JPH02147133A - Method and apparatus for forming end face of steel tube having edge preparation and backing strip - Google Patents

Abstract

PURPOSE:To economically form a shape having a high quality edge preparation and a backing strip by inserting four divided tip diameter expanding cores from an end face of a heated steel tube, expanding them in the radial direction and supporting and securing the internal peripheral wall of the steel tube in a 360 deg. direction. CONSTITUTION:The whole peripheral wall parts of an end face and intermediate part in the formed steel tube 1 are heated nearly equally to a prescribed temperature. Then, the tip-diameter-expanding cores 5, 6 support the internal peripheral wall of the steel tube nearly in a 360 deg. direction and one pair and two sets of core members 5, 6 including a central lengthwise axis of the steel tube 1 and shrunk alternately and respectively in the lengthwise axis direction on the surface rectangular to the peripheral wall surface of the steel tube are contracted as a whole and inserted by a prescribed length from the end face. Then, each of two sets of cores 5, 6 is expanded alternately, supports and secures the front surface of the internal peripheral wall by a tip diameter expanding surface 9. The steel tube wall is formed in cooperation of the core surface by forming rolls 7, 8 having guides which can move forward and backward outside the steel tube and in the central direction of the steel tube and can turn around the same axial center and, at the same time, the guide rolls 7, 8 are turned around the central axis of the steel tube to perform hot rolling integrally on the end face of the steel tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for integrally forming a bevel angle and root spacing on the end face of a steel pipe (square steel pipe, round steel pipe, etc.), and a forming apparatus therefor.

[Prior Art] In order to improve the seismic properties of recent buildings, steel pipe box columns are increasingly being used to assemble steel structures. At that time, when constructing a building with two or more floors, a joint structure is inevitably formed.
In other words, when attempting to assemble a factory-processed bracket-type pillar-beam joint structure, especially a beam-through type joint with a diaphragm penetrating type, the diaphragm plane and the column end face may overlap. It is necessary to use many welded joints. At that time, when butt welding steel materials of a certain thickness or more, the butt end surfaces of the structural materials are usually chamfered in the form of a type or in an X-shape (referred to as chamfering), or the root spacing is taken. Weld the backing metal for
Molten metal is poured into the space and the two parts are joined together.

In the conventional technology, as shown in Fig. 3, in order to create a bevel on the end surface of a steel pipe and form a root spacing, chamfering is performed by gas cutting, mechanical cutting, etc., or a backing metal is temporarily attached to the back surface of the structural material. Preliminary work such as welding and fixing is performed, but since all of this work is done by hand, it is difficult to achieve a uniform and accurate shape, which affects the quality of the welded joint and the shape of the structure. effect. In addition to the aforementioned preliminary work,
It takes more time and effort than it appears, which is the root cause of high costs.

This type of column/beam joint is assembled with steel pipe columns and has many closed cross sections and has a complex structure, so most butt welded joints are done by single-sided welding, and for this reason,
Welding the backing metal to the butt end faces is essential.

Then, there are problems such as poor welding due to a gap between the diaphragm and backing metal, failure of the backing metal due to poor adhesion of the backing metal, and failures due to the flatness of the backing metal not coming out. Various problems such as lack of straightness of welded structures frequently occur.

[Problems to be Solved by the Invention] In order to solve the problems inherent in the prior art as described above, the present invention has been developed by applying standard type specifications in advance in the factory to necessary parts of the end face of the steel pipe in the secondary processing stage. Alternatively, we prepare a steel pipe column with grooves and root spacing formed according to the order specifications, and eliminate the need for the preliminary work described above for assembling columns and beams. The purpose is to provide the market with steel pipe columns for padding.

It also aims to eliminate the mismatch between the materials of the backing metal and the base metal at the end faces of the structural material, and to make the quality of the welded joint good and uniform.

Furthermore, it is an object of the present invention to develop a method for efficiently, relatively inexpensively, and mass producing columns with beveling and backing metal having accurate shapes and uniform quality by preparing dedicated equipment.

Furthermore, it reduces assembly man-hours for columns and beam joints that often use butt welded joints, and improves homogeneity and precision.
The aim is to form columns with beveling and backing metal integrally molded with the base material to increase the reliability of structures, and to produce products with higher added value for column manufacturers.

For other purposes, please refer to the explanation of the invention and
It is believed that the invention will be understood as the description of the embodiments progresses.

