JP2013130252A - Fluid pipe drilling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pipe drilling method, by which a cutting groove with high dimensional accuracy can be easily drilled in a fluid pipe, a load to a cutting edge of a cutting tool is averaged, and durability of the cutting tool is improved.SOLUTION: The cutting groove 1c is formed which penetrates in a circumferential direction in a substantially rectangular shape in a plane view from above to a part of the fluid pipe 1 through a process of advancing an end mill 9b provided at a front edge of a shaft member 9a rotating around the shaft toward a direction orthogonal to a center axis line of the fluid pipe 1 to drill through a pipe wall of the fluid pipe 1, and thereafter a process of parallel-shifting the shaft of the end mill 9a in a cross direction of the fluid pipe 1.

Description

  The present invention relates to a fluid pipe drilling method in which a fluid pipe is drilled by an end mill so that a valve body provided inside a valve housing capable of closing a flow in the fluid pipe is installed in the fluid pipe in an uninterrupted state.

  A conventional method for drilling a fluid pipe for installing a valve body provided inside a valve housing capable of closing a flow in a fluid pipe in a fluid pipe embedded as an existing pipe in an uninterrupted state is provided with a cutting tool. After mounting the sealed case around the fluid pipe so as to rotate freely, the cutting tool is advanced toward the fluid pipe to form a through hole in the fluid pipe. From this state, the sealed case to which the cutting tool is attached is fluidized. By turning in the circumferential direction of the pipe, a cutting groove penetrating the fluid pipe over almost the entire circumference in the circumferential direction is formed. After that, a gate (valve element) is inserted into the fluid pipe from the cutting groove, whereby the flow path in the fluid pipe (For example, see Patent Document 1).

Japanese Patent No. 4516666 (paragraphs [0023], [0024] and FIGS. 4 and 5)

  However, in Patent Document 1, since the heavy sealed case is rotated in the circumferential direction of the fluid pipe in a state where the cutting tool to be rotated is attached, a cutting groove with high dimensional accuracy is formed. In addition to precise center alignment and a large sealed case drive device, the end shape (opening angle of the end portion) of the cutting groove changes according to the amount of rotation of the sealed case in the circumferential direction with respect to the fluid pipe. For this reason, additional work such as reworking the shape of the end of the cutting groove in accordance with the shape of the installation portion of the valve body is required, and there is a problem that it takes time and labor to form the cutting groove.

  The present invention has been made paying attention to such problems, and it is possible to make a cutting groove easily and with high dimensional accuracy in the fluid pipe, and the load on the cutting blade of the cutting tool is averaged, and the cutting is performed. It is an object of the present invention to provide a fluid pipe drilling method that improves the durability of a tool.

In order to solve the above problems, the fluid pipe drilling method of the present invention comprises:
A fluid pipe drilling method for drilling a fluid pipe by an end mill in order to install a valve body provided inside a valve housing capable of closing a flow in the fluid pipe in the fluid pipe in an uninterrupted state,
An end mill provided at the tip of a shaft member rotating about the axis is advanced in a direction perpendicular to the central axis of the fluid pipe to penetrate through the pipe wall of the fluid pipe, and then the end mill shaft is crossed over the fluid pipe. A cutting groove penetrating in a circumferential direction having a substantially rectangular shape in a top view is formed in a part of the fluid pipe by performing a feeding step of translating in the direction.
According to this feature, after penetrating and drilling the pipe wall of the fluid pipe by the end mill, a part of the fluid pipe having a substantially rectangular shape in top view can be obtained by simply translating a shaft member that rotates around the axis provided in the end mill. Since the cutting groove penetrating in the circumferential direction can be formed, the drilling operation can be easily performed, and accurate dimensional accuracy of the cutting groove can be obtained. In addition, since the part of the end mill that cuts the fluid pipe is displaced in the axial direction of the end mill during translation, the load on the cutting blade of the end mill is averaged, and the durability of the end mill is improved.

The fluid pipe drilling method of the present invention includes:
In the feeding step of translating the shaft of the end mill in the transverse direction of the fluid pipe, a first step of translating the shaft member drilled and drilled in one direction, and a first step of translating the shaft member in the other direction via the through drilled portion The second step and the third step of translating in the one direction so as to return to the portion where the through hole has been drilled are performed.
According to this feature, when the cutting groove is drilled, the cutting groove is drilled so that the drilling process in which the rotation direction and the feed direction of the end mill are the same direction and the drilling process in the opposite direction are alternately equal. Therefore, the entire inner surface of the cutting groove can be finished uniformly.

