JP2010052038A - Drawing apparatus and drawing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of forming a boss part thicker than a dehisced portion while utilizing the dehiscing work capable of preventing any breakage by suppressing the plastic deformation in a drawing apparatus and a drawing method. <P>SOLUTION: This invention relates to the drawing apparatus 1 provided with: a mandrel 4 for mounting a base stock W on the distal end of a spindle; a chuck bar 3a for pressing the base stock W against the mandrel 4 at the position facing the spindle; and a roller for executing the drawing work on the base stock W. The drawing apparatus 1 includes: a dehiscing roller R1 as a roller which is moved in the inner-radial direction of the spindle to execute the dehiscing work of the base stock W from an outer circumferential part W1 of the base stock W; a forming roller R2 for forming a boss part B by pressing the dehisced portion W2 subjected to the dehiscing work against the chuck bar 3a; and a regulating means 3b for regulating the movement of the distal end W4 of the dehisced portion W2 in the axial direction of the spindle 2 during the forming by the forming roller R2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a drawing apparatus and method for drawing a material, and in particular, a mandrel that attaches a material to the tip of a main shaft, a chuck bar that presses the material against the mandrel at a position facing the main shaft, and a drawing to the material. The present invention relates to a drawing device that includes a roller for processing, and rotates the main shaft relative to the roller.

Conventionally, using a drawing apparatus, for example, a disk-shaped material is drawn, and a boss portion (for example, a cylindrical portion) protruding from the disk-shaped material is formed near the center. When such a boss portion is formed, a disk-shaped material is attached to a mandrel provided at the tip of the main shaft, and the material is pressed and fixed to the mandrel by a chuck bar disposed at a position facing the main shaft. Then, by pressing the roller against the material while rotating the main shaft relative to the roller, the material is plastically deformed and pressed against the chuck bar to form a desired boss portion.
As such a drawing device, for example, as shown in Patent Document 1, after moving the tearing roller as a roller in the radially inward direction of the main shaft and tearing the material linearly from the outer periphery of the material, A drawing device and method are disclosed in which a forming portion (pressing roller) as a roller is pressed into a chuck bar by pressing a cleavage portion that has been linearly opened to a chuck bar. As a result, the boss is formed by cleaving that suppresses plastic deformation, so it is possible to form a boss that has a relatively small diameter and a large height from the bottom of the disk-shaped material. It becomes.

  In addition, as a drawing device that does not cleave the material, for example, a disk-shaped material is attached and fixed to a mandrel provided at the tip of the main shaft, the main shaft is rotated relative to the pressure roller, and the disk-shaped material is rotated by the pressure roller. By sequentially pressing the surface from the outer diameter side toward the inner diameter side, the material near the surface is sequentially moved to the vicinity of the center of the disk-shaped material, and an axis (coaxial direction with the main axis) arranged near the center of the disk-shaped material. A drawing device and a method capable of forming a boss portion by pressing against the shaft (see, for example, Patent Document 2 and Patent Document 3) are disclosed.

JP 2007-268571 A Japanese Patent No. 3053219 Japanese Patent No. 3365976

  Now, in the above drawing processing apparatus and method, since the disc-shaped material is not cut or the like, the boss portion can be formed without protruding the facet, and there is no need for waste of the material or disposal of the facet, and effective use of resources. It can be said that this is a preferable technique from the viewpoint of the above.

  However, in the drawing apparatus and method disclosed in Patent Document 1, the disc-shaped material is cleaved linearly, the cleaved portion is expanded as it is and pressed against the chuck rod to form a boss portion. The thickness is as thin as the thickness of the cleaved portion. Therefore, even when it is desired to obtain a greater strength at the boss portion, there is a problem that the boss portion cannot be formed thicker than the tear portion.

  Further, in the drawing device and method disclosed in Patent Document 2 and Patent Document 3, the surface side (plane side) of the disk-shaped material is tilted by a predetermined angle from the surface side instead of the outer peripheral side of the disk-shaped material by the pressing roller. Since the pressure is pressed in a state, a force in the direction of the rotation axis (thrust) of the pressure roller is applied to the pressure roller, which is not preferable from the viewpoint of durability.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is to reduce the thickness of the drawing apparatus and method by using a cleaving process capable of suppressing plastic deformation and preventing fracture in a drawing apparatus and method. It is in providing a technique capable of forming a simple boss portion.

  In order to achieve the above object, the present invention includes a mandrel for attaching a material to the tip of a main shaft, a chuck bar for pressing the material against the mandrel at a position facing the main shaft, and a roller for drawing the material. The characteristic configuration of the drawing device for rotating the main shaft relative to the roller is a tearing roller as the roller that is moved inwardly in the radial direction of the main shaft to tear the material from the outer peripheral portion of the material. A forming roller as the roller for forming the boss portion by pressing the cleaved portion to the chuck bar, and an axial direction of the main shaft at the tip of the cleaving portion at the time of forming by the forming roller And a restricting means for restricting movement to the vehicle.

According to the above characteristic configuration, in the case of forming a boss portion protruding near the center of the material by drawing the material, the thickness in the radial direction of the boss portion (hereinafter referred to as “boss portion thickness”) is: It can be formed thicker than the thickness in the axial direction (hereinafter referred to as “cleavage thickness”) of the cleaved portion of the material that has been cleaved from the outer periphery of the material by the cleaving roller.
That is, during the cleaving process, the cleaving roller moves in the radial direction of the main shaft, so that the material is cleaved from the outer peripheral portion of the material with a cleaving thickness that does not cause the material to crack or break. Next, at the time of molding, the cleaved portion is pressed against the periphery of the chuck bar by a forming roller (so as to collapse the cleaved portion), and the cleaved portion is used as a boss portion. It is formed. When the tearing portion is pressed against the peripheral portion of the chuck rod, the tip of the tearing portion may be moved in the axial direction of the main shaft by the restricting means provided between the forming roller and the chuck rod. The boss portion can be molded in a restricted state. Therefore, if the restriction position where the tip of the cleavage part is regulated is made shorter than the length in the radial direction of the main axis of the cleavage part formed by cleavage, the thickness of the cleavage part increases during molding. As a result, it is possible to form the boss portion with a larger thickness than the ruptured thickness in the state of being cleaved.
Therefore, in the drawing apparatus, it is possible to form a boss portion thicker than the cleaved portion by plastically deforming without causing the fracture of the cleaved portion.

