Method for manufacturing workpiece

Abstract

To provide a method for manufacturing a workpiece which is improved in work efficiency.SOLUTION: A method for manufacturing a workpiece includes the steps of: fitting a jig 100 that can change a length in a first extension direction to a wall surface W1 of a workpiece W; removing an outer peripheral surface W2 of the workpiece W while the jig 100 is fitted to the wall surface W1; and in a step of fitting the jig 100, fitting the jig 100 so as to press the wall surface W1 by bringing one end of the jig 100 in the first extension direction into contact with the wall surface W1 while adjusting the length in the first extension direction of the jig 100.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a workpiece. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 63-99145 discloses a method for machining the outer surface of a thin-walled pipe without deforming the pipe, and also discloses a plug and a center for use in the machining. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 63-99145 Summary of the Invention [Problem to be solved by the invention]

[0004] The thin-walled pipe processing method disclosed in Japanese Patent Laid-Open Publication No. 63-99145 may have low work efficiency. In this publication, to prevent deformation and vibration of the pipe during processing, the pipe is filled with fine powder under pressure and a plug is installed at the end. Before processing, the powder is filled and the plug is installed, and after processing, they are removed. These pre-processing and post-processing operations require a lot of time, which may result in a decrease in work efficiency.

[0005] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a method for manufacturing a workpiece with improved work efficiency. [Means for solving the problem]

[0006] In a method for manufacturing a workpiece according to the present disclosure, a workpiece having a cavity is prepared. A jig having an elongated shape and capable of changing its length in a first extension direction is attached to a wall surface of the cavity in the workpiece. With the jig attached to the wall surface, the outer peripheral surface of the workpiece is removed. In the attaching step, while adjusting the length of the jig in the first extension direction, the jig is attached so that one end of the jig in the first extension direction contacts and presses against the wall surface. [Effects of the Invention]

[0007] According to the present disclosure, the jig can be easily attached so as to contact the wall surface of the cavity, thereby providing a method for manufacturing a workpiece with improved work efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an overview of a method for manufacturing a workpiece according to a first example of the first embodiment. FIG. [Figure 2] 3 is a flowchart showing a method for manufacturing a workpiece according to the first embodiment. [Figure 3] 1. FIG. 4 is a schematic diagram showing how the jig inserting step (S2) and the screw rotating / adjusting step (S3) of FIG. 2 are performed by the device of FIG. [Figure 4] FIG. 3 is a schematic diagram showing an embodiment in which the fixing step (S4) in FIG. 2 is performed by the device in FIG. [Figure 5] 5 is a schematic diagram showing a step of adjusting the force with which the jig presses against the wall surface of the pipe in the first embodiment. FIG. [Figure 6] 10 is a schematic diagram showing an overview of a method for manufacturing a workpiece according to a second example of the first embodiment. FIG. [Figure 7] 10 is a flowchart showing a method for manufacturing a workpiece according to a second embodiment. [Figure 8] 8 is a schematic view showing a state in which the measuring tool is pressed against the workpiece in the measuring tool attaching step (S23) of FIG. 7. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1

[0010] (composition)

[0011] FIG. 1 is a schematic diagram showing the overall structure of a method for manufacturing a workpiece according to a first example of the first embodiment. The right side of FIG. 1 shows a side view of the workpiece shown on the left side of FIG. 1 from the right side of the figure. Therefore, unless otherwise specified, the following explanation of FIG. 1 and other figures of the same format will refer to the overall view shown on the left side of FIG. 1. First, an overview of the method for manufacturing a workpiece according to this embodiment will be described using FIG. 1.

[0012] As shown in FIG. 1, in the method for manufacturing a workpiece according to this embodiment, a pipe W is used as the workpiece. The pipe W has a thin-walled shape and extends long in one direction. The pipe W in FIG. 1 extends in the left-right direction, and a cross section perpendicular to the extension direction is annular. In other words, the pipe W has a cavity in the center. The cavity is an area formed inside the wall surface W1 of the pipe W, where no material constituting the pipe W is placed. The pipe W also has an outer peripheral surface W2 on its side. The outer peripheral surface W2 of the pipe W is an outward surface extending in the extension direction. As shown on the right side of FIG. 1, the wall surface W1 and the outer peripheral surface W2 are circular when viewed from a direction perpendicular to the extension direction.

