Flanging method

Abstract

To provide a flanging method for allowing a tapered tool to revolve without rotating a cylindrical member and by which a large tube expansion ratio is attained without heating and a flange portion with more uniform thickness and a larger diameter can be formed compared to the conventional technique.SOLUTION: A flanging method according to the present invention includes: a first step of supporting a cylindrical member so as not rotate the cylindrical member; and a second step of sequentially executing a process cycle in which the inner surface of a pipe end, which is an end of the cylindrical member is pressed radially outward at point contact with the molding tool while revolving a molding tool having a predetermined shape around a tube axis as an axis of the cylindrical member and thereby forming a flange portion at the pipe end. In the process cycle, the molding tool is reciprocated in the direction of the tube axis while changing the revolution diameter of the molding tool.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a flanging method, and more particularly to a flanging method for forming a flange portion at an end of a tubular member. [Background technology]

[0002] For example, when connecting tubular members such as vehicle exhaust pipes and building piping, a fastening method is often used in which flanges (flat, enlarged diameter portions) provided at the ends of both tubular members (hereinafter sometimes referred to as "pipe ends") are brought into close contact with each other and then secured in place by a joint case that encloses them. Alternatively, the flanges may be fastened together by screwing them together using fastening members consisting of a set of bolts and nuts. In either case, it is necessary to integrally form flanges having a diameter (flat surface) sufficient to enable fastening with the pipe ends.

[0003] A typical method for forming a flange at a pipe end by plastic processing is to press multiple taper dies into the pipe end to first raise the pipe end obliquely to the pipe axis, and finally raise the pipe end perpendicular to the pipe axis to form a flange. However, there is a limit to the expansion rate that can be achieved by this pipe expansion method, and it is difficult to form a flange with a large diameter.

[0004] Therefore, a method called rotary plastic processing is used in which a tapered tool is pressed against the inside of the pipe end while rotating (spinning) a cylindrical member around its axis, thereby first raising the pipe end at an angle to the pipe axis, and finally raising the pipe end at a right angle to the pipe axis (see, for example, Non-Patent Document 1). However, in such rotary plastic processing, since the cylindrical member (pipe) itself is rotated, large equipment and a large space are required. Therefore, it is difficult to adopt such rotary plastic processing when it is desired to form a flange (flanging) at a construction site such as a building piping site.

[0005] Alternatively, it is possible to form a flange portion in advance on a short tubular member and weld the tubular member to another long tubular member, as described in the above-mentioned Non-Patent Document 1. However, such a configuration and method is uneconomical and raises concerns about the strength and reliability of the welded portion.

[0006] Therefore, in the technical field, a flanging method is known in which a tapered tool is revolved without rotating (rotating) a cylindrical member. For example, Patent Document 1 (JP Patent Publication 11-188445A) discloses a method of forming a flange portion by moving a tapered tool in the tube axial direction while revolving it, thereby transferring the shape of the root of the tool to the peripheral edge of the cylindrical member. However, there is a limit to the expansion rate that can be achieved by such transfer, and it is difficult to form a flange portion with a large diameter. Specifically, it is possible to form a small flange (lip) on the peripheral edge of the opening of the can body, but it is not suitable for forming a large flange for fastening as described above.

[0007] Therefore, in Patent Document 2 (JP Patent Publication 2002-178043 A), a rotary plastic processing method is proposed in which a tapered tool is rotated and advanced toward the end of the tube in the axial direction while making an angle with respect to the tube axis, and while pressing the inside of the tube end by line contact, the tube end is first raised at an angle to the tube axis, and finally raised at a right angle to the tube axis. However, this method cannot control the flow in the radial direction (radial direction and centripetal direction) of the material (thickness) that constitutes the part where the flange is to be formed, so there is a risk of thinning of the flange and even buckling. For this reason, it is difficult to form a flange with a large diameter (high expansion ratio) using this method.

[0008] In order to solve this problem, Patent Document 2 proposes the use of hot processing (heating the pipe material in advance), but this is inefficient and uneconomical, and the processing limit cannot be increased even if hot processing is used in combination. In addition, the use of heating means (for example, fire) at the construction site is undesirable from the viewpoint of safety management. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 11-188445 [Patent Document 2] JP 2002-178043 A [Non-patent literature]

[0010] [Non-Patent Document 1] Masanobu Nakamura, "Pipe Processing Method", first edition, Nikkan Kogyo Shimbun, September 1982, p.107 Summary of the Invention [Problem to be solved by the invention]

[0011] As described above, in the technical field, there is a demand for a flanging method in which a tapered tool is revolved without rotating (rotating) a cylindrical member, which can achieve a large tube expansion ratio without heating and form a flange portion having a more uniform plate thickness and a larger diameter than the conventional techniques. The present invention has been made to meet such demands. [Means for solving the problem]

[0012] In view of the above problems, the inventors conducted intensive research and discovered that the above problems can be solved by a spinning process in which a forming tool moving along a predetermined pattern is used to expand the inner surface of the tube end through point contact in a sequential manner.