[Means for Solving the Problems] In order to achieve the above-mentioned objectives, the present invention includes the following constituent elements.

(1) After heating the end face or intermediate circumferential wall portion of the steel pipe to be formed to a predetermined temperature almost uniformly, or while heating, the tip diameter is expanded by supporting the inner circumferential wall of the steel pipe approximately in a 360° direction. The core members are equally divided into four parts by a plane that includes the center longitudinal axis of the steel pipe and is perpendicular to the peripheral wall plane of the steel pipe, and the core members are alternately divided into two pairs of opposing core members, and After each core is shrunk in the direction of the central longitudinal axis and the core is shrunk as a whole, it is inserted relatively into the longitudinal axis of the steel pipe by a predetermined length from the end face, and then
The inner peripheral wall of the steel pipe is supported and secured from the front by the expanded diameter surface of the tip by alternately expanding the cores consisting of the sets, and the inner peripheral wall of the steel pipe is supported and secured on the outside of the steel pipe at the location where the inner peripheral wall of the steel pipe is supported by the core surface. A guided roll attached to a frame member that can move forward and backward in the direction of the central axis of the steel pipe and rotate around the same axis forms an end surface profile with a bevel angle and root spacing on the outer periphery. A molded forming roll is advanced in the direction of the central axis, and the outer periphery of the roll is advanced and retractably pressed against the heated and softened peripheral wall surface of the steel pipe, collaborating with the core surface to form the steel pipe wall. At the same time, while keeping the guide roll in contact with the outer circumferential surface of the steel pipe, the forming roll, etc. is rotated around an axis substantially concentric with the center axis of the steel pipe, so that -(2) A means for uniformly heating and softening the end face or a required intermediate part in the circumferential direction, after inserting a predetermined length relatively inward in the direction of the central axis from the end face of the steel pipe,
A core that can be expanded and contracted as a whole by moving apart and close to each other in the radial direction according to the order, and the core supports and secures the inner circumferential wall of the steel pipe with its expanding diameter surface at the tip of its longitudinal axis. The core is approximately defined by two planes that include at least one pair or two sets of members that include the longitudinal axis of the steel pipe and intersect with each other at right angles, and that also intersect perpendicularly with the peripheral wall surface of the steel pipe. The core members of each set, which are divided into four equal parts and have a void inside, and which face each other point-symmetrically with the center axis of the core in the middle, are each shrunk first. A pair of core members whose diameter is cut diagonally along the direction of movement, and the other pair of core members is moved and reduced in diameter so as to overlap the outer surface of the pair of core members whose diameter has been reduced. The core member is configured to reduce the diameter of the core as a whole, the frame member is rotatably supported around an axis substantially concentric with the central axis of the steel pipe and moves on the outside of the steel pipe; The extent to which it is attached to the frame member and runs along the central axis direction of the steel pipe,
A forming roll with a guide that can be elastically advanced and retracted, and the peripheral surface of the forming roll is formed by forming a mold to form the end face outer shape with a bevel angle and root spacing. molding equipment.

[Operation: After the end face of the steel pipe is formed or processed into a substantially right-angled cross section, it is heated to a substantially uniform temperature in the circumferential direction over a predetermined width using known heating means such as high-frequency resistance heating, gas heating, or electric heating. , from the end face of the steel pipe, insert the four-split tip enlarged core,
Inside the steel pipe, with its diameter reduced overall relative to the central axis,
Insert the core by a predetermined length, expand the core radially,
The diameter-enlarged surface at the tip supports and secures the inner circumferential wall of the steel pipe in a 360° direction. At that time, the steel pipe peripheral wall heating section is
It is located on the side closer to the end face of the steel pipe with respect to the bearing surface of the core.

The means for expanding the four-part core is to first expand the first set of each pair of core parts symmetrical about the central axis and support the vicinity of the opposing corners of the inner periphery of the steel pipe, and then The pair of core parts of the second set are expanded to narrow the distance between the edges of adjacent core parts as much as possible. As mentioned above, the guided forming roll is mounted on the outer side of the steel pipe facing the core position and is pivoted on the tip of the plunger of the pneumatic machine, which is attached to a frame member that rotates approximately around the central longitudinal axis of the steel pipe. The forming roll is activated to advance toward the heated wall surface of the steel pipe, and the forming roll is pressed against the heated and softened portion of the peripheral wall of the steel pipe until the guide roll surface comes into contact with the peripheral wall surface of the steel pipe, and the peripheral wall of the steel pipe is pressed between it and the core. Pincer,
The outer circumferential wall of the steel pipe is grooved and provided with a backing metal according to the forming process performed on the circumferential surface.71' Hot roll forming is carried out according to the end surface outline.

