JPH11188421A - Method and equipment for partially thickening tubular body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a partially thickening method for a tubular body in which partial heating is quickly done with smaller heating cost and in addition, in the plate thickness direction, sufficient heating can be cone from inside and outside, and moreover excrescence quantity of the thickening part to outside can be increased. SOLUTION: A tubular body 1 is heated at target position B from an external surface 1a side of the tubular body 1 by an electric heating means 20 located outside the tubular body 1. At the same time, the tubular body 1 is heated at target position B from an internal surface 1b side by heat of the concentrated electric energy from the heating means 60 located inside the tubular body 1. The partial heating is carried out from the external surface 1a side and the internal surface 1b side simultaneously. By giving compressive force of the tubular body longitudinal direction A to the heating position C with a compressive force addition means 13, the part of material of the heating position C thickens to the inside and outside gradually and thus a thickening part which shoots out at the part of the fixed distance 1 from one end plane of the tubular body 1 at the desired quantity to the inside and outside can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, to form a thickened portion at a connecting portion on a side of a column when a column of a steel structure is connected by a beam material. The present invention relates to a method for partially increasing the thickness of a pipe and a facility for partially increasing the thickness of a pipe.

[0002]

2. Description of the Related Art Conventionally, a beam connecting portion on a pillar side cuts a pillar, that is, a round steel pipe or a square steel pipe into a plurality of pieces in a length direction, and performs a beveling process on a cut surface and then a diaphragm. Although the beam penetration method of attachment has been adopted, this method requires a large amount of time and cost for cutting and groove processing, and has problems such as many welding points.

As a method of cutting a round steel pipe or a square steel pipe, for example, as disclosed in Japanese Patent Application Laid-Open No. Hei 7-238636, an inner diaphragm in which a backing metal is tack-welded around both sides is welded inside the steel pipe. After the backing metal on the insertion port side is tack-welded to the inner wall of the steel pipe, the inner wall of the steel pipe and the outer periphery of the inner diaphragm are subjected to elect slug welding using the through holes. A construction method has been proposed, but this method also required welding work.

In order to eliminate the need for a welding operation, it has been proposed to form a thickened portion at a target portion of a metal tube as disclosed in, for example, JP-A-9-76011. In this thickening method, a rectangular tube is set between a fixing device and a compression device, and the rectangular tube is locally heated by a heating device in a state where a longitudinal compressive force is applied to the rectangular tube. The heating portion is moved in the longitudinal direction to form a thickened portion continuously. At that time,
A heat treatment die is set inside the rectangular tube in order to prevent distortion that is likely to occur in the thickened portion.

[0005]

However, according to the above-mentioned thickening method, the heating device must be located at a position distant from the outer surface of the rectangular tube so that it can move outside the thickening portion. Therefore, local heating cannot be performed quickly, heating costs increase, and further, there is a possibility that the inner surface of the rectangular tube (entire plate thickness) cannot be sufficiently heated, and the wall thickness cannot be suitably increased. On the other hand, when the heating device is brought closer to the outer surface of the rectangular tube, the amount of protrusion to the outside of the thickened portion (projection height)
Becomes smaller. In addition, since the heat treatment dies are set inside the square tube, thermal efficiency is deteriorated and workability is deteriorated.

Therefore, the invention according to claim 1 of the present invention is capable of performing local heating quickly, at a low heating cost, sufficiently from the inside and outside in the thickness direction, and furthermore, to the outside of the thickened portion. It is an object of the present invention to provide a method for partially increasing the thickness of a tubular body that can increase the amount of protrusion (projection height) of the tube.

Another object of the present invention is to provide a pipe wall thickening facility capable of suitably implementing the pipe wall thickening method of the first aspect.

[0008]

In order to achieve the above-mentioned object, according to the present invention, a method for partially increasing the thickness of a tubular body according to the first aspect of the present invention uses an electric heating means located outside the tubular body. The target portion of the tube is heated from the outer surface of the tube, and electric energy is collected by the heat generating means located in the tube, and the target portion of the tube is heated by the heat generating means to the target portion of the tube inside. While heating from the beginning, a compressive force in the longitudinal direction of the tube is applied to the heated portion to partially increase the thickness of the material at the heated portion.

