JP6817047B2 - Grooved metal tube manufacturing equipment and manufacturing 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 manufacturing 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. 19 because it is assumed to be used as a skid (sleeper) for placing the packed steel material not directly on the floor surface but with a gap. 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. 19, 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 in the circumferential direction of the outer surface of a metal pipe such as a steel pipe, the concave spherical surface of the ball accommodating portion (bearing portion) having the concave spherical surface is formed. A grooving device having an extratube mechanism having a spherical bearing for rotatably accommodating a sphere and a core having a groove-like recess at a position corresponding to the sphere and arranged in the metal pipe, on the outer circumference of the metal pipe. A patent application for a grooved metal pipe manufacturing apparatus for forming a groove has been filed under the present applicant. The extratube mechanism of the grooving device in the grooving metal tube manufacturing device has a structure in which a sphere is simply received by a concave spherical surface (Japanese Patent Application No. 2016-155253, Japanese Patent Application No. 2016-073758). In the previous application, the spherical bearing is called a spherical holding portion.
This grooved metal tube manufacturing method, in which a concave groove is formed on the outer periphery of the metal tube by a sphere outside the tube of the grooving device and a core inside the tube, is extremely compact and simple, and the space is narrow as a grooved metal tube manufacturing device. It is completed and the equipment cost is low, but further improvement is desired.

In this grooved metal tube manufacturing apparatus, a groove is formed in the metal tube by a sphere outside the tube that pushes the tube wall of the metal tube and a groove-shaped recess in the core that receives the pushed tube wall. A large load acts on the sphere that pushes the tube wall of the tube. There is no problem if the sphere bearing can support the sphere without frictional resistance, but in reality, frictional resistance always occurs.

When this grooving device is installed especially in a pipe making line by an electric sewing pipe manufacturing device to form a concave groove in a metal pipe, if the frictional resistance against the rotation of a sphere is large, a large power is applied as a material feed drive of the pipe making line. I need.
The power required for the pipe making line is the molding power required for molding (including shaping in the sizing zone) and the feed drive power required for feed drive. As described above, the friction with respect to the rotation of the sphere of the grooving device. When the resistance is large, the power required for the feed drive becomes large.
When installing a new pipe making line equipped with a grooving device, it is designed to meet the required forming power and feed drive power, but when installing a grooving device on an existing pipe making line, Since various problems occur in the modification to increase the power of the existing pipe making line, it is usually necessary to reduce the pipe making speed of the pipe making line.

Further, not only when it is installed in the electric sewing tube manufacturing device as described above, but also when a groove is formed in a metal pipe by a grooving device using a spherical bearing, it is possible to reduce the frictional resistance against the rotation of the sphere. , A big advantage.

The present invention has been made under the above circumstances, and when a concave groove extending in the longitudinal direction of a pipe is formed in a metal pipe by an extratube mechanism having a spherical bearing and a core arranged in the metal pipe, the spherical bearing The purpose is to reduce the frictional resistance to the rotation of the sphere in the above, and to facilitate the production of the grooved metal tube.

The invention of claim 1 for solving the above problems is to manufacture a grooved 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 surface of the metal pipe fed and driven in the longitudinal direction of the pipe. It ’s a device,
The sphere and the sphere are rotatably held by a ball accommodating portion forming a concave spherical surface, and the sphere has a sphere bearing consisting of a sphere holder that is immovable in the circumferential direction of the metal pipe and is movable in the center direction of the metal pipe. A plurality of extratube mechanisms provided at intervals in the circumferential direction in a mode of pushing
It has a short rod shape with a cross-sectional shape along the inner surface of the pipe, and is provided with a core that is arranged in the pipe and receives a portion corresponding to the sphere of each sphere bearing.
The outer peripheral surface of the core has a plurality of groove-shaped recesses having a shape corresponding to the sphere only on the front side in the metal tube moving direction from a position facing the sphere of each sphere bearing.
The sphere bearing is characterized in that the sphere is placed on a large number of small spheres arranged on a concave spherical surface of a ball accommodating portion of the sphere holder.

