JP6778543B2 - Grooved metal tube manufacturing equipment and method - Google Patents

Description

The present invention relates to a grooved metal pipe manufacturing apparatus for manufacturing a metal pipe having concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced apart in the circumferential direction of the outer peripheral surface of the pipe by, for example, an electric sewing pipe manufacturing apparatus. Regarding the method.

The electric sewing tube manufactured by the electric sewing tube manufacturing apparatus is widely used for various purposes.
As a method of forming a concave portion in an electric sewing pipe, there is a method of forming a square metal raw pipe having an embossed pattern in Patent Document 1. Patent Document 1 discloses that rectangular recesses (embosses) are formed on both side surfaces of a square metal tube at intervals in the longitudinal direction of the tube.
The rectangular recess of the square metal pipe of Patent Document 1 is shown in FIG. 17 because it is assumed to be used as a skid (sleeper) for placing the packed steel material with a gap instead of directly on the floor surface. As described above, elongated rectangular recesses 30 are formed at intervals in the radial direction (side length direction) of the square metal tube 31 to increase the strength against the crushing load applied in the radial direction of the square metal tube placed as sleepers on the floor. There is.
Conventionally, a metal pipe such as a steel pipe having a concave groove extending in the longitudinal direction of the pipe has not been manufactured by an electric sewing pipe manufacturing apparatus.

When manufacturing a square metal pipe in an electric sewing pipe manufacturing apparatus, as shown in FIG. 17, a plurality of stages (4 stages in the illustrated example) breakdown roll (BDR) is used to perform curved molding in an arc shape, and then a plurality of stages (FIG. In the example, 3 steps) finpass roll (FPR) is used to form an almost circular shape (open circle) in which both edges are close to each other, and then both edges are butt-welded in a welding process using a squeeze roll (SQR) and a high-frequency welding machine. Then, a square metal tube is manufactured by a shaping process using a multi-stage sizing roll (SZR) and a Turks head roll (THR) for straightening.

JP-A-63-111718

As described above, a metal pipe such as a steel pipe having a concave groove extending in the longitudinal direction of the pipe is not manufactured by an electric pipe manufacturing apparatus, but a concave groove extending in the longitudinal direction of the pipe is formed in the metal pipe such as a steel pipe. Then, it is effective to enhance the cross-sectional function. In particular, if concave grooves extending in the longitudinal direction of the pipe are formed on the four surfaces of the square steel pipe used for the column material, the effect of enhancing the cross-sectional function is high.

By the way, as a means for forming concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced apart from each other in the circumferential direction of the outer surface of a metal pipe such as a steel pipe, an outer tube mechanism having a sphere and a groove-shaped concave portion corresponding to the sphere A patent application has been filed under the present applicant for a method and apparatus for manufacturing a grooved metal pipe that forms a concave groove on the outer periphery of the metal pipe by means of a core arranged in the metal pipe. 2016-073758).
This grooved metal tube manufacturing method, which forms a concave groove on the outer circumference of the metal pipe with a sphere outside the pipe and a core inside the pipe, is extremely compact and simple, requires a small space as a grooved metal pipe manufacturing device, and requires equipment costs. Although it is cheaper, further improvement is desired.
In this method and apparatus for manufacturing a grooved metal pipe, when a grooved metal pipe is manufactured by an electric sewing pipe manufacturing apparatus as a means for holding a core arranged in the metal pipe, the grooved metal pipe is substantially in the finpass roll region. The rear end of the rod-shaped body is connected to a fixed portion (for example, an impeder (indicated by reference numeral 13 in FIG. 2) that constitutes a part of a welding device) arranged inside a metal plate in a circularly curved state, and the inside is connected to the tip thereof. A core holding means for attaching the child is adopted.
However, in this core holding means, the rod-shaped body to be arranged in the pipe becomes considerably long, and its attachment work and other handling become complicated, so it is desired that it can be omitted as much as possible.

The present invention was made based on the above background, and as a device for forming concave grooves extending in the longitudinal direction of a metal pipe such as a steel pipe at a plurality of locations spaced apart from each other in the circumferential direction, a sphere and a core are used. By adopting the means using the above, the purpose is to provide a device and method that is compact and simple, requires a small space, and has a low equipment cost. In particular, the core is held by a long rod-shaped body placed in a pipe. It is an object of the present invention to provide an apparatus and method for manufacturing a grooved metal pipe that does not require a core holding means such as.

