JP2010058132A - Pressing method and method for manufacturing ring-shaped belleville spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for accurately manufacturing, by press-forming, a ring-shaped belleville spring having a central circular hole, whose inner surface is rounded. <P>SOLUTION: A small-diameter central circular hole is press-blanked by applying upper preliminary face-striking and lower preliminary face-striking to the central part of a part 12 of a steel material 11, where a ring-shaped belleville spring is to be formed. Next, the rear side part of an inner peripheral face 4a of the central circular hole is rounded by pushing and spreading the part by press-forming using a punch 29 with the outer peripheral face which is rounded (lower final face-striking). The front side part of the inner peripheral face 4a of the central circular hole is rounded by pushing and spreading the part by press-forming using a punch 32 with the outer peripheral face which is rounded (upper final face-striking). Thereafter, the inner peripheral face 4a of the central circular hole is pushed and spread by press-forming, so that the central circular hole becomes a central circular hole having an inner peripheral face 4 rounded (re-sizing). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a press working method capable of forming a circular through hole with a rounded inner peripheral surface by press working on a flat metal plate such as a steel plate. The present invention also relates to a method of manufacturing a ring-shaped disc spring having a circular center hole with a rounded inner peripheral surface by press working.

As a method of manufacturing a ring-shaped disc spring, a flat plate material such as a steel plate of a certain thickness is punched into a ring shape by pressing, the punched flat plate ring is press-bended to be processed into a truncated cone shape, and then quenched. A method for obtaining a ring-shaped disc spring having desired spring characteristics by performing a process such as tempering is known. Also, instead of pressing the flat plate, the elongated wire is bent and formed into an annular shape, both ends are butt welded, and this is pressed to form a flat ring. A method of obtaining a plate spring is also known. Patent Document 1 describes a method for manufacturing these ring-shaped disc springs.
Japanese Patent Laid-Open No. 06-106277

  Here, as a ring-shaped disc spring, a rotating shaft etc. may be passed through the circular center hole. As the ring-shaped disc spring mounted on such a portion, a ring-shaped disc spring is known in which a radius is given to the inner peripheral surface of the circular center hole so as to have the smallest diameter in the central portion in the thickness direction. By rounding the inner peripheral surface shape and managing the inner diameter dimension with high accuracy, the frictional contact surface with the rotating shaft can be minimized, and the friction load acting on the rotating shaft or the ring-shaped disc spring can be reduced.

  However, it is not possible to accurately form such a circular center hole with a rounded inner peripheral surface by press working. In view of this, conventionally, a circular inner peripheral surface after press punching is subjected to lace processing to form a smooth surface with a rounded surface.

  An object of the present invention is to propose a press working method capable of accurately forming an inner peripheral surface with a rounded shape by press working.

  Another object of the present invention is to propose a manufacturing method capable of accurately manufacturing a ring-shaped disc spring having a rounded inner peripheral surface of a circular center hole by press working.

  In order to solve the above problems, according to the present invention, the inner peripheral surface with a rounded shape is formed with high accuracy by press working as follows. In addition, although the code | symbol used in the below-mentioned embodiment is shown in the parenthesis writing, this is intended to facilitate understanding and is intended to limit the present invention to the embodiment. is not.

That is, a press working method for forming a circular through hole (3) having an inner peripheral surface (4) with a round (7, 8) by pressing a metal flat plate material (11) such as a steel plate. Is
Using the punch (23) having an outer diameter that is slightly smaller than the inner peripheral surface (4) of the circular through hole (3), the formation area of the circular through hole in the flat plate material (11) is defined as the flat plate material. By pushing a predetermined amount in the thickness direction from the front surface (11a) side or the back surface (11b) side of (11), an inner peripheral surface smaller than the inner diameter of the inner peripheral surface (4) of the circular through hole (3) is formed. A first preliminary facing process for forming an extruded portion (14) provided;
Using the punch (26) having an outer diameter slightly smaller than the inner peripheral surface (4) of the circular through hole (3), the extruded portion (14) is moved in the thickness direction of the flat plate material (11). A second preliminary surface punching step of forming a small circular through hole (3a) having an inner diameter slightly smaller than the inner diameter of the circular through hole (3) by extruding and punching in the opposite direction along
By pushing a punch (29) having an outer diameter slightly larger than the inner diameter of the small circular through hole (3a) into the small circular through hole (3a) from one side in the thickness direction, the small circular through hole (1a) a first face hitting step for attaching a radius (8) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By pushing a punch (32) having an outer diameter slightly larger than the inner diameter of the small circular through hole (3a) into the small circular through hole (3a) from the other side in the thickness direction, the small circular through hole A second hitting step of attaching a radius (7) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By adjusting the inner diameter dimension of the central portion in the thickness direction of the inner peripheral surface by pushing a punch into the small circular through hole (3a) with rounds (7, 8) on both side portions in the thickness direction, And a resizing step for obtaining the circular through hole (3) having the inner peripheral surface (4).