[0013] During machining, the pipe W is attached to the workpiece gripping portion C of the lathe M. In this state, a jig 100 is attached to the wall surface W1 of the pipe W. The jig 100 extends in the vertical direction in FIG. 1. In this manner, the jig 100 has an elongated shape. When cutting is performed as shown in FIG. 1, one end and the other end of the jig 100 in the extension direction are pressed against opposing portions of the wall surface W1. In other words, in FIG. 1, the top (one end) of the jig 100 is in contact with the top of the wall surface W1, and the bottom (the other end) is in contact with the bottom of the wall surface W1.

[0014] With the jig 100 attached so as to be in contact with the wall surface W1, the outer peripheral surface W2 of the pipe W is removed using a cutting tool T. As shown in FIG. 1, the blade of the cutting tool T is pressed against the outer peripheral surface W2 from a direction substantially perpendicular to the wall surface W2. The direction in which the blade of the cutting tool T is pressed is indicated by an arrow F. The arrow F is the direction toward the center of the circle of the cross section perpendicular to the extension direction of the pipe W.

[0015] Blocks 102 may be installed at one end and the other end in the extension direction of the jig 100. In this case, the two blocks 102 are pressed against the wall surface W1 of the pipe W at the time of the removal process (cutting process) in FIG.

[0016] Next, the removal process shown in FIG. 1 will be described in detail using a flowchart and the like.

[0017] Fig. 2 is a flowchart showing a method for manufacturing a workpiece according to embodiment 1. As shown in Fig. 2, in the method for manufacturing a workpiece according to embodiment 1, after starting, a workpiece is first attached (S1). In step (S1), a pipe W is prepared as the workpiece and attached to a processing device.

[0018] The pipe W may be made of a commonly known material. For example, the material of the pipe W may be steel. Alternatively, the material of the pipe W may be a non-ferrous metal such as aluminum or copper. A plating layer may also be formed on the surface of the pipe W. The shape of the pipe W, i.e., the shape extending in the left-right direction and having a wall surface W1 for forming a cavity therein, is formed by a commonly known pipe manufacturing method. The shaped pipe W is attached to a machining device as shown in FIG. 1. When grinding the outer peripheral surface W2, which is the extending side surface of the pipe W, the pipe W is attached to a lathe M as shown in FIG. 1, for example.

[0019] The lathe M has a workpiece gripping portion C. The workpiece gripping portion C is a general chuck for gripping a workpiece such as a pipe W. As shown in Figure 1, the pipe W is attached to the workpiece gripping portion C. This fixes the pipe W to the lathe M.

[0020] In step (S1), a pipe W having a cavity and a wall surface W1 formed thereon may be attached to the lathe M as shown in FIG. 1. Alternatively, in step (S1), a long-shaped member without a cavity yet formed therein may be attached to the workpiece holding portion C of the lathe M. In this case, after the long-shaped member is attached to the workpiece holding portion C, the member is subjected to cutting processing by the lathe M. The cutting processing forms a wall surface W1 in the workpiece, and a cavity is formed inside the member. As a result, the member becomes a pipe W as shown in FIG. 1.

[0021] Next, the jig 100 is attached to the wall surface W1 of the hollow of the pipe W. This process comprises a jig inserting process (S2), a screw rotating / adjusting process (S3), and an end fixing process (S4) in FIG.

[0022] Fig. 3 is a schematic diagram showing how the jig inserting step (S2) and the screw rotating / adjusting step (S3) of Fig. 2 are performed by the device of Fig. 1. As shown in Fig. 3, the jig 100 includes, for example, a jack 101 and a block 102.

[0023] The jack 101 includes a threaded rod 101a and a rotating screw 101b. As shown in FIGS. 1 and 3, the threaded rod 101a extends in one direction, a first extension direction. The first extension direction is the up-and-down direction in FIGS. 1 and 3. The rotating screw 101b is arranged to extend in a direction intersecting the first extension direction of the threaded rod 101a. The length of the threaded rod 101a in the first extension direction can be changed by rotating the rotating screw 101b. In this way, the length of the jack 101 can be adjusted. Therefore, the length of the entire jig 100 in the first extension direction can be changed.

