JPH0357577A - Manufacturing method of frame for truss structure - Google Patents

Abstract

PURPOSE:To stably obtain a satisfactory junction by using a sleeve whose strength is equal to or higher than a frame and joining the sleeve and the frame by frictional pressure welding without using a backing strip. CONSTITUTION:To the outside of a frame 1 formed by a hollow steel pipe, a surface treatment is performed in advance by plating or painting of zinc, Al, etc. On the other hand, as for a sleeve 2, high strength material is used, a surface treatment is performed in advance to this sleeve, as well, a bolt 5 is inserted through a through-hole 4 of a closed wall surface 3 of the sleeve 2, and a head part 6 of the bolt 5 is positioned in the inside of the sleeve 2. In this state, one of the sleeve 2 or the frame 1 is fixed, the other is rotated, while bringing it to pressure welding, and by friction caused by the rotation, both of the frame 1 and the sleeve 2 are melted and brought to pressure weld ing. As for a ring 7, it is allowed to make it insert through the bolt 5 after joining the frame 1 and the sleeve, and also, it is allowed to make it insert through the bolt 5 in advance, and to rotate the frame 1 or the sleeve 2 by holding the sleeve 2 and the wapper 7. In such a way, a backing strip material is unnecessary and a stable welding joint can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing frames for I-lath structures.

[Prior art] As shown in Fig. 6, in a conventional truss structure whose basic structure is a combination of a frame and a globe, the frame A is made of a hollow steel pipe, and the frame A and sleeve B are joined by welding. It is connected to the glove E via a bolt D passed through the whopper C and the sleeve B. In addition, in the figure, F is the assembly hole, G is the hole 1 to hole,
H is a bottle for rotating bolt D, ■ is welded.

[Problems to be Solved by the Invention] The frame A and the sleeve B are joined by welding I such as covered arc welding and MIG welding. However, if surface treatment is performed by plating or painting with zinc, aluminum, etc., defects such as flow holes, poor penetration, and cracks are likely to occur during welding.

Therefore, if the surface treatment is performed after welding the sleeve and frame, or if the bolt is incorporated into the sleeve or frame at the time of surface treatment, sufficient surface treatment cannot be performed.

Therefore, in an actual truss structure, the bolts are installed after the whopper and bolts are removed and the frame is surface-treated, or the bolts are inserted into the frame because it is not possible to insert the bolt heads into the frame. It becomes necessary to provide an assembly hole F on the side surface of the frame.

In other words, in the conventional method of manufacturing frames using arc welding, etc., in order to minimize welding defects in the frame, the above-mentioned assembly holes are required, which increases the number of man-hours for manufacturing the assembly holes and increases the allowable stress of the frame. resulting in a decrease in

In addition, as shown in Figure 7, most of the frames A are thin, with a wall thickness of about 3 mm, and one side of the frame is welded from the outside, so in order to perform complete welding without burn-through, it is necessary to use a backing. Since the material J is required, the thickness of the sleeve B will inevitably increase, and as a result, the weight will increase, making it necessary to increase the strength of the structure. Furthermore, when a backing material is used, the root portion L is prone to defects such as blowholes, poor penetration, and cracks. Therefore, it is necessary to work carefully and maintain strict quality control.

Therefore, in the present invention, by applying the friction welding method, there is no need for a backing, and by using a material for the sleeve that is stronger than the frame, the wall thickness of the sleeve can be reduced, and it can be used in conventional welding work. In comparison, the purpose is to provide a method that allows simple, reliable, and stable bonding without any quality defects.

[A thousand steps to solve the problem] In order to achieve the above object, the present invention provides a truss structure in which a sleeve is welded to a hollow steel pipe frame, and bolts are passed through the sleeve to connect it to a globe. The method of manufacturing a frame for a truss structure is characterized in that the sleeve and the frame are joined by friction welding using a sleeve with the same or higher pressure without a backing material.

[Function] In the present invention, either the frame or the sleeves are rotated and brought into pressure contact with each other, thereby joining the two in a welded state.

[Example] The structure of the present invention will be explained in detail based on the actual example shown in FIG. Surface treatment is performed by plating or painting.