A second aspect of the present invention is the grooved metal tube manufacturing apparatus according to the first aspect, wherein the spherical bearing has a metal tube moving direction in at least a central region in a left-right direction orthogonal to a metal tube moving direction of a concave spherical surface of the ball accommodating portion. The even-numbered rows of track grooves are formed, and the even-numbered rows of track grooves are composed of a plurality of pairs of shallow grooves and deep grooves, and the shallow grooves and deep grooves in each pair are the ends thereof. It is characterized in that it communicates in a connecting passage which is an inclined surface of the portion, and the small ball can circulate between the shallow groove and the deep groove.

According to claim 3, in the grooved metal tube manufacturing apparatus of claim 2, the even-numbered rows of track grooves on the concave spherical surface of the holder body are located only in the central region in the left-right direction orthogonal to the metal tube moving direction, and the left and right thereof. The region outside the direction is characterized by being a simple concave spherical surface without grooves.

A fourth aspect of the present invention is the apparatus for manufacturing a grooved metal tube according to any one of claims 1 to 3.
It is characterized in that the core is arranged in the pipe in such a manner that it does not receive a binding force other than contacting the inner surface of the pipe.

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

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. ,
The grooved metal pipe manufacturing apparatus according to claim 1 to 4 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. 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 driven in the longitudinal direction of the pipe on the transport table.

In the grooved metal pipe manufacturing apparatus of the invention of claim 1, a concave groove is formed in the metal pipe by the rotating sphere of the spherical bearing and the groove-shaped concave portion of the core with respect to the feed-driven metal pipe. At that time, the sphere does not rotate in direct contact with the concave sphere of the ball accommodating portion, but rotates while being placed on a large number of small spheres arranged on the concave sphere, so that the frictional resistance to the rotation of the sphere is reduced. To.
Therefore, when the extratube mechanism having the spherical bearing and the core arranged in the metal tube form a concave groove extending in the longitudinal direction of the tube in the metal tube, the frictional resistance to the rotation of the spherical body in the spherical bearing is reduced and the groove is formed. The metal tube with bearing can be manufactured smoothly.

In claim 2, when the sphere and the core form a concave groove in the metal tube, the sphere rotates in the same direction as the moving direction of the metal tube.
With respect to this sphere, of the pair of track grooves of the shallow groove and the deep groove in the central region, the small sphere in the shallow groove comes into contact with the sphere and receives a load in the direction opposite to the rotation direction of the sphere (metal). Rotate in the direction opposite to the direction of movement of the tube). On the other hand, the small sphere in the deep groove does not come into contact with the sphere, so it is in a no-load state.
Since the track groove is in the direction of movement of the metal pipe, the globules in the shallow groove move in the direction opposite to the direction of movement of the metal pipe while rotating, and pass through the connecting passage at the end to the adjacent deep groove. to go into. The globules that have entered the deep groove push the globules in the deep groove, and the pressed globules in the deep groove move in the metal tube movement direction (forward direction) in the deep groove and become a shallow groove via the connecting passage on the opposite side. enter. The small sphere that has entered the shallow groove from the deep groove contacts the sphere and receives a load as described above, and rotates in the direction opposite to the rotation direction of the sphere (the direction opposite to the moving direction of the metal tube).
In this way, the small sphere that circulates between the shallow groove and the deep groove supports the rotation of the sphere while rotating in the opposite direction when it is in the shallow groove.
Since the groove direction of the track groove coincides with the metal tube moving direction, the small sphere in the shallow groove supporting the sphere rotating in the metal tube moving direction has a rotation axis substantially parallel to the rotation axis of the rotating sphere. Rotate in mode (opposite direction but rotate in approximately the same direction). Therefore, there is little unnecessary slip between the sphere and the globules, and the frictional resistance between the sphere and the globules is remarkably small.
In a structure in which a large number of small spheres are arranged on a simple concave sphere, the positions of the small spheres are not fixed and the rotation direction is also irregular, so that the frictional resistance to the supporting sphere is also large. According to the sphere bearing, as described above, the small sphere rotates in the direction correctly opposite to the rotation direction of the sphere (movement direction of the moving body) (rotates in the opposite direction in a manner having a rotation axis substantially parallel to the rotation axis of the rotating sphere). ), Therefore, the slip generated between the sphere and the small sphere is small and the frictional resistance is small.