[0024] For example, the threaded rod 101a may correspond to a rack and the rotating screw 101b to a pinion, so that the two have a rack-and-pinion relationship. In this way, the distance from the rotating screw 101b to one end of the threaded rod 101a (the end where one of the two blocks 102 is located) can be changed by rotating the rotating screw 101b. This is because when the rotating screw 101b is rotated, a small gear included therein moves the threaded threaded rod 101a along the first extension direction. Therefore, if the position of the other block 102 relative to the rotating screw 101b is fixed, the distance between the two blocks 102 can be changed by rotating the rotating screw 101b. In other words, the length of the jack 101 in the first extension direction can be changed. The rotation of the rotating screw 101b is indicated, for example, by the arrow R on the right side of FIG. 3. When one end of the threaded rod 101a moves closer to the rotary screw 101b, the distance between the two blocks 102 (the length of the jig 100 in the first extension direction) becomes shorter. Conversely, when one end of the threaded rod 101a moves away from the rotary screw 101b, the distance between the two blocks 102 (the length of the jig 100 in the first extension direction) becomes longer. In this way, the length of the threaded rod can be adjusted by rotating the rotary screw 101b.

[0025] Using the jig 100 configured as described above, a jig inserting step (S2) is performed as shown in FIG. 3. In this step (S2), the jig 100 is inserted into the cavity of the pipe W, and at this time, the threaded rod 101a is shortened in the first extension direction. Specifically, by turning the rotating screw 101b, the length of the jig 100 is adjusted so that the overall length of the jig 100 is shorter than at least the diameter of the circular wall surface W1. The shortened jig 100 is inserted inside the wall surface W1 as shown in FIG. 3.

[0026] Thereafter, a screw rotation / adjustment step (S3) is carried out. In this step (S3), the rotating screw 101b is rotated as shown by arrow R in FIG. 3. This adjusts the length of the jig 100. Specifically, as shown by arrow M1 in FIG. 3, the length of the jig 100 is adjusted so that it is longer than when inserted into the wall surface W1. The inserted jig 100 has one end in the first extension direction in contact with the wall surface W1. The one end is the upper end in FIG. 3.

[0027] When the jig 100 has a block 102 at one end, the block 102 preferably has a curved surface 102s. The curved surface 102s is provided at the end of the block 102 in the first extension direction of the jig 100, facing outward in the extension direction. The curved surface 102s has substantially the same shape as the curved surface shape of the wall surface W1. This allows a wider area of ​​the curved surface 102s to come into contact with the wall surface W1.

[0028] The block 102 is preferably formed from a material (slightly softer material) that is less hard than the material constituting the pipe W, for example, a resin material. This reduces the possibility of damaging the pipe W when the block 102 comes into contact with the wall surface W1 of the pipe W. In addition, the block 102 is preferably larger in dimension than the threaded rod 101a of the jack 101 in a direction intersecting the first extension direction of the jig 100. In this way, the curved surface 102s of the block 102 applies a pressing force to the wall surface W1 over a wider area, and stress concentration due to the pressing force can be prevented.

[0029] Next, a fixing step (S4) at the end portions is carried out. Figure 4 is a schematic diagram showing an embodiment in which the fixing step (S4) of Figure 2 is performed by the apparatus of Figure 1. In this step (S4), as shown in Figure 4, the jig 100 is lengthened so that both one end and the other end of the jig 100 come into contact with the wall surface W1. The other end is the lower end in Figure 4. If blocks 102 are provided at one end and the other end, the curved surfaces 102s of both blocks 102 come into contact with the wall surface W1.

[0030] The portion of the wall surface W1 that the block 102 at one end contacts and the portion of the wall surface W1 that the block 102 at the other end contacts face each other. As a result, the curved surfaces 102s of the block 102 press against the wall surface W1 at both one end and the other end. The force with which the curved surfaces 102s press against the wall surface W1 is directed from the inside to the outside in the radial direction of the pipe W. This allows the entire jig 100, including the block 102, to be attached to the workpiece W. In this way, in the process of attaching the jig 100 to the wall surface W1, the block 102 is pressed against the wall surface W1. Due to this pressing force, the jig 100 will not come off the pipe W even if the pipe W rotates in the subsequent turning process. As described above, in the fixing process (S4), the jig 100 is fixed to the pipe W by the blocks 102 at one and the other ends.

[0031] The jig 100 does not have to have the block 102. In this case, in the fixing step (S4), one end of the jig 100 in the extension direction of the jack 101 may contact the wall surface W1. In this case, the jig 100 is attached to the pipe W so that one end of the jack 101 presses the portion of the wall surface W1 that it contacts. During cutting, the jig 100 may be attached to the pipe W so that the other end of the jack 101 in the extension direction also contacts the wall surface W1 and presses the contacting portion. The portion of the wall surface W1 that is pressed by one end of the jack 101 and the portion that is pressed by the other end are opposite each other. As a result, the jig 100 is fixed to the wall surface W1 of the pipe W at one and the other ends thereof.