On the other hand, sleeve 2 has JIS SM-50, 345C,
A high-strength material such as SCM-435 is used, which is also surface-treated in advance, and the bolt 5 is inserted into the through hole 4 of the closed wall portion 3 of the sleeve 2, and the head 6 of the bolt 5 is inserted into the sleeve 2.
Keep it located inside.

Next, either the sleeve 2 or the frame 1 is fixed, and the other is rotated while being pressed against each other, and both the frame 1 and the sleeve 2 are melted and pressed together by the friction caused by the rotation.

The whopper 7 may be passed through the bolt 5 after the frame 1 and the sleeve 2 are joined, or the whopper 7 may be passed through the bolt 5 in advance.
It is also possible to use means for rotating the frame l or the sleeve 2 while holding the sleeve 2 and the whopper 7.

Alternatively, the frame may be made of an aluminum material such as AIOIO, and the sleeve may be made of a high-strength material such as aluminum A2024 (Suralumin).

Next, a description will be given based on a second embodiment shown in FIG. 2. A sealing material 8 formed by packing is interposed between the head 6 of the bolt 5 and the sleeve 2 to maintain airtightness. , Before friction welding the sleeves 2 and frame 1, a certain rust prevention gas such as a volatile rust preventive agent or a gas that does not easily react with the pipe material is filled, and after filling, friction welding is performed, and the rust prevention gas is By preventing the leakage of metal, the exposed metal parts of the pressure welding parts are prevented from rusting.

In the third embodiment shown in FIG. 3, a packing filling hole 9 is provided in the through hole 4 of the sleeve 2, and a sealing material 8 formed by packing is filled in the hole 9 to maintain airtightness.

In the fourth embodiment shown in FIG. 4, a sealing material 8 in the form of a circle link is provided on the frame 1 side of the closing wall 3 of the sleeve 2 to maintain airtightness between it and the head 6 of the bolt 5. It is something.

In the fifth embodiment shown in FIG. 5, a sealing material 8 shaped like an O-link is provided in the through hole 4 of the sleeve 2 to maintain airtightness with the bolt 5 itself.

[Effects of the Invention] In the present invention, even if the sleeve and frame are surface-treated, during friction welding, the surface-treated materials such as zinc, aluminum, etc. are removed from the welded part by pressure and heating due to the rotation of the sleeve or frame. impurities are removed, and a good joint can be stably obtained.

Therefore, in the present invention, parts such as the frame, sleet saw, whopper, bolt, etc. can be subjected to surface treatment in advance, and then the sleet and the frame can be pressed together. If this is done, there is no need to provide an assembly hole for attaching a bolt to the side of the frame as in the conventional case.

Further, since no backing material is required, the sleeve has a simple shape, leading to a reduction in the weight of the sleeve, and this joining method provides a stable welded joint with fewer defects.

Further, by eliminating the need for a backing material and using a high-strength material for the sleeve, it is possible to obtain a truss structure that is lightweight and has sufficient strength.

Furthermore, the friction welding method is 2 to 5 times faster in welding speed than the coated arc method and the Miku-arc method, which shortens manufacturing time. However, even if there is an additional man-hour for repair plating, there is more than enough to make up for it.

In addition, in the case of maintaining confidentiality, it also has the effect of creating buoyancy, so it can also be used as a marine structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the main parts when carrying out the method for manufacturing a truss structure frame according to the present invention, FIG. 2 is a sectional view of the second embodiment, and FIG. 3 is a sectional view of the third embodiment. Fig. 4 is a cross-sectional view of the fourth embodiment, Fig. 5 is a cross-sectional view of the fifth embodiment, Fig. 6 is a partially cutaway front view of the conventional method, and Fig. 7 is a partially enlarged cross-sectional view. It is a diagram. DESCRIPTION OF SYMBOLS 1...Frame, 2...Sleeve, 3...Closing wall part, 4...Through hole, 5...Bolt, 6...Head, 7...Wanno f-8...・Sealink material, 9...Packing filling no＼O

Claims (1)

[Claims] (1) In a truss structure in which a sleeve is welded to a frame made of hollow steel pipe, and bolts are passed through the sleeve to connect it to the globe, a sleeve with strength equal to or higher than the frame is used to create friction between the sleeve and frame without a backing. A method for manufacturing a frame for a truss structure, characterized by joining by pressure welding.