The invention of claim 1 that solves the above problems
A grooved metal tube manufacturing device having concave grooves extending in the longitudinal direction of the tube at a plurality of locations spaced in the circumferential direction of the outer surface of the metal tube driven in the longitudinal direction of the tube.
A plurality of extratube mechanisms provided at intervals in the circumferential direction in a manner in which a rotatably held sphere pushes the outer surface of the tube.
It has a short rod shape with a cross-sectional shape along the inner surface of the pipe, and is arranged in the pipe independently at a position in the longitudinal direction of the pipe corresponding to the outer mechanism of the pipe and in a manner that does not receive a binding force other than contacting the inner surface of the pipe. the outer peripheral surface of the core and a child, the only metal tube drive forward side respectively from opposite positions in the sphere of the extravascular system, have a plurality of groove-like recess having a shape corresponding to the spherical bodies The end of the groove-shaped recess where the groove starts has a hemispherical concave surface corresponding to the sphere .

2. The second aspect of the present invention is the grooved metal tube manufacturing apparatus of the first aspect.
There is a groove on the outer peripheral surface of the grooveless portion on the side opposite to the metal pipe driving direction from the groove end hemispherical concave surface, which is the end portion of the core in the groove-shaped recess , and on the front side in the metal pipe driving direction from the groove end hemispherical concave surface. It is characterized in that a pipe inner surface pushing-up means for pushing up the pipe inner surface so as to bulge outward is provided on the outer peripheral surface without a groove in the portion.

According to claim 3, in the grooved metal pipe manufacturing apparatus of claim 2, a ball plunger having a ball urged by a spring in a cylindrical case is embedded in the outer peripheral surface of the core as the means for pushing up the inner surface of the pipe. It is characterized by.

The invention of claim 4 has concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe by the apparatus for manufacturing the grooved metal pipe according to any one of claims 1 to 3. A method for manufacturing a grooved metal tube.
At the start of production, with the core placed inside the tip of the metal tube, the sphere of each extratube mechanism is pushed down to the tip of the metal tube to form a short groove, and the metal tube is continuously lengthened. By driving in the manual direction, it is characterized in that concave grooves extending in the longitudinal direction of the pipe are formed at a plurality of locations spaced apart in the circumferential direction of the outer surface of the metal pipe.

In the invention of claim 5, the metal plate is curved and molded into a substantially circular shape by a breakdown roll and a finpass roll, and then both edges of the metal plate in the substantially circular curved state are butt-welded by a squeeze roll and a welding device. The grooved metal pipe manufacturing apparatus according to claims 1 to 3 is installed on the downstream side of the sizing roll in the electric sewing tube manufacturing apparatus which is formed into a circular pipe and then shaped by a sizing roll, and the sphere and the core thereof are used. , A method for manufacturing a grooved metal pipe in which concave grooves extending in the longitudinal direction of the pipe are formed at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe driven in the longitudinal direction of the pipe.
A grooved metal tube is manufactured by the method for manufacturing a grooved metal tube according to claim 4.

The invention of claim 6 is
A method for manufacturing a grooved metal pipe, which forms concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the pipe offline in the metal pipe manufactured by the electric sewing pipe manufacturing apparatus.
The grooved metal pipe manufacturing apparatus according to claims 1 to 3 is installed at an intermediate position of the transport table in a drive device provided with a transport table to drive the metal pipe in the longitudinal direction of the pipe, and the sphere and the core thereof are used. , When forming concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe driven in the longitudinal direction of the pipe on the transport table.
A grooved metal tube is manufactured by the method for manufacturing a grooved metal tube according to claim 4.

According to the grooved metal pipe manufacturing apparatus of the present invention, concave grooves extending in the longitudinal direction of the pipe are provided at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe such as a steel pipe on the electric pipe manufacturing line or offline. It can be formed, and the cross-sectional performance of a metal pipe such as a steel pipe can be improved by forming a concave groove.

After the metal tube is formed, a concave groove is formed in the metal tube by the sphere of the outer tube mechanism and the groove-shaped concave portion of the core inside the tube, so that a metal tube having a modified cross section can be easily obtained. Therefore, it is possible to expand the product types as square tube products.
Further, as compared with the conventional molding method from only one side, molding can be performed from both sides (both sides of the inner and outer surfaces of the pipe), so that the degree of freedom of roll design for the required cross-sectional shape is expanded from the standpoint of the roll designer.

The core placed in the pipe is held in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe, and functions as a floating core floating in the pipe, for example, a welding device. Since a long rod-shaped body or the like connected to a fixed portion such as an impeder that constitutes a part of the above is not required, problems such as complicated installation work and other handling do not occur, and workability is improved in various points. ..

