JP2023095154A - Pipe, pipe manufacturing method, and pipe control number acquisition device - Google Patents

Abstract

To provide a pipe configuration and manufacturing method allowing efficient formation of a pipe having a control number, and an apparatus for forming the control number on the pipe.SOLUTION: A pipe 1 has a straight pipe part 10 and a receiving port 20 that is located at one axial end of the straight pipe part 10. A control number display part 50 including a control number of the pipe 1 is formed in the receiving port 20 by a laser machining apparatus.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a pipe having a straight pipe portion and a socket located at one axial end of the straight pipe portion, a pipe manufacturing method, and a pipe control number acquisition device.

For example, a cast iron pipe (an example of a water pipe) having a spigot and a socket used for water pipes has a predetermined type of pipe, nominal diameter, manufacturing factory, year of manufacture, lot number, manufacturer's mark, etc. A letter, figure, or the like indicating this is formed on the end face or flange face of the receptacle.

As a management method for managing the production history and the like of cast iron pipes as described above, for example, in Patent Document 1, in addition to predetermined casting letters, a management number that differs for each cast pipe is assigned to the end surface or flange surface of the socket. A method for managing the production history and shipping destination of cast tubes formed in The sand mold of the core for socket casting used when casting the socket of the above-mentioned casting pipe has a surface corresponding to the end face or the flange surface of the socket, which has a predetermined character etc. and a different character for each pipe. The control number is engraved in mirror letters. The predetermined characters and the control number are formed on the end surface or flange surface of the socket of the casting pipe by stamping the socket casting core when the socket is formed. .

The cast-iron pipe production history data having the management number and the shipping destination data are associated with each management number in the management system. As a result, the production history data and the shipping destination data can be traced using the control number of the cast iron pipe as a clue.

In the operation of imprinting the mirror characters for casting on the socket casting core, the predetermined characters and the like are stamped on the socket casting core by a core mold for forming the socket casting core. Simultaneously with the formation of the core, it is stamped in place on the socket casting core. On the other hand, the mirror character of the control number is stamped on the socket casting core by a stamping device after the socket casting core is formed. The mirrored characters of the control number are stamped between the characters that have already been stamped on the socket casting core.

Japanese Patent No. 5583571

As disclosed in Patent Document 1, in the operation of imprinting the control number mirror characters on the socket casting core, while checking the positions of the characters already formed on the socket casting core, , it is necessary to engrave the mirrored characters of the management number at a position that is identifiable without overlapping with the already formed characters. The mirrored characters of the control number must be stamped on an annular surface corresponding to the end face of the socket or the flange surface so that the characters are aligned in the circumferential direction while adjusting the angle of the characters.

In this way, when a mirror character such as a control number is stamped between characters etc. stamped on the annular face of the core for socket casting, the space for stamping the mirror character of the control number is It becomes narrower as the tube diameter of the tube becomes smaller. In addition, it is necessary to narrow the space between the mirrored letters of the control number according to the space for engraving the control number and the like. Therefore, the casting pipe having the control number on the end face or flange surface of the socket must be positioned with high accuracy between the already engraved characters, etc., and the mirror characters of the control number can be engraved. It takes time to position the imprint with respect to the core for mouth casting. Therefore, cast iron pipes having the control number could not be produced efficiently.

SUMMARY OF THE INVENTION It is an object of the present invention to realize a structure of a pipe having a management number and capable of being efficiently manufactured, a manufacturing method, and an apparatus for forming a management number on the pipe.

A pipe according to an embodiment of the present invention is a pipe having a straight pipe portion and a socket positioned at one end side of the straight pipe portion in the axial direction. The tube has a management number display section including a management number of the tube formed in the socket by a laser processing device (first configuration).

As disclosed in Patent Document 1, when a control number or the like is formed on the end face or flange face of the socket of a cast iron pipe, the control number or the like is placed in a narrow space with respect to the core for socket casting. It is necessary to engrave mirror letters.

On the other hand, in the configuration described above, the control number display portion is formed at an arbitrary portion of the socket by a laser processing device after casting. In other words, at any timing at which the laser of the laser processing device can be irradiated, the pipe has not only the end face or the flange portion of the socket, but also the outer peripheral surface and the inner peripheral surface that can be irradiated with the laser of the laser processing device. The control number of the tube can be formed on any part including. Therefore, the control number can be efficiently formed, and the pipe can be manufactured efficiently.

In the first configuration, the control number display portion is formed on the outer peripheral surface of the receptacle. (second configuration).

As described above, no letters or the like are formed by casting on the outer peripheral surface of the socket where the control number display portion is formed. Therefore, when forming the control number display portion on the pipe, it is not necessary to adjust the position in the circumferential direction on the outer peripheral surface of the socket. In addition, the laser processing device can be arranged at any position and posture with respect to the outer peripheral surface of the socket. Thereby, the management number can be efficiently formed. Moreover, since the control number display portion is formed on the outer peripheral surface of the socket, the control number can be visually recognized even when another pipe is connected to the pipe.

In the first or second configuration, the control number display portion is formed so that the control numbers are arranged in the axial direction of the pipe (third configuration).

As described above, when the management number on the management number display section is read by the imaging device, the distance between the imaging device and the management number is less likely to change than when the management numbers are arranged in the circumferential direction. Therefore, the imaging device can easily focus on the management number. Therefore, the management number can be recognized with high accuracy.

In any one of the first to third configurations, the control number display section has a flat surface on which the control number is formed (fourth configuration).

As described above, the pipe has a flat surface formed by removing the oxide film, dirt, etc. on the surface of the socket by a laser processing device. The control number is formed on the flat surface from which oxide film, dirt, etc. have been removed. Therefore, the management number can be recognized with high accuracy.

In any one of the first to fourth configurations, the control number display portion is located at a portion of the outer peripheral surface of the socket other than the connecting portion when viewed in the radial direction of the pipe. It is formed in a portion including a portion located radially outward (fifth configuration).

As described above, of the outer peripheral surface of the socket, except for the rubber ring locking groove, the lock ring housing groove, and the connecting portion where the guide portion is formed, which are necessary for fitting other pipes, the pipe A control number display portion is formed on the outer peripheral surface including the portion located radially outward where the thickness of the is the thickest. That is, the control number display portion is formed in a portion having high rigidity in the portion other than the connecting portion of the socket. Therefore, even if the control number display portion is formed on the outer peripheral surface of the socket of the pipe, the quality of the pipe can be maintained.

