JP7401709B1 - Piping processing method - Google Patents

Abstract

The present invention provides a pipe processing method that allows easy butt welding for joining pipes together. [Solution] The pipe processing method is a pipe processing method for butting and welding the pipe ends of a plurality of pipes, and before welding, a first distance from the pipe end of each pipe to a first distance in the axial direction is In order to form a groove in one region, pressure is applied radially outward to the inner circumferential surface of a second region of the pipe from the pipe end to a second distance longer than the first axial distance. In addition, the diameter in the second region of the piping is expanded, and after expanding the diameter in the second region, the diameter in the radial direction of the piping is A jig that applies pressure toward the center is attached, and with the jig attached, a beveling process is performed on the first region of the piping, and after the beveling process, with the jig attached, The pipes having grooves formed in the first region are butted against each other, and the butted pipes are temporarily fixed to each other. [Selection diagram] Figure 1

Description

The present disclosure relates to a pipe processing method for butting and welding pipe ends of pipes together.

BACKGROUND ART A plurality of pipes are joined together by butting the pipe ends of the pipes together and welding them together. The dimensional tolerance defined in the pipe diameter of the pipe may be approximately the same as the thickness of the pipe. Further, since piping having a relatively large diameter is formed by rolling a steel plate and welding the ends of the steel plate to each other, there is a large variation in roundness from piping to piping. For these reasons, when the pipes are butted against each other, there is a possibility that the amount of misalignment in the thickness direction of the pipes, that is, the radial direction of the pipes becomes large.

Regarding the problem of variations in pipe diameter and roundness in piping, for example, Patent Document 1 below discloses that the amount of eccentricity and amount of deformation strain of piping is measured, and the groove is adjusted according to the amount of eccentricity and amount of deformation strain. It is described that processing specifications are determined. Additionally, Patent Document 1 describes that if the amount of eccentricity and deformation strain of the piping is unacceptably large in the beveling machine, a warning is issued and the piping is corrected in advance before beveling. There is.

Japanese Patent Application Publication No. 57-27609

However, the above method cannot solve the problem of misalignment occurring when the pipes are butted together because the pipe diameters and roundness still vary. Additionally, during beveling, if the amount of eccentricity and deformation of the piping is too large to be tolerated by the beveling machine, it is necessary to remove the piping installed in the beveling machine and modify the piping separately. , the work process is complicated.

Therefore, an object of the present disclosure is to provide a pipe processing method that can easily perform butt welding for joining pipes together.

A piping processing method according to an aspect of the present disclosure is a piping processing method for butting and welding the pipe ends of a plurality of pipes, wherein, before performing the welding, the first pipe in the axial direction from the pipe end of each pipe is In order to form a groove in a first region up to a distance, a groove is formed in a radially outward direction of the piping with respect to an inner circumferential surface of a second region from the pipe end of the piping to a second distance longer than the first axial distance. The diameter of the piping in the second region is expanded by applying pressure in the direction, and after expanding the diameter of the piping in the second region, A jig that applies pressure to the outer circumferential surface of the region toward the radial center of the pipe is installed, and with the jig installed, a beveling process is performed on the first region of the pipe, and the After the groove is formed, the pipes with the groove formed in the first region are butted against each other with the jig attached, and the butted pipes are temporarily fixed.

According to the present disclosure, butt welding for joining pipes together can be easily performed.

FIG. 1 is a flowchart showing the flow of a piping processing method according to an embodiment of the present disclosure. FIG. 2 is a side view showing an example of piping before forming a groove in this embodiment. FIG. 3 is an image diagram showing an overview of the diameter expansion process in this embodiment. FIG. 4 is an image diagram showing an overview of the jig mounting process in this embodiment. FIG. 5 is a diagram showing the implementation state of the beveling process in this embodiment. FIG. 6 is a diagram showing the implementation state of the process after beveling in this embodiment. FIG. 7 is an image diagram for explaining a method of calculating a reference point of piping by measurement using an automatic processing machine used in this embodiment. FIG. 8 is an image diagram for explaining a method of calculating the inner diameter and outer diameter of a pipe by measurement using an automatic processing machine used in this embodiment.

[One embodiment]
A piping processing method according to an embodiment of the present disclosure will be described below.