Therefore, according to the first aspect of the present invention, by operating the electric heating means, the target portion of the tube can be heated from the outer surface to the inner surface, and the electric energy of the electric heating means can be further reduced. In summary, when the heat generating means generates heat, the heat energy of the heat generating means can heat the target portion of the tube from the inner surface side. In this way, local heating can be performed simultaneously from both the outer surface side and the inner surface side. Then, by applying a compressive force in the longitudinal direction of the tube to the heated portion by the compressive force applying means, a part of the material of the heated portion is sequentially increased in and out, so that a portion at a predetermined distance from one end surface of the tube is provided. In addition, it is possible to form a thickened portion protruding inward and outward by a desired amount.

According to a second aspect of the present invention, there is provided a method for partially increasing the thickness of a tubular body according to the first aspect of the present invention, wherein the electric heating means comprises a plurality of movable portions which are individually movable in the longitudinal direction of the tubular body. Then, the target portion of the tube is heated by at least one electric heating means, and the electric heating means is moved to both sides in the longitudinal direction of the tube with respect to this heating point, so that both sides of the heating point are moved. While heating from inside and outside, a compressive force in the longitudinal direction of the tube is applied to the heated portion.

Therefore, according to the second aspect of the present invention, the local heating of the target portion of the tube and the heating on both sides of the heating portion by the divided and moved electric heating means group are performed by the inner surface of the electric heating means and the tube body. The gap with the outer surface can be reduced. Then, by applying a compressive force in the longitudinal direction of the tube to the heated portion by the compressive force applying means, a portion of the material of the heated portion is sequentially increased in thickness outward in a portion between the electric heating means,
Thus, a thickened portion projecting outward in a ring shape by a desired amount can be formed at a predetermined distance from one end surface of the tubular body.

According to a third aspect of the present invention, there is provided a method for partially increasing the thickness of a tubular body according to the first or second aspect, wherein the thickening portion is formed at a target portion, and then the electric heating means is formed. The heat generating means and the heat generating means are moved to a next target place separated by a predetermined distance from the thickened portion.

Therefore, according to the third aspect of the present invention, there are two portions: a portion at a predetermined distance from the one end surface of the tube, and a portion separated by a predetermined pitch from the portion at the predetermined distance, and further, at two or more locations. In addition, it is possible to form a thickened portion projected in a ring shape into and out of a desired amount.

According to a fourth aspect of the present invention, there is provided a method of partially increasing the thickness of a tubular body according to the first aspect of the present invention, wherein the heat generating means is formed by impedance. It was done.

According to the fourth aspect of the present invention, by operating the electric heating means, the lines of magnetic force flow from the outer surface to the inner surface with respect to the thickness direction of the tube, and the target portion of the tube is moved to the outer surface. By heating from the side to the inner surface and inserting an impedance having a property of restraining the magnetic field lines therein, the target portion can be heated from the inner surface.

According to a fifth aspect of the present invention, there is provided a pipe wall thickening apparatus, comprising: a tube support means; and a compressive force applying means for applying a longitudinal compressive force to the pipe supported by the support means. An electric heating means positioned outside the tube to heat a target portion of the tube from the outside, and a heat source positioned inside the tube to heat the desired portion of the tube from the outside. Means are provided.

Therefore, according to the fifth aspect of the present invention, the target portion of the tube supported by the supporting means is heated from the inside and outside by the electric heating means and the heat generating means, and the pipe is moved to the heated point by the compressing force applying means. By applying a compressive force in the body longitudinal direction, a thickened portion can be formed at a target location.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

In FIG. 8A, a round steel pipe 1 as an example of a pipe has a thickness of 4.5 mm to 50.0 mm,
SM490A, SM with a diameter of 100mm to 600mm
520B, SS400, SN400B, SN490B and the like are used. In the round steel pipe 1, two locations (one or more locations) in the longitudinal direction A are set as target locations B where the wall thickness is to be increased.