Next, if the frame member is forcibly rotated around its central axis in this state, the forming rolls will hot roll form the peripheral wall surface of the steel pipe in the circumferential direction, while the forming rolls will be moved by the guide rolls. As a result of the controlled advance and retreat in the radial direction along the outer circumferential wall of the steel pipe, it is possible to roll form the beveled and backing metal shape over the 360° direction of the end face of the steel pipe.

As mentioned above, if at least one pair of forming rolls is mounted on the rotating frame symmetrically with respect to the central axis of the steel pipe and moved forward and backward in parallel at the same time, the radial force generated by roll forming of the steel pipe wall can be balanced. This is preferable, and by simply rotating the frame by about 180 degrees, the end face of the steel pipe can be rotated by 36°
Roll forming is possible over 0°. The above technology,
In further development, by attaching one pair of forming rolls to the frame with a phase difference of 90°, the rotating frame can be approximately 90°
Roll forming can be performed on a 360° end face of a steel pipe by simply rotating it.

,4. Using the roll mold provided on the outer peripheral surface of the roll as a pre-processing (-blow molding) mold, first press and mold the pair of preform rolls onto the heated peripheral wall of the steel pipe, and then rotate the frame 90 degrees. , by activating the other pair of final forming (secondary forming) rolls, contacting and pressing them against the peripheral wall surface of the steel pipe at the location where the blow forming was performed, and rotating the frame 180 degrees,
Roll forming of the steel pipe wall can be performed in two stages, and the amount of deformation of the material at one time can be reduced, making it possible to perform roll forming without strain.

Furthermore, if two sets of the above-mentioned pair of preforming rolls and two sets of the pair of final forming rolls are installed equally on the machine frame and operated, the rotating frame part can be rotated by 90'', and the end face of the steel pipe can be rotated by 90 degrees. It is possible to perform roll forming.

After the beveling and forming with a backing metal on the end face of the steel pipe are completed, the forming roll with the guide roll is moved back along the radial direction to isolate it from the peripheral wall of the steel pipe, while the inner wall of the steel pipe is The outer diameter of the pair of four-split cores that were being supported is reduced, and the cores are pulled out from the diameter-reduced end face opening of the steel pipe by molding with a backing metal.

As mentioned above, the roll forming of the end face of a steel pipe is a plastic deformation process by rolling roll forming under high temperature, but the shape of the workpiece after integral forming is accurate and uniform, there is little residual stress, and the part concerned can be welded. However, there is no risk of adversely affecting the quality of the joint.

The forming method of the present invention uses dedicated equipment when forming or cutting column steel pipes, and performs beveling and bevelling of the end face in - times of operations.
Since the forming process into the shape with the backing metal is completed, it is possible to economically provide a high-quality beveled end steel pipe with the backing metal.

Note that the end face forming process of the square steel pipe described above is performed by hot rolling using forming rolls, but it is not impossible to perform processing by hot stamping using the same type of technology.

[Example 1 (Part 1) The present invention will be described below according to an example thereof.

FIGS. 1(a) and 1(b) are schematic front and side views of a high-frequency induction heating device 2 for a steel pipe (column) 1. In the figure, an induction heating coil 3 is placed at a certain distance from the peripheral wall of the column 1. The column 1 is moved along the central axis 0-O of the column 1, which is provided so as to surround the column 1, is perpendicular to a plane containing the annularly formed high-frequency coil 3, and passes through the central axis O of the column 1. The column end face can be supported by ... and transferred in the longitudinal axis direction to send the column end face inside the induction heating coil 3. The column 1 is cut in advance to a predetermined length using a band saw, a cold saw, etc., and its end face is processed to have an accurate right angle and to be substantially flat.

■ is under heating, 30 to 70 degrees from the column end face in the longitudinal axis direction.
The appropriate heating temperature is approximately 700~700℃.
! The temperature is about 100°C.

Although the heating device mentioned above can be replaced with a heating means such as a propane or acetylene gas burner, it is easier to control the heating temperature with an induction heating device.