[0013] Specifically, the flanging method according to the present invention (hereinafter, sometimes referred to as the "invention method") is a flanging method in which a flange portion is formed by performing rotary plastic working on a pipe end, which is the end of a cylindrical member. The inventive method includes the following first and second steps.

[0014] First step: supporting the cylindrical member so that it cannot rotate. Second process: A flange portion is formed on the tube end by sequentially executing a processing cycle in which a forming tool having a predetermined shape is revolved around the tube axis, which is the axis of the tubular member, while the forming tool is pressed radially outwardly by point contact with the inner surface of the tube end.

[0015] Furthermore, in the processing cycle, the forming tool is reciprocated in the direction of the tube axis while changing the revolution radius of the forming tool. Effect of the Invention

[0016] As described above, in the method of the present invention, a processing cycle is sequentially performed in which a forming tool that revolves while making point contact with the inside of a tube end of a cylindrical member presses a processing point. In each processing cycle, the trajectory, number of rotations, and moving speed of the forming tool can be appropriately adjusted according to the material and shape of the cylindrical member and the thickness and shape of the flange portion to be formed. As a result, it is possible to form a flange portion having a desired thickness and diameter by drawing out the maximum processing limit while avoiding the occurrence of defects such as buckling and cracking.

[0017] That is, according to the method of the present invention, in a flanging method in which a tapered tool revolves around a cylindrical member without rotating (rotating), a large expansion ratio can be achieved without heating, and a flange portion having a more uniform plate thickness and a larger diameter can be formed compared to the conventional technology. Furthermore, even if the shape of the cylindrical member to be processed and the flange portion to be formed change, there is no need to change the forming tool, and it can be dealt with by changing the trajectory, number of rotations, and moving speed of the forming tool in the processing cycle.

[0018] Other objects, other features and attendant advantages of the present invention will be easily understood from the following description of each embodiment of the present invention. [Brief description of the drawings]

[0019] [Figure 1]3 is a flowchart showing an example of the flow of each step included in the flanging method (first method) according to the first embodiment of the present invention. [Diagram 2] 5A to 5C are schematic cross-sectional views illustrating specific movement patterns of a forming tool in each working cycle performed in a second step included in the first method. [Diagram 3] 10A to 10C are schematic cross-sectional views illustrating how a flange portion is successively formed at a tube end of a tubular member as a machining cycle is performed in a second step. [Figure 4] 10 is a schematic cross-sectional view illustrating a state in which a second processing cycle is completed in a second step and the center point of the peripheral portion of the forming tool has returned to the starting point. FIG. [Diagram 5] 11 is a schematic cross-sectional view illustrating the position of the center point of the peripheral portion of the forming tool and the shape of the tube end of the tubular member in the middle of the third processing cycle (end point of the forward pass). FIG. [Figure 6] 11 is a schematic cross-sectional view illustrating the position of the center point of the peripheral portion of the forming tool and the shape of the tube end of the tubular member in the middle of a sixth processing cycle (end point of the forward pass). FIG. [Figure 7] 11 is a schematic cross-sectional view illustrating the position of the center point of the peripheral portion of the forming tool and the shape of the tube end of the tubular member during an 11th processing cycle (during the outward movement). FIG. [Figure 8] 11 is a schematic cross-sectional view illustrating a state in which the center point R of the peripheral portion of the forming tool 30 has reached the end point of the forward path of the trajectory T11 in the 11th processing cycle. FIG. [Figure 9] 10 is a schematic diagram illustrating an example of the arrangement of forming tools used in a second step included in a flanging method (second method) according to a second embodiment of the present invention. FIG. [Figure 10] 10 is a flowchart showing an example of the flow of each step included in a flanging method (third method) according to a third embodiment of the present invention. [Figure 11] FIG. 13 is a schematic diagram showing an example of the configuration of a finishing tool used in a third step included in the third construction method. [Figure 12]FIG. 13 is a schematic diagram showing an example of the configuration of a finishing tool used in a third step included in a third construction method according to a preferred embodiment. [Figure 13] FIG. 13 is a schematic diagram showing an example of an arrangement of forming tools and finishing tools in a third step included in a third construction method according to a preferred embodiment. [Figure 14] FIG. 13 is a schematic diagram showing an example of the configuration of a finishing tool used in a third step included in a third construction method according to another preferred embodiment. [Figure 15] FIG. 13 is a schematic diagram showing an example of an arrangement of forming tools and finishing tools in a third step included in a third construction method according to another preferred embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] First Embodiment Hereinafter, a flanging method according to a first embodiment of the present invention (hereinafter, may be referred to as a "first method") will be described.

[0021] <composition> The first method is a flanging method in which a flange portion is formed on a tube end, which is the end of a cylindrical member, by rotary plastic processing. In other words, the first method is a spinning method in which a flange portion is formed on a tube end. The configuration of a spinning processing device is well known to those skilled in the art, so a description thereof will be omitted here.