A method of manufacturing a pipe according to an embodiment of the present invention is a method of manufacturing a pipe having a straight pipe portion and a socket positioned at one end side of the straight pipe portion in the axial direction. a flat surface forming step of forming a flat surface on which the management number of the management number display portion including the management number of the pipe is formed in the socket by a laser processing device; and a flat surface formed by the flat surface forming step. and a management number forming step of forming the management number by the laser processing device (first method).

In the manufacturing method described above, a flat surface is formed on an arbitrary portion of the socket by a laser processing device from which surface oxide films, stains, etc. have been removed. The control number is formed on the flat surface. As a result, a control number display portion, which can be easily recognized by an imaging device, is easily formed at an arbitrary portion of the socket of the tube. Therefore, it is not necessary to form the control number in a narrow space of the pipe. Therefore, it is possible to efficiently manufacture the tube having the control number display portion.

In the first method, the method for manufacturing the pipe comprises: an imaging step of imaging the control number formed in the socket in the control number forming step with an imaging device; and a storing step of combining the management number identified by the identification step and the manufacturing information of the pipe and storing them in a storage device (second method).

Thereby, the control number formed on the socket of the pipe can be imaged by the imaging device, and the control number can be identified from the imaged image. By combining the control number and the manufacturing information of the pipe and storing it in a storage device as traceability information, the manufacturing information of the pipe can be easily obtained using the control number. Therefore, management of manufacturing information of the pipe is facilitated, and traceability of the pipe can be improved.

In the second method, the method for manufacturing the pipe includes a casting step of casting the pipe and an annealing step of annealing the pipe cast by the casting step, and the flat surface forming step and the managing The number forming step and the imaging step are performed between the casting step and the annealing step (third method).

In the post-casting annealing process, the order in which the cast tubes are annealed may change. Therefore, by forming the control number display portion between the casting process and the annealing process and capturing the control number, the casting conditions of the pipe and the control number can be more reliably associated. Therefore, the traceability of the tube can be further improved. In addition, a control number display portion is formed on the pipe immediately after casting by a laser processing device in a short time, and the control number is imaged by an imaging device, thereby suppressing a decrease in the temperature of the pipe and suppressing an extension of the annealing time. be able to.

An apparatus for forming a control number display portion according to an embodiment of the present invention forms a control number display portion including a control number on a pipe having a straight pipe portion and a socket located on one end side of the straight pipe portion. It is a device that The device for forming the control number display portion includes a laser processing device that uses a laser to form a flat surface on the surface of the tube and the control number on the flat surface, and a protective member for suppressing a temperature rise of the laser processing device. and a support device for supporting the laser processing device. The laser processing device is supported at a position separated from the tube by the support device, and at least partially covered by the protection member.

As described above, the device for forming the control number display portion forms the control number display portion on the pipe by the laser processing device. The laser processing device is supported at a position remote from the tube by a support device and covered by a protective member. Therefore, even when forming the management number display part on a high-temperature pipe immediately after casting, the apparatus for forming the management number display part is such that since the laser processing device is separated from the pipe, the pipe immediately after casting is The radiant heat is attenuated, and the radiant heat is shielded by the protective member. As a result, the management number display portion can be formed on the pipe immediately after casting by the laser processing device. Therefore, it is possible to efficiently manufacture the tube having the control number display portion.

A pipe according to an embodiment of the present invention has a straight pipe portion and a socket positioned at one axial end side of the straight pipe portion. The tube has a control number display section including the control number of the tube formed by a laser processing device at the socket.

This makes it possible to easily form the control number on the pipe compared to the conventional structure in which the control number is formed on the end face or flange face of the socket by casting. Moreover, the management number of the pipe can be formed on any portion of the socket that can be irradiated with the laser of the laser processing device. Therefore, pipes having control numbers can be efficiently manufactured.

FIG. 1 is a diagram showing a schematic configuration of a tube. FIG. 2 is a diagram schematically showing a case where the insertion port of another tube is positioned at the retracted position with respect to the socket of the tube. FIG. 3 is a diagram schematically showing a case where the insertion port of another tube is positioned at the extended position with respect to the socket of the tube. FIG. 4 is a diagram showing a schematic configuration of a pipe in which a control number display portion is formed on the inner peripheral surface of the socket. FIG. 5 is a view of the pipe socket and the control number display unit forming device when viewed in the radial direction. FIG. 6 is a diagram showing a process of forming a control number display portion on the socket of a pipe by using a control number display portion forming device. FIG. 7 is a view of the socket of the pipe and the control number acquisition device viewed in the radial direction. FIG. 8 is a diagram schematically showing the manufacturing process of the tube.

Each embodiment will be described below with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals, and the description of the same parts will not be repeated. Note that the dimensions of the constituent members in each drawing do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the respective constituent members, and the like.

In the following description, the axial direction means the direction in which the axis P of the tube 1 extends. Radial direction means the direction perpendicular to the axis P of the tube 1 . The circumferential direction means the direction in which the outer peripheral surface of the pipe 1 extends when the pipe 1 is viewed in the axial direction.

In addition, in the following description, expressions such as “fixed”, “connected” and “attached” (hereinafter referred to as “fixed”) are used not only when members are directly fixed to each other, but also when they are fixed via other members. It also includes cases where it is fixed. That is, in the following description, expressions such as fixing include meanings such as direct and indirect fixing between members.

(tube)
A pipe 1 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a tube 1. FIG.

The pipe 1 is, for example, a cast iron pipe made of ductile cast iron. The pipe 1 has a straight pipe portion 10 , a socket 20 and a spigot 30 .

The straight pipe portion 10 has a cylindrical shape extending linearly along the axis P. As shown in FIG. A socket 20 is positioned on one end side of the straight tube portion 10 . The outer peripheral surface of the straight pipe portion 10 has, at one end in the axial direction, a straight pipe portion inclined surface 11 that is a tapered surface whose outer diameter increases toward the socket 20 . An insertion port 30 is positioned on the other end side of the straight tube portion 10 .

The socket 20 is the part into which the spigot 30 of another tube is inserted. The socket 20 has a cylindrical shape extending in the axial direction of the straight pipe portion 10 from one end side of the straight pipe portion 10 . That is, the base end portion 21 of the socket 20 is connected to the straight pipe portion 10 . The outer peripheral surface of the base end portion 21 of the socket 20 is connected to the straight pipe portion inclined surface 11 of the straight pipe portion 10 . The outer peripheral surface of socket 20 is a tapered surface whose outer diameter increases from base end portion 21 to tip end portion 22 . That is, the minimum outer diameter of the socket 20 is substantially the same as the maximum outer diameter of the straight pipe portion inclined surface 11 of the straight pipe portion 10 .