[0032] As described above, the jig 100 is attached to the wall surface W1 of the pipe W through the jig inserting step (S2), the screw rotating and adjusting step (S3), and the end fixing step (S4) in FIG.

[0033] As shown in FIG. 2, the cutting process step (S5) is performed next. In this process (S5), the outer peripheral surface W2 of the pipe W is cut with the jig 100 attached to the wall surface W1 as shown in FIG. 4. As shown in FIG. 1, the pipe W is rotated around the central axis indicated by the dashed line with the blade of the cutting tool T included in the lathe M pressed in the direction of the arrow F. This removes a portion of the outer peripheral surface W2. This removal process is the cutting process. At this time, because the jig 100 is attached to the wall surface W1, which is the inner peripheral surface of the pipe W, deformation of the pipe W due to stress caused by the cutting process can be suppressed. As a result, the processing accuracy of the pipe W during the cutting process can be improved.

[0034] FIG. 5 is a schematic diagram illustrating a process for adjusting the force with which the jig presses against the wall surface of the pipe in the first embodiment. As shown in FIG. 5, it is preferable to adjust the force with which one end of the jig 100 (the end of the block 102 or the threaded rod 101a in FIG. 5) presses against the wall surface W1 during the cutting process (S5), which is a removal process. That is, as the removal process progresses, the removal process is temporarily stopped when the diameter of the outer circumferential surface W2 of the pipe W becomes smaller than the initial diameter. In this state, the jack 101 is loosened. That is, the length of the jig 100 in the first extension direction is shortened. Thereafter, the jig 100 is lengthened again until the end of the jig 100, such as the block 102, presses against the wall surface W1 with an appropriate force. On the right side of FIG. 5, the arrow M2 indicates the operation of shortening and then lengthening the length of the jig 100 again. As a result, even as the cutting process progresses, the jig 100 is pressed against the wall surface W1 with an optimal pressing force.

[0035] As shown in FIG. 2, once the cutting process step (S5) is completed, the screw rotation step (S6) is carried out. In this step (S6), the threaded rod 101a is shortened by rotating the rotating screw 101b. Specifically, the overall length of the jig 100 becomes shorter than at least the diameter of the circular wall surface W1. In this state, the jig removal step (S7) is carried out. Specifically, the jig 100, whose length has been shortened as described above, is removed from the hollow interior of the pipe W (S7). In this way, the method for manufacturing the workpiece shown in FIG. 2 is completed.

[0036] FIG. 6 is a schematic diagram showing the overall structure of a method for manufacturing a workpiece according to a second example of the first embodiment. In FIG. 6, the same parts as those in FIG. 1 will not be described again. As shown in FIG. 6, the second example, which is a modification of the first embodiment, basically has the same configuration as the method for manufacturing a workpiece shown in FIGS. 1 to 5, and can achieve the same effects. However, in FIG. 6, the jig 100 has a portion extending in a first extension direction and a portion extending in a second extension direction. In this respect, the second example differs from the method for manufacturing a workpiece shown in FIGS. 1 to 5.

[0037] In the second example of the jig 100, the jack 101 includes a threaded rod 101c in addition to the threaded rod 101a. The threaded rod 101a extends in a first extension direction and changes the length of the jig 100 in the first extension direction. In contrast, the threaded rod 101c extends in a second extension direction and changes the length of the jig 100 in the second extension direction. The second extension direction is a direction different from the first extension direction. As shown on the right side of FIG. 6, for example, the second extension direction is a direction perpendicular to the first extension direction, but is not limited to this. The angle between the second extension direction and the first extension direction is arbitrary. Although not shown, the jig 100 may further include a jack 101 (threaded rod) extending in a third extension direction. The third extension direction is different from both the first extension direction and the second extension direction.

[0038] In the second example of FIG. 6, the steps are basically the same as those of the method for manufacturing a workpiece shown in FIG. 2. However, in the second example, in the steps of attaching the jig 100 to the wall surface W1 (steps (S2), (S3), and (S4) in FIG. 2), the jig 100 is attached as follows. The jig 100 is attached so that one end of the portion extending in the first extension direction and one end of the portion extending in the second extension direction press against the wall surface W1. The one end of the portion extending in the second extension direction is, for example, the left end of the threaded rod 101c in the right-hand view of FIG. 6. Thereafter, as shown in FIG. 6, it is preferable that the other end of the portion extending in the first extension direction and the other end of the portion extending in the second extension direction are also attached so as to press against the wall surface W1. After the step of attaching the jig 100 to the wall surface W1 is thus performed, steps (S5), (S6), and (S7) in FIG. 2 are performed.