The fluid pipe drilling method of the present invention includes:
In the feeding step of translating the end mill shaft in the transverse direction of the fluid pipe, the end mill is cut at the end of the parallel movement of the end mill to be moved so that a wall is left in the fluid pipe by the side edge of the cutting groove. An end portion is formed.
According to this feature, since the wall remains in the fluid pipe, a decrease in rigidity of the fluid pipe is reduced, and the valve body can be easily installed by using the wall.

The fluid pipe drilling method of the present invention includes:
In the feeding step of translating the end mill shaft in the transverse direction of the fluid pipe, the range of translation of the end mill is such that the angle formed between the center of the fluid pipe and both circumferential ends of the cutting groove is 90 ° to 150 °. It is characterized by being moved so as to be within a range.
According to this feature, by setting the angle formed by the center of the fluid pipe and both circumferential ends of the cutting groove to 90 ° to 150 °, the circumferential length of the cutting groove can be increased while ensuring the rigidity of the fluid pipe. By limiting the length to a range shorter than the semicircular circumference, the drilling operation can be simplified.

It is a sectional side view which shows the state by which the cutting device was attached to the housing | casing in an Example. It is AA sectional drawing which shows the cutting device in FIG. It is a sectional side view which shows the penetration drilling to the fluid pipe | tube by an end mill. It is front sectional drawing which shows the end mill penetrated to the fluid pipe | tube. It is front sectional drawing which shows the end mill which translates to one of the radial directions of a fluid pipe | tube. It is front sectional drawing which shows the end mill which translates to the other of the radial direction of a fluid pipe | tube. It is front sectional drawing which shows the fluid pipe | tube of the state which the drilling of the cutting groove was completed. (A) is BB sectional drawing which shows the cutting condition of the fluid pipe of the end mill in FIG. 5, (b) is CC sectional drawing which shows the cutting condition of the fluid pipe of the end mill in FIG. It is a sectional side view which shows the state which fitted the antirust core in the cutting groove. It is a sectional side view which shows the state from which the cutting device was removed from the housing | casing. It is a sectional side view which shows the state which attached the valve housing | casing to the housing | casing. It is a sectional side view which shows the state which open | released the branch port and has arrange | positioned the front-end | tip part of the valve body in the fluid pipe | tube. It is a sectional side view which shows the state which interrupted | blocked the flow path of the fluid pipe | tube with the valve body.

  The form for implementing the fluid pipe | tube drilling method which concerns on this invention is demonstrated below based on an Example.

  The valve housing installation method according to the embodiment will be described with reference to FIGS. As shown in FIG. 1, the fluid pipe 1 of the present embodiment is made of, for example, ductile cast iron for waterworks buried in the ground, is formed in a substantially circular shape in cross section, and the inner peripheral surface is a mortar layer 1b. It is covered. The fluid pipe according to the present invention may be made of metal such as cast iron or steel, or made of vinyl chloride, polyethylene or polyolefin. Furthermore, in the present embodiment, the fluid in the fluid pipe 1 is clean water, but the fluid flowing in the fluid pipe is not necessarily limited to clean water. For example, in addition to industrial water, agricultural water, sewage, etc., gas or gas It may be a gas-liquid mixture of liquid and liquid.

  In this embodiment, as shown in FIGS. 11 and 12, a valve housing 13 having a valve body 14 is installed in the fluid pipe 1 configured as described above, and the valve body 14 is operated to operate the fluid. The flow path of the fluid in the pipe 1 is blocked. Hereinafter, in the present embodiment, the installation of the valve housing 13 in the fluid pipe 1 will be described in the order of steps.

  First, as shown in FIGS. 1 and 2, a housing 2 is attached to the outer peripheral surface 1 a of the fluid pipe 1 in a sealed manner. The housing 2 is a so-called split T-shaped tube, which is disposed from above with respect to the fluid pipe 1, and covers a first case 3 that covers the upper side of the outer periphery of the fluid pipe 1 and the fluid pipe 1 from below. The second case 4 is disposed and covers the lower side of the outer periphery of the fluid pipe 1. The first case 3 and the second case 4 are made of a metal material such as cast iron. Note that the housing may have a divided structure including three or more cases. Furthermore, the material of the casing may be various materials like the fluid pipe described above as long as it is applied according to the material of the fluid pipe to which the casing is attached.