Also, the inner diameter of the socket 20 is larger than the inner diameter of the straight pipe portion 10 . Therefore, the inner peripheral surface of the base end portion 21 of the socket 20 and the inner peripheral surface of the straight pipe portion 10 on the one end side are connected via an annular stepped surface.

The socket 20 has a plurality of projections 23 on its end face, which constitute characters, figures, etc. such as the nominal diameter of the pipe 1, the manufacturing plant, the year of manufacture, the lot number, and the mark of the manufacturer. The plurality of protrusions 23 are cast characters formed in the casting process of the manufacturing process of the tube 1 . The plurality of protrusions 23 are arranged in the circumferential direction on the end surface of the tip portion 22 of the receptacle 20 .

The socket 20 has a rubber ring retaining groove 25, a lock ring housing groove 26, and a guide portion 27 on its inner peripheral surface. The rubber ring retaining groove 25, the lock ring accommodating groove 26, and the guide portion 27 are formed with a predetermined machining accuracy by machining after the pipe 1 is cast. The rubber ring locking groove 25, the lock ring housing groove 26, and the guide portion 27 are formed on the inner peripheral surface of the socket 20 from the tip end portion 22 side of the socket 20. , the guide portion 27 .

The rubber ring locking groove 25 is an annular recess that is recessed radially outward along the circumferential direction of the inner peripheral surface of the socket 20 . The rubber ring locking groove 25 is positioned closest to the distal end portion 22 of the socket 20 among the rubber ring locking groove 25 , the lock ring accommodating groove 26 and the guide portion 27 . A rubber ring 41 (see FIGS. 2 and 3) is inserted into the rubber ring locking groove 25 to fill the gap between the inner peripheral surface of the socket 20 and the outer peripheral surface of another pipe inserted into the socket 20. be done. The rubber ring locking groove 25 holds the rubber ring 41 located in the rubber ring locking groove 25 at a predetermined position in the socket 20 when another tube is inserted into the socket 20 .

As shown in FIG. 1 , the lock ring accommodating groove 26 is an annular recess that is recessed radially outward along the circumferential direction of the inner peripheral surface of the socket 20 . The lock ring receiving groove 26 is located closer to the straight pipe 10 than the rubber ring retaining groove 25 is. A lock ring 42 and a lock ring holder 43 (see FIGS. 2 and 3) are inserted into the lock ring accommodating groove 26 . The lock ring 42 is a member that comes into contact with the insertion port protrusion 31 of another tube inserted into the socket 20 . The lock ring holder 43 is an annular member that holds the lock ring 42 .

As shown in FIGS. 2 and 3, the inner diameter of the lock ring 42 held by the lock ring holder 43 positioned within the lock ring accommodation groove 26 is equal to the insertion opening protrusion 31 of another tube inserted into the socket 20. As shown in FIGS. smaller than the outer diameter of Therefore, the lock ring 42 comes into contact with the spigot projection 31 of another tube inserted into the socket 20 . The lock ring receiving groove 26 holds the lock ring holder 43 positioned inside the lock ring receiving groove 26 . In other words, the lock ring accommodating groove 26 prevents the other tube from moving in the axial direction when the insertion opening projection 31 of another tube located closer to the straight tube 10 than the lock ring accommodating groove 26 comes into contact with the lock ring 42 . regulate.

As shown in FIG. 1 , the guide portion 27 is located on the straight pipe 10 side with respect to the lock ring accommodating groove 26 . The guide portion 27 is an inclined surface whose inner diameter increases toward the straight pipe 10 side. As shown in FIG. 3 , the guide portion 27 is designed to prevent the insertion when the insertion port protrusion 31 of another pipe located closer to the straight pipe 10 than the lock ring accommodating groove 26 moves toward the distal end portion 22 of the socket 20 . Guide the mouth projection 31 to the lock ring 42 . As a result, the insertion opening protrusion 31 of the other tube positioned closer to the straight tube 10 than the lock ring accommodating groove 26 can smoothly contact the lock ring 42 .

As shown in FIGS. 1-3, socket 20 has buffer space 28 between guide portion 27 and proximal end 21 . The buffer space 28 is positioned between the straight pipe 10 side of the guide portion 27 and the step surface 21 a of the base end portion 21 of the socket 20 . The buffer space 28 is a space in which the spigot 30 of another tube inserted into the receptacle 20 can move axially.

FIG. 2 is a diagram schematically showing a case where the insertion port 30 of another tube is positioned at the retracted position with respect to the socket 20 of the tube 1. As shown in FIG. FIG. 3 is a diagram schematically showing a case where the insertion port 30 of another tube is positioned at the extended position with respect to the socket 20 of the tube 1. As shown in FIG.

As shown in FIG. 2, when the insertion port 30 of the other pipe inserted into the socket 20 moves toward the straight pipe 10, the tip of the insertion port 30 of the other pipe is contracted to contact the step surface 21a. Move to position. On the other hand, as shown in FIG. 3, when the insertion port 30 of the other tube inserted into the socket 20 moves toward the distal end portion 22 of the socket 20, the insertion port 30 of the other tube moves toward the insertion port protruding portion. 31 moves to the extended position where it contacts the lock ring 42 .

The receptacle 20 can hold the receptacle 30 of another tube inserted into the receptacle 20 at any position between the extended position and the contracted position. As shown in FIG. 1, the range from the distal end portion 22 of the receptacle 20 to the guide portion 27 is formed as a connecting portion 20a that is machined with a predetermined machining accuracy and has sufficient rigidity. By increasing the processing accuracy and rigidity of the connecting portion 20a, the socket 20 can hold another pipe without leaking the fluid flowing through the pipe 1. As shown in FIG.

The insertion port 30 is a cylindrical portion extending in the axial direction of the straight pipe portion 10 from the other end side of the straight pipe portion 10 . The inserting opening 30 has an inserting opening projecting portion 31 projecting radially outward at its tip. The insertion opening protruding portion 31 has an insertion opening inclined surface 31 a on the distal end side of the insertion opening 30 , which is a tapered surface whose outer diameter decreases toward the distal end of the insertion opening 30 . The insertion opening protrusion 31 has a contact surface 31 b that contacts the lock ring 42 at the end on the straight pipe 10 side.