They are arranged in pairs to be symmetrical with respect to the central axis O and to be close to or separated from each other along the radial direction (details will be described later) so that the diameter of the entire core can be reduced or expanded. In the case shown in Figure 1, a pair of forming rolls 7.8 are pressed symmetrically to the peripheral wall of the heated steel pipe 1, and the end face of the steel pipe begins to beveled and roll-formed into a shape with a backing metal. For this reason, the cores 5 and 6 are fully expanded and support and secure the inner circumferential wall of a predetermined steel pipe 1 with their expanded diameter surfaces for each forming roll.

In some cases, a means for moving the object in the direction is applied.

FIG. 2 is a schematic cross-sectional view perpendicular to the central axis 0 direction of the core (steel tube column) showing the positional relationship of the steel pipe column 1, cores 5 to 6, and forming rolls 7.8 in hot rolling processing. 1
are steel pipe columns shown by phantom lines, 5-1, 5-2 and 6-1
6-2 is a core member divided into approximately four parts, and the members 5-1, 6-1, and 5-2, 6-2 are each divided into four parts.
At the tip of the plunger of a pneumatic machine attached to an annular machine frame (not shown), each of which is supported so as to be forcibly rotated around center 0, it is rotatable about axes x and x parallel to the central axis O-O. Plungers (not shown) that are pivotally supported in the steel pipe 1 move symmetrically forward and backward in the radial direction, that is, in the direction of the arrow B1, with respect to the central axis O, and form rolls 6 and 7 with guide rolls are shown in imaginary lines. The circumferential wall surface is pressed to sandwich the steel pipe circumferential wall between the surfaces of the cores 5 and 6, but the guide roll surface 12.12 of the roll contacts the steel pipe outer circumferential wall, and the roll does not move further toward the central axis O side. cannot be approached. The details will be explained according to FIGS. 3(a) and 3(b). The figures show that the cores 5 and 6, the steel pipe 1, and the forming roll 7.8 are cut along a plane including the central axis O-o. This is a schematic diagram for explaining the roll forming process using a side cross-sectional view, in which (a) shows the core 5 relative to the end surface of the heated steel pipe 1.
After inserting the cores 5 to 6, the inner circumferential wall of the steel pipe 1 is supported and secured by the enlarged diameter end portion 9 of the cores 5 to 6. In the figure, lO corresponds to the groove forming surface 15 of No. 8, 10 is the proximal diameter reducing surface of the core, 12 is the guide roll circumferential surface, 16 is the backing metal forming surface, and the forming roll with guide roll 7. 8 in this embodiment, its peripheral surface is adjacent to the guide roll surface 12 and the groove forming surface 15.
and a backing composite (root spacing) surface 16, and the roll is integrally supported for rotation about an axis X--X.

(b) shows that when the axis x-x moves downward in parallel in Figure 1 as the plunger (not shown) advances, the backing composite roll surface 16 of the forming roll 7. The groove-forming roll surface 15 contacts and presses the heated portion between it and the core diameter reducing surface lO to form it into the rib 14 of the backing metal portion of the steel pipe. The process and deformation are performed so that the guide roll surface 12 contacts and presses the unheated peripheral wall surface of the steel pipe 1, and the axis x-x is no longer close to the central axis O. It will be carried out until the end. As a result, in the cross section shown in FIG. 3(b), the end face of the steel pipe has been completed with a groove and a backing metal by roll forming. At this time, the steel pipe column 1 is pressed by the forming rolls 7.8 and receives a force that moves it in the direction opposite to the end face in the longitudinal axis direction, so the steel pipe 1 must always be fixed in the thrust direction during the roll forming process. It won't happen.

Furthermore, the forming roll surface of the longitudinal end face of the backing metal-equivalent portion bone 14 of the steel pipe 1 is open, so that the excess volume of the deformed capacity of the steel pipe wall escapes in the same direction.

Therefore, in order to make the open end surface of the rib 14 corresponding to the backing metal flat, it is necessary to finish the end surface after roll forming.

Referring again to FIG. 2, the illustrated process shows a state in which the forming roll 7.8 with the guide roll is brought close to the central axis 0 along the direction of the arrow B1, as described above.

Therefore, when the annular machine frame (not shown) is driven counterclockwise in the figure, the lower aperture 8 provided on the machine frame rotates in the direction of arrow C around its axis B
The steel pipe heating zone is moved in two directions while being roll-formed. In this way, by driving the machine frame at least 180 degrees, the end face of the steel pipe can be integrally rolled over 360 degrees into a shape with a bevel and a backing metal.