FIG. 1 is a flowchart showing the flow of a piping processing method according to an embodiment of the present disclosure. In the pipe processing method according to the present embodiment, before the pipe ends of a plurality of pipes are butted together and welded, a groove is formed in a first region from the pipe end of each pipe to a first distance in the axial direction.

FIG. 2 is a side view showing an example of piping before forming a groove in this embodiment. As shown in FIG. 2, in the present embodiment, the pipe 1 has a first region A1 from the pipe end 1a to a first distance L1 in the axial direction in a state before forming the groove. is set as . In addition, in the pipe 1 before groove formation, the pipe diameter R2 in the second region A2 from the pipe end 1a to the second distance L2, which is longer than the first axial distance L1, is the pipe diameter in the other region, that is, the pipe diameter in the axial center region. It has a diameter larger than R1. The second area A2 includes the first area A1. In addition, the pipe 1 before groove formation is equipped with a jig 2 that applies pressure toward the radial center of the pipe 1 against the outer peripheral surface in a third region A3 excluding the first region A1 from the second region A2. . In FIG. 2, the difference between the second distance L2 and the first distance L1 is shown as a third distance L3.

In FIG. 2, first areas A1 and the like are set at both ends of the pipe 1. However, when only one pipe end 1a of the pipe 1 is welded to another pipe 1, the setting of the first region A1 etc. may not be necessary at the other pipe end 1a.

In order to form the pipe 1 before the bevel, first, pressure is applied radially outward of the pipe 1 to the inner circumferential surface of the second region A2 of the pipe 1, thereby forming the second region A2 of the pipe 1. The diameter at A2 is expanded (step S1). FIG. 3 is an image diagram showing an overview of the diameter expansion process in this embodiment. The material, size, etc. of the pipe 1 to be prepared are not particularly limited as long as it can be welded at the pipe end 1a. For example, as the piping 1, a stainless steel pipe or the like is used. Further, the pipe 1 is formed by rolling a steel plate and welding the ends of the steel plate to each other. Therefore, it is assumed that the piping 1 does not have sufficient roundness. Note that the pipe 1 may be manufactured as a seamless pipe by drawing or the like. Even in this case, the piping 1 may not have sufficient circularity.

In the diameter expanding process, the pipe 1 is arranged so that the diameter expanding jig 3a of the diameter expander 3 is located inside the pipe. The diameter expanding jig 3a has a structure in which a cylinder is divided into a plurality of pieces in the circumferential direction. Further, the diameter expanding jig 3a is configured such that the plurality of pieces move radially outward when pressure is applied. The plurality of pieces constituting the diameter expanding jig 3a are moved radially outward by pressurization, so that the outer circumferential surfaces of the plurality of pieces press the inner circumferential surface of the pipe 1 inserted therethrough. Thereby, the diameter of the second area A2 of the pipe 1 is expanded. In the example of FIG. 3, both sides of the pipe 1 in the axial direction are expanded in diameter.

As a result, even if the pipe diameter R1 of the pipe 1 before diameter expansion varies within the range of dimensional tolerance among the plurality of pipes 1, the second region A2 of the pipe 1 is expanded to the predetermined diameter R2. By doing so, the pipe diameters, that is, the circumferential lengths of the plurality of pipes 1 in the second region A2 can be unified. Therefore, when a plurality of pipes 1 are butted against each other, it is possible to suppress misalignment caused by different circumferential lengths.

For example, the pipe diameter R2 of the second region A2 of the pipe 1 is set to the maximum value of the dimensional tolerance of the pipe diameter R1 of the pipe 1 before diameter expansion. In this case, depending on the size of the pipe 1, in the second region A2 of the pipe 1, the difference between the circumferential length before diameter expansion and the circumference length after diameter expansion may be less than 1%. As described above, in the diameter expanding step, the degree of machining of the pipe 1 by the diameter expanding machine 3 may be low. For example, one of the reasons why the degree of processing of the pipe 1 cannot be increased is that the degree of diameter expansion of the pipe 1 cannot be increased depending on the product use or quality constraints.