In FIG. 1 to FIG. 3, a support means 11 capable of supporting the round steel pipe 1 is provided in the pipe part thickening facility 10, and the longitudinal direction A of the round steel pipe 1 is changed by the support means 11. Supported as horizontal. The support means 11 is of a roller conveyor type that supports the round steel pipe 1 by, for example, a group of hourglass rollers 12.

Compressive force applying means 13 for applying a compressive force in the longitudinal direction A to the round steel pipe 1 supported by the support means 11
The compression force applying means 13 includes a fixed body 14 that can freely contact one end face of the round steel pipe 1, a movable body 15 that can freely contact the other end face of the round steel pipe 1, and the movable body 15. An example thereof is constituted by a cylinder device 16 that moves toward and away from the body 14 and the like.

Between the fixed body 14 and the movable body 15,
A pair (a plurality) of electric heating means 20 and 40 for heating the target portion B of the round steel pipe 1 from the outer surface 1a side are provided.
These electric heating means 20 and 40 include a high-frequency heating method having a frequency of about 10 KHZ to 20 KHZ,
A medium frequency heating method or the like of HZ to 6 KHZ is adopted, and is formed in a ring shape so as to allow the round steel pipe 1 to pass therethrough. The electric heating means 20, 40 comprises a pair of left and right divided bodies 20A, 20B, 40A, 40B with the vertical direction as a dividing line, and these divided bodies 20A, 20B, 40A, 40B.
Are connected and separated by connecting tools 21 and 41 such as bolts and nuts.

The electric heating means 20 and 40 are individually movable in the longitudinal direction A of the round steel pipe 1 by the operation of the moving means 30 and 50. The moving means 30, 50
Is a screw shaft 3 arranged along the longitudinal direction A of the round steel pipe 1.
1, 51, drive units 32, 52 for rotating the screw shafts 31, 51 in the forward and reverse directions, nut bodies 33, 53 externally fitted and screwed to the screw shafts 31, 51, and the nut bodies 33 , 53 integrated mounting brackets 34, 54
And a guided body 35 integrated with the nut bodies 33 and 53,
One example is constituted by 55 and guide rods 36 and 56 for guiding the guided bodies 35 and 55 to prevent the nut bodies 33 and 53 from rotating.

Then, connecting members 22 and 42 are connected to one of the divided bodies 20A and 40B of the electric heating means 20 and 40, and the connecting members 22 and 42 are attached to the mounting brackets 34 and 54, respectively. The connecting members 23 and 43 such as bolts and nuts can be connected and separated freely.

On the fixed body 14 side, there is provided a heating means 60 located inside the round steel pipe 1 to collect electric energy and generate heat, and to heat the target portion B of the round steel pipe 1 from the inner surface 1b side by the generated heat. Provided. The heat generating means 60 is constituted by impedances 61 arranged at six locations (a plurality of locations) in the circumferential direction, a thermosetting resin body 62 for integrating the impedances 61 and the like. A support 63 is provided at the center of the resin body 62, and the support 63 is set to a length that passes through the through portion 17 formed on the fixed body 14.

The supporting body 63 is in the form of a pipe, and the inside of the supporting body 63 is formed of a cooling type by utilizing the inside thereof. The support 63 is pushed and pulled by an operating means 64 provided on the back side of the fixed body 14,
As a result, the heating means 60 is connected to the electric heating means 20,
It is configured to be movable in the longitudinal direction A of the round steel pipe 1 in synchronization with 40.

The function of increasing the thickness of the pipe in the first embodiment will be described below. First, as shown by the solid line in FIG. 4, the electric heating means 20, 40 is disassembled by detachment of the connecting tools 21, 41, 23, 43 and separated from the mounting brackets 34, 54, for example, a crane or the like. The round steel pipe 1 before partial thickening is placed on the hourglass roller group 12 of the support means 11 by the carrying-in means. At this time, the cylinder device 1 of the compression force applying means 13
The movable body 6 is contracted and the movable body 15 is moved away from the fixed body 14. In addition, as shown by the imaginary line in FIG.
Has been retreated to the side.

In this state, the divided bodies 20A, 40B are connected to the mounting brackets 34, 54 via the connecting members 22, 42 and the connecting members 23, 43.
40A is connected to the divided bodies 20A, 4 via the connecting tools 21, 41.
0B, and as shown in FIG.
The electric heating means 20 and 40 are arranged so as to be fitted to the outside. At this time, the outer fitting is performed in a state where the gap S between the inner surface of the heating means and the outer surface 1a of the round steel pipe 1 is small.

