JP2008303635A - Joint member for steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint member for economically and quickly connecting steel pipes without welding. <P>SOLUTION: The joint member is composed of a first insertion cylinder inserted into the upper steel pipe, and a second insertion cylinder inserted into the already press-fitted steel pipe. A collar plate is located between the first and second insertion cylinders. Each insertion cylinder is cut and raised outward in part to form elastic plates. The tip part of the elastic plate is formed toward the collar plate side, and its end is formed projectingly outward from the outer diameter of each insertion cylinder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steel pipe joint member.

There is known a construction method in which relatively short steel pipes are connected one after another on the same axis and are press-fitted into the ground or placed.
In general, it is more economical to handle long steel pipes because there is no need for connection.
Therefore, the case of connecting a short steel pipe is often required when a long steel pipe cannot be press-fitted due to a restriction in the upper space.
A typical example is a group of steel pipes for taking the reaction force of a jack when a house that has been submerged and inclined is lifted from the basement with a jack.
The actual work of jacking such a sinking house will be explained.
First, as shown in FIG. 3, a work pit K is formed by excavating the ground of the subsidence.
In order to form a reaction force pile from this work pit K, a short steel pipe, that is, a pre-pressed steel pipe p1 is press-fitted into the ground.
A new steel pipe, that is, an upper steel pipe p2 is connected to the already-pressed steel pipe p1 after the press-fitting and press-fitted again.
When the steel pipe group is press-fitted to a certain depth, the jack J is interposed between the upper end of the steel pipe group and the underground beam of the house H that has unevenly subsided.
And the reaction force of this jack J is taken to the steel pipe group, is extended, and the house H that has been sunk unevenly is pushed up.

JP-A-8-27829. JP-A-2005-133417.

The above-described conventional steel pipe joint member has the following problems.
<1> The size of a pit formed by excavating under a house is generally limited to the boundary with a neighboring house, so a large-capacity pit cannot be formed.
<2> Therefore, it is necessary to repeatedly connect short steel pipes.
<3> Generally, a steel pipe and a steel pipe are connected by welding, but it is not easy to reliably weld the entire circumference of the steel pipe in a narrow space.
<4> Welding performed in a narrow pit is an operation under poor conditions in which heat and gas tend to stagnate.
<5> A short steel pipe for joints may be used instead of welding. At that time, since the outer diameter of the joint is larger than the outer diameter of the steel pipe, only the joint portion jumps out to the outer periphery and tends to be press-fit resistance.
<6> Since the accuracy of the inner diameter of the steel pipe is not so high, it is difficult to work with a precisely shaped joint.

In order to solve the above-described problems, a steel pipe joint member according to the present invention is a joint member that connects two steel pipes on the same axis, and is on the same axis as the central axis of one steel pipe at the time of connection. A first insertion cylinder to be inserted into the steel pipe, a second insertion cylinder to be inserted into the steel pipe, which is on the same axis as the central axis of the other steel pipe when connected, and the first and second insertions An elastic plate that is located between the cylinders and protrudes like a bowl in a direction crossing the central axis of each insertion cylinder, and an elastic plate is formed by cutting and raising a part of each insertion cylinder outward. The front end portion of the steel pipe is formed toward the platen side, and the end portion of the steel tube is protruded outside the outer diameter of each insertion tube, and is characterized by a steel pipe joint member.

Since the steel pipe joint member of the present invention is as described above, the following effects can be obtained.
<1> Since welding work on site is unnecessary, efficient and quick joint work can be achieved even in a narrow pit work.
<2> Even if the dimensional accuracy of the outer diameter of each insertion tube and the inner diameter of the steel pipe is not high, a quick and reliable connection is possible. This is because the protruding width of each insertion tube to the outside can be adjusted depending on the length of the elastic plate.
<3> The connection between the steel pipe and the steel pipe is simply press-fitting a new steel pipe from above, but since the steel pipe is supported from the inside by the elasticity of the elastic plate, even when the steel pipe group is lifted under some circumstances, Can be handled in an integrated state.
<4> Steel pipes have tolerances for both inner and outer diameters, and do not necessarily form a perfect circle. In addition, it is often deformed due to an unbalanced load during storage. However, in the joint of the present invention interposed between the steel pipe and the next steel pipe, since the elastic plate protrudes outward, the steel pipe can be firmly held from the inside and the occurrence of rattling can be prevented. .
<5> Since the joint function between the steel pipe and the steel pipe can be reliably achieved, not only is the force transmitted in the vertical direction reliable, but also the tensile force can be transmitted sufficiently when the steel pipe group is pulled up for some reason. it can.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<1> Examples of uses.
As an example of using the joint member of the present invention, a case where a house J that has been sunk unevenly is lifted by a jack J as shown in FIG. 3 will be described.
As described above, it is generally difficult to excavate a large pit K under the house H.
Therefore, in a small volume pit K, a short steel pipe is handled, the joint member A of the present invention is press-fitted into the upper end of the press-fit steel pipe p1, and the upper steel pipe is placed on the same axis on the joint member A. Connect p2 to the steel pipes in sequence.
In this case, the joint member A of the present invention is used to connect the upper and lower steel pipes, and details thereof will be described.