  According to a further feature of the drawing apparatus according to the present invention, the restricting means is formed of a chuck bar recess provided on the outer periphery of the tip of the chuck bar, and the molding roller and the forming roller are formed by the chuck bar recess in the molding process. In the point which is comprised so that the said cleavage part may be accommodated in the space formed between the said chuck | zipper stick | rods.

According to this characteristic configuration, since the chuck rod recess is provided in the outer periphery of the tip of the chuck rod as the regulating means, the space formed between the molding roller and the chuck rod by the chuck rod recess in the molding process by the molding roller. Can accommodate the cleaved portion. Therefore, in the space, the movement of the split shaft in the axial direction of the main shaft is restricted, and an increase in the thickness of the split portion can be allowed. As a result, the boss portion thickness can be reliably increased. Can be increased. Moreover, the boss | hub part of a desired shape can be obtained by selecting the shape in the said space appropriately.
Here, the chuck rod recess is a circumferential recess formed in the outer periphery of the tip of the chuck rod (on the mandrel side in the axial direction of the main shaft), and the recess extends from the outer periphery of the chuck rod toward the other end. And formed over the end portion of the recess (regulatory position) at a predetermined length. Further, the chuck rod recess is formed such that the depth in the radial direction of the main shaft is deeper than the cleaving thickness. Therefore, in forming the cleaved portion, the tip of the cleaved portion in the axial direction of the main shaft can be regulated by the end portion of the crevice so as not to move in the axial direction of the main shaft. The thickness of the open portion can be increased, and as a result, the thickness of the boss portion can be surely increased as compared with the cleavage thickness. It should be noted that the length and thickness of the cleaving portion in the cleaving process, the length and depth of the chuck rod recess, etc., are set so that the volume of the cleaving portion and the volume of the chuck rod recess are substantially the same. It can set suitably according to the thickness.

  A further characteristic configuration of the drawing apparatus according to the present invention is that the tearing roller is a curved tearing roller provided with a curved guide surface that curves the tearing portion.

According to this characteristic configuration, the tearing roller is provided with a curved guide surface for curving the tearing portion where the material is split from the outer periphery of the material on the surface against which the material is pressed. The tearing portion to be formed can be curved along the curved guide surface. In this case, since the cleaved portion is formed to be curved, the non-mandrel side end is closer to the mandrel side than the cleaved portion that is cleaved linearly. Therefore, the restriction by the restricting means at the tip of the curved tearing portion in the axial direction of the main shaft can be more reliably performed in the molding process.
For example, the case where the regulating means is a chuck bar recess provided on the outer periphery of the tip of the chuck rod will be described. The length in the radial direction of the main shaft of the cleaved portion in the cleaved state is longer than the length of the chuck bar recess. If it is long, the tip of the tearing part can be securely stored in the chucking bar recess of the chucking bar simply by pressing the tearing part against the periphery of the chucking bar with the forming roller (falling the tearing part down). May not be possible. In such a case, that is, even when the length of the cleaved portion is relatively long, the main shaft of the curved cleaved portion is curved by bending the cleaved portion along the curved guide surface of the cleaved roller. The length in the radial direction can be made shorter than the length of the concave portion of the chuck rod, and the end of the crevice can be more reliably regulated so as not to move in the axial direction of the main shaft by the end portion of the concave portion. Therefore, despite the fact that the volume of the cleaved portion cleaved by the cleaving process and the volume of the cleaved portion accommodated in the chuck rod recess are the same (that is, the material has a constant amount of material) Since the tip of the curved tearing portion is regulated by the concave end portion of the chuck rod concave portion, the thickness of the boss portion in the radial direction of the main shaft can be reliably increased.

  A further characteristic configuration of the drawing apparatus according to the present invention is that the end position on the non-mandrel side of the curved guide surface of the curved tearing roller in the axial direction of the main shaft is closer to the mandrel side than the regulated position of the regulating means. In that it is configured to be located.

  According to this characteristic configuration, the end position on the non-mandrel side of the curved guide surface of the curved tearing roller (the end position on the side opposite to the side where the mandrel is disposed in the axial direction of the main shaft) is more than the restriction position of the restriction means. In the state where the material has been cleaved, the tip of the cleaved portion that is guided by the curved guide surface of the curved cleave roller is more than the regulated position of the regulating means. It can be reliably guided to the mandrel side. Thereby, at the time of the molding process performed later by the molding roller, the tip of the curved tearing portion can be regulated by the regulation position of the regulation means, and the movement of the main shaft in the axial direction can be reliably prevented. The end position of the curved guide surface of the curved tearing roller on the non-mandrel side will be described, for example, when the restricting means is a chuck bar recess provided on the outer periphery of the tip of the chuck bar. It will be comprised so that it may be located in the mandrel side rather than a termination | terminus part (regulation position).

  A further feature of the drawing device according to the present invention is that the tip side side pressing as the roller capable of executing side pressing for pressing the cleaved portion to the mandrel side in the axial direction of the main shaft. A chamfering roller, wherein the cleaving portion is laterally pressed by the front end side lateral pressing processing roller, and the front end of the cleaving portion is positioned closer to the mandrel than the restricting position of the restricting means by the forming roller in the forming process. It is in the point which performs the shaping | molding process of the said cleavage part located in this.

  According to this characteristic configuration, since the front end side pressing roller capable of executing the side pressing process for pressing the split part to the mandrel side in the axial direction of the main shaft is provided, Even when the tip of the cleaved portion cleaved by the cleaving roller is present on the non-mandrel side with respect to the restriction position of the regulating means, the transverse portion that presses the cleaved portion against the mandrel side by the tip side side pressing roller. By pressing, the tip of the cleaved portion can be reliably positioned closer to the mandrel side than the restriction position of the restriction means. As a result, during the molding process performed later by the molding roller, the tip of the cleaved portion is regulated by the regulation position of the regulation means, and the movement of the main shaft toward the non-mandrel side and regulation of the regulation means are controlled. Deviation from the position can be reliably prevented.

  According to a further feature of the drawing apparatus according to the present invention, the front end side pressing roller has a contact surface that comes into contact with the tearing portion, and the front end side pressing roller completes the horizontal pressing process. And the non-mandrel side end position of the abutment surface of the front end side pressing roller is configured to be positioned closer to the mandrel side than the restricting position of the restricting means.