  Among these, the first case 3 is configured to abut on the outer peripheral surface 1a of the fluid pipe 1 at a part of the inner wall, and at the substantially central portion of the fluid pipe 1 of the first case 3 in the tube axis direction, A branch port 3a is formed toward the head. The branch port 3 a is formed in a noncircular shape in which the width dimension facing the radial direction of the fluid pipe 1 in a plan view is longer than the width dimension facing the pipe axis direction of the fluid pipe 1.

  A work valve 8a is provided in the branch port 3a. The work valve 8a is pivotally supported by a pivot 8b that faces the horizontal direction, which is the radial direction of the fluid pipe 1, and pivots a handle (not shown) attached to the pivot 8b from the outside of the housing 2. By operating, the branch port 3a can be closed. On the other hand, the second case 4 is formed to have a dimension in the tube axis direction of the fluid pipe 1 that is substantially the same as that of the first case 3, and comes into contact with the outer peripheral surface 1 a of the fluid pipe 1 on the inner wall.

  The first case 3 configured as described above is disposed from above with respect to the fluid pipe 1 in a state in which a water stop member is disposed on the inner peripheral surface, and the second case 4 has a water stop on the inner peripheral surface. With the members arranged, the fluid pipe 1 is disposed from below, and the first case 3 and the second case 4 are fastened by fastening flanges (not shown) of the first case 3 and the second case 4 together. The water stop member disposed on the inner peripheral surface of the fluid pipe 1 is attached to the fluid pipe 1 in close contact with the outer peripheral face 1 a of the fluid pipe 1.

  Further, a fixing member such as a push ring is attached across the casing 2 and the fluid pipe 1 from both ends in the pipe axis direction of the fluid pipe 1 of the casing 2, so that the casing 2 is attached to the fluid pipe 1. Thus, it is fixed so as not to move in the tube axis direction and the circumferential direction.

  Next, as shown in FIGS. 1 and 2, a cutting device 9 for drilling a later-described cutting groove 1 c in the fluid pipe 1 is disposed from above the housing 2. The cutting device 9 will be described in detail. The cutting device 9 is formed so as to penetrate in the vertical direction and is hermetically attached to the upper end portion of the branch port 3a, and is slidable in the horizontal direction on the upper end portion of the branch port 3a. 9f, a cutting case 9d mounted on the slide base 9f, and a pivot base 9i which is inserted into a plurality of support posts 9h standing on the upper end of the cutting case 9d and can move up and down along the support posts 9h. The shaft member 9a is pivotally supported on the pivot base 9i so as to be pivotable, and is connected to a driving means (not shown) and advances in the branch port 3a from the cutting case 9d toward the fluid pipe 1 in the axial direction. And the end mill 9b connected to the lower end of the shaft member 9a, and the shaft member 9a and the end mill 9b can be translated in parallel across the fluid pipe 1 by operating from the outside of the cutting device 9. And a handling portion 9c, and is mainly comprised.

  Among them, the end mill 9b is a perforated shaft having a cylindrical shape and provided with cutting blades 9g (see FIG. 8A) on the bottom and side surfaces, and the shaft member 9a of the shaft member 9a is driven by the driving means. By rotating around the axis, the fluid pipe 1 can be cut by these cutting blades 9g. In particular, the cutting blade 9g provided on the side surface of the end mill 9b constitutes the side blade in the present invention. Further, a communication port 9j that communicates with the outside of the cutting device 9 is formed through the cutting case 9d.

  As shown in FIGS. 3 and 4, the cutting device 9 configured in this way first moves the pivot base 9 i downward along the column 9 h to move the end mill 9 b to the fluid pipe 1 in the branch port 3 a. Move to the vicinity of the upper end of. Then, as a step of drilling through the tube wall of the fluid tube 1, the end mill 9 b is made parallel to the direction perpendicular to the tube axis of the fluid tube 1 via the shaft member 9 a that rotates about the axis. By proceeding in the axial direction of the shaft member 9a, a part of the upper end portion of the fluid pipe 1 is cut by the cutting blade at the bottom portion of the end mill 9b in the casing 2 in a continuous flow state. At the time of this cutting, the chips generated at the time of cutting are discharged out of the housing 2 from the communication port 9j. A communication port for discharging chips may be provided in the vicinity of the branch port 3a.