As described in the background technology, when a grooving device using a sphere bearing is installed in a pipe making line by an electric sewing pipe manufacturing device to form a concave groove in a metal pipe, if the frictional resistance to the rotation of the sphere is large, A large amount of power is required to drive the material feed of the pipe making line.
The power required for the pipe making line is the molding power required for molding (including shaping in the sizing zone) and the feed drive power required for feed drive. As described above, the friction with respect to the rotation of the sphere of the grooving device. When the resistance is large, the power required for the feed drive becomes large.
When installing a new pipe making line equipped with a grooving device, it is designed to meet the required forming power and feed drive power, but when installing a grooving device on an existing pipe making line, Since various problems occur in the modification to increase the power of the existing pipe making line, it is usually necessary to reduce the pipe making speed of the pipe making line.
However, according to the grooving device using a spherical bearing as in claim 2, the frictional resistance to the rotation of the sphere is remarkably reduced, so that the power for feeding the material is reduced.
Therefore, even when a grooving device using a spherical bearing is installed in an existing pipe making line, for example, it is not necessary to modify the existing pipe making line to increase the power, and the pipe making speed of the pipe making line is lowered. It is possible to install it without having to do it.

In addition, when the sphere needs to be rotated at a significantly high speed, or when it is used for an application that requires an extremely large load, seizure may occur, but the frictional resistance may be reduced. , Is effective in avoiding such problems.

In a spherical bearing, most of the load received by the concave spherical surface from the spherical surface is near the center of the concave spherical surface. Therefore, as in claim 3, the region where the track groove is provided is limited to the central region in the left-right direction orthogonal to the metal tube moving direction. Is appropriate.

As in claim 4, by arranging the core in the pipe in such a manner that the core does not receive a binding force other than contacting the inner surface of the pipe, complicated core fixing means becomes unnecessary, and a grooving device is configured. Is simplified.

It is a figure schematically explaining an Example of the electric sewing tube manufacturing apparatus which carries out the manufacturing apparatus and manufacturing method of the grooved metal tube of this invention. It is a figure explaining the outline of the main part of this invention in FIG. The main part of an embodiment of the grooving device 10 in FIG. 1 is schematically shown, (a) is a side view of the grooving device, and (b) is a schematic view of the main part of (a). AA cross-sectional view, (c) is a perspective view of the core. The core insertion / evacuation device of one embodiment as a device corresponding to the start of the groove formation in the case of forming the concave groove in the metal pipe by the above-mentioned grooving device is shown, and (a) starts the concave groove formation. The previous preparatory state, (b), indicates the state at the time when the groove formation starts. (A) is a diagram illustrating a desirable gap state between the inner surface of the metal tube and the outer surface of the core in a state where a concave groove is formed in the metal tube by the above grooving device, and a means for realizing the desired gap state. B) is a sectional view taken along line BB in (a). An example of the specific structure of the grooving device 10 described with reference to FIG. 3 is shown. FIG. 3 (a) is a side view of the grooving device 10, and (b) is a removal of the lid 16c of the housing 16 in (a). The front view (right arrow view) and (c) shown in (c) are views showing only the spherical bearing 56 of (b). FIG. 6 is a perspective view showing the spherical bearing 56 in FIG. 6 with the lid of the spherical holder removed. FIG. 7 is a perspective view showing a state in which a sphere is removed in FIG. 7. FIG. 8 is a perspective view showing a state in which small balls are removed in FIG. FIG. 7 is a sectional view taken along line CC in a state where the lid is attached. FIG. 8 is a plan view of FIG. FIG. 9 is a plan view of FIG. FIG. 10 is a diagram showing a state in which a sphere, a small sphere, and a lid are removed. It is an enlarged view of the main part in FIG. It is a figure which shows the outline of the case where the above-mentioned grooving device is installed offline instead of 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 four surfaces of a 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, a mode for carrying out the manufacturing apparatus and manufacturing method of the grooved metal tube of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically explaining a case where the grooved metal tube manufacturing apparatus and the manufacturing method of the present invention are carried out in the electric sewing tube manufacturing apparatus, and FIG. 2 is an outline of a main part of the present invention in FIG. It is a figure to do.
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 a substantially 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 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). A square metal tube may be formed by a shaping step using a sizing roll (SZR), corrected by a Turks head roll (THR), and then grooved by the 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 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.