In order for the core to smoothly and stably perform the groove processing operation in the metal pipe, it is desirable that there is a slight gap c between the outer surface of the core and the inner surface of the metal pipe, and for each surface. It is desirable that the gap c is uniform and constant.
As a means for keeping the gap c uniform and constant, as in claim 2, the outer peripheral surface of the grooveless portion on the side opposite to the groove end hemispherical concave surface of the core and the groove end hemispherical concave surface, and the metal tube from the groove end hemispherical concave surface. It is effective to provide a pipe inner surface pushing-up means for pushing up the inner surface of the pipe so as to bulge outward on the outer peripheral surface without a groove in the grooved portion on the front side in the driving direction.
Further, as the means for pushing up the inner surface of the pipe, as in claim 3, a ball plunger having a ball urged by a spring in a cylindrical case is embedded in the outer peripheral surface of the core to keep the gap c uniform and constant. Can be effectively realized.

Further, as in claim 4, at the start of production, with the core placed inside the tip of the metal pipe, the sphere of the extratube mechanism is pushed down to the tip of the metal pipe to form a recess, and the metal is continued. When the tube is fed and driven, a smooth grooved metal tube can be manufactured.

By installing the grooved metal pipe manufacturing apparatus on the downstream side of the sizing roll in the electric sewing pipe manufacturing apparatus as in claim 5 to manufacture the grooved metal pipe, efficient and shape quality can be obtained. It enables the production of good grooved metal tubes.
However, if necessary, it is possible to manufacture the grooved metal tube offline as in claim 6.

It is a figure which schematically explains the electric sewing tube manufacturing apparatus which carries out the manufacturing apparatus and method of the grooved metal tube of one Example of this invention. It is a figure explaining the outline of the main part of this invention in FIG. FIG. 1 schematically shows a main part of an embodiment of the core grooving device 10, (a) is a side view of the core grooving device, and (b) is a right side of the main part of (a). (C) is a perspective view of the core. The situation at the start of the groove formation when the groove is formed in the metal pipe by the above-mentioned core grooving device is explained, and (a) is an explanatory view of the situation at the tip of the metal pipe immediately before the start of the groove formation. , (B) is a cross-sectional view of the metal pipe at that time, (c) is an explanatory view of the situation of the tip of the metal pipe immediately after the start of forming the groove, and (d) is a cross-sectional view of the tip of the metal pipe at that time. It is a figure explaining the situation of the tip part of a metal pipe when the stopper which receives a core is used at the start of forming a concave groove in the case of forming a concave groove in a metal pipe by the above-mentioned core grooving device, and (a) is The state immediately before the tip of the metal tube reaches the core, (b) is the state at the time when the formation of a concave groove by a sphere starts at the tip of the metal tube, and (c) is the state at which the formation of a concave groove at the tip of the metal tube progresses slightly. At the same time, it is a figure explaining the state which removed the stopper. The core insertion / evacuation device of one embodiment as a device corresponding to the start of the concave groove formation in the case of forming the concave groove in the metal pipe by the above core grooving device is shown, and (a) shows the concave groove formation. The preparatory state before the start, (b) shows the state at the time when the groove formation starts. It is a figure explaining the desirable gap state between the inner surface of a metal tube and the outer surface of a core in a state where a concave groove is formed in a metal tube by the core grooving device. (A) describes another desirable gap state between the inner surface of the metal tube and the outer surface of the core in the state where the concave groove is formed in the metal tube by the above-mentioned core grooving device, and the means for realizing the other desirable gap state. (B) is a sectional view taken along line BB in (a). It is an enlarged view which showed the main part in FIG. 8 (a) (the figure clarified in FIG. 8 (a) because the size of a gap is not shown in the figure). It is a figure which showed the case where the length of the core in the core grooving device is lengthened so that it functions appropriately for forming a concave groove. An example of the specific structure of the core grooving device 10 described with reference to FIG. 3 is shown. FIG. 3 (a) is a side view of the core grooving device 10, and (b) is a lid of the housing 16 in (a). The front view (right arrow view) shown with the body 16c removed, (c) is a view showing only the sphere holding portion 56 of (b). It is a figure explaining the Example which provided the reduction adjustment mechanism by power in the core grooving apparatus 10 of FIG. It is a figure which shows the outline of the case where the core grooved apparatus 10 is installed offline, not in the electric sewing tube production line. An example of manufacturing a quadrangular square metal tube by the method for manufacturing a grooved metal tube of the present invention is shown, and (a) is a case where continuous concave grooves are formed on four surfaces of the square metal tube (b). Indicates a case where elongated concave grooves are intermittently formed on the four surfaces of the square metal tube in the longitudinal direction of the tube. An example of the cross-sectional shape of the grooved metal pipe manufactured by the method for manufacturing the metal pipe of the present invention is shown, and (a) is the grooved metal pipe (grooved square metal pipe) described in the examples, (b). Is a grooved pentagonal metal tube, (c) is a grooved hexagonal metal tube, (d) is a 4-grooved circular metal tube, (e) is a 6-groove grooved circular metal tube, and (f) is a corner. In the case of a square metal pipe with a groove, (g) is a case of a square metal pipe having two grooves on one side. It is a figure which schematically explains the electric sewing tube manufacturing apparatus which manufactures a general square metal tube. It is a figure explaining the conventional square metal tube provided with the rectangular recess which is elongated in the radial direction.

