JP2962954B2 - Friction welding structure of steel using high strength bolts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction joining structure of a steel material in a building steel structure or another steel structure by using high-strength bolts.

[0002]

2. Description of the Related Art Conventionally, in a friction joining structure of a steel structure using high-strength bolts, a naturally occurring red rust has been standard on a friction surface of a steel material (see the Architectural Institute of Japan, JASS6). Therefore, a low slip coefficient value (μ = 0.45) is set in design. As a remedy,
(1) As disclosed in JP-A-51-52336, a method of applying a special coating to the surface of a steel material and joining with a high-strength bolt, (2) JP-A-1-266309
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, there has been proposed a method in which a ceramic material is subjected to a plasma spraying process on a joining surface of a steel material and the steel material is joined with a high-strength bolt.

[0003]

In the case where the above-mentioned conventional red rust is generated, there are large variations in the construction and it is very difficult to control the construction quality. Therefore, a slip coefficient value larger than 0.45 is joined. There is a drawback that it cannot be used for part design. In the case of the previously proposed joining method (1), it is necessary to apply a special coating to the steel material, which is complicated, and furthermore, the conventionally proposed method (2).
Is disadvantageous in that a new dedicated facility is required during the steel processing step. Therefore, none of the previously proposed joining methods (1) and (2) have been widely implemented. The present invention invents a new joint structure in steel friction joints with high strength bolts,
An object of the present invention is to solve the above-mentioned problems and to secure the stability of the construction quality of a frictional joint surface and a high slip coefficient.

[0004]

SUMMARY OF THE INVENTION In order to advantageously solve the above-mentioned problems, in a steel material friction joining structure using a high-strength bolt according to the present invention, a plurality of steel materials which are tightened by a high-strength bolt 1 and frictionally joined. Among them, the surface hardness and the surface roughness of the one steel material 2 on the friction surface side are made larger than the surface hardness and the surface roughness of the other steel material 3. Also, a steel base material 4 that is tightened by the high-strength bolt 1 and frictionally joined.
The above-mentioned problem is also caused by making the surface hardness and the surface roughness of the joint plate 5 at least on the friction surface side larger than the surface hardness and the surface roughness of the base material 4. Can be advantageously solved. In addition,
In the present invention, the surface roughness is the ten-point average roughness Rz (DI
N).

[0005]

1 and 2 show an embodiment of the invention according to the first aspect of the present invention. In the side groove of a steel main beam 6 having an H-shaped cross section, a mounting member perpendicular to the longitudinal direction of the main beam is provided. A steel material 2 made of a steel plate is inserted and fixed by welding, and an end of a steel material 3 made of a web in a steel beam 7 having an H-shaped section extending in a direction perpendicular to the main beam 6 is attached to the steel material 2. The surface hardness and the surface roughness of at least the friction surface side of one of the steel materials 2 are set to be larger than the surface hardness and the surface roughness of the other steel material 3, and each of the steel materials 2 and 3 is inserted therethrough. The plurality of high-strength bolts 1 are tightened and joined with a high axial force.

FIGS. 3 and 4 show an embodiment of the second aspect of the present invention, in which one end of a steel base material 4A made of a steel connection beam having an H-shaped cross section is attached to a steel column 8. An end portion of a steel base material 4B fixed by welding and formed of a steel main beam having an H-shaped cross section is arranged in series with the other end portion of the steel base material 4A, and each steel base material 4A, 4B is provided. The steel joint plate 5 is superimposed on both sides of the web and each flange in
The steel base materials 4A and 4B and the steel joint plate 5 are fastened by the high-strength bolts 1 inserted through the web and the flange.
And are joined by being tightened with a high axial force.

[0007] At the joint corner between the steel column 8 and the steel connection beam, H
One end of a steel base material 4C formed of a steel brace connecting member having a H-shaped cross section is fixed by welding, and an end portion of a steel base material 4D formed of a steel brace having an H-shaped cross section is connected to the steel base material 4C.
Are arranged in series at the other end of each steel base material 4C. The steel joint plates 5 are superposed on both sides of the web and each flange in 4D, and the steel base materials 4A and 4B and the steel base materials 4A and 4B are formed by the high-strength bolts 1 inserted through each steel joint plate 5 and the web and flange. The joint plate 5 is fastened and joined with high axial force.