Thereafter, the cylinder device 16 of the compressing force applying means 13 is extended, the movable body 15 is moved closer to the fixed body 14, and the movable body 15 is brought into contact with the other end surface of the round steel pipe 1. Thereby, the round steel pipe 1 is pushed and moved to the fixed body 14 side, and one end surface of the round steel pipe 1 is brought into contact with the fixed body 14,
Thus, as shown in FIG. 2, the round steel pipe 1 is positioned.

Next, the moving means 30, 50 are operated in accordance with an instruction from a control device (not shown), and as shown in FIG. While stopping, the other electric heating means 4
0 is moved to the movable body 15 side with respect to one electric heating means 20. At this time, the movement by the moving means 30 and 50 is performed by the driving devices 32 and 52 by the screw shafts 31 and 51.
Are rotated in the forward and reverse directions, and the nut bodies 33 and 53 externally fitted and screwed onto the screw shafts 31 and 51 are connected to the guide rod 3.
While receiving guidance of 6,56 etc., the pipe axis 1A of the round steel pipe 1
It becomes possible by moving along.

At about the same time, the moving means 64 is operated in accordance with an instruction from the control device, and the heat generating means 60 is protruded through the support body 63. As shown in FIGS. Is stopped facing the target location B from the inside.

The above-mentioned target location B is determined according to the location and location where the round steel pipe 1 is used as a final product, and is input and set in the control device in advance. Here, a set distance L is set from one end face of the round steel pipe 1, and the set distance L includes a length reduction due to a thickening action.

In the state set as described above, first, one of the electric heating means 20 is operated, and the lines of magnetic force flow from the outer surface 1a side to the inner surface 1b side with respect to the thickness direction of the round steel pipe 1, thereby forming The target location B of the steel pipe 1 is heated from the outer surface 1a to the inner surface 1b. Further, the lines of magnetic force passing from the inner surface 1b to the inside are constrained by the impedance 61, thereby causing the group of impedances 61 to generate heat, and the thermal energy heats the target portion B of the round steel pipe 1 from the inner surface 1b side.

As described above, such local heating is performed because the gap S between the inner surface of the heating means and the outer surface 1a of the round steel pipe 1 is small, and simultaneous heating is performed from both sides of the outer surface 1a and the inner surface 1b. By doing so, heating can be performed quickly and at a low cost, and can be sufficiently performed uniformly over the entire area in the thickness direction.

Next, as shown in FIG. 5, electric heating means 20 and 40 are moved to both sides of the round steel pipe 1 in the longitudinal direction A with respect to the heating point C. This sorting movement is performed by operating the moving means 30, 50 in the forward or reverse direction, and is stopped at a predetermined position under the control of the control device.

In this state, both electric heating means 20 and 40
While the both sides of the heating point C are heated from inside and outside by the operation, the compressive force in the longitudinal direction A of the round steel pipe 1 is applied to the heating point C. This compression force is obtained by extending the cylinder device 16 of the compression force applying means 13. Due to this compressive force, as shown by a virtual line in FIG. 5 and a solid line in FIG.
Part of the material is sequentially increased in and out, whereby the thickened portion 2 is formed.

At this time, since both sides of the heating point C are heated from the inside and outside by the electric heating means 20 and 40 and the heat generating means 60 to form a new heating point C, the compressive force continues. By being applied (or intermittently), the thickened portion 2 is formed continuously (or intermittently), and the amount of protrusion of the thickened portion 2 in and out gradually increases. At this time, the set distance L from the one end face of the round steel pipe 1 to the thickened portion 2 is gradually reduced by the thickening action. On the other hand, as shown by a virtual line in FIG. As the part 2 is protruded and moved as in (a) and (b), both electric heating means 20, 40 are also moved under the control of the control device.