  According to this characteristic configuration, the tip side lateral pressing roller has a contact surface that comes into contact with the tearing portion, and the tip side lateral pressing roller contacts the tip side lateral pressing roller when the lateral pressing processing is completed. Since the non-mandrel side end position of the surface is positioned on the mandrel side with respect to the restricting position of the restricting means, the cleaved portion that abuts on the abutting surface by the movement of the tip side side pressing roller is the abutting surface. Along the side. Then, in the state where the lateral pressing is completed, the tip of the tearing portion guided by the contact surface of the distal side lateral pressing roller can be reliably guided to the mandrel side from the regulation position of the regulation means. Thereby, at the time of the molding process performed later by the molding roller, the tip of the tearing portion can be regulated by the regulation position of the regulation means, and the movement of the main shaft in the axial direction can be surely prevented. The non-mandrel-side end position of the abutment surface of the front end side pressing roller will be described, for example, when the restricting means is a chuck bar recess provided in the outer periphery of the tip of the chuck bar. It will be comprised so that it may be located in the mandrel side rather than the recessed part termination | terminus part (regulation position). The moving direction of the front end side pressing roller is not particularly limited as long as the cleaving portion can be pressed against the mandrel while being in contact with the contact surface.For example, a direction parallel to the radial direction of the main shaft, Alternatively, it can be moved in a direction parallel to the axial direction of the main shaft, and can be moved in a direction in which the cleavage portion is pressed toward the mandrel between these directions.

  A further characteristic configuration of the drawing apparatus according to the present invention is that the rotation shaft of the main shaft and the rotation shafts of the tearing roller and the forming roller are parallel to each other.

  According to this characteristic configuration, since the rotation shaft of the main shaft and the rotation shafts of the tearing roller and the forming roller are parallel, the force applied from the material to the roller is substantially perpendicular to the roller rotation shaft, It is possible to reduce the load on the rotating shaft in the axial direction and prevent damage to the rotating shaft of the roller.

  In order to achieve the above object, the present invention uses a mandrel for attaching a material to the tip of a main shaft, a chuck bar for pressing the material against the mandrel at a position facing the main shaft, and a roller for drawing the material. Then, the characteristic means of the drawing method of drawing the material by rotating the main shaft relative to the roller moves the tearing roller as the roller inwardly of the main shaft, and Using a cleaving process for cleaving from the outer periphery of the material and a forming roller as the roller, the cleaved part that was cleaved in the cleaving process is pressed against the chuck bar and molded to the boss part. A molding process step is performed, and in the molding process step, the movement of the tip of the cleavage portion in the axial direction of the main shaft is restricted.

According to the above characteristic means, in the case of forming a boss portion protruding near the center of the material by drawing the material, the thickness in the radial direction of the boss portion (hereinafter referred to as “boss portion thickness”) is It can be formed thicker than the thickness in the axial direction (hereinafter referred to as “cleavage thickness”) of the cleaved portion of the material that has been cleaved from the outer periphery of the material by the cleaving roller.
That is, in the cleaving process, the cleaving roller moves in the radial direction of the main shaft, so that the material is cleaved from the material outer peripheral portion with a cleaving thickness that does not cause the material to crack or break. Next, in the molding process, the cleaved part is pressed against the periphery of the chuck rod by a molding roller (so that the cleaved part collapses), and the cleaved part is used as a boss part. It is formed. When the cleaved portion is pressed against the peripheral portion of the chuck rod, the boss portion can be molded while the tip of the cleaved portion is regulated in the axial direction of the main shaft. Therefore, if the restriction position where the tip of the cleavage part is regulated is made shorter than the length in the radial direction of the main axis of the cleavage part formed by cleavage, the thickness of the cleavage part increases during molding. As a result, it is possible to form the boss portion with a larger thickness than the ruptured thickness in the state of being cleaved.
Therefore, in the drawing method, it is possible to form a boss portion that is thicker than the cleaved portion by plastically deforming without causing breakage of the cleaved portion.

  According to a further feature of the drawing method according to the present invention, after performing the cleaving step, the cleaved portion that has been cleaved using the tip side side pressing roller as the roller is used as the main shaft. Is pressed against the mandrel side in the axial direction, so that the tip of the cleaved portion is positioned closer to the mandrel than the restriction position that restricts the movement of the tip of the cleaved portion in the axial direction of the main shaft. A step is performed, and in the molding step, the cleaved portion that has been laterally pressed by the front end side lateral pressing roller is molded by the molding roller.

  According to this feature means, after executing the cleaving process and before executing the forming process, it is possible to execute a lateral pressing process that presses the cleaved portion to the mandrel side in the axial direction of the spindle. Since the side pressing process is performed using the tip side pressing roller, for example, the tip of the cleaved portion cleaved by the cleaving roller in the cleaving process is on the non-mandrel side from the regulation position of the regulating means. Even if it exists, the tip of the cleaved portion can be reliably guided to the mandrel side with respect to the restricting position of the restricting means by laterally pressing the cleaved portion. Thereby, in the molding process performed by the molding roller executed later, the tip of the tearing portion is regulated by the regulating position of the regulating means, and the movement of the main shaft toward the non-mandrel side and the regulation means from the regulated position are controlled. Deviations can be reliably prevented.

Schematic plan view of the drawing apparatus of the present invention It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on 1st Embodiment of this invention, (A) is the state before a tearing process is performed, (B) is a tearing process performed. (C) is an explanatory diagram showing a state in which the cleaving process has been completed and the molding process has started, and (D) is a state in which the molding process has been completed. It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on 2nd Embodiment of this invention, (A) is the state before performing a tearing process, (B) performs a tearing process. Explanatory diagram showing the state of the process It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on 2nd Embodiment of this invention, (A) is the state before a tearing process process is complete | finished and a side pressing process is performed, (B ) Is an explanatory view showing a state in which the side pressing process is completed. It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on 2nd Embodiment of this invention, (A) is the state which the horizontal pressing process completed and the forming process started, (B) is shaping | molding. Explanatory drawing which shows the state where processing process was completed It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on another embodiment of this invention, (A) is the state before performing a tearing process and a side pressing process, (B) is a tear. Explanatory drawing which shows the state of the process in which the processing process and the side pressing process are performed It is explanatory drawing which shows the drawing method using the drawing apparatus which concerns on another embodiment of this invention, (A) is the state which the tearing process process was complete | finished and the forming process started, (B) is a forming process Explanatory drawing which shows the state which completed the process

[First Embodiment]
Hereinafter, a first embodiment of the drawing apparatus 1 and method of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic plan view of a drawing apparatus 1 of the present invention, FIG. 2 is an explanatory view showing a drawing method using the drawing apparatus 1 of the present invention, and (A) is a tearing process step. (B) is the state where the tearing process is being performed, (C) is the state where the tearing process is completed and the molding process is started, and (D) is the molding process. The state which the process completed is shown.

