JPH11169994A - Partial thickening method of tube body and partial thickening equipment for tube body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a partial thickening method of a tube body capable of rapidly executing partial heating at a low heating cost up to its inner surface side sufficiently and enlarging the quantity of protrusion toward the outside of a thickening part. SOLUTION: Freely and reparately movable heating means 20, 40 are provided in the longitudinal direction A of the tube body, an objective place B is heated with one heating means 20, heating means 20, 40 are apportioned and moved to both sides in the longitudinal direction A of the tube body with respect to a heating place C, and both sides of the heating place C are heated. Whereby, heating for the objective place B and heating for both sides of the heating place C are executed with a small gap S between the inner surface of the heating means and the outer surface 1a of the tube body. A compressing force in the longitudinal direction A of the tube body is imparted to the heating place C by a compressing force imparting means 13, whereby a part of material in the heating place C is successively thickened inward and outward in the part between the heating means 20, 40, and the thickened part which protrudes inward and outward in a ring shape with a desired quantity is formed in the part of a prescribed distance L from one end surface of the tube body 1.

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-described thickening method, the heating device and the auxiliary heating device are integrated and moved in the same direction, so that the heating device and the auxiliary heating device can be moved outside the thickening portion. It must be remote from the outer surface of the rectangular tube. 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 and the auxiliary heating device are brought closer to the outer surface of the rectangular tube, the amount of protrusion (projection height) outside the thickened portion becomes smaller.

Therefore, according to the first aspect of the present invention, the local heating can be sufficiently performed to the inner surface side quickly and at a low heating cost, and the amount of protrusion of the thickened portion to the outside can be improved. It is an object of the present invention to provide a method for partially increasing the wall thickness of a tubular body that can increase the protrusion height).

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

[0008]

According to a first aspect of the present invention, there is provided a method for partially increasing the thickness of a tubular body, the method comprising: A plurality of individually movable heating means are provided, and at least one heating means heats a target portion of the tubular body,
By moving the heating means to both sides in the longitudinal direction of the tube with respect to this heating point, while heating both sides of the heating point,
The present invention is characterized in that a compressive force in the longitudinal direction of a tube is applied to a heated portion to sequentially increase the thickness of a part of the material of the heated portion.

Therefore, according to the first aspect of the present invention, the local heating of the target portion of the tubular body and the heating of both sides of the heated portion by the divided and moved heating means group are performed by the gap between the inner surface of the heating means and the outer surface of the tubular body. 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 part of the material of the heated portion is sequentially increased in and out in a portion between the heating means, and thus one end face of the tubular body A thickened portion protruding in a ring shape in a desired amount in and out can be formed in a portion at a predetermined distance from.

According to a second aspect of the present invention, there is provided a method of partially increasing the thickness of a pipe body according to the first aspect of the present invention, wherein a thickening portion is formed at a target portion, and then the heating means group increases the thickness. It is characterized in that it is moved to a next target place separated by a predetermined distance from the meat part.

Therefore, according to the second aspect of the present invention, two portions, that is, a portion at a predetermined distance from one end surface of the tube body 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 third aspect of the present invention, there is provided a method for partially increasing the thickness of a tubular body, wherein the heating means is divided on both sides in the longitudinal direction of the tubular body with respect to a heating location in the configuration according to the first or second aspect. Are characterized by being alternately heated.

Therefore, according to the third aspect of the present invention, it is possible to prevent the magnetic fields from interfering with each other between direct currents, and to arrange the heating means closer to that extent. Further, the pipe wall thickening equipment according to claim 4 of the present invention is a pipe body supporting means, a compressive force applying means for applying a longitudinal compressive force to the pipe body supported by the supporting means, and a pipe body. Characterized by being provided with a plurality of heating means positioned outside the tube for heating a target portion of the tubular body, and moving means for individually moving these heating means in the longitudinal direction of the tubular body. It is.

Therefore, according to the fourth aspect of the present invention, a target portion of the tube supported by the support means is heated by at least one heating means, and the heating means is moved by the moving means, and the longitudinal portion of the tube is heated with respect to the heating point. By distributing and moving to both sides in the direction, while applying heat to both sides of the heating point, compressive force applying means applies a compressive force in the longitudinal direction of the tube to the heated point to form a thickened portion at a target point. obtain.