As a result, as shown in phantom lines in FIGS. 6 and 4, a thickened portion 2 is formed at a predetermined distance 1 from one end face of the round steel pipe 1 so as to project inward and outward in a ring shape in a desired amount. I can do it. The electric heating means 20, 40 distributed to both sides in the longitudinal direction A with respect to the heating point C are operated alternately for heating, thereby preventing the magnetic fields of DC from interfering with each other. Accordingly, the electric heating means 20 and 40 can be arranged close to each other. Further, the amount of protrusion of the thickened portion 2 in and out is arbitrarily set according to the purpose of use.

Thereafter, as described above, the electric heating means 2
In a state in which only 0 is disassembled and separated, the moving means 50
The operation of moves the electric heating means 40 toward the center of the tube, and the operation of the moving means 30 moves the portion of the nut body 33 toward the center of the tube. At this time, since the electric heating means 20 is separated, the nut body 33
Can move without being interfered by the thickened portion 2.

Then, the electric heating means 20 is assembled as described above, and is moved to the next destination B, which is a predetermined distance away from the thickened portion 2, and the heating means 60 is moved to the next destination B. After that, first, the next destination B is heated from inside and outside by the one electric heating means 20 and the heat generating means 60.

Next, as shown by the solid line in FIG. 6, the electric heating means 20 and 40 are distributed to both sides of the heating point C, and the electric heating means 20 and 40 and the heat generating means 60 heat the heating point. By applying a compressive force in the longitudinal direction A of the round steel pipe 1 to the heating location C while heating both sides of C from inside and outside, as shown by the phantom line in FIG. In the portion, a part of the material of the heating portion C is increased in and out, so that the next thickened portion 2 is formed in the same manner as described above.

After the thickening portion 2 is formed in a predetermined amount, the electric heating means 20 and 40 are disassembled and separated to form a round steel pipe as shown in FIG. 1
A ring-shaped thickened portion 2 protruding in and out by a desired amount in and out can be formed in a portion at a predetermined distance 1 from the one end surface of the and a portion separated by a predetermined pitch P from the portion at the predetermined distance l. The round steel pipe 1 having the pair of thickened portions 2 thus formed is naturally cooled on a cooling floor or the like. The outer surface 2a of the thickened portion 2 is shaped before and after cooling by a roll pressing method, a cutting method, or the like, if necessary, so that its outer dimensions can be made uniform and smooth.

Then, the round steel pipe 1 as a product is used, for example, for a column, and a beam material is connected to the thickened portion 2 by welding. At that time, as described above, the outer surface 2a of the thickened portion 2
Since the external dimensions are uniform and smooth, there is little gap between them or a uniform and small gap, so good welding (connection) can be performed, and welding accuracy and strength are further improved. I can do it.

The impedance 61 is a cylindrical one shown in FIG. 9A, a radially divided outer layer shown in FIG. 9B, and an impedance 61 shown in FIG. 9C. And an outer layer portion radially divided.

Next, a second embodiment of the present invention will be described with reference to FIG.
Description will be made based on 0. That is, the compression force applying means 70 for applying a compression force in the longitudinal direction A to the round steel pipe 1 supported by the support means 11 is provided. This compression force applying means 7
Reference numeral 0 denotes a fixed body 71 to which one end surface of the round steel pipe 1 can freely contact, a clamp means 72 capable of holding one point in the longitudinal direction A of the round steel pipe 1, and a cart 73 provided with the clamp means 72.
And a cylinder device 74 (an example of a traveling device, which may be a traveling dynamic device mounted system) for moving the carriage 73 in the round steel pipe 1 in the longitudinal direction A.

According to the second embodiment, after the round steel pipe 1 is clamped by the clamping means 72,
By moving the clamp means 72 to the fixed body 71 side via the carriage 73 by the operation of the cylinder device 74, a compressive force in the longitudinal direction A is applied to the round steel pipe 1 between the clamp means 72 and the fixed body 71. obtain. The electric heating means 20 and 40, the heat generating means 60, and the like operate in the same manner as in the first embodiment.

At this time, since a compressive force is applied by the clamp means 72 located near the heated portion C, a sufficient compressive force is uniformly applied to the heated portion C, which is preferable. The thickened portion 2 can be formed, and the non-heated portion of the round steel pipe 1 is not likely to be deformed.