  Then, after cutting the upper end portion of the fluid pipe 1 by a predetermined amount with a cutting blade at the bottom of the end mill 9b and penetrating through, the operator operates the handling portion 9c as the first step of the feeding process in the present invention. The slide base 9f is translated toward one side in the radial direction of the fluid pipe 1. As shown in FIG. 5, the sliding movement of the slide table 9f causes the end mill 9b to move in parallel while maintaining the height position of the end mill 9b, and the fluid pipe is cut by the cutting blade 9g on the side of the end mill 9b. Cut 1

  In this way, the cutting blade 9g is translated toward one side in the radial direction of the fluid pipe 1 to form a vertical cutting surface 1d so that a part of the pipe wall of the fluid pipe 1 remains. . At this time, as shown in FIG. 8 (a), on one side of the cutting surface 1d in the circumferential direction of the fluid pipe 1, the parallel movement direction of the cutting blade 9g and the rotation direction of the cutting blade 9g face the same direction. It is difficult to leave a cutting residue such as 1e. On the other hand, on the other side of the cutting surface 1d in the circumferential direction of the fluid pipe 1, the parallel movement direction of the cutting blade 9g and the rotation direction of the cutting blade 9g are opposite to each other. .

  Next, from the end of parallel movement of the end mill 9b on one side in the radial direction of the fluid pipe 1 shown in FIG. 5, the operator operates the handling unit 9c as the second step of the feeding process in the present invention. The slide base 9f is translated toward the other side in the radial direction of the fluid pipe 1. As shown in FIG. 6, the slide movement of the slide table 9f causes the end mill 9b to move parallel to the fluid pipe 1 while maintaining the height position of the end mill 9b, and the fluid pipe is cut by the cutting blade 9g on the side of the end mill 9b. By cutting 1 to the end of parallel movement of the fluid pipe 1, a cutting groove 1c is formed.

  At this time, as shown in FIG. 8 (b), the other side of the cutting surface 1d in the circumferential direction of the fluid pipe 1 has a variable direction because the parallel movement direction of the cutting blade 9g and the rotation direction of the cutting blade 9g are opposite to each other. It is difficult to leave a cutting residue such as 1e. On the other hand, since the parallel movement direction of the cutting blade 9g and the rotation direction of the cutting blade 9g face in opposite directions on one side of the cutting surface 1d in the circumferential direction of the fluid pipe 1, from the first through hole to the end of the parallel movement In this case, uncut parts such as burrs 1e are easily generated.

  Further, the end mill 9b is translated from the end of the parallel movement of the end mill 9b on one side in the radial direction of the fluid pipe 1 shown in FIG. While drilling, the burr 1e generated on the other side of the cutting surface 1d in the circumferential direction of the fluid pipe 1 is cut.

  Further, as a third step of the feeding process in the present invention, the operator operates the handling portion 9c from the end of parallel movement of the end mill 9b on the other radial side of the fluid pipe 1 shown in FIG. The stage 9f is moved in parallel toward a position where the end mill 9b penetrates the fluid pipe 1 with a cutting blade at the bottom. At this time, since the end mill 9b moves toward one side in the radial direction of the fluid pipe 1, it cuts a cutting residue such as a burr 1e generated on one side in the circumferential direction of the cutting surface 1d.

  By going through the first step to the third step in the above feeding process, the drilling of the cutting groove 1c is completed without leaving any cutting residue such as burrs 1e on the cutting surface 1d. The cutting groove 1c is formed by the end mill 9b, so that the tube axis of the fluid tube 1 and the upper ends of both ends of the cutting surface 1d in the circumferential direction of the fluid tube 1 are formed in a front sectional view of the fluid tube 1. The angle α is formed in the range of 90 ° to 150 °. During parallel movement by the end mill 9b, the portion of the fluid pipe 1 that is cut by the cutting blade 9g is displaced in the axial direction of the end mill 9b, so that the fluid pipe 1 is prevented from being cut at the same location of the end mill 9b. Further, it is possible to prevent a load from being continuously applied to the same portion of the end mill 9b.

  After the cutting groove 1c is drilled by the end mill 9b in this manner, the shaft member 9a and the end mill 9b are retracted from the inside of the housing 2, and the cutting valve 9 is removed from the branch port 3a after operating the work valve 8a.

  Next, as shown in FIG. 9, a rust prevention device 16 in which a rust prevention core 15 capable of closing the cutting groove 1c is disposed is attached to the upper end portion of the branch port 3a in place of the valve housing 13. The rust preventive device 16 is a rust preventive casing 16a that is directly attached to the upper end of the branch port 3a, and a shaft that can move up and down in the rust preventive casing 16a and has a rust preventive core 15 attached to the lower end. The member 16b is mainly composed of.