For example, if the pipe 1 is an inner pipe of a multilayer pipe, the degree of diameter expansion cannot be increased. The multiple tube includes an inner tube and an outer tube arranged concentrically with a gap between the inner tube and the inner tube. Multiple pipes include double pipes, triple pipes, and the like. The multiple tube can be used when it is necessary to block heat from outside the tube from the fluid flowing inside the inner tube. If the diameter of the inner tube of such a multi-layered tube is increased, the gap between the inner tube and the outer tube will become smaller, and there is a possibility that the heat insulation properties and the like will deteriorate. In addition, in this disclosure, the inner pipe of a multiple pipe means the inner pipe of two pipes adjacent in the radial direction, and the outer pipe of the multiple pipe means the inner pipe of two pipes adjacent in the radial direction. means the outside piping.

In this way, when the degree of machining of the pipe 1 by the diameter expander 3 is low, the roundness of the pipe 1 may be temporarily changed due to the pipe 1 being corrected by the diameter expansion jig 3a when the diameter is expanded by the diameter expansion jig 3a. Even if the diameter of the pipe 1 is increased, when the pipe 1 after diameter expansion is removed from the diameter expansion jig 3a, the roundness of the pipe 1 may decrease again due to the elasticity of the pipe 1.

Therefore, a jig 2 is attached that applies pressure toward the radial center of the pipe 1 on the outer circumferential surface of the third region A3 of the pipe 1 whose diameter has been expanded (step S2). FIG. 4 is an image diagram showing an overview of the jig mounting process in this embodiment. The jig 2 includes a plurality of pieces having arcuate cutouts corresponding to the outer diameter of the second region A2 of the piping 1. In this embodiment, the jig 2 includes two pieces 2a and 2b having semicircular arc-shaped notches.

The first piece 2a has a notch corresponding to the upper half of the outer peripheral surface of the pipe 1, and the second piece 2b has a notch corresponding to the lower half of the outer peripheral surface of the pipe 1. A bracket 2c is provided at the lower part of the first piece 2a and the upper part of the second piece 2b for fixing the first piece 2a and the second piece 2b to each other using a fixing device 2d such as a bolt. The bracket 2c of the first piece 2a and the bracket 2c of the second piece 2b are arranged to face each other with the notches of the two pieces 2a and 2b aligned.

In this embodiment, the brackets 2c are fixed to both sides of each piece 2a, 2b as shown in FIG. However, in FIG. 4 and the like, the bracket 2c is shown only on one surface of each piece 2a, 2b, and the bracket 2c on the other surface is omitted. Note that the bracket 2c may be fixed to only one surface of each piece 2a, 2b.

The second piece 2b is placed on a base 5 on which a holder 4 for holding the two pieces 2a and 2b is installed so as to be held by the holder 4. The second region A2 portion of the piping 1 is brought into contact with the cutout portion of the second piece 2b held, and the first piece 2a is attached from above so as to be held by the holder 4. As a result, each of the cutout portions of the two pieces comes into contact with the outer peripheral surface of the second region A2 of the pipe 1.

In this state, a pressurizer 6 such as a hydraulic cylinder is attached to the upper part of the first piece 2a, and the pressurizer 6 applies pressure to the first piece 2a toward the pipe 1 and the second piece 2b. The two pieces 2a, 2b are fixed to each other by fixing the brackets 2c of each piece 2a, 2b using the fixture 2d while applying a predetermined pressure to the first piece 2a.

In this way, the jig 2 is fixed with a predetermined pressure applied to the outer circumferential surface of the third region A3, which does not affect the beveling process, of the second region A2 whose diameter has been expanded in the pipe 1. Thereby, the second area A2 including the third area A3 of the pipe 1 is corrected by the jig 2 into the shape of the notch of the jig 2, and the roundness is increased.

After the jig 2 is attached to the pipe 1, beveling is performed on the first area A1 of the pipe 1 with the jig 2 attached (step S3). Bevel processing is performed by an automatic processing machine. The automatic processing machine may be a general-purpose automatic processing machine such as a machining center, or a dedicated automatic processing machine specialized for bevel processing. Below, a case where a general-purpose automatic processing machine is used will be exemplified.

FIG. 5 is a diagram showing the implementation state of the beveling process in this embodiment. The automatic processing machine 7 includes an installation stand 8, a base 9, a support column 10, and a processing head 11. On the installation stand 8, the piping 1 with a jig attached is installed. The installation stand 8 is movable in the horizontal direction with respect to the base 9 by a first slider 12. The moving direction of the installation base 8 includes a first direction and a second direction that are orthogonal to each other. The piping 1 is installed so that an axis line follows a 1st direction. The support column 10 is fixed to the base 9.