As the compressing force applying means 70, a pair of clamping means 72 capable of freely holding two locations in the longitudinal direction A,
72, a pair of carts 73, 73 provided with the clamping means 72, 72, and a pair of cylinder devices 74, 74 for moving the carts 73, 73 relatively close to and away from each other. It may be.

Next, a third embodiment of the present invention will be described with reference to FIG.
1 will be described. That is, the pipe part-thickening facility 80 is provided with the support means 81 for receiving the round steel pipe 1 with the pipe axis 1A being vertical. This support means 8
1 is an upward receiving stand 8 provided on the fixed portion 82 side.
3 and a guide roller device 85 disposed on the frame 84 from the fixed portion 82 side. Here, the guide roller device 85 is configured by arranging a set of four (plural) hourglass rollers 86 for guiding the outer surface 1a of the round steel pipe 1 in a plurality of stages in the vertical direction. In addition, the hourglass rollers 86 group of the guide roll device 85 are configured to be freely adjustable in position and exchangeable according to a change in the diameter of the round steel pipe 1 or the like.

As a result, the outer surface 1 a of the round steel tube 1 which has been carried (moved) vertically from above is guided by the group of hourglass rollers 86 of the guide roll device 85, and the lower end surface thereof is in contact with the receiving stand 83. The support means 81
Thereby, the tube axis 1A is supported vertically.

A compressive force applying means 90 for applying a compressive force in the longitudinal direction A to the round steel pipe 1 supported by the support means 81 is provided. The compression force applying means 90 includes the receiving table 83 to which the lower end surface of the round steel pipe 1 can freely contact, the clamp means 91 which can hold the lower part of the round steel pipe 1 in the longitudinal direction A, and the clamp means 91. And a lifting device (screw feed type or cylinder type) 93 for moving (elevating) the elevating table 92 in the longitudinal direction A of the round steel pipe 1. The electric heating means 20 and 40 are provided below the clamping means 91.

Hereinafter, the function of increasing the wall thickness of the tubular body in the third embodiment will be described. First, the round steel pipe 1 before partial thickening is carried (moved) from above to below via carrying means (not shown) such as a crane.
That is, the round steel pipe 1 is carried in from the upper side to the lower side with the pipe axis 1A being vertical, and at this time, the round steel pipe 1 is inserted from the clamp means 91 into the electric heating means 20 and 40.

The round steel pipe 1 is supported by the supporting means 81 with its outer surface 1a guided by a group of hourglass rollers 86 of the guide roll device 85 and its lower end surface in contact with the receiving base 83.
Thereby, the tube axis 1A is supported vertically. Next, the clamping means 91 is clamped, whereby the round steel pipe 1 is clamped.

In this state, similarly to the above-described first embodiment, the electric heating means 20 and 40, the heat generating means 60 and the like are operated, whereby the thickened portion 2 is formed. At this time, the clamp unit 91 is moved down by the operation of the elevating device 93. As a result, a compressive force in the direction of the tube axis 1A is applied to the lower portion from the clamp means 91, whereby the thickened portion 2 is formed by the compressive force.

At the time of such forming, since the round steel pipe 1 is arranged with the pipe axis 1A being vertical, for example, the heated portion C heated at a high temperature may be sagged by its own weight or the like. Even if there is, the sagging direction becomes the compression direction, so that the suitable thickened portion 2 can always be formed, and the heating temperature is not so much concerned and the temperature control becomes easy. Then, the round steel pipe 1 on which the thickened portion 2 is formed is carried out upward.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
2. Description will be given based on FIG. That is, a square steel pipe 5 having a square shape is used as another example of the pipe body. Here, the thickness, diameter, and material of the square steel pipe 5 are the same as those of the round steel pipe 1 described above. The support means 11 is configured to support the square steel pipe 5 with the corners in the vertical direction and the horizontal direction. The electric heating means 20 and 40 and the heat generating means 60 are configured according to the cross-sectional shape and direction of the square steel pipe 5.

According to the fourth embodiment, the thickened portion 6 is formed in the same manner as in the first embodiment.
As a result, as shown in FIG.
Can manufacture the square steel pipe 5 that is protruded inward and outward.