  Among these, the rust preventive core 15 is an annular ring provided with an elastically deformable rust preventive member 15a disposed over the entire circumference in the circumferential direction of the rust preventive core 15 and a rust preventive member 15a over the outer peripheral surface. The body is mainly composed of. As shown in FIG. 9, the rust prevention device 16 to which the rust prevention core 15 is attached cuts the rust prevention core 15 by moving the shaft member 16 b toward the fluid pipe 1 after the work valve 8 a is opened. After being arranged in the groove 1c, the clamping part 16c is arranged below the rust prevention member 15a, and is clamped between the lower end part of the shaft member 16b by being operated from the shaft member 16b side. Is operated to elastically deform the rust preventive member 15a. Since the rust preventive member 15a comes into close contact with the entire circumference of the cutting surface 1d of the cutting groove 1c by the elastic deformation of the rust preventing member 15a, the cutting surface 1d is rusted. As shown in FIG. 10, after removing the rust preventive device 16 while leaving the rust preventive core 15 in the cutting groove 1c, the cover 10 is attached to the upper end of the branch port 3a, so that the branch port 3a is temporarily attached. Seal.

  And as shown in FIG. 11, it replaces with the cover body 10 at the upper end part of the branch port 3a, and the valve housing | casing 13 is attached in a sealing form. The valve housing 13 is formed in a cylindrical shape that penetrates in the vertical direction, and a base portion 13a that is directly attached to the upper end portion of the branch port 3a, and is inserted into the base portion 13a in a sealed manner. The base part 13a is mainly composed of a rocking part 13c capable of rocking in the vertical direction. In addition, a valve body 14 for blocking or opening the conduit of the fluid pipe 1 through the cutting groove 1c is disposed inside the peristaltic part 13c in advance.

  The rotating screw 13d is rotatably attached to an insertion hole (not shown) drilled in the top of the peristaltic part 13c, and has an upper end protruding from the peristaltic part 13c. The holding plate 13e is fixed to the upper end surface of the swinging portion 13c with a bolt, and prevents the rotation screw 13d from being pulled out from the insertion hole. With the above configuration, the rotating screw 13d can rotate in both forward and reverse directions with respect to the swinging portion 13c, but does not move up and down.

  Reference numeral 13f denotes a screw portion having a circumferential surface screwed over substantially the entire length except for the upper end portion of the rotating screw 13d. The screw portion 13f is provided at the upper end portion of the valve body 14, and is screwed into a guide portion 14a formed in substantially the same shape as the internal shape of the swinging portion 13c. For this reason, the valve body 14 has the guide portion 14a along the screw portion 13f because the screw portion 13f rotates according to the rotation of the rotation operation portion 13b formed at the upper end portion of the rotary screw 13d. Can move up and down.

  Then, as shown in FIG. 12, the lower end portion of the valve body 14 is moved into the cutting groove 1c by swinging the swinging portion 13c toward the fluid pipe 1 in the base portion 13a after opening the work valve 8a. It is arranged at the upper end of the. And the base part 13a and the rocking | fluctuation part 13c are fastened with a volt | bolt and a nut, and the rocking | fluctuation part 13c is fixed to the base part 13a so that a vertical movement is impossible.

  Thereafter, as shown in FIG. 13, the valve body 14 moves downward by the rotation of the rotation operation portion 13 b by a handle (not shown), thereby elastically deforming the inner peripheral surface of the fluid pipe 1 and sealingly contacting the fluid pipe 1. The flow path of the pipe 1 is blocked, and the pipe of the fluid pipe 1 is opened by moving upward by the rotation of the rotation operation unit 13b by the handle.

  As described above, in the fluid pipe drilling method according to the present embodiment, the end mill 9b provided at the tip of the shaft member 9a rotating around the axis is advanced in the direction perpendicular to the central axis of the fluid pipe 1 to make the fluid pipe 1 through a tube wall and a feed step in which the shaft of the end mill 9b is translated in the transverse direction of the fluid tube 1 in the circumferential direction in a substantially rectangular shape when viewed from above. Since the penetrating cutting groove 1c is formed, after the end mill 9b penetrates the tube wall of the fluid pipe 1, the shaft member 9a that rotates about the axis provided in the end mill 9b is simply moved in parallel, so that the fluid pipe 1 Since the cutting groove 1c penetrating in the circumferential direction having a substantially rectangular shape in a top view can be formed in a part, the drilling operation can be easily performed and the accurate dimensional accuracy of the cutting groove 1c can be obtained. Further, since the portion of the end mill 9b that cuts the fluid pipe 1 is displaced in the axial direction of the end mill 9b during translation, the load on the cutting blade 9g of the end mill 9b is averaged, and the durability of the end mill 9b is improved.

