JP2005002599A - Connection structure of joint and steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure of a joint and a steel pipe capable of manufacturing the joint at a low cost even if it has a complicated shape without making cutting processing by forming the joint of ductile cast iron and easily connecting the joint of the ductile cast iron having difficulty in welding to the steel pipe. <P>SOLUTION: A ring-shaped groove 4 is formed in the side circumference section of male and female joints 1 and 2 on the side connected to the steel pipe 3, a circular arc-shaped steel piece 5 is fittingly inserted in the ring-shaped groove 4, and the male and female joints 1 and 2 are combined with the steel pipe 3 by welding 6 the fittingly inserted circular arc-shaped steel piece 5 to the steel pipe 3 to form the connection structure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection structure of a joint used for a ready-made pile, and more particularly to a connection structure of a joint made of ductile cast iron and a steel pipe pile.
[0002]
[Prior art]
Conventionally, various mechanical joints applied to steel pipe piles have been proposed. Hereinafter, a screw-type joint will be described as an example of a mechanical joint. The ones shown in Japanese Patent Application Laid-Open Nos. 7-82738 and 9-3875 are typical ones. About the connection method of such a screw type mechanical joint and a steel pipe pile, as the example is shown by Unexamined-Japanese-Patent No. 10-252060 and Unexamined-Japanese-Patent No. 2000-345558, a groove is attached to a screw type mechanical joint and a steel pipe. Welding is performed, or a backing metal is provided integrally on the threaded joint side to form a groove, and welding is performed.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-82738 [Patent Document 2]
JP-A-9-3875 [Patent Document 3]
Japanese Patent Laid-Open No. 10-252060 [Patent Document 4]
Japanese Patent Laid-Open No. 2000-345558
[Problems to be solved by the invention]
However, these examples can be carried out when the steel material of the screw-type mechanical joint and the steel pipe pile can be directly welded, and when the screw-type mechanical joint is made of steel material, ductile cast iron, which is difficult to weld directly with the steel pipe. Was difficult to apply. That is, when directly welding a steel pipe and cast iron, there is a problem that a special treatment such as a heat treatment is required to prevent cracking and deformation after welding.
[0005]
The present invention solves the above-mentioned problems, and the object is to form a joint with ductile cast iron, so that the joint can be manufactured at low cost even if it has a complicated shape without cutting, and welding is difficult. We propose a connection structure that can easily join a joint made of ductile cast iron and a steel pipe.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the joint-steel pipe connection structure according to the present invention is a joint-steel pipe connection structure formed of ductile cast iron, and is connected to the outer peripheral portion of the side face of the joint connected to the steel pipe. The joint and the steel pipe are formed as an integrated structure by forming a circular groove, inserting an arc-shaped iron piece into the ring-shaped groove, and welding the inserted arc-shaped iron piece and the steel pipe. .
[0007]
Since this invention was comprised as mentioned above, since a coupling is manufactured with ductile cast iron, a complicated shape can be formed irrespective of cutting. In addition, since the arc-shaped iron pieces inserted into the ring-shaped grooves formed on the outer periphery of the joint and the steel pipe can be easily welded, even if the joint is made of ductile cast iron, the steel pipe is not subjected to special heat treatment. Can be connected.
[0008]
The arc-shaped iron pieces are prepared in a plurality of types having different inner diameters, and the ring-shaped grooves provided in the outer peripheral portion of the side surface of the joint are formed with different depths corresponding to the inner diameters of the different types of the arc-shaped iron pieces. In the case where the joint and the steel pipe are integrated by welding the arc-shaped iron piece that fits into the ring-shaped groove and then welding the arc-shaped iron piece and the steel pipe, the projection of the shallow ring-shaped groove The part and the arcuate iron piece inserted into the deep ring-shaped groove are brought into contact with each other, and the rotational torque acting on the pile connected to the steel pipe or the pile made of the steel pipe itself can be transmitted.
[0009]
Also, the joint can be easily manufactured as a threaded joint. The threaded joint may be a male screw or a female screw. Moreover, the connection structure of the joint and steel pipe which concerns on this invention can be applied when connecting a joint to a steel pipe pile.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a joint-steel pipe connection structure according to the present invention will be specifically described with reference to the drawings. 1 is a cross-sectional view showing a male joint, a female joint and a steel pipe connected by a connection structure of a joint and a steel pipe according to the present invention, FIG. 2 is an enlarged cross-sectional view showing the relationship between the female joint, the steel pipe and the arc-shaped iron piece, 3 is a cross-sectional view taken along the line AA in FIG.
[0011]
In FIG. 1, in order to connect a steel pipe 3, a male joint 1 having a male screw 1a formed on the outer peripheral surface and a female joint 2 having a female screw 2a formed on the inner peripheral surface are formed as a screw-type joint by casting with ductile cast iron. Has been. Since the male and female joints 1 and 2 are cast, if a mold is made, a threaded joint having a complicated shape can be accurately and easily manufactured at low cost without cutting.
[0012]
A ring-shaped groove 4 having a rectangular cross section is formed in the outer peripheral portion of the side surface of the male-female joints 1 and 2 on the side connected to the steel pipe 3. As shown in FIG. 3, the ring-shaped grooves 4 of the present embodiment are formed with different depths corresponding to the inner diameters of a plurality of types of arc-shaped iron pieces 5 having different inner diameters. Deep ring-shaped grooves 4a and shallow ring-shaped grooves 4b, which are equally divided in circumference, are alternately arranged.
[0013]