The processing head 11 holds a processing tool 13. The processing head 11 is supported by the support column 10 with the attachment axis of the processing tool 13 oriented in the first direction. The processing head 11 is movable in the height direction with respect to the support column 10 by the second slider 14.

Bevel processing is performed on the outer circumferential surface and inner circumferential surface of the first region A1 of the pipe 1 by such an automatic processing machine 7.

Note that the automatic processing machine 7 is not limited to the above configuration. For example, the automatic processing machine 7 may be configured such that the pipe 1 is fixed to the base 9 and the processing head 11 is moved three-dimensionally with respect to the base 9.

After performing the beveling process, the pipes 1 with grooves formed in the first area A1 are butted against each other with the jig 2 attached, and the butted pipes 1 are temporarily fixed to each other (step S4 ). FIG. 6 is a diagram showing the implementation state of the process after beveling in this embodiment. By butting the pipes 1 together with the jig 2 attached, the pipes 1 are butted against each other while the roundness of the first area A1 in which the groove is formed in the pipe 1 is corrected. The deviation in the circumferential length of the first region A1 in the plurality of pipes 1 is suppressed by the diameter expansion process, and the pipes 1 are connected to each other in a state in which the roundness of the first region A1 is high in the plurality of pipes 1 by installing the jig 2. By abutting against each other, the amount of misalignment in the radial direction between the abutted pipes 1 is suppressed.

By temporarily fixing the pipes 1 to each other in this state, joining with a small amount of misalignment can be realized. For example, temporary fixing may be performed by tack welding, also called tack welding.

After the temporary fixing is performed, the jig 2 is removed before performing the actual welding (step S5). By removing the jig 2, the roundness of the pipes 1 in the first region A1 may be reduced, but the amount of misalignment between the pipes 1 is maintained to be small due to temporary fixation.

After removing the jig 2, main welding is performed (step S6). In this embodiment, main welding is performed by automatic welding machine 15. The automatic welding machine 15 is configured by, for example, an articulated robot having joints of multiple axes. When the automatic welding machine 15 welds the groove portion of the pipe 1, various tracing controls are executed. Thereby, even if the roundness of the pipes 1 is reduced to some extent compared to when the jig 2 is attached, the amount of misalignment between the pipes 1 is small due to temporary fixation, so that appropriate welding can be easily performed.

As explained above, according to the pipe processing method of the present embodiment, the diameter of the pipe end of the pipe 1 is expanded to a predetermined circumference, and the jig 2 pressurizes the pipe 1. It is installed in Therefore, in the plurality of pipes 1, the tube ends of the pipes 1 are maintained with the same circumferential length and high roundness. With the jig 2 mounted in this manner, a groove is formed in the first region A1 including the tube end, and the plurality of pipes 1 with grooves formed therein are butted against each other. This makes it possible to reduce the amount of misalignment between the pipes 1 when they are butted together, so it is possible to easily perform butt welding to join the pipes 1 together. Since the jig 2 is attached to the third area A3 on the outer peripheral surface of the pipe 1, avoiding the first area A1 where the groove is formed, the jig 2 is prevented from interfering with the formation of the groove. be able to.

Furthermore, by forming the groove and butting a plurality of pipes 1 with each other with the jig 2 attached, the accuracy of butting the pipes 1 with each other can be increased even if the degree of machining in the diameter expansion process is low. I can do it. Therefore, the pipe processing method of this embodiment can be easily applied to the pipe 1 that cannot be processed to a high degree due to product usage or quality constraints.

Further, since the mounted state of the jig 2 is maintained when the pipes 1 are butted together, the amount of misalignment in the radial direction between the butted pipes 1 matches each other with high accuracy. By temporarily fixing the pipes 1 to each other in this state, joining with a small amount of misalignment can be realized. As a result, butt welding for joining the pipes 1 together can be easily performed. Therefore, butt welding can be automated, and highly accurate and highly productive welding can be achieved.

Furthermore, according to the present embodiment, the jig 2 is removed after temporary fixing and before the actual welding, so that the jig 2 can be prevented from becoming an obstacle during the actual welding. Therefore, automatic welding machine 15 can be easily introduced in the main welding.