Hereinafter, embodiments for carrying out the apparatus and method for manufacturing a grooved metal tube of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically illustrating a case where the grooved metal tube manufacturing apparatus of the present invention is implemented in an electric sewing tube manufacturing apparatus, and FIG. 2 is a diagram illustrating an outline of a main part of the present invention in FIG. is there.
The metal plate 1 unwound from the uncoiler (not shown) is curved in an arc shape by a plurality of stages (4 stages in the illustrated example) breakdown roll (BDR) through a leveler, a looper, a pinch roll, etc. (all not shown). It is formed, and then formed into an almost circular shape (open circle) in which both edges are close to each other by a multi-stage (three stages (# 1, # 2, # 3) in the illustrated example) finpass rolls (FPR), followed by a squeeze roll. Both edges are butt-welded in a welding process using (SQR) and a high-frequency welder to form a circular tube, and then formed into a square metal tube by a shaping process using a multi-stage sizing roll (SZR). In this embodiment, a concave groove is formed in the quadrangular metal tube.
Then, it is grooved by the core grooving device 10 of the embodiment of the present invention to obtain a grooved quadrangular metal tube in the illustrated example.
After this grooving process, it is straightened with a Turks head roll (THR). The square metal tube may be shaped by a shaping step using a sizing roll (SZR), straightened by a Turks head roll (THR), and then grooved by the core grooving device 10.

FIG. 2 is an enlarged view of the finpass roll (FPR) of FIG. 1 with a part downstream from the first stand (# 1) omitted. The core grooving device 10 is attached to the grooving stand 11 indicated by the chain double-dashed line.
In the figure, 13 is an impeder. The impeder 13 is a magnetic core for collecting the magnetic flux generated by the coil of the high frequency induction heating device and efficiently heating the butt portion of both edges of the metal plate, and the rear end portion is a fin pass roll (FPR). ), It is connected to the fixing portion 15 arranged inside the curve of the metal plate 1 which is in a substantially circular curved state.

FIG. 3 schematically shows an embodiment of the core grooving device 10 in FIG. 1, (a) is a side view schematically showing the core grooving device 10, and (b) is (a). A cross-sectional view schematically showing the main part of the above, (c) is a perspective view of the core described later.
The core grooving device 10 is a portion for directly performing grooving in the grooved metal tube manufacturing device of the present invention, and the sphere 55 held rotatably is spaced in the circumferential direction in a manner of pushing the outer surface of the tube. Four open outer pipe mechanisms 19 and a short rod-shaped cross section along the inner surface of the pipe, at a position in the longitudinal direction of the pipe corresponding to the outer pipe mechanism 19, and a binding force other than contacting the inner surface of the pipe. A core 20 and a core 20 arranged in the pipe in a manner that does not receive the receiver are provided in the housing 16. A metal pipe guide 17 for guiding the metal pipe 8 "before being grooved is provided on the side of the housing 16 opposite to the metal pipe driving direction. FIG. 3 (c) shows the core 20 in a perspective view.
In this embodiment, since the concave groove 8a is formed on each of the four surfaces of the quadrangular metal tube 8 ”, the cross-sectional shape of the core 20 is a quadrangular cross section, and the four outer peripheral surfaces of the core 20 have the four. Only on the front side in the metal pipe driving direction from the position facing each sphere 55 of the extratube mechanism 19, there are four groove-shaped recesses 20a having a shape corresponding to each sphere 55. The groove end of the groove-shaped recess 20a ( The end portion where the groove starts) is a hemispherical concave surface (groove end hemispherical concave surface) 20a'. The rectangular cross-sectional portion (grooveless portion) of the core 20 without the groove-shaped recess 20a is indicated by 20b.
The sphere 55 of the extratube mechanism 19 is provided in the housing 16 so as to be adjustable in reduction as described later. The sphere 55 shown by the alternate long and short dash line indicates the state before being compressed.