At this time, the forming rolls 7.8 are mounted point-symmetrically with respect to the central axis 0 and operate point-symmetrically, so that the reaction force due to roll forming is balanced with respect to the axis O.

However, it is not possible to eliminate the torque generated around the center axis due to roll forming.
During processing, it is necessary to securely fix the steel pipe column 1.

The guided forming roll 7.8 is pivoted on a plunger pushed out by a pneumatic machine or a hydraulic machine with a pressure gas tank, so that the guide roll surface 12 is placed inside the roll forming chamber along the outer peripheral surface of the steel pipe 1, and the center When moving closer to or away from axis 0, the forming rolls 7.8 also follow the outer circumferential surface of the steel pipe accordingly, i.e., the forming rolls 7.8 each Although it moves away from the central axis O along the direction of arrow B1, it is pressed against the outer circumferential wall of the steel tube with enough pressure to hot roll form the circumferential wall of the steel tube with the end surface of the steel tube sandwiched between the core and the core.

However, the locus of the forming rolls 7.8 can be moved along the outer peripheral surface of the steel pipe cross section by controlling the supply and discharge amount of oil from a hydraulic mechanism according to the rotational drive of the annular machine frame, or by NC control, etc. That is clear. In short, guide rolls are not necessarily required.

It is also not necessary for the guide roll to be formed integrally with the forming roll 6.7.

FIGS. 4(a) and 4(b) are cross-sectional views showing the core in this example cut along a plane perpendicular to the central axis ○,
Figure (a) shows that the two sets of core members 5-1.6-1 and 5-2.6-2 in the upper, lower and left-right directions are expanded in the directions of arrows DI and D2, respectively, and the inner corner The radius is the same as the radius of the curved surface of the corner, indicating the reduced diameter surface of the core member. The cross-sectional shape of the cores 5 to 6 taken along a plane including the central axis O is substantially the same as that shown in the third figure.

At the core position in Figure (a), the above-mentioned guided forming roll 7.
8 is subjected to hot roll forming, but at that time, the steel pipe 1 material hardly enters into the gap created between the edges of the core. Even if there is a slight intrusion,
The second pair of core members 5-2, 6-2 do not interfere with the diameter reduction in the direction of the arrow (dotted line), and this point shows the state in which the first pair of core members are secured. It shows the position of the core immediately before or after hot roll forming of the end face of the steel pipe.

In the figure, 5-1 and 6-1 are a pair of first core members indicated by the arrow D
In Figure IIn2, it is movable in the Y-axis direction and expands and contracts in diameter with respect to the central axis ○, but there is an order in the movement stroke. In R and 10, the edges of these core members are each given an inclination of approximately 45° with respect to the peripheral surface of the steel pipe so as not to prevent diameter reduction in the direction of the central axis O of the steel pipe column cross section. ing.

Referring to FIG. 4(b), a pair of second core members 5-2.
6-2 first moves along the direction of the central axis 0 with the arrow DIIn2.
When the core members 5-2, 6-2 are moved and reduced in diameter, each side end surface of the first core member 5-2, 6-2 is cut in a plane parallel to the direction of movement, as described above, so that the first core member 5-1. 6-1, the inner peripheral surface of the formed steel pipe 1 and the outer peripheral surface 9 of the second core member A fairly large gap is created between them.

Next, the first core member 5-1.6-1 is moved and reduced in diameter along the direction of the central axis O in the direction of arrow D2 so as to fit into the above-mentioned cavity. As a result, the inner diameter of the backing metal equivalent portion 14 on the end face of the formed steel pipe expands to support the inner circumferential surface of the steel pipe, which is larger than the diameter of the outer circumferential surface 9 of the reduced diameter first core member. Then, the second core member 5-2.6-2 is similarly expanded in the direction of arrow D2 to support and hold the inner circumferential surface of the steel pipe, as shown in FIG. 4(a). put it in a state.

In the above explanation, the left and right directions in the figure are the first core member, the top,
The same effect can be obtained by applying the second core member downward.

As mentioned above, the expansion and diameter reduction mechanism of the core member accompanying the core device is not only a hydraulic means but also a toggle mechanism, a crank mechanism, a cam device, or a screw feed, and it is desirable to make it horizontally and thinly. The core must be of a structure that can sufficiently support the load generated by hot roll forming.