The surface hardness and surface roughness of at least the friction surface side of each steel joint plate 5 are determined by the steel base materials 4A, 4A.
B, 4C, and 4D are set to be larger than the surface hardness and the surface roughness.

The surface roughness on the friction surface side of the one steel material 2 and the steel joint plate 5 can be set to an arbitrary roughness by blasting or the like usually performed before painting. It is desirable to adopt.

The other steel material 3 and steel base materials 4A, 4B,
The surface roughness of the friction surface in 4C and 4D may be at least 40 μm by glider, shot blast, grid blast or the like.

FIG. 5 shows the results of a survey on the joints shown in FIG. 7. The steel base material 4 and the steel joint plate 5 are used to measure the surface hardness of the steel base material 4 on the friction surface side. Hv1
About 60, surface roughness of about 40μ, steel joint plate 5
The hardness ratio of the steel base metal to the surface hardness was 1.0,
It shows the results of investigating the relationship between the slip coefficient and the surface roughness for steel materials having six types of hardness of 1.3, 1.7, 2.0, 2.5, and 3.0, Regarding the surface hardness of the steel joint plate 5, when the surface roughness is about 40 μ, only a slip coefficient (about 0.45) which is almost the same as that of a conventional friction joint can be secured. However, it can be seen that increasing the surface roughness of the steel joint plate 5 increases the slip coefficient, and reaches a certain value when a certain surface roughness is reached. Although the surface roughness at which the slip coefficient is stable varies depending on the hardness of the steel material, it can be seen that the slip coefficient can be stabilized at any hardness by increasing the surface roughness to 120 μ or more. For example, when a steel material having a surface hardness ratio of 2.5 to the steel base material 4 is used, a slip coefficient of 0.85 can be secured. Thus, it is possible to develop a stable and high slip coefficient according to the hardness of various steel materials.

Particularly, when the surface hardness ratio of the steel material 2 and the steel joint plate 5 is 1.3 or more, the surface roughness is set to 70 μm.
With the above setting, the friction coefficient becomes 0.6 or more, and it is possible to significantly improve the performance as compared with the conventional frictional joint. The upper limit of the surface roughness of the steel material 2 and the steel joint plate 5 is about 150 μ. The reason is that even if a higher surface roughness is secured, the coefficient of friction does not increase, and it is extremely difficult and uneconomical to secure a higher surface roughness. .

FIG. 6 shows the results of investigation on the ratio of the hardness of the steel member 4 to the hardness of the steel joint plate 5 and the slip coefficient. When their surface hardness is the same as the surface hardness of the steel member 4, the slip coefficient is almost the same as that of the conventional case (about 0.4).
It can be seen that 5) increases only slightly, while increasing the surface hardness ratio improves the slip coefficient even with various surface roughnesses. It can be seen that the slip coefficient is stabilized by setting the ratio of the hardness of the steel member 4 to the hardness of the steel joint plate 5 to 2.5 or more for various surface roughnesses. From the above, when the surface roughness of the other steel material 3 and the steel member 4 is set to about 40 μ, the surface of the one steel material 2 and the steel joint plate 5 is set to 70 μ or more and the one steel material 2 By making the ratio of the hardness of the other steel member 3 and the steel member 4 to the hardness of the steel joint plate 5 1.3 times or more, the performance is improved as compared with the conventional high-strength bolt friction joint structure. It is possible to secure a slip coefficient of 0.6 or more. When the other steel member 3 and the steel member 4 have a surface roughness of about 40 μ, the one steel member 2 and the steel joint plate 5 have a surface of 120 μm.
μ or more, or the other steel material 3 and the steel member 4 with respect to the hardness of the one steel material 2 and the steel joint plate 5.
When the hardness ratio is 2.5 times or more, a stable slip coefficient can be ensured, but no further improvement in performance can be obtained. In the frictional joint structure using the high-strength bolt according to the present invention, the obtained slip coefficient differs depending on the surface characteristics of the other steel material 3 and the steel member 4 and the one steel material 2 and the steel joint plate 5. And a surface roughness of 70 to 12 depending on the slip coefficient required by the designer.
0 μ and a surface hardness ratio of 1.3 to 2.5 times.