When the insertion port 30 is inserted into the socket 20 of another tube, the insertion port inclined surface 31a of the insertion port projecting portion 31 is inserted into the buffer space 28 beyond the lock ring 42 . Thereby, the spigot 30 of the tube 1 is connected to the socket 20 of another tube.

(Management number display part)
As shown in FIG. 1 , the pipe 1 has a control number display portion 50 on the outer peripheral surface of the socket 20 . The control number display part 50 is a part that displays a control number associated with information such as the raw material, processing, shipping, distribution, sales, construction, and disposal history of the pipe 1 . The control number display portion 50 includes a control number and a flat surface 51 forming the control number.

A flat surface 51 included in the control number display portion 50 is parallel to any plane passing through the axis P of the pipe 1 . The flat surface 51 is formed by a laser processing device 110 (see FIG. 5) at a portion of the outer peripheral surface of the socket 20 that overlaps the portion forming the buffer space 28 when viewing the tube 1 in the radial direction. That is, the flat surface 51 is formed in a portion overlapping the buffer space 28 in the socket 20 except for the connecting portion 20a where machining accuracy and rigidity are required when viewing the pipe 1 in the radial direction. The flat surface 51 is formed on the outer peripheral surface of the receptacle 20 by the laser processing device 110 . Moreover, the flat surface 51 is formed in a rectangular shape whose longitudinal direction is the axial direction of the pipe 1 . At this time, dirt such as an oxide film and sand adhering to the outer peripheral surface of the socket 20 is removed by the heat of the laser.

The flat surface 51 is formed on the outer peripheral surface of the socket 20 that includes the radially outermost portion of the outer peripheral surface of the socket 20 that overlaps the portion forming the buffer space 28 when the pipe 1 is viewed in the radial direction. . In other words, when viewing the pipe 1 in the radial direction, the flat surface 51 is the thickest portion (thickness It is formed on the outer peripheral surface of t1). Therefore, the socket 20 can maintain the processing accuracy and rigidity of the connecting portion 20a.

FIG. 4 is a diagram showing a schematic configuration of the pipe 1 in which the control number display portion 50 is formed on the inner peripheral surface of the socket 20. As shown in FIG.

As shown in FIG. 4 , when the control number display portion 50 is formed on the inner peripheral surface of the socket 20 , the flat surface 51 forms the buffer space 28 of the inner peripheral surface of the socket 20 by the laser processing device 110 . It is formed in the part where That is, the control number display portion 50 is formed in a portion overlapping the buffer space 28 in the socket 20 except for the connection portion 20a where machining accuracy and rigidity are required when viewing the pipe 1 in the radial direction. It is preferable that the management number display portion 50 be provided at a position close to the connecting portion 20a side of the inner peripheral surface forming the buffer space 28 of the socket 20 . Thereby, the management number contained in the management number display portion 50 can be easily confirmed from the tip portion 22 side of the receptacle 20 . Moreover, the control number display section 50 including the control number can be provided on the inner peripheral surface of the socket 20 of the pipe 1 which is hard to get dirty and scratched. Therefore, the management number can be recognized with high accuracy.

The control number is a character string composed of a combination of numbers, alphabets, symbols, etc., individually assigned to each tube 1 . The control number is represented by a dented portion obtained by removing a portion of the flat surface 51 with the laser processing device 110 . The control number is a character string arranged along the axial direction of the pipe 1 .

After casting, the pipe 1 is formed with a control number display portion 50 by a laser processing device 110 on arbitrary portions such as the outer peripheral surface and the inner peripheral surface of the socket 20 that can be irradiated with the laser of the laser processing device 110 . There is no difference in shape in the circumferential direction between the outer peripheral surface and the inner peripheral surface of the receptacle 20 . Therefore, the control number display portion 50 can be formed on the outer peripheral surface and the inner peripheral surface of the socket 20 of the pipe 1 without adjusting the position in the circumferential direction. Therefore, the control number display section 50 can be formed efficiently and easily. Furthermore, when the pipe 1 has the control number display portion 50 on the outer peripheral surface of the socket 20, the control number display portion 50 can be visually recognized even when another pipe is connected to the pipe 1.

The management number of the management number display portion 50 arranged in the axial direction of the pipe 1 is different from the case where the management numbers are arranged in the circumferential direction, and each character is read from the imaging device 210 (see FIG. 7) when imaging by the imaging device 210 (see FIG. 7). The fluctuation width of each distance to the character and the fluctuation width of the inclination of each character with respect to the imaging surface, which is the surface on which the image is formed in the camera, are small. Therefore, the imaging device 210 can more easily focus the management numbers arranged in the axial direction of the pipe 1 than the management numbers arranged in the circumferential direction of the pipe 1 . Therefore, the management number can be recognized with high accuracy.

As described above, in the present embodiment, the pipe 1 is a pipe having the straight pipe portion 10 and the socket 20 positioned at one end side of the straight pipe portion 10 in the axial direction. A management number display portion 50 containing the management number of the pipe 1 is formed in the socket 20 by the laser processing device 110 . The control number display portion 50 is formed on the outer peripheral surface of the socket 20, for example.

As a result, since the control number is formed at an arbitrary position of the socket 20 of the pipe 1, it is not necessary to align the pipe 1 so that a specific portion of the pipe 1 in the circumferential direction is irradiated with the laser. Moreover, it is not necessary to form the management number in a narrow space. Therefore, the control number can be easily formed on the pipe 1, and the pipe 1 can be manufactured efficiently.

Further, the management number display portion 50 is formed so that the management numbers are arranged in the axial direction of the pipe 1 . Furthermore, the control number display portion 50 has a flat surface 51 on which the control number is formed.

This makes it easier for the imaging device 210 to focus on the management number when reading the management number of the management number display section 50 with the imaging device 210 described later, compared to the case where the management numbers are arranged in the circumferential direction. Further, the control number is formed on the flat surface 51 from which the oxide film, dirt, etc. have been removed. Therefore, the management number can be recognized with high accuracy.

Further, the control number display portion 50 is formed on a portion of the outer peripheral surface of the receptacle 20 that includes a portion that is positioned radially outermost and other than the connecting portion 20a when the pipe 1 is viewed in the radial direction.