<2> Overall configuration.
The joint member A of the present invention includes a first insertion cylinder 1, a second insertion cylinder 2 that is positioned coaxially with the first insertion cylinder 1, a gutter plate 3 that is positioned in a direction crossing the central axis, and each insertion cylinder. The elastic plate 4 elastically protrudes outward from the outer side.

<3> First insertion cylinder 1.
The first insertion cylinder 1 is a hollow cylinder.
The first insertion cylinder 1 is located on the same axis as the central axis of the upper steel pipe p2 when the steel pipe is connected in the vertical direction using the joint member A of the present invention, and the first insertion cylinder 1 is located inside the steel pipe p2. It is a cylinder for insertion.
Therefore, the outer diameter of the first insertion cylinder 1 is formed so as to have an outer diameter smaller than the inner diameter of the upper steel pipe p2 to be connected.
However, generally the accuracy of the inner diameter of the steel pipe to be connected is not so high.
In addition, there are many cases where the steel pipe is not deformed to form a perfect circle during transportation or at the stage of being stacked and stocked.
Therefore, the outer diameter of the first insertion cylinder 1 is formed to a sufficiently small dimension with a margin with respect to the inner diameter of the target upper steel pipe p2.
Therefore, when the upper steel pipe p2 is inserted from the top of the first insertion cylinder 1, a wide gap is generated between the two, and rattling occurs, but this point is surely engaged by the elastic plate 4 described later. You can expect.
Each insertion cylinder may be a simple cylinder. However, in order to reduce weight and material cost, a number of windows 5 may be opened as in the example on the right side of FIG.

<4> Second insertion cylinder 2.
The second insertion cylinder 2 is also a steel cylinder.
And the 2nd insertion cylinder 2 is a cylinder which is on the same axis line as the center axis | shaft of the already press-fit steel pipe p1 at the time of a connection, and is inserted in the inside of the steel pipe p1.
The relationship between the outer diameter of the second insertion cylinder 2 and the inner diameter of the pre-pressed steel pipe p1 is the same as the relationship between the outer diameter of the first insertion cylinder 1 and the inner diameter of the upper steel pipe.
Therefore, when the second insertion cylinder 2 is fitted into the pre-pressed steel pipe p1, rattling occurs between the two, but the elastic plate 4 can also be reliably fitted due to the elasticity.

<5> Plate 3
The plate 3 is a donut-shaped steel plate.
The gutter plate 3 is located between the first and second insertion cylinders 1 and 2.
And this collar board 3 protrudes in the shape of a bowl in the direction which crosses the central axis of each insertion cylinder.
That is, both insertion cylinders constitute an integral cylindrical body via the gutter plate 3.
The outer diameter of the steel plate 3 is substantially equal to the outer diameter of the steel pipe to be inserted. As a result, when two steel pipes are connected via the joint member A of the present invention, the steel plate 3 protrudes outside the steel pipe. There is no, and the outer peripheral surface after connection is formed smoothly.

<6> Elastic plate 4.
A part of each insertion tube is cut and raised outward to form the elastic plate 4 in the shape of an outward wing plate.
The elastic plate 4 is formed such that the base end is not cut off and the tip end is cut away from the surface of the insertion tube, and the tip end is directed toward the side plate 3.
Therefore, from each insertion cylinder, the elastic plate 4 presents a state in which the tip projects obliquely outwardly with the tip toward the flange plate 3.
Since the tip of the elastic plate 4 is expanded to the outside rather than the surface of the insertion tube, when the joint member A of the present invention is viewed in plan, the elastic plate 4 has a larger diameter than the outer diameter of the insertion tubes 1 and 2. The tip protrudes to the outside.

<7> Elasticity of the elastic plate 4.
Each elastic plate 4 protruding from the outer diameter of each insertion tube is required to have appropriate elasticity, although it varies depending on the thickness and length of the insertion tube.
In this case, the moderate elasticity means that the steel pipe to be connected is inserted into each insertion cylinder under pressure as will be described later, but it is deformed inward but remains elastic and does not undergo plastic deformation. To do.