In each of the above-described embodiments, the form comprising the group of impedances 61 is shown as the heating means 60, but the number of impedances 61 is arbitrary. Other forms, such as a heating scheme, are also possible.

In each of the embodiments described above, the moving means 30 and 50 are of the screw feed type, but may be of the cylinder type or the like. In each of the above-described embodiments, the round steel pipe 1 and the square steel pipe 5 formed with the thickened portions 2 and 6 are all heated as uniformly as possible by a heating furnace or the like (for example, at a temperature exceeding the A3 transformation point). By reheating the thickened portions 2 and 6 and heating other portions to the same temperature, removal of stress generated inside the pipe,
Recovery of remarkable deterioration of material due to processing becomes possible,
It is possible to obtain a high-quality thickened pipe (product) by homogenizing the performance and, when used as a steel column material of a building, to improve the round steel pipe 1 and the square steel pipe 5 from the thickened parts 2, 6 during an earthquake. The stress is smoothly transmitted to the main body, and further absorption of seismic energy can be expected in combination with the superiority due to the shape of the thickened pipe (product).

In each of the above embodiments, two (one pair)
The electric heating means 20 and 40 are movable.
This may be a type in which heating is performed by a single fixed or movable electric heating means.

In each of the above embodiments, two (one pair)
The heating is performed by the electric heating means 20 and 40 described above, but the heating may be performed by two or more electric heating means. Electric heating means 20, 4
0 may be provided with auxiliary heating means.

In each of the embodiments described above, the first heating is performed by one electric heating means 20, but this may be performed by both electric heating means 20 and 40. In each of the above-described embodiments, both electric heating means 20 and 40
Are heated alternately, but in an arrangement where the magnetic fields do not interfere with each other, both electric heating means 20, 40 may be heated simultaneously.

In each of the above-described embodiments, the ring-shaped thickened portions 2 and 6 are formed at two locations, but may be formed at one location or at two or more locations.

[0064]

According to the first aspect of the present invention, by operating the electric heating means, the target portion of the tube can be heated from the outer surface side to the inner surface side, and the electric heating means can be heated. The energy is collected to cause the heat generating means to generate heat, and the heat energy of the heat generating means can heat the target portion of the tube from the inner surface side. Such localized heating is
By performing simultaneous heating from both the inside and outside, the heating can be performed quickly and at low cost, and uniformly over the entire area in the thickness direction. Then, by applying a compressive force in the longitudinal direction of the tube to the heated portion by the compressive force applying means, it is possible to sequentially increase the thickness of a part of the material of the heated portion in and out, so that a portion at a predetermined distance from one end surface of the tube is provided. In addition, it is possible to form a thickened portion projecting in and out of a desired amount.

According to the second aspect of the present invention,
Local heating of the target location of the pipe, and heating of both sides of the heating location by the distributed and moved electric heating means group can be performed quickly by reducing the gap between the inner surface of the electric heating means and the outer face of the pipe. In addition, the heating cost can be reduced, and the heating can be performed sufficiently to the inner surface side. Then, by applying a compressive force in the longitudinal direction of the tube to the heated portion by the compressive force applying means, a portion of the material of the heated portion is sequentially increased in thickness outward in a portion between the electric heating means. A ring-shaped thickened portion protruding outward in a desired amount by a desired amount can be formed in a portion at a predetermined distance from one end surface.

According to the third aspect of the present invention, two portions, that is, a portion at a predetermined distance from the one end surface of the tube body and a portion separated by a predetermined pitch from the portion at the predetermined distance, and further two or more portions At a plurality of places, a thickened portion protruding in a ring shape into and out of a desired amount can be formed.

Further, according to the fourth aspect of the present invention, by operating the electric heating means, the lines of magnetic force flow from the outer surface side to the inner surface side with respect to the thickness direction of the tube, and the purpose of this tube is The location can be heated from the outer side to the inner side, and the target location can be heated from the inner side by inserting an impedance having a property of restricting the lines of magnetic force inside.