In order to support and secure the steel pipe to be processed using the two sets of cores 5 to 6 described above, insert the cores 5 to 6 in the state shown in Figure (b) from the end face of the steel pipe, and first insert the cores 5 to 6 into the first core. The members 5-1 and 6-1 will be explained as follows along the cross-sectional view of the arrow DI in FIG.

In the figure, 1 is a steel pipe column, 5 and 6 are core members, 9 is an enlarged diameter surface at the tip of the core member, and lO is a reduced diameter surface at the base of the same member. 1. A surface that supports and secures the inner circumferential wall and an inner diameter surface of a member 16 corresponding to a backing metal on the end surface of the steel pipe.

Reference numeral 11 denotes an inclined surface zone connecting surfaces 9 and 10.

Reference numeral 17 denotes a tapered wedge member, which is located on the axial center 0 side with respect to the core members 5 and 6, and moves in the direction of arrow E along the axial direction O-O. , the diameters of the core members 5 to 6 are expanded and contracted in the direction of arrow D1.2, respectively.

At that time, by inserting the wedge member 17 into the core member, the core member 5-1.
-1 is expanded to support the inner wall of the diagonal portion of the steel pipe by its tip enlarged diameter surface 9, and then the other set of core members 5-2.
6-2 is expanded, and the inside of the steel pipe (Fig. 3(c)) is the forming roll 7.
．． This shows another embodiment of No. 8, in which the backing metal forming surface 16 of the forming roll is made of a single cylindrical surface, and the end surface of the backing metal corresponding portion 14 is open. ,
In this embodiment, the backing metal forming surface 16 of the aforementioned forming roll 7.8 is formed into a two-stage cylindrical surface with different diameters, and the end surface of the backing metal corresponding portion 14 on the end surface of the steel pipe 1 is formed on the forming roll 7. .8
It is designed to be shaped and regulated by. Therefore, in this case, the diameter of the backing metal equivalent member 5-2.6-2 is reduced.

In this way, if it is possible to form the groove in the 360° direction with respect to the central axis 0 of the end face of the steel pipe and form the entire shape of the backing, the core 5~
The diameter of each pair of cores 5 to 6 is reduced in the 0 direction of the axis, and the overall outer diameter is made smaller than the inner diameter of the inner diameter of the end surface of the part corresponding to the backing metal, which has been reduced in diameter by forming, than the inner diameter of the steel pipe. is extracted from the end face of the steel pipe, and one cycle of hot roll forming of the same end face is completed.

(Part 2) (Part 3) In the embodiment (Part 1), as shown in FIG. It was designed so that the reaction force based on the pressing force of the forming rolls was balanced by operating the rollers.

In this embodiment, in addition to a forming roll with a guide roll attached to the annular machine frame on a line passing through the center axis 0, the forming roll is usually installed 90 degrees out of phase with the line, and is approximately connected to the forming roll. It is constructed by applying preforming rolls with a similar mechanism to an annular machine frame.

After supporting and holding the end face of the steel pipe from its inner wall face by the core, first, the preforming roll is advanced to sandwich the steel pipe wall between it and the core face, and the peripheral wall of the heated steel pipe is rolled down and deformed.
After approximately driving the annular machine frame 90', a forming roll, that is, a finishing roll, is brought into contact with and rolled down the rolled/deformed end face of the annular machine frame as described in Example (Part 1), and then at least the annular machine frame is moved. By rotating the frame 180°,
Bevel processing can be performed over 360° on the end face of steel pipes without any difficulty.
Root spacing can be formed.

The shape of the outer circumferential surface of the finishing roll is as shown in Example (Part 1)
This is the same as explained in .

According to this embodiment, the amount of reduction of each roll and the amount of deformation of the steel pipe material can be distributed at an arbitrary ratio.
- A variety of processing methods can be used, such as making the amount of work relatively small each time and not placing an extreme load on forming with the finishing roll, making it possible to perform roll forming processing that does not put stress on equipment or materials. shall be.

Note that the angle of intersection between the axis of the preform roll and the axis of the finishing roll must be 9
It does not need to be 0°; it may be 456, for example.

(Part 4) In the above embodiment (Part 3), the guided forming rolls are formed into a preforming roll and a finishing roll, respectively, and the central axes of the pair of forming roll devices are set at 90° to each other. By separating them and attaching them to the rotating machine frame,
The machine frame was rotated l♂0° to perform forming roll processing of 360° on the end face.