Further, according to the present embodiment, the jig 2 includes a plurality of pieces 2a, 2b each having an arc-shaped notch, and the plurality of pieces 2a, 2b are provided on the outer peripheral surface of the third area A3 of the piping 1. The plurality of pieces 2a, 2b are fixed to each other in a state where each of the notch portions is brought into contact with each other and pressure is applied to one of the plurality of pieces 2a, 2b. Thereby, it is possible to easily configure the jig 2 for applying pressure to the outer peripheral surface of the third region A3 of the piping 1 toward the radial center of the piping 1 to increase the roundness of the piping 1. .

Furthermore, in this embodiment, during bevel processing, a predetermined dimension of the pipe 1 after diameter expansion and attachment of the jig 2 is measured, and it is determined whether the predetermined dimension is within a predetermined reference range. You can also do that. As described above, in this embodiment, the bevel processing is performed by the automatic processing machine 7. The automatic processing machine 7 can automatically select and mount a processing tool 13 to be mounted on the processing head 11 from among a plurality of processing tools 13. The plurality of processing tools 13 include a touch probe 13a. During bevel processing, the automatic processing machine 7 brings the touch probe 13a into contact with a predetermined position in the first area A1 of the pipe 1 with the pipe 1 equipped with the jig 2 installed at a predetermined position. , measure the predetermined dimensions of the piping 1.

In this embodiment, the predetermined dimensions include a maximum inner diameter value Rix and a minimum outer diameter value Ron. In order to measure these values, the automatic processing machine 7 specifies a reference point C, which is the radial center position of the pipe 1, using the touch probe 13a with respect to the pipe 1 installed on the installation stand 8.

FIG. 7 is an image diagram for explaining a method of calculating a reference point of piping by measurement using an automatic processing machine used in this embodiment. In FIG. 7, with the piping 1 installed on the installation stand 8, the left and right direction is the X direction, the up and down direction is the Y direction, and the central axis direction is the Z direction. First, the automatic processing machine 7 moves the touch probe 13a in the Z direction from the pipe end 1a of the piping 1 at a predetermined position in the XY direction, and determines the Z coordinate of the position where the touch probe 13a contacts the surface of the jig 2. Measure. The automatic processing machine 7 performs the main measurement at a plurality of positions in the XY direction, and sets the average value of the measured Z coordinates as the reference position Zo in the Z direction. For example, the Z coordinate is measured at one location above and below the pipe 1. In subsequent measurements, the position of the touch probe 13a is fixed at the reference position Zo in the Z direction.

Next, the automatic processing machine 7 moves the touch probe 13a in the Y direction from the outside of the pipe 1 in the Y direction at the operation center Xa in the X direction of the processing head 11 of the automatic processing machine 7, so as to touch the outer surface of the pipe 1. Let them come into contact with you. The automatic processing machine 7 determines the Y coordinate YaH of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved from above the pipe 1 downward, and the Y coordinate YaH of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved from the bottom to the top of the pipe 1. The Y coordinate YaL of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved is measured. The automatic processing machine 7 calculates a midpoint Ya between the two obtained Y coordinates YaH and YaL.

Next, the automatic processing machine 7 moves the touch probe 13a in the X direction from the outside of the pipe 1 in the X direction to bring it into contact with the outer surface of the pipe 1 at the calculated point Ya in the Y direction. The automatic processing machine 7 determines the X coordinate XoL of the position where the touch probe 13a contacts the piping 1 when the touch probe 13a is moved from the left side of the piping 1 to the right side, and The X coordinate XoR of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved leftward is measured. The automatic processing machine 7 calculates the midpoint Xo of the two obtained X coordinates XoL and XoR.

Next, at the calculated point Xo in the X direction, the automatic processing machine 7 again moves the touch probe 13a in the Y direction from the outside of the pipe 1 in the Y direction to bring it into contact with the outer surface of the pipe 1. The automatic processing machine 7 determines the Y coordinate YoH of the position where the touch probe 13a abuts the pipe 1 when the touch probe 13a is moved from above the pipe 1 downward, and the Y coordinate YoH of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved from the bottom to the top of the pipe 1. The Y coordinate YoL of the position where the touch probe 13a contacts the pipe 1 when the touch probe 13a is moved is measured. The automatic processing machine 7 calculates the midpoint Yo of the two obtained Y coordinates YoH and YoL.

The coordinates (Xo, Yo, Zo) obtained in this way become the coordinates of the reference point C. Note that the Y coordinate Ya obtained in the above method may be used as the Y coordinate of the reference point C.