  Further, in the feeding step of translating the shaft of the end mill 9b in the transverse direction of the fluid pipe, the first step of translating the shaft member 9a that has been drilled and drilled in one direction, and the translation in the other direction through the site of drilling and drilling. Since the second step to be performed and the third step to translate in one direction so as to return to the through-drilled portion again, when the cutting groove 1c is drilled, the rotation direction and feed direction of the end mill 9b Since the cutting grooves 1c are drilled so that the drilling process in which they are in the same direction and the drilling processes in the opposite direction are alternately equal, the entire inner surface of the cutting groove 1c can be finished uniformly.

  Further, in the feeding step in which the axis of the end mill 9b is translated in the transverse direction of the fluid pipe 1, the end mill 9b is cut at the end of the parallel movement of the end mill 9b to be translated, and a wall remains in the fluid pipe 1 by the cutting blade 9g. Thus, since the end of the cutting groove 1c is formed, a wall remains in the fluid pipe 1, so that a decrease in rigidity of the fluid pipe 1 is reduced and the valve body 14 can be installed by using the wall. It becomes easy.

  Further, in the feeding step in which the axis of the end mill 9b is translated in the transverse direction of the fluid pipe 1, the range in which the end mill 9b is translated is such that the angle α formed between the center of the fluid pipe 1 and both ends in the circumferential direction of the cutting groove 1c. Since it moves so that it may be in the range of 90 ° to 150 °, the angle α formed by the center of the fluid pipe 1 and both ends in the circumferential direction of the cutting groove 1c is set to 90 ° to 150 °, whereby the rigidity of the fluid pipe 1 is increased. The drilling operation can be simplified by keeping the circumferential length of the cutting groove 1c within a range shorter than the semicircular circumference while ensuring it.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  For example, in the above-described embodiment, the valve body 14 moves downward by the rotation of the rotation operation unit 13b by a handle (not shown), thereby elastically deforming the inner peripheral surface of the fluid pipe 1 and sealingly contacting the fluid pipe 1. The switch body is described as a switching valve that opens the conduit of the fluid pipe 1 by moving upward by the rotation of the rotation operation unit 13b by the handle, but the valve body includes a butterfly valve, a gate valve, a plug It may be an emergency shutoff valve or the like.

DESCRIPTION OF SYMBOLS 1 Fluid pipe 1c Cutting groove 1d Cutting surface 2 Housing | casing 9a Shaft member 9b End mill 9g Cutting blade (side blade)
13 Valve housing 14 Valve body

Claims (4)

A fluid pipe drilling method for drilling a fluid pipe by an end mill in order to install a valve body provided inside a valve housing capable of closing a flow in the fluid pipe in the fluid pipe in an uninterrupted state,
An end mill provided at the tip of a shaft member rotating about the axis is advanced in a direction perpendicular to the central axis of the fluid pipe to penetrate through the pipe wall of the fluid pipe, and then the end mill shaft is crossed over the fluid pipe. A fluid pipe drilling method comprising forming a cutting groove penetrating in a circumferential direction having a substantially rectangular shape in a top view in a part of a fluid pipe by passing through a feeding step of translating in a direction.   In the feeding step of translating the shaft of the end mill in the transverse direction of the fluid pipe, a first step of translating the shaft member drilled and drilled in one direction, and a first step of translating the shaft member in the other direction via the through drilled portion 2. The fluid pipe drilling method according to claim 1, wherein the fluid pipe drilling method includes a step of 2 and a third step of translating in one direction so as to return to the through-piercing portion again. 3.   In the feeding step of translating the end mill shaft in the transverse direction of the fluid pipe, the end mill is cut at the end of the parallel movement of the end mill to be moved so that a wall is left in the fluid pipe by the side edge of the cutting groove. The fluid pipe drilling method according to claim 1, wherein an end portion is formed.   In the feeding step of translating the end mill shaft in the transverse direction of the fluid pipe, the range of translation of the end mill is such that the angle formed between the center of the fluid pipe and both circumferential ends of the cutting groove is 90 ° to 150 °. 4. The fluid pipe drilling method according to claim 1, wherein the fluid pipe is moved so as to fall within a range.

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