[0022] Fig. 1 is a flow chart showing an example of the flow of each step included in the first method. As shown in Fig. 1, the first method includes the first step and the second step listed below. The first step performed in step S01 is to support the cylindrical member so that it cannot rotate. The second process, which is performed in step S02, is a process of forming a flange portion at the tube end by sequentially performing a processing cycle in which a forming tool having a predetermined shape is revolved around the tube axis, which is the axis of the tubular member, while the forming tool is pressed radially outwardly by point contact with the inner surface of the tube end.

[0023] The configuration (e.g., cross-sectional shape, axial length and thickness, and constituent material, etc.) of the tubular member that is the workpiece to be processed by the first method is not particularly limited as long as it is possible to form a flange portion at the pipe end by the first method. Typically, the first method is applied to a metallic tubular member such as a steel pipe.

[0024] In the first step, the cylindrical member is supported and fixed in the spinning device so as not to rotate. Therefore, in the first method, large-scale equipment and a large space for rotating the cylindrical member itself are not required. Note that the mechanism and method for supporting the cylindrical member in the spinning device so as not to rotate are also well known to those skilled in the art, so a description thereof will be omitted here.

[0025] Next, in the second step, a forming tool having a predetermined shape is revolved around the tube axis, which is the axis of the cylindrical member, while sequentially executing a processing cycle in which the forming tool presses the inner surface of the tube end radially outward in a point contact manner. The forming tool can be appropriately selected from various forming tools commonly used in spinning, such as forming rollers and spatulas, depending on, for example, the configuration of the cylindrical member to be processed as the workpiece (e.g., cross-sectional shape, axial length and thickness, and constituent materials), the desired shape of the flange portion, and processing conditions and constraints (e.g., performance and specifications of the spinning device), etc.

[0026] Incidentally, "revolving the forming tool around the tube axis" refers to rotating the forming tool around the tube axis and the axis of the flange portion to be formed. Typically, the forming tool can be revolved around a straight line passing through the tube axis of a cylindrical member supported and fixed so as not to rotate, by rotating a face plate equipped with a bracket that supports the forming tool in a spinning processing device. In this way, in the first method, the forming tool is revolved without rotating (rotating) the cylindrical member, so that large equipment and a large space are not required, unlike the prior art described above. Therefore, flange formation (flanging) can be performed by such rotational plastic processing, especially at construction sites such as building piping.

[0027] However, if it is possible to secure large-scale equipment and a large space in the environment in which the first method is performed, the spinning apparatus may be configured so that the tubular member rotates (rotates on its axis) and the forming tool does not revolve. Alternatively, the spinning apparatus may be configured so that the tubular member rotates (rotates on its axis) and the forming tool revolves. In other words, it is sufficient to relatively revolve the forming tool around the tube axis of the tubular member.

[0028] Furthermore, in the processing cycle, the forming tool is reciprocated in the direction of the tube axis while changing the revolution diameter of the forming tool. Here, "reciprocating the forming tool in the direction of the tube axis while changing the revolution diameter of the forming tool" refers to controlling the moving direction of the forming tool so that the tube end of the cylindrical member can be expanded at a desired angle to approach the desired shape of the flange portion. The change in the revolution diameter of the forming tool and the reciprocating motion in the direction of the tube axis do not necessarily occur simultaneously. For example, in each processing cycle, there may be a period in which the change in the revolution diameter of the forming tool and the reciprocating motion in the direction of the tube axis occur simultaneously, and a period in which only one of the change in the revolution diameter of the forming tool or the reciprocating motion in the direction of the tube axis occurs. Furthermore, in each processing cycle, there may be a period in which neither the change in the revolution diameter of the forming tool nor the reciprocating motion in the direction of the tube axis occurs, and the forming tool stops at a predetermined position.

[0029] The specific movement pattern (tool operation) of the forming tool in each processing cycle is not particularly limited, and can be appropriately selected from various tool operations generally adopted in spinning processing which performs rotational plastic processing, depending on, for example, the configuration of the tubular member which is the workpiece to be processed (e.g., cross-sectional shape, axial length and plate thickness, and constituent material, etc.), the desired shape of the flange portion, and the processing conditions and constraints (e.g., performance and specifications of the spinning processing equipment, etc.).

[0030] Here, a specific movement pattern (tool operation) of the forming tool in each processing cycle executed in the second step included in the first method will be described in detail below with reference to the drawings. Fig. 2 is a schematic cross-sectional view illustrating a specific movement pattern of the forming tool in each processing cycle executed in the second step included in the first method. Note that in Fig. 2, only one side of the tube axis AX of the cylindrical member 10 is drawn in order to facilitate understanding of the first method using a simple drawing.

[0031] In the example shown in Fig. 2, a cylindrical tubular member 10, which is the workpiece to be processed, is supported and fixed so as not to rotate by a clamp and pressing die 20 provided on a spinning processing device (not shown in its entirety). That is, Fig. 2 illustrates the state after the above-mentioned first step is completed. Also, a flange portion 11 has already been formed on one tube end (the left side as one faces the drawing) of the tubular member 10 illustrated in Fig. 2. That is, Fig. 2 illustrates the state of the tubular member 10 after the second step is completed.