3 (a) to 3 (c) schematically show a configuration that is generally a prerequisite for the grooving device 10 in the present invention, and is a spherical bearing 56 that is a main part in the present invention (details in FIGS. 6 to 14). (Described later) shows only the sphere 55, (a) is a side view of the grooving device 10, (b) is a sectional view taken along the line AA schematically showing the main part of (a). (C) is a perspective view of the core described later.
The grooving device 10 is a portion for directly performing grooving, and is provided with four spheres 55 rotatably held in the sphere bearing 56, which will be described in detail later, at intervals in the circumferential direction in a manner of pushing the outer surface of the pipe. The outer tube mechanism 19 has a short rod shape with a cross-sectional shape along the inner surface of the pipe, is located in the longitudinal direction of the pipe corresponding to the outer tube mechanism 19, and in the illustrated example, receives no binding force other than contacting the inner surface of the pipe. A core 20 arranged in the pipe in the embodiment is provided in the housing 16. A metal pipe guide 17 for guiding the metal pipe 8 "before grooving is provided on the side opposite to the metal pipe moving direction (metal pipe driving direction) of the housing 16. The core 20 is viewed from the perspective of FIG. 3 (c). Shown in the figure.
As described above, in this embodiment, the core 20 is arranged in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe, and can be said to be a floating core, but the core is fixed. It may be provided in. In this case, the core may be connected to, for example, the tip of the impeder 13 via a rod-shaped body.
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 moving 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 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.
In this grooving device 10, when the metal tube 8 "before grooving is driven in the direction of the arrow in FIG. 3 (a), the tube wall becomes the outer surface including the sphere 55 and the groove-shaped recess 20a of the core 20. By passing between the grooves, the concave grooves 8a are continuously formed on the four surfaces of the metal tube. That is, the cross-sectional shape is similar to that of the grooved square metal tube of FIG. ) Is formed as a continuous groove 8a.

Since the core 20 in the grooving device 10 of the embodiment is arranged in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe, for example, it is shown in FIG. 4 at the start of grooving the tip of the metal pipe. It is preferable to hold the core with such a child insertion / evacuation device 60.
The core insertion / evacuation device 60 receives, for example, a main body frame 61 provided at the position of the sphere 55 of the grooving device, a swivel arm 62 rotatably attached to the main body frame 61, and a core 20. The receiving portion 63, the receiving portion holder 64 which holds the core receiving portion 63 fixedly and is slidably mounted along the swivel arm 62, and the receiving portion when the swivel arm 62 is in a horizontal state. It has a forward / backward drive device (not shown) capable of moving the holder 64 forward / backward along the swivel arm 62. 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 machining the concave groove at the tip of the metal pipe, as shown in FIG. 4 (a), the swivel arm 62 is previously made horizontal and the receiving portion holder 64 is made vertical. 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. 4A, the metal tube is temporarily stopped before the tip reaches the sphere 55 of the grooving device, and the receiving portion holder 64 is advanced along the swivel arm 62 by the forward / backward drive device (not shown). Then, the core 20 is inserted into the tip of the metal tube as shown in FIG. 4 (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. 4A, the swivel arm 62 is swiveled to the vertical retracted position indicated by the chain double-dashed line to retract and the metal pipe is fed and driven. Recessed grooves 8a are continuously formed on the four surfaces of the pipe. That is, a continuous concave groove 8a as shown in FIG. 16A is formed with a cross-sectional shape like the grooved quadrangular metal tube shown in FIG. 17A.

When forming a grooved metal pipe 8'with recessed grooves 8b spaced in the longitudinal direction of the pipe as shown in FIG. 16B, each spherical bearing 56 can be quickly moved up and down. A mechanism is provided to raise each spherical bearing 56 in a region where no groove is 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. 16B can be obtained. In this case, the core 20 in FIG. 6 is fixedly provided, for example, by connecting it to the tip of the impeder 13 in FIG. 2 via a rod-shaped body.
By pulling the position of the spherical bearing 56 (the position of the spherical body 55) in the grooving device 10 away from the core 20 (releasing the reduction), a quadrangular metal tube without a concave groove can be manufactured.