[0039] It should be noted that only the rotating screw 101b is shown in Fig. 6. However, in Fig. 6, it is preferable to provide a separate rotating screw for changing the length of the threaded rod 101c in the second extending direction.

[0040] (Action and effect)

[0041] In a method for manufacturing a workpiece according to the present disclosure, first, a workpiece (pipe W) having a cavity is prepared. A jig 100 whose length in a first extension direction is changeable is attached to a wall surface W1 of the cavity of the pipe W (steps (S2), (S3), and (S4) in FIG. 2). With the jig 100 attached to the wall surface W1, the outer peripheral surface W2 of the pipe W is removed (cut by a lathe M) (step (S5)). In the step of attaching the jig 100 (steps (S2), (S3), and (S4) in FIG. 2), the jig 100 is attached so that one end of the jig 100 in the first extension direction contacts the wall surface W1 and presses against the wall surface W1, while adjusting the length of the jig 100 in the first extension direction.

[0042] In the removal process (step (S5)), a force is applied from the cutting tool T to the pipe W in the direction indicated by arrow F in Figure 1. The direction of the force indicated by arrow F is the same as the force with which the cutting tool T presses the outer peripheral surface W2. The cutting process is performed by the blade of the cutting tool T digging into the outer peripheral surface W2 of the pipe W and cutting the surface layer of the outer peripheral surface W2. The thin-walled portion between the wall surface W1 and the outer peripheral surface W2 of the pipe W has a thin radial thickness. Therefore, the pipe W has low radial rigidity. The pipe W may deform radially due to the force applied by the cutting tool T, resulting in dimensional defects. In other words, radial deformation may reduce the circularity of the annular cross-section of the pipe W and reduce quality. Furthermore, because the pipe W has low radial rigidity, the force applied by the cutting tool T may cause chatter vibrations. Chatter vibrations during removal may worsen the surface roughness of the outer peripheral surface W2. In particular, when the radial thickness of the thin-walled portion of the pipe W is 5 mm or less and the extending length of the pipe W exceeds 1000 mm, processing becomes difficult.

[0043] In the present disclosure, both ends of a jig 100 are attached to, for example, a pair of opposing portions of a wall surface W1 of a hollow cavity of a pipe W, as shown in FIG. 1 . The pressing portion of the jig 100 presses the wall surface W1 from the inside to the outside in the radial direction. This suppresses radial deformation and vibration of the pipe W during processing. This is because the force indicated by the arrow F is offset by the pressing force of the jig 100, resulting in high rigidity in the thin-walled portion of the pipe W.

[0044] Such an effect can be obtained simply by attaching the jig 100 to the wall surface W1 of the pipe W. According to the above-described method for manufacturing a workpiece, pre- and post-processing steps to prevent deformation and vibration during processing can be completed in a shorter time than, for example, when micropowder is pressurized and filled into the inside of the pipe W and then the end is plugged.

[0045] In summary, according to this embodiment, by increasing the rigidity of the pipe W using the jig 100, the machining accuracy of the outer diameter of the outer surface W2 can be improved. This stabilizes the removal process. It also enables more precise machining accuracy. For example, it can handle high-precision machining requiring accuracy in the 0.01 mm range. Furthermore, for example, when the pipe W is supported by inserting a rod-shaped metal rod into the cavity of the pipe W, a gap may occur between the wall surface of the pipe W and the outer surface of the metal rod. If a gap occurs, the outer surface of the metal rod cannot support the pipe W. In contrast, according to this embodiment, almost no gap occurs between the end of the jig 100 and the wall surface W1. Therefore, the wall surface W1 can be reliably supported by the jig 100, enabling high-precision machining. As a result, the roundness of the manufactured pipe W can be improved.

[0046] In the above-described method for manufacturing a workpiece, blocks 102 are installed on one end and the other end of the jig 100. In the process of attaching the jig 100, the block 102 is pressed against the wall surface W1. By pressing the block 102 against the wall surface W1, a wider area of ​​the wall surface W1 can be pressed and stress concentration due to the pressing force can be prevented compared to when a jack 101 without the block 102 is pressed against the wall surface W1. This is because the curved surface 102s of the block 102 functions as a support point that receives the force indicated by the arrow F. Therefore, machining defects caused by the force indicated by the arrow F are minimized, enabling high-precision removal machining.