  As shown in FIG. 1, the drawing apparatus 1 of the present invention includes a main shaft 2 disposed on a frame 11 so as to be rotatable relative to a roller by a driving device M such as a motor, and a disk-like shape at the tip of the main shaft 2. A mandrel 4 for mounting a workpiece W (an example of a material), a chuck base 3 having a chuck bar 3a for pressing the workpiece W against the mandrel 4 at a position facing the spindle 2, and a roller for drawing the workpiece W. A plurality of turret stands 5 are provided.

  The chuck base 3 is disposed at a position facing the main shaft 2, and a chuck bar 3 a is disposed at the tip of the chuck base 3 on the main shaft 2 side. The chuck bar 3a is formed in a cylindrical shape, and is rotatably disposed on the chuck base 3 via a bearing or the like so as to rotate on the same axis as the main shaft 2. With the chuck bar 3a, the work W attached to the mandrel 4 can be pressed and supported from the chuck base 3 side toward the mandrel 4. The outer diameter of the chuck bar 3a is appropriately selected by calculating back from the final outer diameter of the boss part B and the thickness of the boss part B according to the shape of the boss part B to be formed, and the selected chuck bar 3a is selected from the chuck base. 3 can be replaced.

  The mandrel 4 is formed in a cylindrical shape and is disposed at the tip of the main shaft 2. One end side of the mandrel 4 is connected to the main shaft 2 driven by the driving device M, and the other end side is a disk-shaped workpiece W to be drawn. It is configured to be attachable.

  The turret base 5 is configured to be movable on the traveling base 6 in the radial direction of the main shaft 2 by driving a pulse motor or the like. The traveling base 6 on which the turret base 5 is mounted moves on the moving base 7 in the axial direction of the main shaft 2. It is configured to be movable by driving a pulse motor or the like. The moving direction on the traveling platform 6 and the moving platform 7 shows an example in which the traveling platform 6 moves in the radial direction of the main shaft 2 and the moving platform 7 moves in the axial direction of the main shaft 2. The moving table 7 may be configured in the radial direction of the main shaft 2 in the two axial directions.

  In the drawing device 1 according to the present embodiment, the turret base 5 is moved in the radially inward direction of the main shaft 2 to bend the workpiece W from the workpiece outer peripheral portion W1. An example of a roller) and a forming roller R2 which moves in the radial direction of the main shaft 2 and presses the cleaved portion W2 against the chuck bar 3a to form the boss B (see FIG. 2). To do. By rotating the turret base 5 by a predetermined angle, the curved tearing roller R1 pressed against the workpiece W and the forming roller R2 can be selectively switched.

As shown in FIGS. 1 and 2A and 2B, the curved tearing roller R1 is configured to be rotatable about a rotation axis A1, and the turret base 5 is moved inwardly of the main shaft 2. The workpiece W can be pressed in the radial direction. In the axial sectional view of the main shaft 2, the mandrel 4 side end portion of the outer peripheral portion of the curved tearing roller R <b> 1 has a tearing edge portion R <b> 11 (in FIG. 2, the curved tearing portion R <b> 1) Left end of the outer peripheral portion of the opening roller R1. Further, in the axial sectional view of the main shaft 2, the diameter of the outer periphery of the curved tearing roller R <b> 1 increases toward the mandrel 4 side from the mandrel 4 side end to the chuck base 3 side end and returns to the original diameter. A curved guide surface R12 (which is reduced in diameter after being expanded as viewed from the main shaft 2 side) is provided.
As shown in FIGS. 2C and 2D, the forming roller R2 is configured to be rotatable about the rotation axis A1, and the turret base 5 moves inwardly in the radial direction of the main shaft 2 so that the workpiece W can be moved. It is possible to press in the radial direction. The outer peripheral portion of the forming roller R2 is configured by a flat surface R21 having no irregularities in the axial sectional view of the main shaft 2. Therefore, when the tearing process or the molding process is performed, the curved tearing roller R1 and the molding roller R2 rotate on the same rotation axis A1. The rotation axis A1 is parallel to the rotation axis A2 of the main shaft 2.

  Moreover, in the drawing apparatus 1 according to the present embodiment, as shown in FIGS. 1 and 2, when forming by the forming roller R <b> 2, in the axial direction of the tip W <b> 4 of the cleavage portion W <b> 2 in the axial direction of the main shaft 2. A chuck bar recess 3b (an example of a restricting means) is provided in the chuck bar 3a. The chuck bar recess 3b is a circumferential recess formed in the outer periphery of the tip of the chuck bar 3a, and this recess extends from the outer periphery of the tip of the chuck bar 3a (the left end of the chuck bar 3a in FIG. 2). It is formed over the recessed terminal portion 3b1 (regulated position) located at a predetermined length toward the other end side (the right side in FIG. 2). The length L1 obtained by adding the tearing thickness X1 to the length in the axial direction of the main shaft 2 that is the predetermined length (hereinafter sometimes referred to as the length L1 of the chuck bar recess 3b) is the length of the tearing portion W2. It is formed to be longer than the axial length L3 of the main shaft 2 after being cleaved by the curved cleaving roller R1. The chuck bar recess 3b is formed such that the radial depth X2 of the main shaft 2 is deeper than the cleavage thickness X1 of the cleaved portion W2 where the workpiece W is cleaved by cleaving. A space S is formed between the forming roller R2 and the chuck bar recess 3b by the chuck bar recess 3b, and the volume of the space S is V1.

  A drawing method for forming the disk-shaped workpiece W so that the center side of the disk-shaped workpiece W becomes the boss portion B using the drawing device 1 having the above-described configuration will be described.

  First, as shown in FIG. 2 (A), the workpiece W is attached to the mandrel 4 by a manual or automatic conveyance device, and is pressed and fixed by the chuck bar 3a. Then, the turret base 5 is slid in a direction parallel to the axial direction of the main shaft 2 on the moving rail 7a laid on the moving base 7, and the tearing edge portion R11 of the curved tearing roller R1 is moved to the outer peripheral portion of the workpiece W. It is located in the vicinity of W1. When this tearing edge portion R11 is positioned in the vicinity of the workpiece outer peripheral portion W1, the cracking portion W2 (curved portion W3), which will be described later, is cracked to such an extent that cracking and cracking of the workpiece W do not occur due to tearing and forming. The opening thickness is set to X1.