Furthermore, the automatic processing machine 7 measures the inner diameter value and outer diameter value at a plurality of circumferential positions of the pipe 1 using the obtained reference point C. FIG. 8 is an image diagram for explaining a method of calculating the inner diameter and outer diameter of a pipe by measurement using an automatic processing machine used in this embodiment.

The automatic processing machine 7 sets an imaginary line direction extending in the radial direction of the piping 1 from the reference point C, moves the touch probe 13a from the position of the reference point C toward the imaginary line direction, and cuts the inner periphery of the piping 1. Measure the X and Y coordinates of the position in contact with the surface. The automatic processing machine 7 performs similar measurements in a plurality of virtual line directions. In the example of FIG. 8, the plurality of virtual line directions are set in eight directions centering on the reference point C. Note that the number of virtual line directions may be greater than or less than eight directions. In this way, the coordinates of the inner circumferential surface positions U1, . . . , U8 corresponding to the plurality of imaginary line directions are measured.

Further, the automatic processing machine 7 moves the touch probe 13a from outside the pipe 1 toward the reference point C in a plurality of imaginary line directions, and calculates the X and Y coordinates of the position where it touches the outer peripheral surface of the pipe 1. measure. In this way, the coordinates of the outer circumferential surface positions T1, . . . , T8 corresponding to a plurality of imaginary line directions are measured.

The automatic processing machine 7 calculates inner diameter values in a plurality of imaginary line directions by calculating the distances between the reference point C and each inner circumferential surface position U1, . . . , U8. Similarly, the automatic processing machine 7 calculates outer diameter values in a plurality of virtual line directions by calculating the distances between the reference point C and each outer circumferential surface position T1,..., T8. The automatic processing machine 7 sets the largest value among the calculated inner diameter values as the maximum inner diameter value Rix, and sets the smallest value among the calculated outer diameter values as the minimum outer diameter value Ron. Further, the automatic processing machine 7 has a position having a minimum inner diameter value Rin, which is the smallest value among the calculated inner diameter values, and a position having a maximum outer diameter value Rox, which is the largest value among the calculated outer diameter values. to remember.

The automatic processing machine 7 determines whether beveling is possible for the pipe 1 by determining whether the set maximum inner diameter value Rix and minimum outer diameter value Ron are within a predetermined reference value range. decide. The automatic processing machine 7 stores a target inner diameter value Rt and a dimensional tolerance width for the target inner diameter value Rt as a target value of the inner diameter value in the first region A1 after beveling. The dimensional tolerance width for the target inner diameter value Rt includes a positive dimensional tolerance width Tp, which is the dimensional tolerance width toward the outer diameter side, and a negative dimensional tolerance width Tm, which is the dimensional tolerance width toward the inner diameter side.

Further, the automatic processing machine 7 stores a minimum wall thickness tolerance Dn, which is the minimum thickness tolerance in the first region A1 before beveling. These setting values may be input and set to the automatic processing machine 7 each time, or may be stored in advance in the memory of the automatic processing machine 7.

The automatic processing machine 7 uses these set values, the maximum inner diameter value Rix, and the minimum outer diameter value Ron to perform the following determination. First, the automatic processing machine 7 determines whether the value obtained by subtracting the minimum thickness tolerance value Dn from the minimum outer diameter value Ron is greater than the maximum inner diameter value Rix. That is, the automatic processing machine 7 determines whether Ron-Dn>Rix is satisfied as the first condition. If the first condition is not satisfied, the automatic processing machine 7 determines that beveling cannot be performed because there is a possibility that the minimum thickness cannot be ensured in the state before beveling.

Further, the automatic processing machine 7 determines whether the value obtained by subtracting the minus dimensional tolerance width Tm from the target inner diameter value Rt is less than the value obtained by subtracting the minimum wall thickness dimensional tolerance value Dn from the minimum outer diameter value Ron. . That is, the automatic processing machine 7 determines whether Rt-Tm≦Ron-Dn is satisfied as the second condition. If the second condition is not satisfied, the automatic processing machine 7 secures the minimum thickness and processes the inner diameter value described later within the dimensional tolerance range W (Rt-Tm≦W≦Rt+Tp) for the target inner diameter value Rt. It is determined that beveling cannot be performed because it is not possible to set Rp, or it may not be possible to secure the root surface within the target misalignment amount after securing the minimum thickness. .