[0047] In the above-described method for manufacturing a workpiece, the jig 100 includes a jack 101. The jack 101 includes a threaded rod 101a and a rotating screw 101b. The threaded rod 101a extends in a first extension direction. The rotating screw 101b is disposed to extend in a direction intersecting the threaded rod 101a in order to change the length of the threaded rod 101a in the first extension direction. The length of the threaded rod 101a can be changed by rotating the rotating screw 101b.

[0048] In this case, the end of the threaded rod 101a is pressed against the wall surface W1 by rotating the rotary screw 101b. This allows the jig 100 to be attached to the wall surface W1. Therefore, the jig 100 can be installed and removed from the pipe W in a short time. There is no other member other than the jig 100 that supports the pipe W from the inner periphery (hollow side), and fixing the jig 100 requires only the simple task of rotating the rotary screw 101b to extend or retract the threaded rod 101a. This allows the work before and after processing to be completed in a short time.

[0049] In this embodiment, by using the jig 100 having such a screw, it is possible to easily increase the rigidity of the thin-walled portion of the thin-walled pipe shape of the pipe W and stabilize the processing dimensions of the pipe W. Furthermore, since the structure of the jig 100 is simple, the jig 100 can be manufactured inexpensively.

[0050] The method for manufacturing the workpiece described above may further include a step of adjusting the force with which one end of jig 100 presses against wall surface W1 during the removal processing step (step (S5)).

[0051] For example, if machining continues while maintaining the pressing force of the jig 100 against the wall surface W1 at the start of machining, there is a risk that the deformation of the pipe W will increase as the thin-walled portion of the pipe W becomes thinner during machining. This is because the rigidity of the thin-walled portion decreases as the thin-walled portion becomes thinner. This makes it difficult to machine the pipe W with high precision. Therefore, once machining has progressed a little, the jig 100 is temporarily removed from the wall surface W1, even if it is still in the middle of machining. The force with which the jig 100 presses against the wall surface W1 is adjusted so that it presses against the wall surface W1 with a different force than before. In other words, as cutting of the pipe W progresses, the thickness of the thin-walled portion becomes thinner. Therefore, once cutting has progressed a little, the force with which the cutting tool T presses against the pipe W is readjusted to match the wall thickness at that time. In this way, by reapplying the jig 100 or its block 102 to the wall surface W1 with an appropriate force, the jig 100 can press against the wall surface W1 with an appropriate force from the beginning to the end of machining. As a result, machining defects due to deformation or vibration of the thin-walled portion can be more reliably prevented, enabling high-precision machining.

[0052] 5, the length of the threaded rod 101a of the jig 100 can be adjusted while the pipe W is still attached to a machine such as a lathe M. This also reduces the time required for advance preparation using the jig 100, leading to higher efficiency in the entire work.

[0053] In the above-described method for manufacturing a workpiece, the jig 100 may have a portion extending in a first extension direction and a portion extending in a second extension direction, as shown in FIG. 6 . The second extension direction is different from the first extension direction. In the step of attaching the jig 100 (steps (S2), (S3), and (S4) in FIG. 2 ), the jig 100 is attached so that one end of the portion extending in the second extension direction presses against the wall surface W1, in addition to one end of the portion extending in the first extension direction. In other words, while the basic form is the embodiment shown in FIG. 1 , the number of threaded rods 101 a and 101 c of the jig 100 may be increased as shown in FIG. 6 . This increases the number of points at which the ends of the jig 100 support the wall surface W1. For example, while there are two support points in FIG. 1 , there are four support points in FIG. 6 . As shown on the right side of FIG. 6 , the block 102 presses against the wall surface W1 at four points: top, bottom, left, and right. By increasing the number of support points, deformation and vibration of the pipe W during processing can be more reliably eliminated than when there are fewer support points.

[0054] (remarks)

[0055] In Fig. 1, two jigs 100 are arranged side by side with a distance L between them in the extension direction of the pipe W, i.e., in the left-right direction. In the processing method of this embodiment, when the thickness of the thin-walled portion of the pipe W after processing is t, it is preferable that L / t is 100 or less. This enhances the effect of suppressing deformation and vibration of the pipe W during removal processing.