[0032] The forming tool 30 illustrated in FIG. 2 is a forming roller rotatably supported around a rotating shaft 31. As in a general spinning processing device, the forming tool 30 is fixed to a bracket 40 via the rotating shaft 31. The bracket 40 is connected to a face plate 50 configured to rotate concentrically with a tube axis (processing axis) AX (see the thick dashed arrow shown in the figure). The face plate 50 has a built-in drive control mechanism 51 (e.g., a plate cam or actuator) for moving the bracket 40 in the radial direction (radial direction and centripetal direction) (see the X-axis shown in the figure by the thick solid double arrow). This allows the position (revolution diameter) of the bracket 40 on the X-axis to be arbitrarily controlled while the face plate 50 is rotating.

[0033] On the other hand, the movement of the bracket 40 in the tube axis direction can be realized by moving the face plate 50 (the spinning processing device body to which it is attached) in the tube axis direction (see the Z axis shown in the figure by the thick solid double arrow). Alternatively, without being limited to this, a mechanism for controlling the position of the bracket 40 on the Z axis may be provided, or the bracket 40 itself may be configured to be extendable and retractable in the Z axis direction.

[0034] The forming tool 30 is rotatably supported by the bracket 40 so that the radial direction of the forming tool 30 is inclined at a predetermined angle (about 45 degrees in FIG. 2) with respect to a plane (normal plane) perpendicular to the direction of the tube axis AX. The inclination angle of the forming tool 30 with respect to the normal plane is not limited to this, and can be set appropriately depending on, for example, the configuration of the tubular member that is the workpiece to be processed (e.g., the shape of the cross section, the length and thickness in the axial direction, and the constituent materials), the shape of the desired flange portion, and the processing conditions and constraints (e.g., the performance and specifications of the spinning processing device), etc.

[0035] The forming tool 30 illustrated in Fig. 2 is a disk-shaped forming roller with a rounded chamfered outer edge, and the chamfered outer edge comes into point contact with the inner surface of the tube end of the tubular member 10. Therefore, the position of the processing point P is always a position that is away from the center point R of the chamfered peripheral portion by the radius of that portion. The three-dimensional trajectory of the forming tool 30 in the second step can be controlled by specifying the position of the center point R, for example, by programming. The position of the center point R can be controlled by coordinated control of the revolution angular velocity of the forming tool 30, the position on the X axis, and the position on the Z axis.

[0036] The second step is a step of forming a flange portion 11 at the tube end by sequentially executing a processing cycle in which the forming tool 30 is used to press the inner surface of the tube end of the tubular member 10 outward in the radial direction (X-axis direction) by point contact while revolving the forming tool 30 around the tube axis AX by controlling the three-dimensional trajectory of the forming tool 30 as described above. In the example shown in Fig. 2, processing cycles are sequentially executed in which the center point R of the peripheral portion of the forming tool 30 is moved along each of the trajectories (paths) shown from T01 to T11, thereby forming the flange portion 11 at the tube end of the tubular member 10.

[0037] For example, for the purpose of ensuring the plate thickness of the flange portion 11, the forming tool 30 may be controlled to press the inner surface of the tube end of the tubular member 10 on the outward path in each pass, and not to contact the inner surface of the tube end of the tubular member 10 on the return path. Furthermore, the number of times that the forming tool 30 reciprocates through each pass is not necessarily limited to one, and the forming tool 30 may be controlled to reciprocate through each pass multiple times. In particular, for the final pass, from the viewpoint of finishing the flange surface smoothly, it is preferable to control the forming tool 30 to reciprocate through each pass multiple times.

[0038] Next, the processing cycles sequentially performed in the second step will be described in more detail below with reference to the drawings. Fig. 3 is a schematic cross-sectional view illustrating the sequential formation of a flange portion at the tube end of a cylindrical member as the processing cycles are performed in the second step. Fig. 3 is a drawing similar to Fig. 2, except that the shape of the flange portion in each processing cycle is depicted, and the trajectory of the center point R of the peripheral portion of the forming tool 30 is depicted simply. However, in Fig. 3, the arrow indicating that the forming tool 30 revolves around the tube axis AX, the double arrow indicating the X-axis and Z-axis, and the symbols (T01 to T11) indicating the individual trajectories of the center point R of the peripheral portion of the forming tool 30 are omitted.

[0039] As described above, in the processing cycle, the forming tool 30 is reciprocated in the direction of the tube axis AX while changing the revolution diameter of the forming tool 30. By sequentially executing such processing cycles, the tube end of the tubular member 10 is gradually raised for each pass, and finally the flange portion 11 is formed, as shown in FIG.

[0040] 4 is a schematic cross-sectional view illustrating a state in which the second processing cycle in which the center point R of the peripheral portion of the forming tool 30 is reciprocated along a trajectory T02 in the second step is completed and the center point R has returned to the starting point. The second processing cycle causes the tube end of the tubular member 10 to be slightly raised. After this, a third processing cycle is started in which the center point R of the peripheral portion of the forming tool 30 is reciprocated along a trajectory T03.