In the concave 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 the groove-end hemispherical concave surface 20a'slightly larger than that of the other surface without the welded portion, as shown in FIG. .. In this case, the outer bead of the welded portion is ground to be flat, but the inner bead is raised inward, so that the gap g between the sphere 55 and the groove end hemispherical concave surface 20a'of the core 20 is increased. If this is done (that is, if the amount of reduction (pushing amount) of the core 20 is reduced), a gap g of an appropriate size is generated between the groove end hemispherical concave surface 20a'of the core 20 and the inner surface of the metal tube, and the inner bead. Can be prevented from being damaged.
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 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 there is, and that the gap c is 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. 5, a grooveless portion (groove) on the side opposite to the metal pipe moving 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 in the metal pipe movement direction from the groove end hemispherical concave surface 20a', 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.
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 in which a ball urged by a spring is provided in a cylindrical case.
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, although not shown, it is effective to eliminate the tilt and back-and-forth movement of the core 20 as much as possible by, for example, increasing the length of the core.
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.

Although the above-mentioned FIG. 3 shows a configuration that is generally a prerequisite for the grooving device 10 in the present invention, FIG. 6 shows an embodiment including a spherical bearing 56 that is a main part in the present invention.
FIG. 6A is a side view of the grooving device 10, and FIG. 6B is a front view (right arrow view) showing the housing 16 in (a) with the lid 16c removed.
The extratube mechanism 19 mentioned in FIG. 3 includes a spherical bearing 56 and a reduction adjustment mechanism 57.
The sphere bearing 56 is arranged on a sphere holder 54 for accommodating the sphere 55 and the sphere 55 in a ball accommodating portion 54a forming a concave spherical surface and a concave spherical surface of the ball accommodating portion 54a, and a large number of small spheres on which the sphere 55 is placed. It is composed of 80, and is provided at intervals in the circumferential direction in such a manner that the sphere 55 pushes the outer surface of the pipe.
The core 20 has a configuration as described with reference to FIG. 3, has a short rod shape having a cross-sectional shape along the inner surface of the pipe, and is arranged in the pipe to receive a portion corresponding to the sphere 55 of each sphere bearing 56. It has a recess 20a on its outer peripheral surface. The groove-shaped recess 20a is formed only on the front side in the metal pipe moving direction (front in the metal pipe driving direction) from the position facing the sphere 55 of each of the sphere bearings 56.

Each spherical bearing 56 is slidable in the housing 16 in a direction toward the center of the core 20.
The reduction adjustment mechanism 57 fixes the reduction screw 57a rotatably connected to the upper portion of the spherical bearing 56, the adjustment nut 57b screwed into the reduction screw 57a, and the adjustment nut 57b to the housing body 16a so as to be rotatable only. It is composed of a nut holding portion 57c. The reduction can be adjusted by turning the adjusting nut 57b to adjust the position of the spherical bearing 56 (the position of the spherical 55).
The housing body 16a of the housing 16 is integrated with the inner base portion 16a', and slidably accommodates four spherical bearings 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 two-dot chain line in FIG. 2 and the base portion 16a'.
When it is necessary to rotate the grooving device 10, the frame plate 26 may be formed into a disk shape and attached to the grooving stand 11 so that the rotation can be adjusted.
When the metal tube 8 ”passes through the 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 in FIG. As explained.
The reduction adjustment mechanism 57 is an adjustment mechanism that manually turns the adjustment nut 57b, but a power reduction adjustment mechanism can be provided.