[0015]

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 a round steel pipe 1 is provided in a 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 heating means 20 and 40 for heating the target location B of the round steel pipe 1 from the outer surface 1a side are provided. As the heating means 20, 40, a high-frequency heating method, a medium-frequency heating method, or the like is adopted, and is configured in a ring shape so as to allow the round steel pipe 1 to be inserted. And heating means 20, 40
Are a pair of left and right divided bodies 20A, 2
0B, 40A, and 40B, and these divided bodies 20A,
20B, 40A, and 40B are configured to be connectable and separable by connecting tools 21 and 41 such as bolts and nuts.

The two heating means 20, 40 are provided with moving means 30,
By the operation of 50, the round steel pipe 1 is configured to be individually movable in the longitudinal direction A. The moving means 30, 50 are provided with screw shafts 31, 51 disposed along the longitudinal direction A of the round steel pipe 1.
And drive units 32 and 52 for rotating the screw shafts 31 and 51 in the normal and reverse directions, nut bodies 33 and 53 fitted and screwed to the screw shafts 31 and 51, respectively, and the nut bodies 33 and 5
3, mounting brackets 34 and 54 integrated with the nuts 3, guided members 35 and 55 integrated with the nuts 33 and 53,
The nuts 33, 5 are guided by guiding the guided members 35, 55.
One example is constituted by the guide rods 36 and 56 for stopping the rotation of 3.

Then, connecting members 22 and 42 are connected to one of the divided bodies 20A and 40B of the heating means 20 and 40, and the connecting members 22 and 42 are bolted to the mounting brackets 34 and 54. Connecting tools 2 such as nuts
3, 43 so that they can be connected and separated freely.

Hereinafter, the function of increasing the thickness of the pipe body in the first embodiment will be described. First, as shown by the solid line in FIG. 4, the heating means 20, 40 is disassembled by detachment of the connecting tools 21, 41, 23, 43 and separated from the mounting brackets 34, 54, and then, for example, a crane or the like is carried in. Round steel pipe 1 before partial thickening by means
Is mounted on the hourglass roller group 12 of the support means 11. At this time, the cylinder device 16 of the compression force applying means 13 is contracted, and the movable body 15 is moved away from the fixed body 14.

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, and then the divided bodies 20B, 40B are connected.
40A is connected to the divided bodies 20A, 4 via the connecting tools 21, 41.
0B, and as shown in FIG.
The heating means 20 and 40 are fitted to the outside. At this time, the outer fitting is performed by the gap S between the inner surface of the heating means and the outer surface 1a of the round steel pipe 1.
Is performed in a small state.

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. 3, one of the heating means 20 is stopped so as to face the target point B. At the same time, the other heating means 40 is moved toward the movable body 15 with respect to the one heating means 20.
At this time, the movement by the moving means 30 and 50 is performed by rotating the screw shafts 31 and 51 forward and reverse by the driving devices 32 and 52, respectively.
It is possible to move the nut bodies 33, 53 fitted and screwed onto the screw shafts 31, 51 along the pipe axis 1A of the round steel pipe 1 while being guided by the guide rods 36, 56 and the like. Become.

The 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 set in advance by inputting it to the control device. 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 heating means 20 is operated to heat the target portion B of the round steel pipe 1. Since the gap S between the inner surface of the heating means and the outer surface 1a of the round steel pipe 1 is small as described above, the local heating can be performed quickly and at a lower heating cost, and can be sufficiently performed to the inner surface 1b side.

Next, as shown in FIG. 5, the 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, a compressive force in the longitudinal direction A of the round steel pipe 1 is applied to the heating point C while heating both sides of the heating point C by the operation of both the heating means 20 and 40. This compression force is obtained by extending the cylinder device 16 of the compression force applying means 13. As shown by the imaginary line in FIG. 5 and the solid line in FIG.
In the intermediate portion, a part of the material of the heating portion C 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 by the two heating means 20 and 40 to become a new heating point C, the compressive force continues (or is interrupted).
By being applied, the thickened portion 2 is formed continuously (or intermittently), and the amount of protrusion of the thickened portion 2 in and out is gradually increased. At this time, the 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 unit 2 is protruded and moved as in (a) and (b), the two heating means 20, 40 are also moved under the control of the control device.

As a result, as shown in FIG. 6, a thickened portion 2 protruding in a ring shape in a desired amount in and out can be formed at a predetermined distance 1 from one end surface of the round steel pipe 1. The heating means 20, 40 distributed to both sides in the longitudinal direction A with respect to the heating portion C are operated alternately by heating.
This can prevent the magnetic fields from interfering with each other due to the direct current. Further, the amount of protrusion of the thickened portion 2 in and out is arbitrarily set according to the purpose of use.