[0041] 5 is a schematic cross-sectional view illustrating the position of center point R and the shape of the tube end of the tubular member 10 in the middle (end point of the forward path) of the third processing cycle in which center point R of the peripheral portion of the forming tool 30 is reciprocated along the trajectory T03 in the second step. The third processing cycle is performed, and the tube end of the tubular member 10 is further raised. After this, on the return path, center point R is returned to the starting point while controlling so that the forming tool 30 does not come into contact with the inner surface of the tube end of the tubular member 10, and the fourth to sixth processing cycles are performed sequentially, and the tube end of the tubular member 10 is further raised.

[0042] 6 is a schematic cross-sectional view illustrating the position of center point R and the shape of the tube end of the tubular member 10 in the middle (end point of the outward path) of the sixth processing cycle in which center point R of the peripheral portion of the forming tool 30 is reciprocated along a trajectory T06 in the second step. By performing the sixth processing cycle, the tube end of the tubular member 10 is raised even further. After this, on the return path, center point R is returned to the starting point while controlling so that the forming tool 30 does not come into contact with the inner surface of the tube end of the tubular member 10, and the seventh to eleventh processing cycles are sequentially performed, thereby further raising the tube end of the tubular member 10.

[0043] 7 is a schematic cross-sectional view illustrating the position of center point R and the shape of the tube end of the tubular member 10 during an 11th processing cycle (during the forward path) in which center point R of the peripheral portion of the forming tool 30 is reciprocated along a trajectory T11 in the second step. The 11th processing cycle is the final processing cycle, but since the forming tool 30 is in the middle of the forward path in the state shown in FIG. 7, although the portion that will become the flange portion has been raised perpendicular to the tube axis AX up to the middle, the portion radially outside of this portion has not yet been raised perpendicular to the tube axis AX.

[0044] 8 is a schematic cross-sectional view illustrating a state in which the center point R of the peripheral portion of the forming tool 30 has reached the end point of the forward path of the locus T11 in the 11th and final processing cycle. As the center point R of the peripheral portion of the forming tool 30 has reached the end point of the forward path of the locus T11, the entire portion that will become the flange portion is raised perpendicular to the tube axis AX, completing the formation of the flange portion.

[0045] <effect> As described above, in the first method, a processing cycle is sequentially performed in which a forming tool that revolves while making point contact presses a processing point on the inside of a tube end of a tubular member. In each processing cycle, the trajectory, number of rotations, and moving speed of the forming tool can be appropriately adjusted according to the material and shape of the tubular member and the thickness and shape of the flange portion to be formed. As a result, it is possible to form a flange portion having a desired thickness and diameter by drawing out the maximum processing limit while avoiding the occurrence of defects such as buckling and cracking.

[0046] That is, according to the first method, in a flanging method in which a tapered tool revolves around a cylindrical member without rotating (rotating), a large expansion ratio can be achieved without heating, and a flange portion having a more uniform plate thickness and a larger diameter can be formed compared to the conventional technology. Furthermore, even if the shape of the cylindrical member to be processed and the flange portion to be formed change, there is no need to change the forming tool, and it can be dealt with by changing the trajectory, number of rotations, and moving speed of the forming tool in the processing cycle.

[0047] Second Embodiment Hereinafter, a flanging method according to a second embodiment of the present invention (hereinafter, may be referred to as a "second method") will be described.

[0048] <composition> The second method is the above-mentioned first method, and is a flanging method in which, in the second step, a plurality of forming tools revolve on the same orbit and synchronously execute the above-mentioned processing cycle sequentially.

[0049] 9 is a schematic diagram illustrating the arrangement of the molding tools used in the second step included in the second method, and is a view observed from the side of a cylindrical member (not shown) in the direction of the tube axis. In the example shown in FIG. 9(a), two molding tools 30 are arranged via brackets 40 at equal distances from each other in the radial direction from the rotation axis of the face plate 50 (coaxial with the tube axis AX). On the other hand, in the example shown in FIG. 9(b), three molding tools 30 are arranged via brackets 40 at equal distances from each other in the radial direction from the rotation axis of the face plate 50 (coaxial with the tube axis AX).

[0050] The number of forming tools 30 used in the second step included in the second method is not limited to the above, and a configuration in which four or more forming tools 30 are provided and the above-mentioned processing cycles are sequentially performed in synchronization while revolving on the same orbit is also not excluded in the second method. In addition, it is preferable that the multiple forming tools 30 are arranged so as to be rotationally symmetrical as exemplified in FIG. 9.