  Next, the spindle 2 is rotated by the driving device M, and the work W pressed and fixed to the mandrel 4 by the chuck bar 3a is rotated. Then, as shown in FIG. 2B, the turret base 5 is arranged on the turret base 5 by sliding and moving in a direction parallel to the radial direction of the main shaft 2 on the travel rail 6 a laid on the travel base 6. A cleaving process is performed in which the cleaving edge portion R11 of the curved cleaving roller R1 is pressed from the workpiece outer peripheral portion W1 of the workpiece W toward the inner radial direction of the main shaft 2, and the workpiece outer peripheral portion W1 is cleaved in the inner radial direction of the main shaft 2. Perform (dehiscence process). At this time, as described above, the cleavage edge portion R11 is formed on the workpiece outer peripheral portion W1 at a position where the cleavage thickness X1 is such that cracks and cracks of the workpiece W are not generated by the cleavage processing and the forming processing. When pressed, a cleavage portion W2 having a cleavage thickness X1 is formed. The radial length of the main shaft 2 of the cleaved portion W2 is L2, and the volume of the cleaved portion W2 is V2.

Then, the cleaved portion W2 cleaved in the cleaving process is curved along the curved guide surface R12 of the curved cleaved roller R1 as the curved cleaved roller R1 moves in the radially inward direction. (See arrow in FIG. 2B). Here, the length L3 of the curved portion W3 is shorter than the length L2 of the radial cleaved portion W2 of the main shaft 2 in a non-curved state (for example, a cleaved state before being curved). It has become.
Therefore, when the tearing process is completed, as shown in FIG. 2C, the curved portion W3 has a length L3 that can be accommodated in the chuck bar recess 3b formed on the outer periphery of the tip of the chuck bar 3a. Since the length L3 is shorter than the length L1 of the chuck rod recess 3b, the tip W4 of the curved portion W3 is accommodated in the space formed by the chuck rod recess 3b, and in the vicinity of the end portion 3b1 of the chuck rod recess 3b. It will be arrange | positioned at (dehiscence process).

Next, as shown in FIG. 2C, the turret base 5 is rotated 90 degrees to change from the curved tearing roller R1 to the forming roller R2, and the turret base 5 is slid in a direction parallel to the radial direction of the main shaft 2. Move it.
Then, as shown in FIG. 2 (D), the curved portion W3 that has been cleaved and curved by the curved cleaving roller R1 is pressed against the chuck bar recess 3b that is the periphery of the chuck bar 3a by the forming roller R2, and the boss Completing the molding of part B (molding process).

In this molding process, as shown in FIG. 2D, the distal end W4 of the curved portion W3 is restricted from moving in the axial direction of the main shaft 2 by the concave end portion 3b1 of the chuck rod concave portion 3b. The boss portion B is molded in a state where the entire volume of the portion W3 is accommodated in the space S formed between the chuck rod recess 3b and the molding roller R2 by the chuck rod recess 3b.
Accordingly, the length L2 of the tearing portion W2 in the radial direction of the main shaft 2 is curved to become the length L3, which is shorter than the length L1 of the chuck rod recess 3b, and the volume V2 of the curved portion W3 and the chuck rod. Since the volume V1 of the concave portion 3a is substantially the same, a boss portion having a boss portion thickness X2 that is thicker than the cleavage thickness X1 can be formed.
Therefore, it is possible to reliably form the boss portion B having the thickness X2 which is thicker than the thickness X1 in the axial direction of the main shaft 2 of the cleavage portion W2 which has been subjected to the cleavage processing in the cleavage processing step. .

[Second Embodiment]
In the first embodiment, the forming process is performed after the cleaving process is executed. For example, the tip W4 of the cleaved part W2 cleaved in the cleaving process is the chuck recess 3b. If the tip W4 is not guided to the mandrel 4 side with respect to the recessed end portion 3b1 (regulation position), etc. It is also possible to adopt a configuration in which a side pressing process by the front end side pressing roller R5 is executed before the processing process. As a result, the tip W4 of the tearing portion W2 is guided to the mandrel 4 side in the chuck rod recess 3b, in particular, the recess end portion 3b1 (regulatory position), and the recess end portion 3b1 in the molding process executed later. Movement of the tip W4 toward the non-mandrel side in the axial direction of the main shaft 2 and deviation from the chuck rod recess 3b, particularly from the recess end 3b1 (regulation position) can be reliably prevented.

  Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 3, 4, and 5. 3-5 is explanatory drawing which shows the drawing method using the drawing apparatus 1 which concerns on 2nd Embodiment of this invention, and FIG. 3 (A) is the state before a tearing process process is performed, (B) is the state of the process in which the cleaving process is performed, FIG. 4 (A) is the state before the cleaving process is completed and the side pressing process is performed, and (B) is the side pressing process. FIG. 5A is an explanatory diagram showing a state in which the side pressing process is completed and the molding process is started, and FIG. 5B is an explanatory diagram showing a condition in which the molding process is completed. In addition, about the structure similar to 1st Embodiment, since it is easy, description is abbreviate | omitted suitably.

  In the present embodiment, in addition to the curved tearing roller R1 and the forming roller R2, the distal end side pressing roller R5 is provided, and the turret base 5 includes the curved tearing roller R1, the leading end side pressing roller. R5 and forming roller R2 are arranged in the order of description at a predetermined angle. By rotating the turret base 5 by a predetermined angle, a curved tearing roller R1, a front end side pressing roller R5, and a forming roller R2 that are pressed against the workpiece W can be selectively switched.