<8> Connection process.
Next, the case where two steel pipes p1 and p2 are connected on the same axis using the joint member A of the present invention will be described.

<9> Insertion of the second insertion cylinder 2.
First, one preceding steel pipe is press-fitted into the ground, and this is defined as a pre-pressed steel pipe p1.
The second insertion cylinder 2 of the joint member A of the present invention is installed on the same axis line and inserted into the upper end of the pre-pressed steel pipe p1.
In the second insertion cylinder 2, an elastic plate 4 protruding upward, that is, facing upward is projected.
For this purpose, the elastic plate 4 is inserted in contact with the inner surface of the pre-pressed steel pipe p1 in a pressurized state.
Therefore, even if there is a slight difference between the inner diameter of the press-fit steel pipe p1 and the outer diameter of the second insertion cylinder 2, the second insertion cylinder 2 is firmly fixed to the inner surface of the press-fit steel pipe p1 by the pressure applied by the elastic plate 4. The
The insertion amount of the second insertion cylinder 2 is determined by the position of the cover plate 3, and the cover plate 3 serves as a stopper to prevent further insertion.
Since the outer periphery of the saddle plate 3 is formed substantially equal to the outer periphery of the steel pipe, the outer peripheral piece of the saddle plate 3 does not protrude outside the steel pipe.
The press-fitting of the second insertion cylinder 2 of the joint member A is performed by extension of a jack interposed between the lower surface of the foundation of the house and the upper end of the joint member A.
Thus, the joint member A of the present invention is firmly attached to the upper end of the pre-pressed steel pipe p1.

<10> Insertion of the first insertion cylinder 1.
Next, the upper steel pipe p2 connected to the upper part is lifted and installed on the pre-pressed steel pipe p1.
That is, the lower end of the upper steel pipe p2 is fitted in a pressurized state from above the first insertion tube 1 of the joint member A of the present invention.
Since the elastic plate 4 projecting downward from the first insertion tube 1 protrudes from the outer periphery of the first insertion tube 1, the upper steel pipe p2 is press-fitted in a state where the elastic plate 4 is pushed down.
For this purpose, the elastic plate 4 is inserted in contact with the inner surface of the upper steel pipe p2 in a pressurized state.
Therefore, even if there is some difference between the inner diameter of the upper steel pipe p2 and the outer diameter of the first insertion cylinder 1, the first insertion cylinder 1 is firmly fixed to the inner surface of the upper steel pipe p2 by the pressure applied by the elastic plate 4.
The amount of insertion of the first insertion cylinder 1 is also determined by the position of the cover plate 3, and the cover plate 3 serves as a stopper and no further insertion is possible.
Since the outer periphery of the saddle plate 3 is formed substantially equal to the outer periphery of the steel pipe, the outer peripheral piece of the saddle plate 3 does not protrude outside the steel pipe.
The press fitting of the upper steel pipe p2 is performed by extension of a jack interposed between the lower surface of the foundation of the house and the upper end of the upper steel pipe p2.
In this way, the upper steel pipe p2 is firmly attached to the upper end of the pre-pressed steel pipe p1 on the same axis as the central axis of the steel pipe via the joint member A of the present invention.
By repeating the above steps, a short steel pipe is successively continued without performing welding work to form a long foundation pile.

Explanatory drawing of the Example of the coupling member of the steel pipe of this invention. Explanatory drawing of the connection state of a steel pipe. Explanatory drawing of a usage example.

Explanation of symbols

1: First insertion tube
2: Second insertion tube
3: Mortarboard
4: Elastic plate
5: Window
p1: Pre-pressed steel pipe p2: Upper steel pipe

Claims (2)

A joint member connecting two steel pipes on the same axis,
A first insertion cylinder that is on the same axis as the central axis of one of the steel pipes when connected, and is inserted into the steel pipe;
A second insertion cylinder that is on the same axis as the central axis of the other steel pipe at the time of connection, and is inserted into the steel pipe;
Located between the first and second insertion tube,
A gutter plate protruding in a bowl shape in a direction crossing the central axis of each insertion cylinder,
Cut and raise part of each insertion tube outward to form an elastic plate,
The tip of the elastic plate is formed toward the platen side,
And the end portion is formed to protrude outside the outer diameter of each insertion tube,
Steel pipe joint member.
Each elastic plate protruding from the outer diameter of each insertion tube
Configured to maintain elasticity to the extent that it is deformed inward but not plastically deformed by pressure insertion into each insertion tube into the steel pipe to be connected,
The steel pipe joint member according to claim 1.

Images