As described above, on the outer peripheral surface of the socket 20, the connecting portion 20a is formed with the rubber ring retaining groove 25, the lock ring receiving groove 26, and the guide portion 27 necessary for fitting another pipe. Except for , the control number display portion 50 is formed on the outer peripheral surface including the thickest portion (thickness t1) of the pipe 1 . In other words, the control number display portion 50 is formed in a portion of the receptacle 20 excluding the connection portion 20a with high rigidity. Therefore, even if the control number display portion 50 is formed on the socket 20 of the pipe 1, the quality of the pipe 1 can be maintained.

(Management number display part forming device)
Next, the management number display section forming apparatus 100 that forms the management number display section 50 will be described with reference to FIGS. 5 and 6. FIG. FIG. 5 is a view of the socket 20 of the pipe 1 and the control number display portion forming device 100 viewed in the radial direction. FIG. 6 is a diagram showing a process of forming the control number display portion 50 on the socket 20 of the pipe 1 by the control number display portion forming apparatus 100. As shown in FIG. The control number display portion forming apparatus 100 has a laser processing device 110 , a support device 120 , a protective member 130 and a cooling device 140 .

The laser processing device 110 is a device that processes an object into an arbitrary shape using heat from a YAG laser, a CO2 laser, a semiconductor laser, or the like. The laser processing device 110 heats and evaporates a portion of the tube 1 with laser heat. The laser processing device 110 is supported by a support device 120 at a position separated from the pipe 1 by a predetermined distance. The support device 120 is configured such that the axial position, radial position, etc. of the laser processing device 110 with respect to the pipe 1 can be changed according to the nominal diameter of the pipe 1, the processing position, and the processing conditions.

At least a portion of the laser processing device 110 is covered with a protective member 130 . The protective member 130 is a member that protects the laser processing device 110 from the radiant heat of the heated tube 1 immediately after casting. The protective member 130 is, for example, a protective cover that combines a material with high heat resistance and a material with high heat insulation. The protective member 130 covers the surface that receives the radiant heat from the heated pipe 1 after casting in the laser processing apparatus 110 . In this embodiment, the entire laser processing apparatus 110 except for the irradiation port for laser irradiation is covered with a protective member 130 .

The laser processing device 110 is cooled by a cooling device 140 . The cooling device 140 is a device that circulates cooling gas or liquid in at least one of the laser processing device 110 and the protective member 130 . The cooling device 140 operates to keep the temperature of the laser processing device 110 below a certain temperature. Note that the cooling device may cool the laser processing device 110 using a thermoelectric element.

The laser processing apparatus 110 is supported at a position radially spaced apart from the outer peripheral surface of the pipe 1 with a laser irradiation direction radially inward of the pipe 1 . The laser processing device 110 acquires information on the management number from a manufacturing control device (not shown). The laser processing device 110 irradiates the outer peripheral surface of the socket 20 with laser. The laser processing apparatus 110 removes the laser-irradiated portion of the outer peripheral surface of the socket 20 with laser heat to form a flat surface 51 included in the control number display portion 50 . Subsequently, the laser processing device 110 forms a groove 52 representing the control number on the flat surface 51 .

When forming the control number display portion 50 on the inner peripheral surface of the socket 20, the laser processing apparatus 110 directs the laser irradiation direction outward in the radial direction of the pipe 1, and radially from the inner peripheral surface of the pipe 1. They are supported at predetermined spaced positions. The laser processing device 110 forms the control number display portion 50 on the inner peripheral surface of the socket 20 .

When forming the control number display portion 50 on the end face or flange face of the socket 20, the laser processing device 110 directs the laser irradiation direction in the direction of the axis P of the pipe 1, and the direction of the laser from the end face or flange face of the pipe 1 to the axis line. They are supported at positions spaced apart by a predetermined distance in the P direction. The laser processing device 110 forms the control number display portion 50 on the end face or flange face of the socket 20 .

As described above, the control number display portion forming apparatus 100 forms the control number display portion 50 including the control number on the pipe 1 having the straight pipe portion 10 and the socket 20 located on one end side of the straight pipe portion 10 . The management number display part forming device 100 includes a laser processing device 110 for forming the management number on the flat surface 51 and the flat surface 51 on the surface of the tube 1 by laser, and a protective member for suppressing the temperature rise of the laser processing device 110. 130 and a support device 120 that supports the laser processing device 110 . The laser processing device 110 is supported at a position away from the pipe 1 by a support device 120 . At least a portion of the laser processing device 110 is covered with a protective member 130 .

The laser processing device 110 is located at a predetermined distance from the pipe 1 immediately after casting. Therefore, the radiant heat emitted by the pipe 1 immediately after casting is attenuated according to the distance to the laser processing device 110 . Furthermore, radiant heat is shielded by the protective member 130 . Also, the laser processing device 110 is cooled by a cooling device 140 . Therefore, the control number display portion forming device 100 can suppress the temperature of the laser processing device 110 within an operable range. By forming the control number display portion 50 on the pipe 1 immediately after casting, the casting conditions for each pipe 1 can be associated more reliably. In addition, since the control number display portion 50 is formed on the tube 1 immediately after casting by the laser processing device 110 in a short time, it is possible to suppress the temperature drop of the tube and the extension of the annealing time.

(Management number acquisition device)
Next, a control number acquisition device 200 for acquiring control numbers formed on the outer peripheral surface of the socket 20 of the pipe 1 will be described with reference to FIG. FIG. 7 is a diagram of the socket 20 of the pipe 1 and the control number acquisition device 200 viewed in the radial direction.

The management number acquisition device 200 has an imaging device 210 , an imaging device support device 220 , a rotary drive device 230 , a control device 240 and a storage device 250 . In this embodiment, the control number acquisition device 200 rotates the pipe 1 around the axis P by the rotary drive device 230 and images the control number display portion 50 of the pipe 1 by the imaging device 210 .

The imaging device 210 images the control number display portion 50 formed on the tube 1 . The imaging device 210 is, for example, a camera. The imaging device 210 is fixed to an imaging device support device 220 . The imaging device support device 220 is configured such that the axial position, radial position, etc. of the imaging device 210 with respect to the pipe 1 can be changed according to the nominal diameter of the pipe 1, the imaging position, and the imaging conditions. The imaging device 210 is supported at a position radially spaced apart from the outer peripheral surface of the pipe 1 by a predetermined distance, with the imaging direction directed inward in the radial direction of the pipe 1 . The imaging device 210 images at least part of the outer peripheral surface of the socket 20 including the control number display portion 50 . The imaging device 210 transmits the captured image to the control device 240 .