As shown in FIGS. 3 (A) and 3 (B), the curved tearing roller R1 has a work W placed on the outer periphery of the curved tearing roller R1 at the end of the curved tearing roller R1 on the mandrel 4 side. A cleaving edge portion R11 (in FIG. 3A and FIG. 3B, the left end portion of the outer peripheral portion of the curved cleaving roller R1) that can be cleaved from the portion W1 is provided. The angle of the cleavage edge R11 is formed at an angle (right angle) where the radial direction of the main shaft 2 and the axial direction intersect. Note that this angle can be adjusted as appropriate, and any angle can be used as long as the workpiece W can be cleaved satisfactorily.
In addition, in the axial sectional view of the main shaft 2, the mandrel 4 side of the outer periphery of the curved tearing roller R1 is gradually expanded from the mandrel 4 side end (the tearing edge portion R11) toward the chuck base 3 side end. A curved guide surface R12 is provided (which is reduced in diameter as viewed from the main shaft 2 side). This curved guide surface R12 is formed on the outer peripheral portion of the curved tear roller R1 from a tearing edge R11 to a predetermined position before the end on the chuck base 3 side (non-mandrel side end position R13 of the curved guide surface R12). . A length L4 in the axial direction of the main shaft 2 from the cleavage edge R11 on the curved guide surface R12 to the non-mandrel-side end position R13 (the right end of the curved guide surface R12 in FIGS. 3A and 3B). Is set to a length slightly longer than the length L1 of the chuck bar recess 3b. Although the curvature radius of the curved guide surface R12 can be set as appropriate, in FIGS. 3A and 3B, the curvature radius decreases rapidly from the tearing edge R11 to the non-mandrel-side termination position R13. It is formed to become.

As shown in FIGS. 4 (A) and 4 (B), the front end side pressing roller R5 is configured to be rotatable about a rotation axis A1, and is a direction in which the turret base 5 approaches the mandrel 4, It moves in a direction shifted by a predetermined angle with respect to the inward direction and the axial direction of the main shaft 2 (in FIGS. 4A and 4B, the direction is inclined by about 45 degrees with respect to the inward direction of the main shaft 2 and the axial direction). Thus, the workpiece W can be pressed against the mandrel 4 side. The moving direction of the front end side pressing roller R5 is not particularly limited as long as the cleaving portion W2 can be pressed against the mandrel 4 in a state of being in contact with a contact curved surface R52 (an example of a contact surface) described later. For example, it can be moved in a direction parallel to the radial direction of the main shaft 2 or in a direction parallel to the axial direction of the main shaft 2, and in a direction approaching the mandrel 4 side in a direction inclined by a predetermined angle with respect to these directions. It may be moved. The rotation axis A1 of the front end side pressing roller R5 is not limited to being parallel to the rotation axis A2 of the main shaft 2. If the rotation is possible while appropriately pressing the tearing portion W2, the rotation axis A1 is rotated. It is also possible to deviate from the axis A2 by a predetermined angle. For example, a rotation axis perpendicular to the moving direction of the front end side pressing roller R5 can be adopted as the rotation axis A1.
Further, the front end side pressing roller R5 has an edge portion R51 (in FIG. 4, the front end side side pressing roller) on the mandrel 4 side end of the outer peripheral portion of the front end side pressing roller R5 in the axial sectional view of the main shaft 2. Left end of the outer peripheral portion of the processing roller R5). The angle of the edge portion R51 is formed at an angle (right angle) where the radial direction of the main shaft 2 and the axial direction intersect. This angle can be adjusted as appropriate.
Furthermore, in the axial cross-sectional view of the main shaft 2, the mandrel 4 side of the outer peripheral portion of the front end side pressing roller R5 gradually expands from the mandrel 4 side end (edge portion R51) toward the chuck base 3 side end. An abutting curved surface R52 that has a diameter (successively reduces the diameter as viewed from the main shaft 2 side) is provided. The contact curved surface R52 is formed from the edge portion R51 to a predetermined position before the end on the chuck base 3 side (non-mandrel end position R53 of the contact curved surface R52) on the outer peripheral portion of the front end side pressing roller R5. Yes. The radius of curvature of the contact curved surface R52 can be set as appropriate. In FIGS. 4A and 4B, the radius of curvature is formed so as to decrease rapidly from the edge portion R51 to the non-mandrel side end position R53. Has been. The length L5 in the axial direction of the main shaft 2 from the edge portion R51 on the contact curved surface R52 to the non-mandrel side end position R53 (the right end portion of the contact curved surface R52 in FIGS. 4A and 4B) is: The length is set shorter than the length L1 of the chuck bar recess 3b.

  A drawing method for forming the disk-shaped workpiece W so that the center side of the disk-shaped workpiece W becomes the boss portion B using the drawing device 1 having the above-described configuration will be described.

First, as shown in FIGS. 3A and 3B, the workpiece W is cleaved by the curved cleaving roller R1. Since this tearing process is substantially the same as that of the first embodiment, detailed description thereof is omitted.
Here, the length L4 in the axial direction of the main shaft 2 from the tearing edge portion R11 to the non-mandrel side end position R13 on the curved guide surface R12 of the curved tearing roller R1 is the chuck bar recess 3b in the axial direction of the main shaft 2. It is configured to be slightly longer than the length L1. Therefore, the tip W4 of the curved portion W3 that has been cleaved by the curved cleaving roller R1 after the cleaving process has been completed is the axis of the main shaft 2 as shown in FIGS. 3B and 4A. In some cases, the chuck rod recess 3b may be positioned slightly on the non-mandrel side (the chuck base 3 side on the right side in FIGS. 3B and 4A) with respect to the recess end portion 3b1 (regulatory position). In such a case, the side pressing process shown in FIGS. 4A and 4B is performed. Even in this case, the length L3 of the curved portion W3 is the length of the radial cleaved portion W2 of the main shaft 2 in a state where the curved portion W3 is not curved (for example, a cleaved state before being curved). It is shorter than L2.

Next, the turret base 5 is rotated 90 degrees to change from the curved tearing roller R1 to the front end side pressing roller R5. Then, the turret base 5 is slid and moved in a direction approaching the mandrel 4 at a predetermined angle (for example, 45 degrees) with respect to the radial direction and the axial direction of the main shaft 2 (see the arrow in FIG. 4A).
Then, as shown in FIG. 4B, the curved portion W3 that has been cleaved and curved by the curved cleaving roller R1 is brought into contact with the abutting curved surface R52 of the front end side pressing roller R5 so as to move toward the mandrel 4 side. Perform horizontal pressing (horizontal pressing process). Here, as described above, the length L5 in the axial direction of the main shaft 2 from the edge portion R51 to the non-mandrel side end position R53 on the contact curved surface R52 of the front end side pressing roller R5 is the axial direction of the main shaft 2 The chuck rod recess 3b is slightly shorter than the length L1. As a result, the tip W4 of the curved portion W3 that has been cleaved is positioned on the non-mandrel side in the axial direction of the main shaft 2 with respect to the concave end portion 3b1 (regulatory position) of the chuck rod concave portion 3b. By processing, the tip W4 of the curved portion W3 is guided along the contact curved surface R52 to the vicinity of the non-mandrel side end position R53 (see the arrow in FIG. 4B). Therefore, the tip W4 can be moved to the mandrel 4 side of the recess end portion 3b1 in the chuck rod recess 3b, particularly in the axial direction of the main shaft 2, in a state where the side pressing process is completed. In this case, the contact portion of the curved portion W3 that contacts the contact curved surface R52 is the outer peripheral surface or the tip W4 of the curved portion W3.