On the other hand, a plurality of types of arc-shaped iron pieces 5 having an inner diameter corresponding to the depth of the ring-shaped groove 4 are prepared, and in this embodiment, the inner diameter and the length corresponding to the deep ring-shaped groove 4a have a width. A large arcuate iron piece 5a and a small arcuate iron piece 5b having an inner diameter and a length corresponding to the shallow ring-shaped groove 4b are prepared.
[0014]
And after inserting the arc-shaped iron piece 5 which fits each ring-shaped groove | channel 4, each arc-shaped iron piece 5 and the steel pipe 3 are welded 6, and the male-female joints 1 and 2 and the steel pipe 3 are made into an integral structure. I can do it.
[0015]
After the plurality of arc-shaped iron pieces 5 are inserted into the ring-shaped groove 4, as shown in FIG. 2, the arc-shaped iron pieces 5 are attached to the ring-shaped grooves 4 of the male and female joints 1 and 2 by performing temporary fixing welding 7. It can be handled as one part in the inserted state.
[0016]
Grooves 3a and 5c are provided at the end of the steel pipe 3 and the part of the arcuate iron piece 5 opposite to the end of the steel pipe 3, respectively. Further, on the steel pipe 3 side of the arcuate iron piece 5, the inner side of the steel pipe 3 is provided. An extending backing portion 5d is formed.
[0017]
Then, the arcuate iron piece 5 and the steel pipe 3 are butt welded 6 using the groove portions 3a and 5c in a state where the backing part 5d of the arcuate iron piece 5 protrudes to the inner surface side of the steel pipe 3, and the arcuate iron piece. 5 and the steel pipe 3 are connected.
[0018]
In this embodiment, as shown in FIG. 3, the arc-shaped iron piece 5 has two different inner diameters, the ring-shaped groove 4 is formed so as to conform to the different inner diameters, and the arc-shaped iron piece 5 rotates and moves. It is inserted alternately so as not to occur.
[0019]
By configuring in this way, the protruding portion of the shallow ring-shaped groove 4b and the large arcuate iron piece 5a inserted into the deep ring-shaped groove 4a are brought into contact with each other, and the pile is connected to the steel pipe 3. If the steel pipe 3 itself is a steel pipe pile, the rotational torque acting on these piles can be transmitted.
[0020]
In addition, in the said embodiment, although the connection structure of the male-female joint comprised as a screw type joint and a steel pipe pile was demonstrated, after connecting the steel pipe 3 and the male-female joints 1 and 2, concrete is thrown into the steel pipe 3 inside. The present invention can also be applied to a connection structure between a joint and a steel pipe in the case of manufacturing a steel pipe concrete pile or a concrete column having a shell steel pipe manufactured by centrifugal molding or the like.
[0021]
Moreover, this invention is applicable also to couplings other than a screw-type mechanical coupling.
[0022]
【The invention's effect】
Since the present invention has the above-described configuration and action, the joint can be manufactured with ductile cast iron, so that the joint can be manufactured at a low cost, and a complicated shape can be formed regardless of cutting. For this reason, various joints can be economically supplied by simply using ductile cast iron.
[0023]
Moreover, since the joint material and steel pipe, which are difficult to weld, such as ductile cast iron, can be joined without direct welding, the joint can be manufactured easily and economically. Arc-shaped iron pieces inserted into ring-shaped grooves formed on the outer periphery of the joint and the steel pipe can be easily welded. Therefore, even if the joint is made of ductile cast iron, it can be connected to the steel pipe without any special heat treatment. I can do it.
[0024]
Also, multiple types of arc-shaped iron pieces with different inner diameters are prepared, and the ring-shaped grooves provided on the outer peripheral portion of the side surface of the joint are formed with different depths corresponding to the inner diameters of different types of arc-shaped iron pieces, and the ring shape After inserting the arc-shaped iron piece suitable for the groove and welding the arc-shaped iron piece and the steel pipe to make the joint and the steel pipe as an integral structure, the shallow ring-shaped groove protrusion and the deep ring-shaped groove Rotating torque acting on a pile connected to the steel pipe or a pile made of the steel pipe itself can be transmitted.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a male joint, a female joint and a steel pipe connected by a joint-steel pipe connection structure according to the present invention.
FIG. 2 is an enlarged cross-sectional view showing the relationship between a female joint, a steel pipe, and an arcuate iron piece.
3 is a cross-sectional view taken along the line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Male joint 1a ... Male screw 2 ... Female joint 2a ... Female screw 3 ... Steel pipe 3a ... Groove part 4, 4a, 4b ... Ring-shaped groove 5, 5a, 5b ... Arc-shaped iron piece 5c ... Groove part 5d ... Backing part 6 ... Welding 7 ... Temporary welding

Claims (5)

A connection structure of a joint and a steel pipe formed of ductile cast iron,
By forming a ring-shaped groove on the outer peripheral side surface of the joint on the side connected to the steel pipe, inserting an arc-shaped iron piece into the ring-shaped groove, and welding the inserted arc-shaped iron piece and the steel pipe A connection structure of a joint and a steel pipe, wherein the joint and the steel pipe are integrated. The arc-shaped iron pieces are prepared in a plurality of types having different inner diameters, and the ring-shaped grooves provided on the outer peripheral portion of the side surface of the joint are formed with different depths corresponding to the inner diameters of the different arc-shaped iron pieces, The joint according to claim 1, wherein the joint and the steel pipe are integrated with each other by welding the arc-shaped iron piece and the steel pipe after inserting the arc-shaped iron piece suitable for the ring-shaped groove. And steel pipe connection structure. The joint structure according to claim 1 or 2, wherein the joint is a threaded joint. The joint structure according to claim 3, wherein the threaded joint is a male screw or a female screw. The said steel pipe consists of a steel pipe pile, The connection structure of the joint and steel pipe of any one of Claims 1-4 characterized by the above-mentioned.

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