Since the core 20 in the core grooving device 10 of the present invention is arranged in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe, at the start of grooving the tip of the metal pipe, for example, FIG. It is necessary to take the measures shown in (a) and (c).
In the illustrated example, the tip of the metal tube 8 "before grooving is stopped at a position directly below the sphere 55 as shown in FIG. 3 (a). Next, the core 20 is inserted into the tip of the metal tube. However, as shown in the drawing, the groove-shaped recess 20a is inserted so that the groove end hemispherical concave surface 20a'is at a position facing the sphere 55.
Next, the sphere 55 is pressed down to form a short groove 8a at the tip of the metal tube as shown in FIGS. 4 (c) and 4 (d). The portion (grooved metal tube) in which the concave groove 8a is formed is indicated by reference numeral 8.
After that, when the metal pipe is fed and driven (driven in the longitudinal direction of the pipe), the pipe wall passes between the sphere 55 and the outer surface including the groove-shaped recess 20a of the core 20 to reach the four surfaces of the metal pipe. The concave groove 8a is continuously formed. That is, a continuous concave groove 8a as shown in FIG. 14A is formed with a cross-sectional shape like the grooved quadrangular metal pipe shown in FIG. 15A.
The core 20, which is also called a floating core while floating in the pipe, receives a force in the metal pipe feeding direction due to a frictional force between the core 20 and the inner surface of the metal pipe to be fed, but the groove end of the groove-shaped recess. Since the hemispherical concave surface 20a'does not pass through the sphere 55, it remains even if it is not fixed somewhere (for example, it is not connected to the impeder by a rod as in the invention of the previous application). It stays in the state of FIG. 4 (c) and acts to form a concave groove in the metal tube.

FIG. 5 shows an example in which a stopper 14 for receiving the core 20 is used as a response at the start of grooving at the tip of the metal pipe. In the illustrated stopper 14, for example, a holding portion 14b having a square cross section for holding the core 20 is integrally provided with a stopper main body portion 14a for receiving the core 20.
FIG. 3A shows a state immediately before the tip of the metal tube 8 ”before grooving reaches the core. The core 20 is held by the stopper 14 in a state where it cannot move forward. The sphere 55 is held by the core 20. The groove-shaped recess 20a is arranged in a state in which a groove can be formed in the metal pipe with a gap slightly wider than the plate thickness t of the metal pipe.
FIG. 3B shows a state at the time when the formation of a concave groove by the sphere 55 is started at the tip of the metal tube. The tip of the metal tube enters the gap between the sphere 55 and the core 20 whose movement is restricted, and a short concave groove 8a is formed. Once the tip of the metal tube enters the gap between the sphere 55 and the core 20 to form a short recessed groove 8a, after that, if the metal tube is fed and driven, the sphere will be as described in FIG. 4 (b). Since the groove 8a is continuously formed on the four surfaces of the metal tube by the groove-shaped recess 20a of the core 20 and the core 20, the stopper 14 is shown in FIG. 5 (c) from the state of FIG. 5 (b). Evacuate to. The stopper 14 can be retracted by moving it forward as shown by the solid arrow and then lowering it. Depending on the structure of the holding portion 14b, it is also possible to rotate and retract as shown by the alternate long and short dash line.

FIG. 6 shows a core insertion / evacuation device 60 as a specific embodiment of a device corresponding to the start of machining a concave groove at the tip of a metal pipe. The core insertion / evacuation device 60 is, for example, a core groove. A main body frame 61 provided at the position of the sphere 55 of the attachment device, a swivel arm 62 rotatably attached to the main body frame 61, a core receiving portion 63 for receiving the core 20, and the core receiving portion 63. The receiving portion holder 64 that is fixedly held and slidably mounted along the swivel arm 62, and the receiving portion holder 64 that is moved forward and backward along the swivel arm 62 when the swivel arm 62 is in a horizontal state. It has a forward / backward drive device (not shown) which is possible. The core receiving portion 63 is smaller than the outer shape of the metal tube fixed to the receiving portion holder 64 integrally with the core supporting portion 63a inserted into the hole provided in the core 20 and the core supporting portion 63a. It is composed of an outer core stopper portion 63b.
In the case of the core insertion / evacuation device 60, at the start of grooving at the tip of the metal pipe, as shown in FIG. 6A, the swivel arm 62 is set horizontally in advance and the receiving portion holder 64 is set vertically. The core support portion 63a of the child receiving portion 63 is inserted into the central hole 20d of the core 20 to support the core 20. The core 20 is provided with a central hole 20d into which the core receiving portion 63 is inserted.
Then, as shown in FIG. 6A, the metal tube is temporarily stopped before the tip reaches the sphere 55 of the core grooving device, and the receiving portion holder 64 is moved along the swivel arm 62 by the forward / backward drive device (not shown). The core 20 is inserted into the tip of the metal tube as shown in FIG. 6 (b).
When the sphere 55 is pressed down to a predetermined position in this state and then the metal tube is slightly advanced, a concave groove is formed in the vicinity of the tip of the metal tube. In this case, since the core stopper portion 63b of the core receiving portion 63 receives the core 20, the core 20 acts to form a concave groove in the stable metal tube.
Next, after the receiving portion holder 64 is retracted to the position shown in FIG. (A), the swivel arm 62 is swiveled to the vertical retracted position indicated by the chain double-dashed line to retract the metal tube, and then the metal tube is fed and driven. The concave groove 8a is continuously formed.