Furthermore, the automatic processing machine 7 determines whether the value obtained by adding the plus dimension tolerance width Tp to the target inner diameter value Rt is greater than or equal to the maximum inner diameter value Rix. That is, the automatic processing machine 7 determines whether Rt+Tp≧Rix is satisfied as the third condition. If the third condition is not satisfied, the automatic processing machine 7 cannot set the machining inner diameter value Rp, which will be described later, within the dimensional tolerance range W (Rt-Tm≦W≦Rt+Tp) for the target inner diameter value Rt, or It is determined that beveling cannot be performed because there is a possibility that the root surface cannot be secured within the target misalignment amount while ensuring the minimum thickness.

The automatic processing machine 7 determines that bevel processing is possible when all of the first, second, and third conditions are satisfied. In this way, the automatic processing machine 7 can determine whether or not the pipe 1 has an appropriate circumferential length and roundness through the diameter expansion process and the jig installation process before the beveling process.

If it is determined that beveling is possible, the automatic processing machine 7 calculates the machining inner diameter value Rp when actually beveling according to the following cases.

(Case 1) When Rt+Tp≦Ron-Dn and Rt-Tm≧Rix
→Rp=Rt
(Case 2) When Rt+Tp>Ron-Dn and Rt-Tm<Rix
→Rp=(Ron-Dn+Rix)/2
(Case 3) When Rt+Tp≦Ron-Dn and Rt-Tm<Rix
→Rp=(Rt+Tp+Rix)/2
(Case 4) When Rt-Tm≧Rix and Rt+Tp>Ron-Dn
→Rp=(Rt-Tm+Rix-Dn)/2

The automatic processing machine 7 performs bevel processing on the pipe 1 based on the processing inner diameter value Rp calculated as described above and the coordinates (Xo, Yo, Zo) of the reference point C. In addition, when machining the outer circumferential surface side, the automatic processing machine 7 starts cutting in bevel machining from the position of the maximum outer diameter value Rox. In machining the inner peripheral surface side, the automatic processing machine 7 starts cutting in bevel machining from the position of the minimum inner diameter value Rin. In this way, by setting the machining inner diameter value Rp based on the value actually measured in the pipe 1 that has been determined to be capable of beveling, it is possible to perform beveling more appropriately in accordance with the actual product. Further, by setting the machining start position based on the actually measured value, machining defects can be prevented and machining accuracy can be increased.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various improvements, changes, and modifications can be made without departing from the spirit thereof.

[Other embodiments]
For example, in the above embodiment, an example is shown in which the automatic welding machine 15 performs the main welding, but instead of this, the main welding may be performed manually. Similarly, in the embodiment described above, an example was shown in which the automatic processing machine 7 performs the beveling process, but the beveling process may also be performed manually.

Further, in the above embodiment, an example is shown in which the jig 2 is removed after temporary fixation and before the main welding is performed, but the main welding may be performed with the jig 2 attached.

Further, in the above embodiment, an example was shown in which the jig 2 has two pieces 2a and 2b, but the jig 2 may have three or more pieces.

Further, temporary welding may be performed by automatic welding machine 15. Temporary fixing does not need to be by welding as long as the pipes 1 can be temporarily fixed to each other. For example, the pipes 1 may be temporarily fixed to each other using a special jig that is fixed to the pipes 1 using bolts or the like. Further, for example, the pipes 1 may be temporarily fixed to each other with an adhesive, adhesive tape, or the like.

[Summary of this disclosure]
[Item 1]
A piping processing method according to an aspect of the present disclosure is a piping processing method for butting and welding the pipe ends of a plurality of pipes, wherein, before performing the welding, the first pipe in the axial direction from the pipe end of each pipe is In order to form a groove in a first region up to a distance, a groove is formed in a radially outward direction of the piping with respect to an inner circumferential surface of a second region from the pipe end of the piping to a second distance longer than the first axial distance. The diameter of the piping in the second region is expanded by applying pressure in the direction, and after expanding the diameter of the piping in the second region, A jig that applies pressure to the outer circumferential surface of the region toward the radial center of the pipe is installed, and with the jig installed, a beveling process is performed on the first region of the pipe, and the After the groove is formed, the pipes with the groove formed in the first region are butted against each other with the jig attached, and the butted pipes are temporarily fixed.