The detailed structure of the spherical bearing 56 is shown in FIGS. 7 to 14. 7 is a perspective view showing the spherical bearing 56 in FIG. 6 with the lid 54c of the spherical holder 54 removed, FIG. 8 is a perspective view showing a state in which the spherical body 55 is removed in FIG. 7, and FIG. 9 is a view. 8 is a perspective view showing a state in which the small ball 80 is removed in No. 8. 10 is a sectional view taken along the line CC with the lid 54c attached in FIG. 7, FIG. 11 is a plan view of FIG. 8, FIG. 12 is a plan view of FIG. 9, and FIG. 13 is a lid 54c and a sphere 55 in FIG. The figure showing the state excluding the small ball 80 and the small ball 80, FIG. 14 is an enlarged view of the main part in FIG.
In the ball accommodating portion 54a of the holder body 54b, an even-numbered row of track grooves forming the metal pipe moving direction X is formed in the central region in the Y direction orthogonal to the metal pipe moving direction (arrow X direction) of the concave spherical surface. ing.
The even-numbered track grooves are composed of a plurality of sets consisting of a pair of shallow grooves 81a and deep grooves 81b, and the shallow grooves 81a and deep grooves 81b in each set are connecting passages 81c which are inclined surfaces at their ends. The globules 80 are configured to be able to circulate between the shallow groove 81a and the deep groove 81b. A circulation path including a shallow groove 81a, a deep groove 81b, and a connecting passage 81c is indicated by 81.
The shallow groove 81a and the deep groove 81b are both grooves having an arc cross section that matches the shape of the small sphere 80, and the shallow groove 81a, the deep groove 81b, and the boundary wall are indicated by 82a. The boundary wall between the pair of shallow grooves 81a and deep grooves 81b is indicated by 82b.
The shape of the lower surface portion (the dovetail groove portion) of the holder body 54b in the spherical bearing 56 shown in FIGS. 7 to 12 is different from the shape of the holder body 54b in the spherical bearing 56 shown in FIG. Either is fine.

In this embodiment, two sets of track grooves are formed on both sides of the central position in the direction orthogonal to the metal tube moving direction, and the other regions of the concave spherical surface are simply concave spherical regions 83 without grooves. is there. The boundary wall between the grooved region and the non-grooved region is indicated by 82c.
The depth of the shallow groove 81a is the depth at which the globules 80 come into contact with the sphere 55, and the globules 80 in the shallow groove 81a rotate and move while receiving a load while supporting the rotating sphere 55. The depth of the deep groove 81b is such that the small sphere 80 does not come into contact with the sphere 55 and is not loaded by the sphere 55.
The diameter of the small sphere 80 of the embodiment is, for example, 4.0 mm with respect to the sphere 55 having a diameter of 40 mm. The gap h between the sphere 55 and the small sphere 80 in the deep groove 81b is 0.5 mm.

In the above-mentioned grooved metal tube manufacturing apparatus, a groove 8a is formed in the metal tube by the rotating sphere 55 of the spherical bearing 56 and the groove-shaped recess 20a of the core 20 with respect to the moving metal tube. At that time, the sphere 55 does not rotate in direct contact with the concave sphere of the ball accommodating portion 54a, but rotates while being placed on a large number of small spheres 80 arranged on the concave sphere, so that friction with respect to the rotation of the sphere 55 Resistance is reduced.
Therefore, when the extratube mechanism 19 having the spherical bearing 56 and the core 20 arranged in the metal tube form a concave groove 8a extending in the longitudinal direction of the tube in the metal tube, the rotation of the spherical 55 in the spherical bearing 56 The frictional resistance is reduced, and the grooved metal tube 8 can be smoothly manufactured.