  Here, in the first preliminary beveling step and the second preliminary beating step, the punch (26, 29) having a conical outer peripheral surface whose outer diameter is gradually reduced toward the tip is used. The meat of the inner peripheral surface portion of the small circular through hole (3a) is brought closer to the center in the thickness direction from the front surface (11a) and back surface (11b) side of the flat plate material (11).

  In the first and second surface punching steps, the outer peripheral surface punch having a rounded shape complementary to the shape of the inner peripheral surface (4) of the circular center hole (3) ( 29, 32), the inner peripheral surface (4a) of the small circular center hole (3a) is rounded.

  Next, the present invention is characterized in that a ring-shaped disc spring having a rounded inner peripheral surface of the center hole along the thickness direction is manufactured using the above-described pressing method.

That is, the manufacturing method of the ring-shaped disc spring according to the present invention is as follows.
A method for producing a ring-shaped disc spring (1) comprising a circular center hole (3) and having a rounded inner peripheral surface (4) of the circular center hole (3),
Using the punch (23) having an outer diameter that is slightly smaller than the inner peripheral surface (4) of the circular center hole (3), the circular center hole is formed in a flat metal plate (11) such as a steel plate. By extruding (12) by a predetermined amount in the thickness direction from the front surface (11a) side or back surface (11b) side of the flat plate material (11), the inner peripheral surface (4) of the circular center hole (3) A first preliminary facing process for forming an extruded portion (14) having an inner peripheral surface smaller than the inner diameter;
Using the punch (26) having an outer diameter slightly smaller than the inner peripheral surface (4) of the circular center hole (3), the extruded portion (14) is moved in the thickness direction of the flat plate material (11). A second preliminary surface punching step of forming a small circular center hole (3a) having an inner diameter slightly smaller than the inner diameter of the circular center hole (3) by extruding and punching in the opposite direction along
By pushing a punch (29) having an outer diameter slightly larger than the inner diameter of the small circular center hole (3a) into the small circular center hole (3a) from one side in the thickness direction, the small circular central hole (1a) a first face hitting step of attaching a radius (8) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By pushing a punch (32) having an outer diameter slightly larger than the inner diameter of the small circular center hole (3a) into the small circular center hole (3a) from the other side in the thickness direction, the small circular central hole A second hitting step of attaching a radius (7) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
The inner diameter of the inner peripheral surface (4a) is adjusted by pushing a punch into the inner peripheral surface (4a) of the small circular center hole (3a) with rounds (7, 8) on both sides in the thickness direction. A resizing step of forming a circular center hole (3) having the inner peripheral surface (4);
A press bending step of press-molding a ring-shaped portion centering on the circular center hole (3) in the flat plate material (11);
A press-punching step of press-pulling the ring-shaped part that has been press-bent,
The ring-shaped disc spring material (1a) that has been punched out is finished to obtain a ring-shaped disc spring (1).

  Here, in the first preliminary beveling step and the second preliminary beating step, the punch (26, 29) having a conical outer peripheral surface whose outer diameter is gradually reduced toward the tip is used. The meat of the inner peripheral surface portion of the small circular center hole (3a) is brought closer to the center in the thickness direction from the front surface (11a) and the back surface (11b) side of the flat plate material (11).

  Further, in the first and second face-striking steps, the outer periphery with a round (7, 8) complementary to the shape of the inner peripheral surface (4) of the circular center hole (3). A round-shaped punch (29, 32) is used to attach a radius (7, 8) to the inner peripheral surface (4a) of the small circular center hole (3a).

  Further, in the press punching step, the outer peripheral portion surrounding the ring-shaped disc spring forming portion (12) in the flat plate material (11) is restrained so as not to move in the plane direction of the flat plate material (11), In this state, it is desirable to press the ring-shaped disc spring forming portion (12) using a die (41) and a punch (42) having substantially zero clearance. If it does in this way, the outer peripheral surface of a ring-shaped part can be made into a smooth surface with a high squareness, and there exists an advantage that it is not necessary to give finishing processing to an outer peripheral surface after a press release.