In the groove processing performed by inserting the tube wall of the metal pipe into the gap between the sphere 55 and the groove-shaped recess 20a of the core 20, the groove processing is performed with a large frictional force, so that an excessive pressing force acts on the welded portion. Then, the welded part may be damaged. In order to prevent this, it is effective to make the gap g between the sphere 55 and the groove-shaped recess 20a of the core 20 particularly between the groove-end hemispherical concave surface 20a's slightly larger than the other surface without the welded portion. In this case, the outer bead of the welded portion is ground to be flat, but the inner bead is raised inward. Therefore, as shown in FIG. 7, between the sphere 55 and the groove end hemispherical concave surface 20a'of the core 20 If the gap g is increased (that is, if the reduction amount (pushing amount) of the core 20 is reduced), a gap δ of an appropriate size is provided between the groove end hemispherical concave surface 20a'of the core 20 and the inner surface of the metal tube. Can be prevented from damaging the inner bead.
For example, when the gap g is formed in a square steel pipe having a diameter of □ 2.3 × 80 × 80 mm or □ 3.2 × 80 × 80 mm by using a sphere 55 having a diameter of 40 mmφ to form a concave groove 8a having a depth of 6 mm. The gap g between the sphere 55 and the groove end hemispherical concave surface 20a'of the core 20 is preferably, for example, a plate thickness t + 1.3 ± 0.2 mm.

In order for the core 20 to smoothly and stably perform the groove processing operation in the metal pipe, there is a slight gap c between the outer surface of the core 20 (the outer surface in the square cross-sectional portion 20b) and the inner surface of the metal pipe. It is desirable that the gap c be uniform and constant for each surface (four surfaces in the case of the embodiment).
As a measure to make the gap c uniform and constant on each surface, in the embodiment shown in FIG. 8, a grooveless portion (groove) on the side opposite to the metal pipe driving direction from the groove end hemispherical concave surface 20a'of the core 20. None Square cross section) 20b outer peripheral surface and grooved outer surface of grooved portion (groove square cross section) 20c on the front side of the groove end hemispherical concave surface 20a'in the metal pipe drive direction, the inner surface of the pipe is urged outward. A ball plunger 31 as a means of urging the inner surface of the pipe is embedded in the outer circumference of the core. FIG. 9 shows an enlarged view of the vicinity of the ball plunger 31.
In the illustrated example, the ball plungers 31 are provided at 12 locations in total, 3 locations near the corner portions and the central portion on both sides of the four surfaces of the square cross-sectional portion 20b of the core 20. The ball plunger 31 has a structure having a ball 31c urged by a spring 31b in a cylindrical case 31a.
By urging the four inner surfaces of the pipe to the outside by a spring force by these ball plungers 31, the gap c between the outer surface of the core 20 and the inner surface of the metal pipe can be made equal for each surface. The size of the gap c can be stabilized so as not to fluctuate.
In the case of □ 2.3 × 80 × 80 mm or □ 3.2 × 80 × 80 mm, the gap c between the outer surface of the core 20 and the inner surface of the metal tube is appropriately about 0.5 mm.

As a measure to keep the gap c as uniform and constant as possible, it is important to suppress the movement of the core, which is not restricted in movement, as much as possible. Therefore, it is effective to eliminate the tilt and back-and-forth movement of the core 20 as much as possible.
FIG. 10 shows that the length of the core is lengthened mainly to eliminate the inclination, and the length L2 of the long core 20'in the illustrated example is the length of the core 20 shown in FIGS. 3 to 5 and 8. It is about 2.5 times as large as that of L1.
By lengthening the core, the contact area between the lengthened core and the inner surface of the metal tube becomes large, and the effect of stabilizing the core without moving back and forth unnecessarily can be obtained.