In this embodiment, four sets of the aforementioned pair of guided forming rolls are installed on the machine frame, that is, their central axes are separated by 45 degrees from each other, and the preforming rolls are placed in contact with the heated end surface of the steel pipe. After pressing, rotate the machine frame 45 degrees around the center axis O.
After rotating the finishing rolls by 90 degrees, if each finishing roll is brought into contact with and pressed against the forming trajectory, the machine frame can be rotated 90 degrees, the amount of forming processing per roller unit can be relatively small, and the end surface of the steel pipe can be Bevel processing and molding with a backing metal are possible over 360°.

Of course, if it is acceptable to increase the amount of deformation per roller unit, by forming the circumferential surface of all forming rollers into finishing rollers, the rotating machine frame can be rotated by at least 45 degrees, which will cover 360 degrees. Roll forming of the end face of a steel pipe is not impossible.

(Part 5) In the cores 5 and 6 in Example (Part 1), R is applied to the ridge of the core member having a chevron-shaped cross section, core = Zhang μ, 2: =
、SoC widened diameter 〒; 、2-7 steel■It was designed to support and secure the large armor wall almost 360 degrees, including the corners, without any clearance.

On the other hand, the core member in this embodiment has a plate-like cross section, and the adjacent side edges are at right angles or 45
The core member structure is simplified by cutting the core member into a shape such that each core member surface supports the peripheral wall on each side of the steel pipe column.

Fig. 5 shows an example of the embodiment, and Fig. 5 (a) shows two sets of core members 5-3.6- for each pair of upper, lower, left, and right directions.
3 and 5-4.6-4 were each expanded in the direction of arrow F1, and approximately 360° of the inner wall surface of the steel pipe 1 (indicated by a virtual line) was supported and held by the expanded diameter surface 9 of each core member. It shows the state of the core, and shows the position of the core immediately before or after hot roll forming of the end face of the steel pipe. However, in the case of this embodiment, due to the structure of the core member, a gap is created inside the corner of the steel pipe that cannot be supported by the surface of the core member.

Therefore, for the same part, at least the outside of the steel pipe "fl"
Assuming that y is in the form of =i-shape =-'〆, (the amount of deformation of the six-layer wall of the steel pipe cannot be positively regulated.

However, since the shape of this part is a butt-welded joint on the end face of a steel pipe, there is no particular influence, so there will be no inconvenience in use due to the inability to control the shape.

The above-mentioned cross sections of the core members 5-3.6-3 and 5-4.6=4 along the plane including the central axis 0 are as shown in FIGS. 3 and 4 as described in the embodiment (part 1). As shown below.

FIG. 5(b) shows a state in which a pair or two sets of core members 5 to 6 each face the central axis 0 and are reduced in diameter in the direction of arrow F2. The end side edges of the core are in contact with each other at an approximately 45° angle or at a right angle, and the outer diameter of the entire core is further reduced so that its diameter is smaller than the cross-sectional inner diameter of the molded backing metal member on the end surface of the steel pipe. Other mechanisms and operating conditions in the embodiment in which the core member is small and mature in the illustrated state are similar to those described in Embodiments (Part 1) to (Part 4), so please refer to them.

[Effects of the Invention] As described above, the present invention provides groove processing and root spacing that are integrally formed with the base material as preliminary work for butt welding of column end faces when assembling bracket-type columns and beam joints, etc. Since we can provide steel pipes with attached (backing metal tacking) end faces at an economical price from the stage of stock removal from column manufacturers, these steel pipes can be used easily, and if the above-mentioned columns are used, high-rise steel frames can be constructed. Not only does it significantly reduce the number of man-hours required for assembling pillars and beam joints of structures, contributing to shortening the construction period, but it also enables the assembly of high-precision steel structures.
In addition, it eliminates various problems that constantly occur during conventional manual assembly processing, such as damage to welded parts due to poor welding and forming of the backing metal, and welding defects due to poor route spacing, and prevents accidents. Contribute.

As mentioned above, the end faces of steel pipes, which were previously processed exclusively by hand as preliminary work for construction, are now hot roll-formed all at once using special equipment, resulting in high processing efficiency and savings in man-hours and labor costs. In addition to being able to provide a product that is relatively inexpensive considering the added value of steel pipe processing, the shape of the steel pipe butt end face is uniform, and the backing metal member is integrally molded with the base material. Combined with this, it is possible to obtain high-quality and highly reliable welded joints.