[0051] The multiple forming tools 30 arranged as described above are controlled to sequentially execute the above-mentioned processing cycle in synchronization while revolving on the same orbit. The specific movement pattern of the forming tools (tool operation) in such control can also be appropriately selected from various tool operations generally adopted in spinning processing for performing rotary plastic processing, for example, according to the configuration of the cylindrical member to be processed as the workpiece (e.g., cross-sectional shape, axial length and plate thickness, and constituent material, etc.), the shape of the desired flange portion, and processing conditions and constraints (e.g., performance and specifications of the spinning processing device, etc.).

[0052] <effect> As described above, in the second process, the multiple forming tools revolve on the same orbit and sequentially execute the above-mentioned processing cycle in synchronization in the second step. As a result, the reaction force (from the processing point P) acting on the forming tool can be used as a processing force by the other forming tools, so that the processing efficiency is improved and the processing time can be shortened.

[0053] Third Embodiment Hereinafter, a flanging method according to a third embodiment of the present invention (hereinafter, may be referred to as a "third method") will be described.

[0054] <composition> The third method is the above-mentioned first or second method, and is a flanging method that further includes a third step after the second step in which a finishing tool having a machining surface which is a cylindrical outer peripheral surface, supported so as to be rotatable around the axis of the machining surface, and arranged so that the axis of the machining surface is perpendicular to the tube axis, is revolved around the tube axis while pressing the flange portion in line contact with the machining surface in the direction of the tube axis.

[0055] Fig. 10 is a flow chart showing an example of the flow of each step included in the third method. As shown in Fig. 10, the third method further includes a third step of pressing the flange surface of the flange portion with the processing surface of a finishing tool after the second step.

[0056] The specific configuration of the finishing tool is not particularly limited as long as it has a configuration that satisfies the above requirements. However, it is typically configured by a columnar or cylindrical member, such as the finishing tool 60 illustrated in Fig. 11. As illustrated in Fig. 11, the cylindrical outer circumferential surface of the finishing tool 60 forms a processing surface 61, and the finishing tool 60 is supported by a support member (not shown) so as to be rotatable around the axis RX of the processing surface 61 (see the thick dashed double arrow). In addition, the finishing tool 60 is disposed so that the axis RX of the processing surface 61 is perpendicular to the tube axis AX.

[0057] The size, shape and constituent material of the finishing tool 60 can be selected appropriately depending on, for example, the configuration of the flange portion that will be the workpiece to be processed (e.g., the size, shape, plate thickness and constituent material of the flange surface, etc.) and the processing conditions and constraints (e.g., the performance and specifications of the spinning processing equipment, etc.).

[0058] As described above, by performing the third step after the second step and pressing the flange surface of the flange portion in line contact with the processing surface of the finishing tool, the flange surface can be finished even more smoothly. Therefore, for example, the third method can be applied to the formation of flange portions of tubular members such as pipes used in applications requiring high liquid-tightness and / or air-tightness in the connection between tubular members connected by flange portions.

[0059] The third step included in the third method can be performed in an apparatus separate from the spinning apparatus that performed the first and second steps. However, from the viewpoint of improving the processing efficiency of the third method, it is preferable to perform the third step in the spinning apparatus that performed the first and second steps.

[0060] Therefore, in the third method according to a preferred embodiment, a finishing tool is connected to a common face plate with the above-mentioned forming tool. However, if the finishing tool comes into contact with the cylindrical member being machined by the forming tool in the above-mentioned second step, it becomes difficult to form a flange portion having the desired shape, so the finishing tool is retreated to a position where it does not come into contact with the cylindrical member in the second step. On the other hand, in the third step, as described above, the finishing tool is revolved around the tube axis while the processing surface presses the flange portion in line contact in the direction of the tube axis, thereby finishing the flange surface further smoothly. If the forming tool comes into contact with the flange portion pressed by the finishing tool in such a third step, it becomes difficult to finish the flange surface having the desired smoothness, so the forming tool is retreated to a position where it does not come into contact with the flange portion in the third step. Thus, in the third method according to a preferred embodiment, the forming tool and the finishing tool are supported by a common face plate, but it is configured so that while one of the forming tool and the finishing tool is being machined, the other is always retreated to a position where it does not interfere with the object to be machined. In such a retraction drive, both the forming tool and the finishing tool may be controlled independently, but it is preferable that they are driven in a counter-intuitive manner, for example by a mechanism provided on the face platen, so that while one tool is performing processing, the other tool is always retracted.

[0061] FIG. 12 is a schematic diagram showing an example of the configuration of a finishing tool used in the third step included in the third method according to a preferred embodiment. FIG. 12(a) is a schematic diagram illustrating the arrangement of a forming tool and a finishing tool used in the third method according to a preferred embodiment, and is a view observed from the side of a cylindrical member not shown in the direction of the tube axis. In the example shown in FIG. 12(a), similar to the configuration illustrated in FIG. 9(a), two forming tools 30 are arranged via brackets 40 at positions equidistant in the radial direction from the rotation axis of the face plate 50 (coaxial with the tube axis AX). In addition, two finishing tools 60 are arranged between the two forming tools 30 at intervals of 180° each via support members 62. In addition, the forming tools 30 and the finishing tools 60 are arranged at intervals of 90° each other.