[0056] Embodiment 2

[0057] (composition)

[0058] FIG. 7 is a flowchart showing a method for manufacturing a workpiece according to the second embodiment. As shown in FIG. 7, the manufacturing method of this embodiment is basically the same as the manufacturing method of the first embodiment, and can achieve the same effects. Here, the description of the parts that are the same as those of the first embodiment will not be repeated. In this embodiment, a measuring tool mounting step (S23) is provided between the jig insertion step (S2) and the screw rotation / adjustment step (S3). The timing at which the measuring tool mounting step (S23) is performed is not limited to the above. For example, the measuring tool mounting step (S23) may be performed between the workpiece mounting step (S1) and the jig insertion step (S2).

[0059] Fig. 8 is a schematic diagram showing how the measuring tool MS is pressed against the workpiece in the measuring tool attachment step (S23) of Fig. 7. As shown in Fig. 8, the measuring tool MS is installed so as to be in contact with the outer peripheral surface W2 of the workpiece, i.e., the pipe W. The measuring tool MS measures the radial coordinate of the outer peripheral surface W2 of the pipe W.

[0060] In this embodiment, when performing the steps of attaching the jig 100 to the wall surface W1 (steps (S2), (S3), and (S4) in FIG. 8), the deformation amount of the pipe W is measured using the measuring tool MS. While measuring the deformation amount of the pipe W, the jig 100 is fixed to the block 102 (step (S4)). In other words, while measuring the deformation amount of the pipe W, the jig 100 is installed so that one and the other ends of the jig 100 press against the wall surface W1.

[0061] The method for attaching and fixing the jig 100 to the pipe W while measuring the deformation of the pipe W is as follows. The measuring tool MS shown in FIG. 8 is, for example, a commercially available dial gauge. The measuring tool MS is installed so that, for example, the tip end to which a sensor is attached is in contact with the outer peripheral surface W2. When the tip end of the measuring tool MS begins to contact the outer peripheral surface W2, the scale of the measuring tool MS is set to zero. At this point, the jig 100 is not in contact with the wall surface W1.

[0062] Then, the jig 100 is extended inside the pipe W, and its end is brought into contact with the wall surface W1. Specifically, the length of the jig 100 is increased as shown by the arrow M1 on the right side of Figure 8. By further extending the jig 100, the end is pressed against the wall surface W1. This pressure deforms the pipe W. As a result, the value displayed on the scale of the measuring tool MS changes. This change in value is the amount of deformation of the pipe W. In this way, the amount of deformation of the pipe W is measured by the measuring tool MS. This is because the tip of the measuring tool MS is maintained in contact with the outer peripheral surface W2. As shown in Figure 8, it is preferable that the position of the tip of the measuring tool MS be opposite the part of the jig 100 that contacts the wall surface W1.

[0063] As shown in Fig. 7, a change in the scale of the measuring instrument MS due to fixation at the end (S4) is measured as the deformation amount of the pipe W. If this deformation amount is 0.01 mm or less, the cutting process step (S5) is performed as in the first embodiment. If the deformation amount exceeds 0.01 mm, the steps (S3) and (S4) for readjusting the jig 100 are repeated until the deformation amount becomes 0.01 mm or less. This is because if the cutting process step (S5) is performed when the deformation amount of the pipe W due to pressing the jig 100 is large, the deformation of the pipe W will be large when the jig 100 is removed.

[0064] (Action and effect)

[0065] In the method for manufacturing a workpiece according to the present disclosure, in the steps of attaching the jig 100 (steps (S2), (S3), and (S4) in FIG. 8), the jig 100 is attached while measuring the amount of deformation of the pipe W. This makes it possible to suppress deformation of the pipe W when it is fixed. This allows for high-precision processing in the cutting process step (S5). In other words, the roundness of the pipe W can be improved. According to the present disclosure, the deformation state of the pipe W can be confirmed using the measuring tool MS. This makes it possible to adjust the strength with which the end blocks 102 and the like press against the wall surface W1 by adjusting the extension and contraction of the jig 100. [Example]

[0066] The pipe W shown in FIG. 1 was used as a workpiece, and its outer surface W2 was machined using a cutting tool T of a lathe M. In this example, the material of the pipe W was aluminum. The diameter of the outer surface W2 perpendicular to the extension direction of the pipe W was 100 mm or more and 250 mm or less, and the thickness of the thin-walled portion was 4 mm or more and 10 mm or less. The pipe W was machined on a long lathe. The lathe M and jig 100 shown in FIG. 1 were used for lathe finishing in the long lathe machining of the pipe W.