FIG. 11 shows an example of a specific structure of the core grooving device 10 described with reference to FIG. 3, where (a) is a side view of the core grooving device 10 and (b) is a housing in (a). It is a front view (right arrow view) shown by removing the lid body 16c of 16.
As shown in the figure, the core grooving device 10 includes four extratube mechanisms 19 outside the tube and one core 20 inside the tube in the housing 16.
As shown in FIG. 11C, the extratube mechanism 19 accommodates and supports the sphere 55 in surface contact with the concave spherical seat 54a of the seat portion 54 having the concave spherical seat 54a so as to be rotatable in an arbitrary direction. The spherical surface holding portion 56 is provided, and the reduction adjustment mechanism 57 is provided. The seat portion 54 includes a seat portion main body 54b having the concave spherical seat 54a and a lid body 54c that presses the upper part of the sphere 20.
Each sphere holding portion 56 is slidable in the housing 16 in a direction toward the center of the core 20.
The reduction adjustment mechanism 57 has a reduction screw 57a rotatably connected to the upper surface of the sphere holding portion 56, an adjustment nut 57b screwed into the reduction screw 57a, and the adjustment nut 57b rotatably attached to the housing body 16a. It includes a nut holding portion 57c for fixing. The reduction can be adjusted by turning the adjusting nut 57b to adjust the position of the sphere holding portion 56 (the position of the sphere 55).
The housing body 16a of the housing 16 is integrated with the inner base portion 16a', and slidably accommodates the four sphere holding portions 56 as described above. The outer lid body 16c is fixed to the housing body 16a with bolts.
A metal pipe guide 17 shown by a two-dot chain line in FIG. 3 for guiding the “metal pipe before grooving” is fixed to the base portion 16a'of the housing body 16a, and details thereof will be omitted. Is connected by four rods 25 between the frame plate 26 attached to the grooving stand 11 shown by the alternate long and short dash line in FIG. 2 and the base portion 16a'.
When it is necessary to rotate the core grooving device 10, it is preferable to make the frame plate 26 into a disk shape and attach it to the grooving stand 11 so that the rotation can be adjusted.
When the metal tube 8 ”passes through the core grooving device 10, a concave groove 8a is formed by the sphere 55 outside the tube and the core 20 inside the tube to obtain the grooved metal tube 8. It is as explained in 3.

When forming a grooved metal tube 8'having a groove 8b spaced apart in the longitudinal direction of the tube as shown in FIG. 14B, each sphere holding portion 56 can be quickly driven up and down. A moving mechanism is provided to raise each sphere holding portion 56 in a region where a concave groove is not formed.
As a result, a grooved metal tube 8'having recessed grooves 8b spaced in the longitudinal direction of the tube as shown in FIG. 14B can be obtained.
By pulling the position of the sphere holding portion 56 (the position of the sphere 55) in the core grooving device 10 away from the core 20 (releasing the reduction), a quadrangular metal tube without a concave groove can be manufactured.

The reduction adjustment mechanism 57 shown in FIG. 11 is an adjustment mechanism that manually turns the adjustment nut 57b, but as shown in FIG. 12, a power reduction adjustment mechanism 67 can be provided. In this case, for example, a means for transmitting the rotation of the output shaft of the drive motor 67a by changing the direction by 90 °, for example, rotating the reduction screw 57a via a rotation shaft conversion mechanism 67b by a gear mechanism can be adopted.

FIG. 13 is a diagram showing an outline of an embodiment in which the core grooving device 10 is installed offline instead of in the electric sewing tube production line.
In this case, the core grooving device 10 is installed at an intermediate position of the transfer roller 74. For example, a stopper 72 is attached to the end of a wire 71 passed through the tube of a quadrangular metal tube 8 "without a concave groove, the wire 71 is pulled by a winch 73, and the quadrangular metal tube 8" on the transport roller 74 is inserted into a core groove. Pass the attachment device 10. Rollers 74a for holding and guiding a quadrangular metal tube from above are provided in front of and behind the core grooved device 10. In this case, the core 20 is provided with a hole for passing the wire 71.
Similar to the above, when the quadrangular metal tube 8 without a groove passes through the core grooving device 10, the groove 8a is formed by the sphere 55 outside the tube and the core 20 inside the tube, and the grooved metal tube is formed. The fact that 8 is obtained is as described in FIG.
Although detailed description is omitted, the core insertion / evacuation device 60 described with reference to FIG. 6 can also be used when the core grooving device 10 is installed offline as in FIG. In this case, instead of pulling the wire 71 with the stopper 72 attached to the end end by the winch 73 to drive the metal pipe in the longitudinal direction of the pipe as shown in FIG. 13, for example, a hydraulic cylinder is attached to the rear end of the metal pipe. It can be provided so that the hydraulic cylinder pushes out the metal tube.
In the illustrated example, the grooving is performed by the method of extruding the metal tube, but it is also possible to perform the grooving by the drawing method.

In the above-described embodiment, the grooved quadrangular metal pipe (grooved quadrangular metal pipe of FIG. 15A) has been described, but the present invention is not limited to this, and for example, the grooved pentagonal metal pipe shown in FIG. A grooved polygonal metal tube such as the grooved hexagonal metal tube shown in 15 (c) can be manufactured. In addition to the square shape, it is also possible to manufacture a grooved circular metal tube having four grooves shown in FIG. 15 (d), a grooved circular metal tube having six grooves shown in FIG. 15 (e), and the like. ..
Further, as shown in FIG. 15 (f), it is possible to manufacture a quadrangular metal tube (polygonal metal tube) having a groove in the corner portion and having a groove in the corner portion, and as shown in FIG. 15 (g), for example. It is also possible to manufacture a quadrangular metal tube (polygonal metal tube) having a plurality of grooves such as two on one side.