In addition, since the steel pipe column end face processing is hot forming, unnecessary internal residual stress is not generated after the forming process, and the end face shape is entirely made of the same material as the steel pipe body.

Etc., compared to the conventional technology, the present invention has exceptional functions and effects.

[Brief explanation of the drawing]

1 is a schematic structural explanatory diagram of a heating device for the end face of a steel pipe column, which is an embodiment of the forming apparatus of the present invention; FIG. 2 is an explanatory diagram of an embodiment of the hot roll forming apparatus for the end face of a column; The figure is a process diagram for hot roll forming the end face of a steel pipe using a guided forming roll and a core member, and Figures 4 and 5 are diagrams explaining the types of core members used in the device and their operating states. It is. ... Steel pipe (column), ... High frequency induction heating device, ... High frequency coil, ... Steel pipe transfer roll 1. 6...core, 7.8...forming roll with guide, 9...tip enlarged diameter part (surface) of core, lO...reduced diameter part (plane) of core , 11... Inclined band, 12... Guide roll, 13... Grooved surface, 14... Backing metal equivalent portion, 15... Beveled portion forming roll surface , 16... Molding roll surface of the portion corresponding to the backing metal, 17... Wedge.

Claims (2)

[Claims] (1) After heating the end face or intermediate circumferential wall portion of the steel pipe to be formed to a predetermined temperature almost uniformly, or while heating, the tip diameter is expanded by supporting the inner circumferential wall of the steel pipe approximately in a 360° direction. The core members are equally divided into four parts by a plane that includes the center longitudinal axis of the steel pipe and is perpendicular to the peripheral wall plane of the steel pipe, and the core members are alternately divided into two pairs of opposing core members, and After each core is shrunk in the direction of the central longitudinal axis and the core is shrunk as a whole, it is inserted relatively into the longitudinal axis of the steel pipe by a predetermined length from the end face, and then
The inner peripheral wall of the steel pipe is supported and secured from the front by the expanded diameter surface of the tip by alternately expanding the cores consisting of the sets, and the inner peripheral wall of the steel pipe is supported and secured on the outside of the steel pipe at the location where the inner peripheral wall of the steel pipe is supported by the core surface. A guided roll attached to a frame member that can move forward and backward in the direction of the central axis of the steel pipe and rotate around the same axis forms an end surface profile with a bevel angle and root spacing on the outer periphery. A molded forming roll is advanced in the direction of the central axis, and the outer periphery of the roll is advanced and retractably pressed against the heated and softened peripheral wall surface of the steel pipe, collaborating with the core surface to form the steel pipe wall. At the same time, while keeping the guide roll in contact with the outer circumferential surface of the steel pipe, the forming roll, etc. is rotated around an axis concentric with the center axis of the steel pipe, thereby integrally forming a bevel on the end face or intermediate peripheral wall of the steel pipe. A forming method characterized by hot roll forming the end face of a steel pipe with a processed and backing metal. (2) A means for uniformly heating and softening the end face of the steel pipe or a required intermediate part in the circumferential direction, which is inserted from the end face of the steel pipe for a predetermined length relatively inward in the direction of the central axis, and then radially radially A core that can be expanded and contracted as a whole by moving apart and close to each other along the axis, and the core has at least a pair of two each member includes a longitudinal axis of the steel pipe and intersects with each other at right angles to the peripheral wall surface of the steel pipe;
A core is roughly divided into four equal parts by two orthogonal planes, each having a void inside, and each set is symmetrically opposed to each other with the central axis of the core in the middle. The core members move synchronously along the radial direction with a time difference, and the opposing edges of the adjacent core members are aligned with the diameter of the pair of core members whose diameters are reduced first. The core members are cut diagonally along the moving direction and molded, and the diameter of the core member as a whole is reduced by moving and reducing the diameter of the other pair of core members so as to overlap the outer surface of the pair of core members whose diameter has been reduced. The core member is configured to shrink; the frame member is rotatably supported around an axis substantially concentric with the central axis of the steel pipe and moves on the outside of the steel pipe; A forming roll with a guide that is held so as to be elastically advanced and retracted to a certain extent along the central axis direction, and the peripheral surface of the forming roll is formed with a mold for forming the end face outer shape with a bevel angle and root spacing. Bevel processing and forming equipment for steel pipe ends with backing metal.