According to the above method, the diameter of the pipe end of the pipe is expanded to a predetermined circumferential length, and a jig is attached to the pipe under pressure. Therefore, in the plurality of pipes, the pipe ends of the pipes are maintained with the same circumferential length and high roundness. With such a jig installed, a groove is formed in the first region including the pipe end, and the plurality of pipes with grooves formed therein are butted against each other. This makes it possible to reduce the amount of misalignment between the pipes when they are butted together, making it possible to easily perform butt welding for joining the pipes together.

[Item 2]
In the piping processing method of item 1, the jig may be removed after the temporary fixing and before the main welding. Thereby, it is possible to prevent the jig from getting in the way during the main welding. Therefore, an automatic welding machine can be easily introduced in the main welding.

[Item 3]
In the piping processing method of item 1 or 2, the jig includes a plurality of pieces having arc-shaped notches corresponding to the outer diameter of the third region of the piping, and the outer circumferential surface of the third region has: The plurality of pieces can be fixed with each of the cutout portions of the plurality of pieces being in contact with each other, and when installing the jig, one of the plurality of pieces can be fixed. The pieces may be fixed together while applying pressure. Thereby, it is possible to easily configure a jig for applying pressure to the outer peripheral surface of the third region of the piping toward the radial center of the piping to improve the roundness of the piping.

[Item 4]
In the piping processing method according to any one of items 1 to 3, the beveling is performed by an automatic processing machine, the automatic processing machine is equipped with a touch probe, and the jig is attached during the beveling. By bringing the touch probe into contact with a predetermined position in the first area of the pipe with the pipe installed at a predetermined location, a predetermined dimension of the pipe is measured, and a predetermined dimension is measured using the predetermined dimension. It is also possible to determine whether or not the above-mentioned conditions are met, and to not perform the beveling process if the above-mentioned conditions are not met. In this case, the automatic processing machine determines that bevel processing is possible when the conditions using the predetermined dimensions of the pipe are satisfied. In this way, it is possible to determine whether the pipe has an appropriate circumferential length and roundness through the diameter expansion process and the jig installation process before the beveling process is performed using an automatic processing machine.

[Item 5]
In the piping processing method according to any one of items 1 to 4, the piping may be an inner tube of a multilayer tube in which an outer tube and an inner tube are arranged concentrically with a gap between them.

1 Piping 2 Jig 2, 2b Piece 7 Automatic processing machine 13a Touch probe 15 Automatic welding machine A1 First area A2 Second area A3 Third area

Claims (5)

A piping processing method for butting and welding the pipe ends of multiple piping,
Before performing the welding, in order to form a groove in a first region of each pipe from the pipe end to a first distance in the axial direction,
The second region of the piping is applied radially outwardly to the inner circumferential surface of the second region of the piping from the pipe end to a second distance longer than the first axial distance. by increasing the diameter of
After enlarging the diameter in the second region, a jig that applies pressure toward the radial center of the pipe on the outer peripheral surface of the third region of the pipe excluding the first region from the second region. Attach the
performing beveling on the first region of the piping with the jig attached;
After performing the groove processing, the pipes in which the grooves have been formed in the first region are butted against each other with the jig attached, and the pipes that are butted against each other are temporarily fixed. . The piping processing method according to claim 1, wherein the jig is removed after performing the temporary fixing and before performing the main welding. The jig includes a plurality of pieces having arcuate notches corresponding to the outer diameter of the third region of the piping, and each of the cutout portions of the plurality of pieces is formed on the outer peripheral surface of the third region. The plurality of pieces can be fixed to each other while in contact with each other,
The piping processing method according to claim 1 or 2, wherein when installing the jig, the pieces are fixed while applying pressure to any one of the plurality of pieces. The bevel processing is performed by an automatic processing machine,
The automatic processing machine includes a touch probe,
During the bevel processing, the touch probe is brought into contact with a predetermined position in the first area of the pipe with the pipe equipped with the jig installed at a predetermined location, thereby forming a predetermined dimension of the pipe. Measure the
The piping processing method according to claim 1 or 2, wherein it is determined whether a predetermined condition is satisfied using the predetermined dimension, and the groove processing is executed when the condition is satisfied. 3. The piping processing method according to claim 1, wherein the piping is an inner tube of a multi-layered tube arranged concentrically with an outer tube and an inner tube having a gap therebetween.

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