According to the fifth aspect of the present invention,
The target portion of the tube supported by the supporting means is heated by the electric heating means and the heat generating means, and the compressive force applying means applies compressive force in the longitudinal direction to the heated portion by the compressive force applying means. The thickened portion can be formed at the position where the pipe is to be formed, whereby the method for partially increasing the thickness of the tubular body according to claim 1 can be suitably realized.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a partially cutaway plan view when a target portion is heated in a pipe part thickening facility.

FIG. 2 is a partially cut-away side view of a partially thickening facility of the pipe body.

FIG. 3 is a partially cutaway front view when a target portion is heated in a partial thickness increasing facility of the pipe body.

FIG. 4 is a partially cutaway front view of the pipe when setting the pipe in the partial thickening facility of the pipe.

FIG. 5 is a cross-sectional plan view of an essential part of the pipe body in a partial thickness increasing facility at the time of a thickening operation.

FIG. 6 is a cross-sectional plan view of an essential part of another portion of the pipe body in a partial thickness increasing facility at the time of increasing the thickness of another portion.

FIG. 7 is an enlarged cross-sectional view of a main part at the time of a thickening operation in a partial thickening facility of the pipe body.

FIG. 8 is a partially cutaway perspective view showing the round steel pipe before and after forming the thickened portion.

FIG. 9 is a cross-sectional view showing various shapes of the impedance.

FIG. 10 shows a second embodiment of the present invention, and is a partially cutaway side view of a facility for partially increasing the thickness of a pipe body.

FIG. 11 shows a third embodiment of the present invention, and is a partially cutaway side view of a facility for partially increasing the thickness of a pipe body.

FIG. 12 shows a fourth embodiment of the present invention, and is a partially cutaway front view when heating a target portion in a partial wall thickening facility for a tubular body.

FIG. 13 is a partially cutaway perspective view showing the round steel pipe before and after forming the thickened portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Round steel pipe (tube) 1a Outer surface 1b Inner surface 2 Thickening part 5 Square steel pipe (tube) 6 Thickening part 10 Partial thickening equipment 11 Supporting means 13 Compressive force applying means 14 Fixed body 15 Movable body 20 Electric heating means Reference Signs List 20A split body 20B split body 30 moving means 31 screw shaft 32 drive device 33 nut body 40 electric heating means 40A split body 40B split body 50 moving means 51 screw shaft 52 drive device 53 nut body 60 heat generating means 61 impedance 62 resin body 63 Supporting body 64 Actuating means 70 Compressing force applying means 71 Fixed body 72 Clamping means 73 Truck 80 Partial thickening equipment 81 Supporting means 90 Compressive force applying means 91 Clamping means 92 Elevating table A Longitudinal direction B Target point C Heating point L Setting distance l Predetermined distance S Clearance P Predetermined pitch

Claims (5)

[Claims] 1. A target portion of a tubular body is heated from the outer surface side of the tubular body by an electric heating means located outside the tubular body, and electric energy is collected by a heating means located in the tubular body. While heating the target portion of the tube from the inside of the tube by the heat generated by the heat generating means, applying a compressive force in the longitudinal direction of the tube to the heated portion to sequentially increase the thickness of a part of the material at the heated portion. A method for partially increasing the thickness of a tubular body. 2. A plurality of electric heating means which are individually movable in the longitudinal direction of the tubular body, and heat a target portion of the tubular body by at least one electric heating means. On the other hand, the electric heating means is distributed to both sides in the longitudinal direction of the tubular body, and a compressive force in the longitudinal direction of the tubular body is applied to the heated place while heating both sides of the heated place from inside and outside. The method for partially increasing the thickness of a tubular body according to claim 1. 3. After forming a thickened portion at a target location, the electric heating means and the heat generating means are moved to a next target location at a predetermined distance from the thickened portion. The method for partially increasing the thickness of a tubular body according to claim 1 or 2, wherein: 4. The method according to claim 1, wherein the heat generating means is formed by impedance. 5. A means for supporting a tube, a compressing force applying means for applying a longitudinal compressive force to the tube supported by the supporting means, and a target portion of the tube located outside the tube. Characterized by being provided with an electric heating means for heating the pipe from the outer surface side and a heat generating means located inside the pipe body and heating a target portion of the pipe body from the inner surface side. Equipment to increase meat.