When capturing an image of the inner peripheral surface of the socket 20 , the imaging device 210 is supported at a position radially spaced apart from the inner peripheral surface of the pipe 1 with the imaging direction facing radially outward of the pipe 1 . It is The imaging device 210 images at least part of the inner peripheral surface of the socket 20 including the control number display portion 50 .

When imaging the end face or the flange surface of the socket 20, the imaging device 210 faces the direction of the axis P, and is positioned at a predetermined distance in the direction of the axis P from the end face or the flange surface of the pipe 1. Supported. The image capturing device 210 captures an image of at least part of the end surface or flange surface of the receptacle 20 including the control number display portion 50 .

The rotary drive device 230 is a device that rotates the tube 1 around the axis P. As shown in FIG. The rotation driving device 230 has, for example, a pair of roller portions 231 and a driving portion 232 . In this embodiment, the rotary drive device 230 has two pairs of roller portions 231 . A pair of roller portions 231 support the tube 1 so as to be rotatable around the axis P. As shown in FIG. The pair of rollers 231 make their respective rotation axes P1 parallel to the axis P of the tube 1, and contact the outer peripheral surface of the straight tube portion 10 of the tube 1 on the socket 20 side and the insertion port 30 side, respectively. are doing. A pair of roller portions 231 support the tube 1 between the rollers.

The driving portion 232 provides a rotational driving force for rotating the tube 1 around the axis P to the pair of roller portions 231 . The drive unit 232 is, for example, a motor. The driving portion 232 rotates at least one of the pair of roller portions 231 . The tube 1 supported by the pair of roller portions 231 rotates in a direction opposite to the direction of rotation of the pair of roller portions 231 .

The control device 240 controls driving of the drive unit 232 of the rotary drive device 230 and also controls the imaging device 210 to obtain image data captured by the imaging device 210 . The control device 240 determines whether or not an image related to the management number is included in the captured image while acquiring data of the image captured by the image capturing device 210, and determines whether the image related to the management number is included in the captured image. The tube 1 is rotated by the rotary drive device 230 until the tube 1 is rotated.

The control device 240 acquires information about the management number of the pipe 1 from data of the captured image of the imaging device 210 by image processing or the like. That is, the control device 240 detects a character string that constitutes the management number from the captured image of the imaging device 210, and specifies characters, numbers, and the like from the detected character string. The control device 240 recognizes the identified letters, numbers, etc. as the management number of the pipe 1 . The control device 240 outputs the acquired information about the management number to the storage device 250 together with the captured image data.

The storage device 250 is a device that stores management numbers, manufacturing histories, shipping histories, and the like. The storage device 250 receives information related to the management number from the control device 240 together with the data of the captured image, and receives product information, manufacturing information, etc. (hereinafter referred to as manufacturing information, etc.) of the tube 1 from a manufacturing control device (not shown). . The product information includes information regarding the size and material of the tube 1 . The manufacturing information includes information on the manufacturing conditions of the tube 1, manufacturing date and time, material composition, manufacturing history such as dimensions, shipping history, and the like. Note that the product information does not have to be stored in the storage device 250 .

The storage device 250 has a storage control device (not shown) that associates the information on the management number with the manufacturing information and the like. As a result, the storage device 250 stores traceability information in which the management number and the manufacturing information are associated with each other.

The storage device 250 may be provided on a network, or may be provided in a manufacturing system for manufacturing the pipe 1, for example. Various information stored in the storage device 250 can be retrieved by a server or a computer terminal.

The management number acquisition device 200 having the above configuration takes an image of a part of the outer peripheral surface of the socket 20 including the management number, and identifies the management number as character information. In addition, the management number acquisition device 200 stores information associating the specified management number with manufacturing information and the like as traceability information.

The management number acquisition device 200 acquires manufacturing information and the like in each manufacturing process of the pipe 1 to be described later, and obtains traceability information by associating it with the management number of the pipe 1 . In addition, since the control number display portion 50 including the control number is formed on the outer peripheral surface of the socket 20 of the pipe 1, the pipe 1 can be manufactured by extracting or reinserting the pipe 1 in the manufacturing process of the pipe 1. Even if the order is changed, the management number acquisition device 200 can associate the manufacturing information of the pipe 1 with the management number.

(Manufacturing method of tube)
Next, a method for manufacturing the tube 1 according to the present invention will be described with reference to FIG. 8A and 8B are diagrams schematically showing the manufacturing process of the tube 1. FIG.

As shown in FIG. 8, the method of manufacturing the pipe 1 comprises a casting step S1, a control number display portion forming step S2, an annealing step S3, a surface treatment step S4, a processing step S5, a painting step S6, and a control number and an obtaining step S7.

The casting step S1 is a step of forming the pipe 1 using molten metal. In the casting step S1, the straight pipe portion 10 and the spigot 30 of the pipe 1 are cast, for example, by centrifugal casting. Centrifugal force casting utilizes the centrifugal force of a rapidly rotating mold to form molten ductile iron into a hollow cylinder. The socket 20 of the tube 1 is cast using a sand mold.

In the casting step S1, the pipe 1 is cast using the casting mold and socket core having the above configuration. Further, in the casting step S1, predetermined characters or the like are formed as casting characters on the end surface of the tip portion 22 of the socket 20 . After the casting step S1, the cast pipe 1 is removed from the casting mold.

The control number display portion forming step S2 is a step of forming the control number display portion 50 on the pipe 1 . The control number display portion forming step S2 is a step between the casting step S1 and the annealing step S3. That is, the control number display portion forming step S2 is a step performed before the pipe 1 cast in the casting step S1 is annealed in the annealing step S3. The control number display portion forming step S2 includes a flat surface forming step S2A and a control number forming step S2B.

The flat surface forming step S2A is a step of forming the flat surface 51 in the socket 20 of the pipe 1. FIG. In the flat surface forming step S2A, the immediately cast pipe 1 pulled out of the mold is positioned at a predetermined position. At this time, the circumferential position of the tube 1 is not adjusted. The positioned pipe 1 is formed with a rectangular flat surface 51 having its longitudinal direction in the axial direction at a predetermined axial position by the control number display portion forming device 100 . The flat surface 51 is processed by the laser processing device 110 to remove oxide films, stains, etc. adhering to the surface of the socket.