[0067] When attaching the jig 100 so as to press the wall surface W1 of the pipe W, a dial gauge, which is a measuring instrument MS, was set as shown in Figure 8. When the wall surface W1 was pressed by the extension of the threaded rod 101a of the jack 101, the deformation amount of the outer diameter side of the pipe W was set to within 0.05 mm.

[0068] As a result, high machining accuracy of the pipe W was ensured. This prevented the end of the jig 100 from slipping or coming off, and prevented scratches on the wall surface W1 where the block 102 contacted. As a result, cutting was performed with good machining accuracy for all workpieces. In particular, the pipe W, whose thin-walled portion had a radial thickness of 4 mm, was machined so that the tolerance was within the allowable range.

[0069] The features described in the above-described embodiments may be applied in appropriate combinations within the scope of technical compatibility.

[0070] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The basic scope of the present disclosure is defined by the claims, not by the above description, and it is intended to include all modifications within the meaning and scope of the claims.

[0071] (Addendum)

[0072] Various aspects of the present disclosure are summarized below as appendices.

[0073] (Appendix 1) providing a workpiece having a cavity; a step of attaching a jig capable of changing the length in a first extension direction to a wall surface of the cavity of the workpiece; and removing the outer peripheral surface of the workpiece while the jig is attached to the wall surface, A method for manufacturing a workpiece, wherein in the attaching process, the jig is attached so that one end of the jig in the first extension direction contacts the wall surface and presses against the wall surface while adjusting the length of the jig in the first extension direction.

[0074] (Appendix 2) Blocks are provided at the one end and the other end of the jig, 2. The method for manufacturing a workpiece according to claim 1, wherein the attaching step presses the block against the wall surface.

[0075] (Appendix 3) the jig includes a jack; The jack includes a threaded rod extending in the first extension direction and a rotating screw arranged to extend in a direction intersecting the threaded rod to change the length of the threaded rod in the first extension direction, 3. The method for manufacturing a workpiece according to claim 1 or 2, wherein the length of the threaded rod can be changed by rotating the rotating screw.

[0076] (Appendix 4) The method for manufacturing a workpiece according to any one of appendices 1 to 3, further comprising the step of adjusting the force with which the one end presses against the wall surface during the removal processing step.

[0077] (Appendix 5) the jig includes a portion extending in the first extension direction and a portion extending in a second extension direction different from the first extension direction, A method for manufacturing a workpiece according to any one of appendices 1 to 4, wherein in the attaching step, the jig is attached so that in addition to the one end of the portion extending in the first extension direction, one end of the portion extending in the second extension direction presses against the wall surface.

[0078] (Appendix 6) 6. The method for manufacturing a workpiece according to any one of claims 1 to 5, wherein in the attaching step, the jig is attached while measuring the amount of deformation of the workpiece. [Explanation of symbols]

[0079] 101 jack, 101a, 101c threaded rod, 101b rotating screw, 102 block, 102s curved surface, C workpiece gripping portion, M lathe, MS measuring tool, W pipe, W1 wall surface, W2 outer peripheral surface.

Claims

1. providing a workpiece having a cavity; a step of attaching a jig capable of changing the length in a first extension direction to a wall surface of the cavity of the workpiece; and removing the outer peripheral surface of the workpiece while the jig is attached to the wall surface, A method for manufacturing a workpiece, wherein in the attaching process, the jig is attached so that one end of the jig in the first extension direction contacts the wall surface and presses against the wall surface while adjusting the length of the jig in the first extension direction.

2. Blocks are provided at the one end and the other end of the jig, The method for manufacturing a workpiece according to claim 1 , wherein the block is pressed against the wall surface in the attaching step.

3. the jig includes a jack; The jack includes a threaded rod extending in the first extension direction and a rotating screw arranged to extend in a direction intersecting the threaded rod in order to change the length of the threaded rod in the first extension direction, The method for manufacturing a workpiece according to claim 1 or 2, wherein the length of the threaded rod is changeable by rotating the rotary screw.

4. The method for manufacturing a workpiece according to claim 1 or 2, further comprising the step of adjusting a force with which said one end presses said wall surface during said removing step.

5. the jig includes a portion extending in the first extension direction and a portion extending in a second extension direction different from the first extension direction, 3. The method for manufacturing a workpiece according to claim 1 or 2, wherein in the attaching step, the jig is attached so that in addition to the one end of the portion extending in the first extension direction, one end of the portion extending in the second extension direction presses against the wall surface.

6. 3. The method for manufacturing a workpiece according to claim 1, wherein in the attaching step, the jig is attached while measuring a deformation amount of the workpiece.

Images