[0062] Fig. 12(b) is a schematic diagram illustrating the arrangement of the forming tools in the middle stage of forming the flange portion in the second step, and is a schematic cross-sectional view taken along the line AA shown in Fig. 12(a) and a plane passing through the tube axis (not shown). That is, Fig. 12(b) is a diagram similar to Fig. 4 referred to in the explanation of the first method. As illustrated in Fig. 12(b), at this stage, the inner surface of the tube end of the tubular member 10 is pressed radially outward by the forming tool 30 supported by the bracket 40, and the portion of the tube end that is to become the flange portion is gradually raised.

[0063] On the other hand, FIG. 12(c) is a schematic diagram illustrating the arrangement of the finishing tools in the middle stage of forming the flange portion in the second step, similar to FIG. 12(b), and is a schematic cross-sectional view of a plane passing through the line BB shown in FIG. 12(a) and the tube axis (not shown). The line BB overlaps with the rotation axis RX of the two finishing tools 60. As illustrated in FIG. 12(c), the support member 62 is connected to a face plate 50 configured to rotate concentrically with the tube axis (machining axis) AX. The face plate 50 has a built-in drive control mechanism 63 (e.g., a plate cam or an actuator) for moving the support member 62 in the direction of the tube axis AX (see the Z axis shown in the figure by a thick solid double-headed arrow). As a result, at the stage illustrated in FIG. 12(c), the finishing tool 60 is retreated to a position where it does not contact the cylindrical member 10 in the second step.

[0064] Depending on the position, size, shape, etc. of the flange portion formed by executing the second process, the drive control mechanism 63 may be configured to move the support member 62 in the radial direction (radial direction and centripetal direction) (see the X-axis indicated in the figure by the thick solid double arrow).

[0065] Next, Fig. 13 is a schematic diagram showing an example of the arrangement of the forming tools and the finishing tools in the third step included in the third method according to a preferred embodiment. Fig. 13(a) is a schematic diagram showing an example of the arrangement of the forming tools at the time when the third step is about to be started after the formation of the flange portion in the second step is completed, and is a schematic cross-sectional view taken along the line AA shown in Fig. 12(a) and a plane passing through the tube axis (not shown). As shown in Fig. 13(a), at this point in time, the formation of the flange portion 11 is completed, and the forming tool 30 supported by the bracket 40 is retracted to a position where it does not come into contact with the flange portion 11.

[0066] On the other hand, Fig. 13(b) is a schematic diagram illustrating the arrangement of a finishing tool pressing the flange portion (flange surface) in the third step after the formation of the flange portion in the second step is completed, similar to Fig. 13(a), and is a schematic cross-sectional view along a plane passing through the line BB shown in Fig. 12(a) and the tube axis (not shown). As illustrated in Fig. 13(b), a support member 62 that rotatably supports the finishing tool 60 is moved in the X-axis direction (radial direction) and Z-axis direction (direction of the tube axis AX) by a drive control mechanism 63, and while revolving around the tube axis AX by the rotation of the face platen 50 (see the thick dashed arrow shown in the figure), the flange portion 11 (flange surface) is pressed in line contact with the processing surface of the finishing tool 60 in the direction of the tube axis AX.

[0067] As described above, the bracket 40 supporting the forming tool 30 and the support member 62 supporting the finishing tool 60 are supported by the common face plate 50, but while processing is being performed by one of the forming tool 30 and the finishing tool 60, the other is always retracted to a position where it does not interfere with the object to be processed. As described above, in such a retraction drive, both the bracket 40 and the support member 62 may be controlled independently, but it is preferable that they are driven in a counter-intuitive manner, for example by a mechanism (not shown) provided in the face plate 50, so that while processing is being performed by the other, the other is always retracted.

[0068] With the above-described configuration, the third method, which is a preferred embodiment, makes it possible to avoid the problem of it being difficult to form a flange portion having the desired shape due to a finishing tool coming into contact with the tubular member being processed by the forming tool in the second step, while performing the third step in the spinning processing apparatus that performed the first and second steps, thereby further smoothing the flange surface of the flange portion.

[0069] 12, the finishing tool 60 is connected to the face plate 50 via a support member 62 separate from the bracket 40 supporting the forming tool 30, and the face plate 50 is configured to be able to move the support member 62 at least in the Z-axis direction by a drive control mechanism 63 provided in the face plate 50. However, the support member 62 supporting the finishing tool 60 and the drive control mechanism 63 for moving the support member 62 may be disposed on the bracket 40 supporting the forming tool 30.

[0070] That is, in the third method according to another preferred embodiment, the finishing tool is connected to the face plate via a bracket common to the forming tool. Fig. 14 is a schematic diagram showing an example of the configuration of the finishing tool used in the third step included in the third method according to another preferred embodiment. More specifically, Fig. 14 is a schematic diagram illustrating the arrangement of the forming tool in the middle stage where the flange portion is formed in the second step, and is a schematic cross-sectional view taken along the line AA shown in Fig. 12(a) and a plane passing through the tube axis (not shown). That is, Fig. 14 is a view corresponding to Fig. 4 referred to in the explanation of the first method.

