from the upper and lower surfaces of the bolt hole of the steel structural material, and the stainless steel structural material is inserted through the washer. The gist of the present invention is to join and assemble steel structural members such that bolts and nuts do not come into direct contact with the steel structural members. (Structure of the invention) The structure of the invention will be explained in detail below based on a specific example in which the structure of the invention is applied to a steel fish reef. FIG. 1 is a sectional view of a joint portion of a steel reef, FIG. 2 is an enlarged cutaway perspective view of an insulating washer, and FIG. 3 is a sectional view of the insulating washer shown in FIG. 2. In the drawing, the steel plates WA constituting the steel reef,
When assembling the WB using the stainless steel bolt 1 and the stainless steel nut 2, as shown in FIGS.
First, a pair of insulating washers 3 consisting of
Insert the cylindrical protrusions 32 into the bolt holes from the top and bottom surfaces of the bolt holes H of WA and WB, and attach them so that their tips butt against each other, and apply insulation coating from the vicinity of the bolt holes H to the inside of the bolt holes. Then, the stainless steel bolt 1 and nut 2 are attached to the steel structural member W via the stayless washers 4, 4, respectively.
Steel structural members are joined and assembled in such a way that they do not come into direct contact with the steel. The insulating washer 3 is preferably manufactured from electrically insulating synthetic resin or inorganic molded material. For example, when manufactured from a synthetic resin material such as neoprene rubber material, the insulating washer 3 is manufactured from A to G shown in FIG. It is desirable to set the dimensions as shown in Table 1.

【table】

[Table] (Function and effect of the invention) According to the invention, in an underwater steel structure such as a steel fish reef, which is assembled by joining steel structural members such as steel plates with bolts and nuts, the above-mentioned stainless steel bolt 1 and Since the steel structural members are joined and assembled using the nuts 2, it is not only possible to construct a corrosion-resistant joint assembly structure for underwater steel structures at a relatively low cost compared to resin etc. Since the steel structural members are joined and assembled so that the stainless steel bolts 1 and nuts 2 do not come into direct contact with the steel structural members W, the electrolytic corrosion phenomenon caused by contact between dissimilar metals is suppressed, and corrosion of the bolt holes is prevented. This prevents expansion, making it extremely practical as a dissimilar metal joint assembly structure for underwater steel structures. Although the present invention has been described using a steel fish reef as a specific example, it can be widely applied to joint assembly structures of underwater steel structures.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a joint portion of a steel reef, FIG. 2 is an enlarged cutaway perspective view of an insulating washer, and FIG. 3 is a sectional view of the insulating washer shown in FIG. 2. 1... Bolt, 2... Nut, 3... Insulating washer.

Claims (1)

[Claims for Utility Model Registration] In an underwater steel structure assembled by joining steel structural members such as steel plates with bolts and nuts, the bolts 1 and nuts 2 are made of stainless steel, and the flange portion 31 and the Cylindrical projection 32 protruding at the center position of the flange portion
The cylindrical projections 32 of the pair of insulating washers 3 are inserted into the bolt holes from the upper and lower surfaces of the bolt holes H of the steel structural material W, and the stainless steel bolts 1 and nuts 2 are inserted into the steel through the washers 3. A joint assembly structure for an underwater steel structure, characterized in that steel structural members are joined and assembled in such a way that they do not come into direct contact with manufactured structural members W. The joint assembly structure according to the above item, wherein the underwater structure is a steel fish reef.