When the sphere 55 and the core 20 form a concave groove 8a in the metal tube, the sphere 55 of the sphere bearing 56 rotates in the same direction as the movement direction of the metal tube.
With respect to the sphere 55, the small sphere 80 in the shallow groove 81a of the pair of track grooves of the shallow groove 81a and the deep groove 81b in the central region comes into contact with the sphere 55 and receives a load while receiving a load on the sphere 55. It rotates in the direction opposite to the direction of rotation (the direction opposite to the direction of movement of the metal tube). On the other hand, the small sphere 80 in the deep groove 81b does not come into contact with the sphere 55, so that it is in a no-load state.
Since the track groove is in the moving direction of the metal pipe, the small ball 80 in the shallow groove 81a moves in the shallow groove 81a in the direction opposite to the moving direction of the metal pipe while rotating, and passes through the connecting passage 81c at the end thereof. After that, it enters the next deep groove 81b. The globules 80 in the deep groove 81b push the globules 80 in the deep groove 81b, and the pressed globules 80 in the deep groove 81b move in the deep groove 81b in the metal tube moving direction (forward direction) to the opposite side. Enter the shallow groove 81a via the connecting passage 81c. The small sphere 80 that has entered the shallow groove 81a from the deep groove 81b rotates in the direction opposite to the rotation direction of the sphere 55 (opposite to the moving direction of the metal tube) while contacting the sphere 55 and receiving a load as described above. ..
In this way, the small sphere 80 that circulates between the shallow groove 81a and the deep groove 81b supports the rotation of the sphere 55 while rotating in the opposite direction when it is in the shallow groove 81a.
Since the groove direction of the track groove coincides with the metal tube moving direction, the small sphere 80 in the shallow groove 81a supporting the sphere 55 rotating in the metal tube moving direction is substantially parallel to the rotation axis of the rotating sphere 55. It rotates in a mode with a rotation axis (the direction is opposite, but it rotates in almost the same direction). Therefore, there is little unnecessary slip between the sphere 55 and the globules 80, and the frictional resistance between the spheres 55 and the globules 80 is remarkably small.

As described in the background technique, when the grooving device 10 using the sphere bearing 56 is installed in the pipe making line by the electric sewing pipe manufacturing device to form the concave groove 8a in the metal pipe, the frictional resistance against the rotation of the sphere 55 If is large, the pipe making line requires a large amount of material feed drive power.
The power required for the pipe making line is the molding power required for molding (including shaping in the sizing zone) and the feed drive power required for feed drive. As described above, the rotation of the sphere 55 of the grooving device 10 When the frictional resistance with respect to is large, the power required for the feed drive becomes large.
When installing a new pipe making line equipped with a grooving device, it is designed to satisfy the required forming power and feed drive power, but when installing the grooving device 10 on an existing pipe making line, Since various problems arise in the modification to increase the power of the existing pipe making line, it is usually necessary to reduce the pipe making speed of the pipe making line.
However, according to the grooving device 10 using the spherical bearing 56 described above, the frictional resistance against the rotation of the spherical 55 is remarkably reduced, so that the power for feeding the material is reduced.
Therefore, even when the grooving device 10 using the spherical bearing 56 is installed in an existing pipe making line, for example, it is not necessary to modify the existing pipe making line to increase the power, and the pipe making speed of the pipe making line is not required. It is possible to install it without having to lower it.

Further, when the sphere 55 is used for an application that needs to be rotated at a remarkably high speed or an application that needs to bear an extremely large load, seizure may occur, but the frictional resistance is reduced. Is effective in avoiding such problems.

In the spherical bearing 56, most of the load received by the concave spherical surface from the spherical surface 55 is near the center of the concave spherical surface. Therefore, as in the embodiment, the region where the track groove is provided is limited to the central region in the left-right direction orthogonal to the metal tube moving direction. Is appropriate.

As in the embodiment, since the core 2 is arranged in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe, complicated core fixing means becomes unnecessary and the configuration of the grooving device is simplified. Be transformed.

FIG. 15 is a diagram showing an outline of an embodiment in which the above-mentioned grooving device 10 is installed offline instead of in the electric sewing tube production line.
In this case, the grooving device 10 is installed at an intermediate position of the transfer roller 74. A stopper 72 is attached to the end of a wire 71, for example, which is passed through a square metal tube 8 "without a groove, and the wire 71 is pulled by a winch 73 to connect the square metal tube 8" on the transport roller 74 to a grooved device. Pass 10 through. Rollers 74a for pressing and guiding the quadrangular metal tube from above are provided before and after the 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 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 8 is formed. What is obtained is as described in FIG.
The core insertion / evacuation device 60 described with reference to FIG. 4 can be used even when the grooving device 10 is installed offline as shown in FIG. 15, although detailed description thereof will be omitted. 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. 15, for example, a hydraulic cylinder is attached to the rear end of the metal pipe. It can be provided so that the metal pipe can be pushed out by this hydraulic cylinder.
In the illustrated example, the concave groove processing is performed by the method of extruding the metal tube, but the concave groove processing may be performed by the drawing method.