[0071] However, as illustrated in FIG. 14, in the third method according to another preferred embodiment, a support member 62 supporting a finishing tool 60 and a drive control mechanism 63 for moving the support member 62 are connected to a face plate 50 via a bracket 40 supporting the forming tool 30. That is, the finishing tool 60 is connected to the face plate 50 via a bracket 40 common to the forming tool 30. At the stage illustrated in FIG. 14, the inner surface of the tube end of the tubular member 10 is pressed radially outward by the forming tool 30 supported by the bracket 40, and the portion of the tube end that is to become the flange portion is gradually raised. Therefore, at this stage, the finishing tool 60 is retreated to a position where it does not come into contact with the tubular member 10 in the second step.

[0072] On the other hand, Fig. 15 is a schematic diagram illustrating the arrangement of a finishing tool pressing the flange portion (flange surface) in the third step after the formation of the flange portion in the second step is completed, and is a schematic cross-sectional view taken along a plane passing through the line BB shown in Fig. 12(a) and the tube axis (not shown). As illustrated in Fig. 15, a support member 62 that rotatably supports the finishing tool 60 is moved in the X-axis direction (radial direction) and Z-axis direction (direction of the tube axis AX) by a drive control mechanism 63, and while revolving around the tube axis AX by the rotation of the face platen 50 (see the thick dashed arrow shown in the figure), the flange portion 11 (flange surface) is pressed in line contact with the processing surface of the finishing tool 60 in the direction of the tube axis AX.

[0073] With the above-mentioned configuration, the third construction method, which is another preferred embodiment, also makes it possible to avoid the problem that it becomes difficult to form a flange portion having the desired shape when a finishing tool comes into contact with the tubular member being processed by the forming tool in the second step, while performing the third step in the spinning processing apparatus that performed the first and second steps, thereby making it possible to further smoothly finish the flange surface of the flange portion.

[0074] <effect> As described above, in the third method, the third step is performed after the second step, and the flange surface of the flange portion is pressed in line contact with the processing surface of the finishing tool, thereby making it possible to finish the flange surface more smoothly. Therefore, for example, the third method can be applied to the formation of flange portions of tubular members such as pipes used in applications requiring high liquid-tightness and / or air-tightness in the connection between tubular members connected by flange portions.

[0075] Furthermore, according to the third method according to the preferred embodiment and another preferred embodiment, the third step can be performed in the spinning apparatus that performed the first and second steps, while avoiding the problem that it becomes difficult to form a flange portion having a desired shape due to the finishing tool coming into contact with the tubular member being machined by the forming tool in the second step. Therefore, since the third step can be performed in the spinning apparatus that performed the first and second steps, the processing efficiency of the third method can be improved.

[0076] For the purpose of explaining the present invention, several embodiments having specific configurations have been described with reference to the attached drawings. However, the scope of the present invention should not be construed as being limited to these exemplary embodiments, and it goes without saying that appropriate modifications can be made within the scope of the claims and the matters described in the specification. [Explanation of symbols]

[0077] 10...Cylindrical member 11...Flange section 20...Clamp and press type 30…Forming tool 31...Rotation axis 40…Bracket 50…face board 51...Drive control mechanism, 60...Finishing tools 61...Machined surface 62...Support member 63...Drive control mechanism P…Processing point R…Center point of the periphery of the forming tool T1~T11…Trajectory in machining cycle AX: Axis of the cylindrical member RX: Axis of the finishing tool machining surface

Claims

1. A flanging method for forming a flange portion by performing rotary plastic working on a tube end, which is an end portion of a cylindrical member, a first step of supporting the cylindrical member so as to be non-rotatable; a second process for forming the flange portion at the tube end by sequentially executing a processing cycle in which a forming tool having a predetermined shape is revolved around a tube axis that is the axis of the tubular member while pressing the inner surface of the tube end radially outward in a point contact with the forming tool; Including, In the processing cycle, the forming tool is reciprocated in the direction of the tube axis while changing the revolution radius of the forming tool. Flanging method.

2. The flanging method according to claim 1, In the second step, the plurality of forming tools revolve on the same orbit and sequentially execute the processing cycle in synchronization with each other. Flanging method.

3. The flanging method according to claim 1 or 2, and a third step, which is performed after the second step, of pressing the flange portion in a line contact with the processing surface in the direction of the tube axis while revolving a finishing tool around the tube axis, the finishing tool having a processing surface that is a cylindrical outer peripheral surface, supported so as to be rotatable about the axis of the processing surface, and disposed so that the axis of the processing surface is perpendicular to the tube axis. Flanging method.

4. The flanging method according to claim 3, The finishing tool is connected to a common face plate with the forming tool, and is retreated to a position where it does not contact the cylindrical member in the second step. Flanging method.

5. The flanging method according to claim 4, The finishing tool is connected to the face platen via a bracket common to the forming tool. Flanging method.

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