The one steel material 2 and the steel joint plate 5;
The ratio of the surface hardness between the other steel material 3 and each of the steel base materials 4A to 4D needs to be 1.3 or more, and a preferable range is about 1.3 to 2.5. When the ratio of the surface hardness is set to 1.3 or more, the performance is remarkably improved as compared with the conventional friction joining strength (slip coefficient = about 0.45). Further, even if the hardness of the one steel material 2 and the steel joint plate 5 is set to be 2.5 times or more of the hardness of the other steel material 3 and each of the steel base materials 4A to 4D, the slip coefficient is soft. It is governed by the surface properties of the steel material 3 and the steel base materials 4A to 4D, and further improvement in performance cannot be obtained. Therefore, the upper limit of the surface hardness ratio is desirably 2.5.

As the steel material 2 and the steel joint plate 5 having a high surface hardness constituting the steel material friction joining structure according to the present invention, a hardenable steel having a higher hardness by heat treatment or a high hardness is used. It is possible to use a high-strength steel or a multi-layer steel sheet provided with a steel sheet having high hardness only in the surface layer. Furthermore, when a high hardness material is used as the steel joint plate 5, the strength of the joint plate 5 is large, so that the thickness of the steel joint plate 5 can be reduced in design.

[0016]

According to the present invention, at least the surface hardness and the surface roughness of at least the friction surface side of one of the steel materials 2 are tightened by the high-strength bolt 1 and frictionally joined. At least the friction in the joint plate 5 of the steel base material 4 and the steel joint plate 5 that is larger than the surface hardness and surface roughness of the steel material 3 or that is friction-joined by being tightened by the high-strength bolt 1 Since the surface hardness and the surface roughness of the surface side are made larger than the surface hardness and the surface roughness of the base material 4, the plurality of steel materials 2 and 3 or the steel base material 4 and the steel joint plate are formed by simple means. 5 can be strongly and reliably friction-joined by the high-strength bolt 1. As a result, the frictional joint can be made compact by the high-strength bolt, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing a steel material friction joining structure using a high-strength bolt according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a side view showing a steel material frictional joint structure using a high-strength bolt according to the embodiment of the second aspect of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a view showing a relationship between a slip coefficient and surface roughness of a joint plate and a hard steel material.

FIG. 6 is a view showing a relationship between a value obtained by dividing the hardness of a joint plate or a hard steel material by the hardness of a base material or a soft steel material (surface hardness ratio) and a slip coefficient.

FIG. 7 is a perspective view showing another example of a steel material friction joining structure using high-strength bolts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-strength bolt 2 Steel material 3 Steel material 4 Steel base material 5 Steel joint plate 6 Steel main beam 7 Steel beam 8 Steel column

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-268940 (JP, A) JP-A-6-49913 (JP, A) JP-A-56-84186 (JP, A) JP-A-5-84186 331918 (JP, A) JP-A-1-266309 (JP, A) JP-A-51-52336 (JP, A) JP-A-4-237744 (JP, A) JP-A-5-280102 (JP, A) JP-A-51-52628 (JP, A) JP-A-62-85602 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04B 1/58 506 F16B 5/02

Claims (2)

(57) [Claims] 1. A surface hardness and a surface roughness of a friction surface side of one steel material 2 and a surface hardness and a surface hardness of a steel material 3 Steel friction joint structure using high-strength bolts larger than the surface roughness. 2. Among the steel base material 4 and the steel joint plate 5 which are tightened and frictionally joined by the high-strength bolt 1, the surface hardness and the surface roughness of at least the friction surface side of the joint plate 5 are determined. And a steel material friction joining structure using high-strength bolts larger than the surface hardness and surface roughness of the base material 4.