  Then, as shown in FIGS. 5 (A) and 5 (B), the side end pressing process is performed by the front end side pressing roller R5, and the front end W4 is inserted into the chuck bar recess 3b, particularly in the axial direction of the main shaft 2, from the recess end portion 3b1. Also, the curved portion W3 moved to the mandrel 4 side is pressed against the chuck bar recess 3b, which is the peripheral part of the chuck bar 3a, by the molding roller R2 to complete the molding of the boss B (molding process).

Thereby, even when the tip W4 of the curved portion W3 is positioned on the non-mandrel side in the axial direction of the main shaft 2 with respect to the concave end portion 3b1 (regulatory position) of the chuck rod concave portion 3b in the tearing process, By performing the pressing process, the tip W4 is guided in the chuck rod recess 3b, particularly toward the mandrel 4 side from the recess end part 3b1 (regulation position), and in the molding process, the tip W4 of the curved portion W3 is moved. By the recess end portion 3b1 of the chuck bar recess 3b, it is reliably prevented from moving to the non-mandrel side in the axial direction of the main shaft 2 and deviating from the inside of the chuck rod recess 3b, particularly from the recess end portion 3b1 (regulation position). (See FIG. 5B). The boss portion B is molded in a state where the entire volume of the curved portion W3 is accommodated in the space S formed between the chuck rod recess 3b and the molding roller R2 by the chuck rod recess 3b.
Therefore, the length L2 of the tearing portion W2 in the radial direction of the main shaft 2 is curved and laterally pushed to become the length L5, which is surely shorter than the length L1 of the chuck rod recess 3b, and the volume of the curved portion W3. Since V2 and the volume V1 of the chuck bar recess 3b are substantially the same, it is possible to form a boss portion having a boss portion thickness X2 that is thicker than the tearing thickness X1.
Therefore, it is possible to reliably form the boss portion B having the thickness X2 which is thicker than the thickness X1 in the axial direction of the main shaft 2 of the cleavage portion W2 which has been subjected to the cleavage processing in the cleavage processing step. .

[Another embodiment]
(1) In the second embodiment, the tearing process is performed using the curved tearing roller R1, and the lateral pressing process is performed using the distal side lateral pressing roller R5. As shown in FIG. 6, a configuration may be adopted in which a roller that performs both processes is shared, and both processes are performed simultaneously. FIG. 6 is an explanatory view showing a drawing method using the drawing device 1 according to another embodiment of the present invention, in which (A) is a state before the tearing process and the side pressing process are performed, B) is an explanatory view showing a state of a process in which a cleaving process and a side pressing process are performed. In addition, about the structure similar to 1st, 2nd embodiment, since it is easy, description is abbreviate | omitted suitably.
In this case, as shown in FIGS. 6A and 6B, in the curved tearing roller R1 used in the second embodiment, the non-mandrel extends from the tearing edge R11 in the curved guide surface R12 of the curved tearing roller R1. The length L6 in the axial direction of the main shaft 2 up to the side end position R13 (in FIG. 6, the right end of the curved guide surface R12) is set to be shorter than the length L1 of the chuck bar recess 3b. However, the ratio of the length L6 to the length L1 is such that the tip W4 can be guided to the mandrel 4 side with respect to the recessed end portion 3b1 (regulation position), and the curved portion W3 is broken or pressed by the forming roller R2 later. It sets suitably in the range which can avoid the bending etc. in the recessed part 3b, for example, sets to about 90 to 70%. In FIG. 6, the ratio of the length L6 to the length L1 is set to about 80%. The curved tearing roller R1 is configured to rotate around the rotation axis A1 and to move parallel to the radial direction of the main shaft 2.
Thereby, it becomes possible by using curved tearing roller R1 to perform the said tearing process and lateral pressing process simultaneously.
Specifically, the tearing edge portion R11 of the curved tearing roller R1 is pressed from the workpiece outer peripheral portion W1 of the workpiece W in the radially inward direction of the main shaft 2, and the workpiece outer peripheral portion W1 is split in the radially inward direction of the main shaft 2. A cleaving process is performed (a cleaving process).
Then, the cleaved portion W2 cleaved in the cleaving process is curved along the curved guide surface R12 of the curved cleaved roller R1 as the curved cleaved roller R1 moves in the radially inward direction. (See arrow in FIG. 6B). The length L3 of the curved portion W3 is shorter than the length L2 of the radial cleaved portion W2 of the main shaft 2 in a state where the curved portion W3 is not curved (for example, a state where the curved portion W3 has been cleaved before being curved). .
Here, as described above, the axis of the main shaft 2 from the tearing edge portion R11 on the curved guide surface R12 to the non-mandrel side end position R13 (the right end portion of the curved guide surface R12 in FIGS. 6A and 6B). The length L6 in the direction is set to be shorter than the length L1 of the chuck bar recess 3b.
Accordingly, simultaneously with the tearing process, the curved portion W3 is pressed against the mandrel 4 side by the curved guide surface R12, and the distal end W4 of the curved portion W3 is closer to the mandrel 4 side than the non-mandrel side end position R13 of the curved guide surface R12. That is, it is guided to the mandrel 4 side in the chuck rod recess 3b, particularly from the recess end portion 3b1 (regulation position) (lateral pressing process).
Therefore, by performing the tearing process and the lateral pressing process simultaneously by the curved tearing roller R1, the tip W4 of the curved part W3 is surely guided to the mandrel 4 side from the concave end part 3b1 (regulation position). Can do.
Then, as shown in FIGS. 5A and 5B, the tip W4 is moved to the mandrel 4 side of the recess end portion 3b1 in the chuck bar recess 3b, particularly in the axial direction of the main shaft 2, by the curved tearing roller R1. The curved portion W3 in the state is pressed against the chuck bar recess 3b, which is the peripheral part of the chuck bar 3a, by the molding roller R2 to complete the molding of the boss B (molding process).
Therefore, it is possible to reliably form the boss portion B having the thickness X2 which is thicker than the thickness X1 in the axial direction of the main shaft 2 of the cleavage portion W2 which has been subjected to the cleavage processing in the cleavage processing step. .