Thereafter, with the heating means 20 disassembled and separated as described above, the heating means 40 is moved toward the center of the pipe by the operation of the moving means 50, and the moving means 30 is operated by the operation of the moving means 30. Then, the portion of the nut body 33 is moved toward the center of the pipe. At this time, by separating the heating means 20, the portion of the nut body 33 can move without being interfered by the thickened portion 2.

After assembling the heating means 20 as described above, and moving the heating means 20 to the next destination B which is a predetermined distance away from the thickening portion 2, one of the heating means 20 is actuated to start the next. The target portion B is heated. Next, as shown by the solid line in FIG.
In the state where 0 and 40 are distributed and moved, both heating means 2
By applying a compressive force in the longitudinal direction A of the round steel pipe 1 to the heating point C while heating both sides of the heating point C by the operations of 0 and 40, as shown by the phantom line in FIG. , 40, 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 two heating means 20 and 40 are disassembled and separated to form the round steel pipe 1 as shown in FIG. At a portion at a predetermined distance 1 from the one end face and at a portion away from the portion at the predetermined distance 1 by a predetermined pitch P, a thickened portion 2 protruding in a ring shape in a desired amount in and out can be formed. 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.

The round steel pipe 1 as a product is used, for example, for a column, and a beam 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.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. That is, the compressive force applying means 60 for applying a compressive 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 60
Is a fixed body 61 to which one end surface of the round steel pipe 1 can freely contact, and a clamp means 6 which can hold one place in the longitudinal direction A of the round steel pipe 1.
2, a truck 63 provided with the clamping means 62,
The truck 63 is configured by a cylinder device (an example of a traveling device, which may be a traveling motion device mounting system, etc.) 64 for traveling the round steel pipe 1 in the longitudinal direction A.

According to the second embodiment described above, after the round steel pipe 1 is clamped by the clamping means 62,
By moving the clamp means 62 toward the fixed body 61 via the carriage 63 by the operation of the cylinder device 64, a compression force in the longitudinal direction A is applied to the round steel pipe 1 between the clamp means 62 and the fixed body 61. obtain. In addition, both heating means 20,
Reference numerals 40 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 62 located near the heating point C, a sufficient compressive force is uniformly applied to the heating point 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 60, a pair of clamping means 62, which can hold two places in the longitudinal direction A, can be used.
62, a pair of carts 63, 63 provided with the clamping means 62, 62, and a pair of cylinder devices 64, 64 for moving the carts 63, 63 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.
Description will be made based on 0. That is, the pipe part partial thickness increasing equipment 70 is provided with the support means 71 for receiving the round steel pipe 1 with the pipe axis 1A being vertical. This support means 7
Reference numeral 1 denotes an upward receiving base 7 provided on the fixing portion 72 side.
3 and a guide roller device 75 disposed on the frame 74 from the fixed portion 72 side. Here, the guide roller device 75 is configured by arranging a set of four (plural) hourglass rollers 76 for guiding the outer surface 1a of the round steel pipe 1 in a plurality of stages in the vertical direction. The hourglass roller group 76 of the guide roll device 75 is 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 1a of the round steel pipe 1 which has been carried (moved) vertically from above is guided by the group of hourglass rollers 76 of the guide roll device 75 and the lower end surface of the round steel tube 1 is received by the receiving base 73. In the contact state, the tube axis 1A is supported vertically by the support means 71.

A compressive force applying means 80 for applying a compressive force in the longitudinal direction A to the round steel pipe 1 supported by the support means 71 is provided. The compression force applying means 80 is provided with the receiving table 73 on which the lower end surface of the round steel pipe 1 can freely contact, the clamp means 81 which can hold one position in the longitudinal direction A of the round steel pipe 1, and the clamp means 81. And a lifting device (screw feed type, cylinder type, etc.) 83 for moving (elevating) the elevating table 82 in the longitudinal direction A of the round steel pipe 1. The heating means 20, 40 and the like are provided below the clamping means 81.

The function of increasing the wall thickness of the pipe in the third embodiment will be described below. 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 that time, the round steel pipe 1 is inserted from the clamp means 81 to the heating means 20 and 40.

The round steel pipe 1 is supported by the supporting means 71 in a state where the lower outer surface 1a is guided by the group of hourglass rollers 76 of the guide roll device 75 and the lower end face is in contact with the receiving base 73. 1A is supported vertically. Next, the clamping means 81 is clamped, whereby the round steel pipe 1 is moved.
Is clamped.