1 Metal plate 8, 8'Groove metal tube 8 "Square metal tube 8a before grooving Concave groove 8b (formed at intervals in the longitudinal direction of the tube) Concave groove 10 Core grooving device 14 Stopper 14a Stopper body Part 14b Holding part 16 Housing 16a Housing body 16a'(of the housing body) Base part 16c Lid 17 Metal pipe guide 19 Outer tube mechanism 20 Core 20a Grooved recess 20a' Groove end hemispherical concave surface 20b Square cross section (grooveless part)
25 Rod 26 Frame plate 31 Ball plunger (means for pushing up the inner surface of the pipe)
54 Seat 54a Concave spherical seat 54b Seat body 54c Lid 55 Sphere 56 Sphere holding 57 Reduction adjustment mechanism 57a Reduction screw 57b Adjustment nut 57c Nut holding 60 Core insertion / evacuation device 61 Main body frame 62 Swivel arm 63 Core receiver 63a Core support 63b Core stopper 64 Receiver holder

Claims (6)

A grooved metal tube manufacturing device having concave grooves extending in the longitudinal direction of the tube at a plurality of locations spaced in the circumferential direction of the outer surface of the metal tube driven in the longitudinal direction of the tube.
A plurality of extratube mechanisms provided at intervals in the circumferential direction in a manner in which a rotatably held sphere pushes the outer surface of the tube.
It has a short rod shape with a cross-sectional shape along the inner surface of the pipe, and is arranged in the pipe independently at a position in the longitudinal direction of the pipe corresponding to the outer mechanism of the pipe and in a manner that does not receive a binding force other than contacting the inner surface of the pipe. With a child,
Wherein the outer peripheral surface of the core, the only metal tube drive forward side respectively from opposite positions in the sphere of the extravascular mechanisms, which have a plurality of groove-like recess having a shape corresponding to the spherical bodies, the A grooved metal tube manufacturing apparatus, characterized in that the end portion of the groove-shaped recess where the groove starts has a hemispherical concave surface corresponding to the sphere . There is a groove on the outer peripheral surface of the grooveless portion on the opposite side of the groove end hemispherical concave surface, which is the end portion of the core in the groove-shaped recess , and on the front side in the metal tube drive direction from the groove end hemispherical concave surface. The grooved metal pipe manufacturing apparatus according to claim 1, wherein a pipe inner surface pushing-up means for pushing up the inner surface of the pipe so as to bulge outward is provided on an outer peripheral surface without a groove in the portion. The grooved metal tube manufacturing apparatus according to claim 2, wherein a ball plunger having a ball urged by a spring is embedded in the outer peripheral surface of the core as the means for pushing up the inner surface of the pipe. A method for manufacturing a grooved metal pipe having concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe by the grooved metal pipe manufacturing apparatus according to any one of claims 1 to 3. And
At the start of production, with the core placed inside the tip of the metal pipe, the sphere of each extratube mechanism is pushed down to the tip of the metal pipe to form a short groove, and the metal pipe is continuously lengthened. A method for manufacturing a grooved metal pipe, which comprises forming concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe by driving in the manual direction. The metal plate is curved and molded into a substantially circular shape with a breakdown roll and a finpass roll, and then, with a squeeze roll and a welding device, both edges of the metal plate in the substantially circular curved state are butt-welded to form a circular tube, and then a sizing roll. The grooved metal pipe manufacturing apparatus according to claims 1 to 3 is installed on the downstream side of the sizing roll in the electric sewing tube manufacturing apparatus to be shaped by the above, and is driven in the longitudinal direction of the pipe by the sphere and the core. This is a method for manufacturing a grooved metal pipe in which concave grooves extending in the longitudinal direction of the pipe are formed at a plurality of locations spaced apart from each other in the circumferential direction of the outer surface of the metal pipe.
Method of manufacturing a slotted metal tube you characterized by producing a grooved metal pipe by the manufacturing method of the grooved metal tube according to claim 4. A method for manufacturing a grooved metal pipe, which forms concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the pipe offline in the metal pipe manufactured by the electric sewing pipe manufacturing apparatus.
The grooved metal pipe manufacturing apparatus according to claims 1 to 3 is installed at an intermediate position of the transport table in a drive device provided with a transport table to drive the metal pipe in the longitudinal direction of the pipe, and the sphere and the core thereof are used. , When forming concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced in the circumferential direction of the outer surface of the metal pipe driven in the longitudinal direction of the pipe on the transport table.
A method for manufacturing a grooved metal tube, which comprises manufacturing a grooved metal tube by the method for manufacturing a grooved metal tube according to claim 4.

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