The management number forming step S2B is a step of forming a management number on the flat surface 51 formed in the flat surface forming step S2A. In the control number forming step S2B, a control number is formed on the flat surface 51 by the control number display portion forming device 100 of the pipe 1 having the flat surface 51 formed at a predetermined position in the axial direction. The management number display unit forming device 100 forms the management number so that the character strings are arranged in the longitudinal direction of the flat surface 51 by the laser processing device 110 .

The annealing step S3 is a step of removing residual stress generated during casting of the ductile cast iron forming the pipe 1 and simultaneously improving workability and ductility of the material. In the annealing step S3, the tube 1 having the control number display portion 50 formed thereon is heated in an annealing furnace at a predetermined temperature for a predetermined period of time.

The surface treatment step S4 is a step of performing a shot treatment on the outer surface of the pipe 1 to remove stains, scales, and the like on the outer surface of the pipe 1 .

The machining step S5 is a step of machining the pipe 1 . In the processing step S5, the inner peripheral surface of the socket 20 of the pipe 1 is processed. A rubber ring retaining groove 25 and a lock ring housing groove 26 are formed on the inner peripheral surface of the socket 20 . In addition, in the processing step S<b>5 , the insertion opening projecting portion 31 is formed on the outer peripheral surface of the insertion opening 30 by welding a ring member or by overlay welding.

The painting step S6 is a step of painting the pipe 1 . In the coating step S6, all surfaces including the inner and outer peripheral surfaces of the pipe 1 machined in the processing step S5 may be coated, or only the outer peripheral surface may be coated.

The management number obtaining step S7 is a step of obtaining the management number of the pipe 1 by the management number obtaining device 200 and associating the management number with the production history of the pipe 1 and the like. The management number acquisition step S7 is performed before and after the process of changing the manufacturing order of the pipe 1 due to extraction, re-insertion, or the like in each process of the pipe 1 manufacturing method. Specifically, the control number acquisition step S7 includes, for example, between the control number display portion forming step S2 and the annealing step S3, between the annealing step S3 and the surface treatment step S4, and between the surface treatment step S4 and the processing step S5. is performed at least once between the processing step S5 and the coating step S6, and after the coating step S6 and before shipment.

The management number obtaining step S7 includes an imaging step S7A, an identifying step S7B, and a storing step S7C.

The imaging step S7A is a step of imaging the control number of the control number display section 50 using the imaging device 210 . Specifically, in the image pickup step S7A, the image pickup device 210 picks up an image of the control number display portion 50 including the control number of the socket 20 by rotating the rotational drive device 230 around the axis P. As shown in FIG. The imaging device 210 transmits the captured image data of the management number display section 50 to the control device 240 (see FIG. 7).

The identification step S7B is a step of identifying the control number included in the image. Specifically, in the identification step S7B, the control device 240 identifies the management number of the pipe 1 using the image data transmitted from the imaging device 210 . Information about the management number identified by control device 240 is sent to storage device 250 .

The storage step S7C is a step of storing the management number of the pipe 1 identified in the identification step S7B, the manufacturing information of the pipe 1, etc. in combination in the storage device 250. FIG. In the storage step S7C, information related to the management number transmitted from the control device 240 is input to the storage device 250, and manufacturing information and the like are input from the manufacturing control device (not shown). In the storage device 250, a storage control device (not shown) stores the management number and the manufacturing information in association with each other. That is, the traceability information of the tube 1 is stored in the storage device 250 .

As described above, the control number acquisition step S7 includes, for example, between the control number display portion forming step S2 and the annealing step S3, between the annealing step S3 and the surface treatment step S4, and between the surface treatment step S4 and the processing step S5. is performed at least once between the processing step S5 and the coating step S6, and after the coating step S6 and before shipment. As a result, even if the manufacturing order of the tubes 1 is changed due to extraction, reinsertion, etc., the management number of the tubes 1 and the manufacturing information can be associated and stored in the storage device 250 . Therefore, the traceability information stored in the storage device 250 can be updated. Note that post-shipment information of the pipe 1 (stock destination, shipping destination, delivery destination, installation location of the pipe 1, etc.) may be associated with the management number of the pipe 1 and stored in the storage device 250 .

A control number display portion 50 including a control number is formed on the outer peripheral surface of the socket 20 of the tube 1 manufactured by the manufacturing method described above. In the tube 1 having the control number display section 50 including the control number, the manufacturing information of the tube 1 and the like can be easily confirmed from the control number. Therefore, the management of the manufacturing information of the tube 1 becomes easy, and the traceability of the tube 1 can be improved.

The method for manufacturing the pipe 1 of the present embodiment is a method for manufacturing the pipe 1 having the straight pipe portion 10 and the socket 20 positioned at one end side of the straight pipe portion 10 in the axial direction. This manufacturing method includes a flat surface forming step S2A in which a flat surface 51 on which the management number is formed in the management number display portion 50 including the management number of the pipe 1 is formed in the socket 20 by the laser processing device 110; and a management number forming step S2B of forming a management number on the flat surface 51 formed in the step S2A by using the laser processing device 110 .

As a result, a flat surface 51 is formed on an arbitrary portion of the receptacle 20 from which oxide films, stains, etc., have been removed from the surface by the laser processing device 110 . A control number is formed on the flat surface 51 . The tube 1 is easily formed with a control number display portion 50 including a flat surface 51 that can be easily recognized by the imaging device 210 at any portion of the socket 20 . Therefore, it is not necessary to form the control number in a narrow space of the pipe 1. Therefore, the tube 1 having the control number display portion 50 can be manufactured efficiently and easily.

Further, the method for manufacturing the tube 1 includes an imaging step S7A in which the imaging device 210 takes an image of the management number formed in the socket 20 in the management number forming step S2B; and a storage step S7C of combining the management number identified by the identification step S7B and the manufacturing information of the pipe 1 and storing them in the storage device 250. The manufacturing information includes information on manufacturing conditions, manufacturing date, material components, dimensions, and the like of the tube 1 .

Further, in the method for manufacturing the tube 1, the control number formed on the socket 20 of the tube 1 is imaged by the imaging device 210, and the control number can be identified from the imaged image. By combining the management number and the manufacturing information of the pipe 1 and storing it in the storage device 250 as traceability information, it is possible to easily acquire the manufacturing information of the pipe 1 from the management number. Therefore, the management of the manufacturing information of the tube 1 becomes easy, and the traceability of the tube 1 can be improved.