In this state, similarly to the first embodiment described above, the heating means 20, 40 and the like are operated, and the thickened portion 2 is formed. At that time, the clamping means 81
Is lowered by the operation of the lifting / lowering device 83. As a result, a compressive force in the direction of the tube axis 1A is applied to a portion below the clamp means 81, and 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, there is a possibility that 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.
1, will be described with reference to 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 heating means 20 and 40 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 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)
Although the heating is performed by the heating means 20 and 40, the heating may be performed by two or more heating means. Further, the heating means 20 and 40 may be provided with auxiliary heating means.

In each of the above-described embodiments, the first heating is performed by one heating means 20, but this may be performed by both heating means 20 and 40. In each of the above-described embodiments, the heating units 20 and 40 are alternately heated, but when the magnetic fields do not interfere with each other, the heating units 20 and 40 may be simultaneously heated.

In each of the embodiments described above, the thickened portions 2 and 6 are formed in the round steel pipe 1 and the square steel pipe 5. By heating the entirety as uniformly as possible, and by hot forming into a square shape, the square steel pipe 5 having the thickened portion 6 can be obtained. Further, in this case, the above-described effect of overall heating can be obtained automatically.

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.

[0054]

According to the first 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 heating means group are performed by the inner surface of the heating means and the tube body. Since the gap with the outer surface can be reduced, the heating can be performed quickly and at a lower cost, and the inner surface side can be sufficiently performed. 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 in a portion between the heating means, and thereby one end surface of the tubular body A thickened portion projecting in a ring shape in a desired amount in and out can be formed in a portion at a predetermined distance from.

According to the second aspect of the present invention,
It was protruded in a ring shape with a desired amount in and out at two places, a part at a predetermined distance from one end face of the tube, and a part separated by a predetermined pitch from the part at the predetermined distance, and further at two or more places. A thickened portion can be formed.

According to the third aspect of the present invention, the magnetic fields can be prevented from interfering with each other by direct current, and the heating means group can be arranged closer to that extent, and the heating by the heating means group can be further reduced. Further, the heating can be performed more quickly and at a lower cost, and further to the inner surface side.

Further, according to the fourth aspect of the present invention, the target portion of the tube supported by the supporting means is:
Heating by at least one heating means, moving the heating means by the moving means to both sides in the longitudinal direction of the tube with respect to the heating point, moving while heating both sides of the heating point,
By applying a compressive force in the longitudinal direction of the tubular body to the heated portion by the compressive force applying means, it is possible to form a thickened portion at a target location, so that the method for partially increasing the thickness of the tubular body according to claim 1 is suitably realized. it can.

[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 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. 10 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. 11 shows a fourth embodiment of the present invention, and is a partially cutaway front view when a target portion is heated in a pipe part thickening facility.

FIG. 12 is a partially cutaway perspective view showing the round steel pipe before and after the formation of the thickened portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Round steel pipe (tube body) 2 Thickening part 5 Square steel pipe (tubing) 6 Thickening part 10 Partial thickening equipment 11 Support means 13 Compressive force applying means 14 Fixed body 15 Movable body 20 Heating means 20A Split body 20B Split body Reference Signs List 30 moving means 31 screw shaft 32 driving device 33 nut body 40 heating means 40A divided body 40B divided body 50 moving means 51 screw shaft 52 driving device 53 nut body 60 compressive force applying means 61 fixed body 62 clamping means 63 bogie 70 partial thickening Equipment 71 Supporting means 80 Compressing force applying means 81 Clamping means 82 Lifting table A Longitudinal direction B Target point C Heating point L Set distance l Set distance S Gap P Predetermined pitch

Claims (4)

[Claims] 1. A plurality of heating means which are located outside the tube and which are individually movable in the longitudinal direction of the tube are provided, and a target portion of the tube is heated by at least one heating means. A heating means is distributed to both sides in the longitudinal direction of the tube with respect to the heated portion, and while heating both sides of the heated portion, a compressive force in the longitudinal direction of the tube is applied to the heated portion, and a portion of the heated portion is heated. A method for partially increasing the thickness of a tubular body, characterized by sequentially increasing the thickness of a material. 2. A heating means group is moved to a next target place which is separated from the thickened part by a predetermined distance after forming a thickened part at a target place. 1
A method for partially increasing the thickness of a tubular body as described above. 3. The method according to claim 1, wherein the heating means distributed to both sides in the longitudinal direction of the tube with respect to the heating portion are alternately heated. 4. A tube supporting means, 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 positioned outside the tube Characterized in that a plurality of heating means for heating the pipes and a moving means for individually moving the heating means in the longitudinal direction of the pipe are provided.