(2) In the above embodiment, the chuck rod recess 3b as the restricting means is provided in the chuck rod 3a. However, the movement of the tip W4 of the curved portion W3 (dehiscence portion W2) in the axial direction of the main shaft 2 is sufficiently regulated. If it is the structure which can do, it can employ | adopt without a restriction | limiting especially. For example, as shown in FIGS. 7A and 7B, a molding roller recess R31 may be provided in the molding roller R3 as a restricting means. In this case, similarly to FIGS. 2 (A) and 2 (B) of the first embodiment, the tearing process is performed by the curved tearing roller R1, and then the forming roller R3 as shown in FIGS. 7 (A) and 7 (B). Thus, it is possible to perform a forming process step of pressing the curved portion W3 against the peripheral portion of the chuck bar 3c to form the boss portion B. Thereby, it becomes possible to form the boss B having the same thickness as the depth X3 in the radial direction of the main shaft 2 of the molding roller recess R31.
Therefore, it is possible to reliably form the boss portion B having the thickness X3 which is thicker than the thickness X1 in the axial direction of the main shaft 2 of the split portion W2 which has been split in the splitting step. .

(3) In the above embodiment, as the restricting means, the chuck rod recess 3b is provided on either the chuck rod 3a or the forming roller recess R31 on either the forming roller R3, and the bending portion W3 (the tearing portion W2) is provided by these restricting means. Is configured to restrict the movement of the tip W4 in the axial direction of the main shaft 2, but can sufficiently restrict the movement of the tip W4 of the curved portion W3 (dehiscence portion W2) in the axial direction of the main shaft 2. If it is, it can employ | adopt without a restriction | limiting especially. For example, the chuck rod recess 3b and the forming roller recess R31 are both provided as the restricting means, and the curved portion W3 (cleavage portion W2) is accommodated in the space formed by both the recesses, It can also be configured to restrict the movement of the tip W4 of the open part W2).

  INDUSTRIAL APPLICABILITY The present invention can be effectively used as a technique capable of forming a boss part thicker than a cleaved part while using a cleaving process capable of suppressing plastic deformation and preventing fracture in a drawing apparatus and method. Is possible.

DESCRIPTION OF SYMBOLS 1 Drawing apparatus 2 Spindle 3a Chuck bar 3b Chuck bar recessed part (regulation means)
3b1 Concave end (regulation position)
4 Mandrel R1 Curved tearing roller (Tearing roller)
R12 Curved guide surface R13 Non-mandrel side end position R2 Forming roller R5 Tip side side pressing roller R52 Contact curved surface (contact surface)
R53 Non-mandrel end position W Workpiece (material)
W1 Workpiece outer periphery (material outer periphery)
W2 Cleaved portion W3 Curved portion W4 Tip of cleaved portion (curved portion) B Boss portion X1 Thickness of cleaved portion in the axial direction of main shaft X2 Thickness of boss portion in the radial direction of main shaft

Claims (9)

A mandrel for attaching a material to a tip of the main shaft; a chuck bar for pressing the material against the mandrel at a position facing the main shaft; and a roller for drawing the material; and rotating the main shaft relative to the roller Drawing device,
A tearing roller as the roller that is moved in the radial direction of the main shaft and tears the material from the outer periphery of the material;
A molding roller as the roller that presses the cleaved portion that has been cleaved against the chuck bar to mold the boss portion;
A drawing device comprising: a restricting means for restricting movement of the tip of the cleaved portion in the axial direction of the main shaft during forming by the forming roller.   The restricting means is formed of a chuck bar recess provided on the outer periphery of the tip of the chuck bar, and the crack is formed in a space formed between the forming roller and the chuck bar by the chuck bar recess in the molding process. The drawing apparatus according to claim 1, wherein the open portion is accommodated.   The drawing apparatus according to claim 1 or 2, wherein the cleaving roller is a curved cleaving roller having a curved guide surface that curves the cleaved portion.   The non-mandrel side end position of the curved guide surface of the curved tearing roller in the axial direction of the main shaft is configured to be positioned closer to the mandrel side than the regulated position of the regulating means. Drawing device. A tip side lateral pressing roller as the roller capable of performing lateral pressing that presses the split part to the mandrel side in the axial direction of the main shaft;
The cleaving portion is laterally pressed by the front end side lateral pressing roller, and the front end of the cleaving portion is positioned closer to the mandrel than the regulating position of the regulating means by the molding roller in the molding process. The drawing apparatus according to any one of claims 1 to 4, wherein the forming process of the cleaved portion is performed.   The front end side pressing roller includes a contact surface that comes into contact with the cleaved portion, and the front end side pressing roller completes the side pressing process when the side pressing process is completed. The drawing apparatus according to claim 5, wherein the non-mandrel side end position is positioned closer to the mandrel side than the restriction position of the restriction means.   The drawing apparatus according to any one of claims 1 to 6, wherein a rotation shaft of the main shaft and rotation shafts of the tearing roller and the forming roller are parallel to each other. Using a mandrel that attaches a material to the tip of the main shaft, a chuck bar that presses the material against the mandrel at a position facing the main shaft, and a roller that draws the material, the main shaft is rotated relative to the roller. A drawing method for drawing the material,
A cleaving process for moving the cleaving roller as the roller in the radially inward direction of the main shaft and cleaving the material from the outer periphery of the material,
And using a molding roller as the roller to perform a molding process step of pressing the cleaved portion that was cleaved in the cleaving process step against the chuck bar and molding the boss portion,
A drawing method for restricting movement of the tip of the cleaved portion in the axial direction of the main shaft in the molding step. After performing the cleaving step, the cleaving portion that has been cleaved is pressed against the mandrel side in the axial direction of the main shaft by using a front end side pressing roller as the roller, and the cleaving is performed. Performing a side pressing process for positioning the tip of the part closer to the mandrel than the restriction position for restricting movement of the tip of the split part in the axial direction of the main shaft;
The drawing method according to claim 8, wherein, in the forming step, the tearing portion that has been laterally pressed by the tip side lateral pressing roller is formed by the forming roller.

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