Further, the method for manufacturing the pipe 1 includes a casting step S1 for casting the pipe 1 and an annealing step S3 for annealing the pipe 1 cast in the casting step S1. S2B is performed between the casting step S1 and the annealing step S3.

In the method for manufacturing the tube 1, the order of annealing the cast tube 1 may be changed in the post-casting annealing step S3. Therefore, by forming the control number display portion 50 between the casting process S1 and the annealing process S3 and capturing an image of the control number, the casting conditions of the pipe 1 and the control number can be reliably associated. Therefore, traceability of the tube 1 can be further improved.

In addition, the control number display portion 50 is formed in a short time by the laser processing device 110 on the tube 1 immediately after casting, and the image of the control number is imaged by the imaging device 210, thereby suppressing the temperature decrease of the tube 1 and shortening the annealing time. Extension can be suppressed.

(Other embodiments)
Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, without being limited to the above-described embodiment, it is possible to modify the above-described embodiment as appropriate without departing from the spirit thereof.

In the above-described embodiment, the pipe 1 has the control number display portion 50 formed on the outer peripheral surface of the socket 20 . However, as long as it is the port of the pipe, the control number display portion may be formed on a portion other than the outer peripheral surface.

In the above embodiment, the pipe 1 is provided with one control number display portion 50 . However, the tube may have more than one control number indicator. The pipe may have, for example, a control number indicator on the outer peripheral surface and the inner peripheral surface of the socket.

In the above-described embodiment, the management number display section 50 contains a management number that is a combination of characters and the like. However, the management number display part may include the management number displayed by a graphic such as a bar code.

In the embodiment, the management number display portion 50 has the management number formed on the flat surface 51 . However, the control number display portion may be configured without a flat surface. For the control number display portion, for example, a groove representing the control number may be formed on the outer peripheral surface of the socket by a laser processing device.

In the above embodiment, the control number display portion forming step S2 is performed between the casting step S1 and the annealing step S3. However, the control number display portion forming step may be performed other than between the casting step and the annealing step.

In the above-described embodiment, the control number acquisition step S7 is performed before and after the steps in the manufacturing method of the pipe 1 in which the order of manufacture of the pipes is changed by extraction, re-insertion, or the like. However, the management number acquisition step may be performed in each step of the pipe manufacturing method other than before and after the step of changing the pipe manufacturing order due to extraction, re-insertion, or the like.

In said embodiment the tube 1 does not have a flange at the socket 20 . However, the tube may have a flange at the socket. In this case, the flange may be provided with characters, figures, etc. indicating the nominal diameter of the pipe, the manufacturing plant, the year of manufacture, the lot number, the mark of the manufacturer, and the like.

In the above-described embodiment, the control number acquisition device 200 rotates the tube 1 by the rotation drive device 230 and images the control number display section 50 . However, the control number acquisition device may rotate the imaging device instead of rotating the tube to capture the image of the control number display portion.

In the above-described embodiment, the control number acquisition device 200 rotates the tube 1 by a pair of rollers 231 included in the rotation drive device 230 . However, the rotary drive device may be configured to rotate the tube.

INDUSTRIAL APPLICABILITY The present invention is applicable to a pipe having a straight pipe portion and a socket located at one axial end of the straight pipe portion, a pipe manufacturing method, and a pipe management number acquisition device.

1 Pipe 10 Straight pipe portion 11 Straight pipe portion inclined surface 20 Receiving port 20a Connecting portion 21 Base end portion 21a Stepped surface 22 Tip portion 23 Convex portion 25 Locking groove for rubber ring 26 Lock ring accommodating groove 27 Guide portion 28 Buffer space 30 Insertion opening 31 Insertion opening protrusion 31a Insertion opening inclined surface 31b Contact surface 41 Rubber ring 42 Lock ring 43 Lock ring holder 50 Control number display part 51 Flat surface 52 Groove 100 Control number display part forming device 110 Laser processing device 120 Support device 130 Protective member 140 Cooling device 200 Management number acquisition device 210 Imaging device 220 Imaging device support device 230 Rotation drive device 231 Pair of rollers 232 Drive unit 240 Control device 250 Storage device P Axis

Claims (9)

A pipe having a straight pipe portion and a socket positioned at one axial end of the straight pipe portion,
A pipe, wherein a management number display section containing a management number of the pipe is formed in the socket by a laser processing device. A tube according to claim 1, wherein
The pipe, wherein the control number display portion is formed on the outer peripheral surface of the socket. 3. A tube according to claim 1 or 2,
The pipe, wherein the management number display portion is formed such that the management numbers are arranged in the axial direction of the pipe. A tube according to any one of claims 1 to 3,
The tube, wherein the control number display section has a flat surface on which the control number is formed. A tube according to any one of claims 1 to 4,
The pipe, wherein the control number display portion is formed in a portion of the outer peripheral surface of the socket that includes a portion located radially outermost and other than the connecting portion when the pipe is viewed in the radial direction. A method for manufacturing a pipe having a straight pipe portion and a socket positioned at one axial end of the straight pipe portion, the method comprising:
a flat surface forming step of forming a flat surface on which the management number of the management number display portion including the management number of the pipe is formed in the socket by a laser processing device;
a control number forming step of forming the control number on the flat surface formed by the flat surface forming step using the laser processing apparatus;
having
A method of manufacturing a tube. A method for manufacturing a tube according to claim 6,
an imaging step of imaging the management number formed in the socket by the management number forming step with an imaging device;
an identification step of identifying the management number from the image captured by the imaging step;
a storage step of combining the management number identified by the identification step and the manufacturing history of the pipe and storing the combination in a storage device;
having
A method of manufacturing a tube. In the method of manufacturing a tube according to claim 7,
a casting step for casting the tube;
an annealing step of annealing the pipe cast by the casting step;
The flat surface forming step, the control number forming step, and the imaging step are performed between the casting step and the annealing step,
A method of manufacturing a tube. A device for forming a management number display section containing a management number on a pipe having a straight pipe portion and a socket positioned at one end of the straight pipe portion,
a laser processing device for forming a flat surface on the surface of the tube with a laser and forming the control number on the flat surface;
a protective member for suppressing a temperature rise of the laser processing device;
a support device for supporting the laser processing device,
The laser processing device is
supported at a position remote from the tube by the support device and at least partially covered by the protection member;
A device that forms a control number display unit.

Images