In the above-described embodiment, the grooved quadrangular metal pipe (grooved quadrangular metal pipe of FIG. 17 (a)) has been described, but the present invention is not limited to this, for example, the grooved pentagonal metal pipe shown in FIG. 17 (b). A grooved polygonal metal tube such as the grooved hexagonal metal tube shown in 17 (c) can be manufactured. Further, not limited to the square shape, it is also possible to manufacture a grooved circular metal tube having four grooves shown in FIG. 17 (d), a grooved circular metal tube having six grooves shown in FIG. 17 (e), and the like. ..
Further, as shown in FIG. 17 (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. 17 (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 Grooving device 11 Grooving stand 16 Housing 16a Housing body 16a'(housing body) base 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 (no groove)
25 Rod 26 Frame plate 31 Ball plunger (means for pushing up the inner surface of the pipe)
54 Sphere holder 54a Ball accommodating part (concave spherical surface)
54b Holder body 54c Lid 55 Sphere 56 Sphere bearing 57 Reduction adjustment mechanism 57a Reduction screw 57b Adjustment nut 57c Nut holding part 60 Core insertion / evacuation device 61 Main body frame 62 Swivel arm 63 Core receiving part 63a Core support 63b Child stopper 64 Receiver holder 80 Small ball 81 Circulation path (shallow groove, deep groove and connecting passage)
81a Shallow groove 81b Deep groove 81c Communication passage 82a Shallow groove, deep groove and boundary wall 82b Boundary wall between a pair of shallow groove and deep groove 82c Boundary wall between grooved area and non-grooved area 83 Simple concave without groove Spherical area

Claims (6)

A grooved metal pipe manufacturing device 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 fed and driven in the longitudinal direction of the pipe.
The sphere and the sphere are rotatably held by a ball accommodating portion forming a concave spherical surface, and the sphere has a sphere bearing consisting of a sphere holder that is immovable in the circumferential direction of the metal pipe and is movable in the center direction of the metal pipe. A plurality of extratube mechanisms provided at intervals in the circumferential direction in a mode of pushing
It has a short rod shape with a cross-sectional shape along the inner surface of the pipe, and is provided with a core that is arranged in the pipe and receives a portion corresponding to the sphere of each sphere bearing.
The outer peripheral surface of the core has a plurality of groove-shaped recesses having a shape corresponding to the sphere only on the front side in the metal tube moving direction from a position facing the sphere of each sphere bearing.
The spherical bearing is a grooved metal tube manufacturing apparatus, characterized in that the spherical bearing is placed on a large number of small balls arranged on a concave spherical surface of a ball accommodating portion of the spherical holder. The spherical bearing is formed by forming an even-numbered row of track grooves forming a metal pipe moving direction in at least a central region in the left-right direction orthogonal to the metal pipe moving direction of the concave spherical surface of the ball accommodating portion. The groove is composed of a plurality of sets consisting of a pair of a shallow groove and a deep groove, and the shallow groove and the deep groove in each set are connected in a connecting passage which is an inclined surface at the end thereof, and the small sphere is shallow. The apparatus for manufacturing a grooved metal tube according to claim 1, wherein the groove and the deep groove can be circulated. An even-numbered row of track grooves on the concave spherical surface of the holder body is provided only in the central region in the left-right direction orthogonal to the metal tube moving direction, and the outer region in the left-right direction is simply a concave spherical surface without grooves. The apparatus for manufacturing a grooved metal tube according to claim 2. The apparatus for manufacturing a grooved metal tube according to any one of claims 1 to 3, wherein the core is arranged in the pipe in a manner that does not receive a binding force other than contacting the inner surface of the pipe. 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 4 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. 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 apart in the circumferential direction of the outer surface of the metal pipe. It is a method for manufacturing a grooved metal pipe that forms concave grooves extending in the longitudinal direction of the pipe at a plurality of locations spaced off in the circumferential direction of the outer surface of the pipe in the manufactured metal pipe.
The grooved metal pipe manufacturing apparatus according to claim 1 to 4 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. 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 apart in the circumferential direction of the outer surface of the metal pipe driven in the longitudinal direction of the pipe on a transfer table.