  In the present invention, the circular through hole forming portion of the flat plate material (the circular central hole forming portion of the ring-shaped disc spring forming portion) is extruded in a half-punched state, and the portion extruded from the opposite direction is punched out, thereby reducing the small diameter. Form a circular through hole (circular center hole), and then press-mold alternately from both sides in the thickness direction to remove the meat on both sides in the thickness direction of the inner peripheral surface of the circular through hole (circular center hole). While collecting at the center in the thickness direction, rounding is applied to both side portions of the inner peripheral surface, and thereafter resizing is performed to expand the center portion in the thickness direction. According to the method of the present invention, a smooth inner peripheral surface with a radius can be formed with high accuracy by press working.

  Embodiments of a method for manufacturing a ring-shaped disc spring to which the present invention is applied will be described below with reference to the drawings.

  1A to 1C are a plan view, a half cross-sectional view, and a partially enlarged cross-sectional view showing an enlarged inner peripheral surface portion of the circular center hole. The ring-shaped disc spring 1 includes a ring-shaped portion 2 that is pressed into a truncated cone shape, and a circular center hole 3 is formed at the center thereof. The circular inner peripheral surface 4 of the circular central hole 3 has rounded surfaces 7 and 8 at the corners on the spring surface 5 side and the corners on the spring back surface 6 side in the thickness direction. Has a curved surface portion 9 slightly projecting inward along the spring thickness direction, and the central portion of the curved surface portion 9 in the thickness direction has the smallest inner diameter. The ring-shaped disc spring 1 is manufactured, for example, by pressing from a steel plate having a plate thickness of 2 mm. The size is, for example, an outer diameter D1 of 4 mm, an inner diameter D2 of 2 mm, and a height H in the thickness direction of 3 mm. is there.

  2 and 3 are schematic process diagrams showing the main manufacturing steps of the ring-shaped disc spring 1, and FIGS. 4 and 5 are explanatory diagrams showing the shape of the punch. First, as shown in FIG. 2 (a), the ring-shaped disc spring forming portion 12 in the long steel plate 11 having a constant width is positioned between the die 22 and the punch 23 in the press machine 21 for lower preliminary surface beating. Then, the punch 23 is pushed up to form a semi-punched circular protruding base portion 14 in the circular central hole forming portion of the ring-shaped disc spring forming portion 12. Both the outer diameter on the convex side and the inner diameter on the concave side of the circular protruding base portion 14 are set to be slightly smaller than the inner diameter of the circular center hole 3.

  Next, as shown in FIG. 2 (b), the steel plate 11 is fed out by a constant pitch and positioned between the die 25 and the punch 26 in the upper preliminary surface pressing machine 24, and the punch 26 is pushed down to half-punch. The circular protruding base portion 14 in the state is pressed downward. Thereby, a small diameter circular center hole 3a is formed.

  Here, FIG. 4 shows the shapes of the tip portions of the lower preliminary surface punch 23 and the upper preliminary surface punch 26. A half-punch punch 23 indicated by a solid line includes a cylindrical main body portion 23a and a truncated cone-shaped tip portion 23b, and a slightly curved annular step between the main body portion 23a and the tip portion 23b. A surface 23c is formed. The outer diameter of the main body portion 23 a is smaller than the inner diameter of the circular center hole 3 of the ring-shaped disc spring 1. The punch 26 for punching indicated by a one-dot chain line also includes a cylindrical main body portion 26a and a truncated cone-shaped tip portion 23b, and a slightly curved annular step between the main body portion 26a and the tip portion 26b. A surface 26c is formed. The outer diameter of the main body portion 26 a is slightly larger than the outer diameter of the main body portion 23 a of the punch 23, but is smaller than the inner diameter of the circular center hole 3 of the ring-shaped disc spring 1. The frustoconical tip portions 23b, 26b of both punches 23, 26 have the same size.

  Next, as shown in FIG. 2 (c), the steel plate 11 is fed by a certain pitch, and the ring-shaped disc spring forming portion 12 in which the small-diameter circular center hole 3 a is formed is used in the press machine 27 for bottom face punching. Positioning is performed between the die 28 and the punch 29, and the punch 29 is pressed down to perform a press forming operation for expanding the small-diameter circular center hole 3a from the steel back surface 11b side. As shown in FIG. 2 (d), the bottom surface of the inner peripheral surface 4a of the small-diameter circular center hole 3a is rounded at the corners of the steel material back surface 11b.

  Thereafter, as shown in FIG. 2 (e), the steel plate 11 is fed by a fixed pitch, and the small-diameter circular center hole 3a is positioned between the die 31 and the punch 32 in the press machine 30 for top face punching, The punch 32 is pushed up to perform a press forming operation of pushing the small-diameter circular center hole 3a from the steel surface 11a side. As shown in FIG. 2 (f), the top surface strikes the corner 7 of the steel surface 11a on the inner peripheral surface 4a of the small-diameter circular center hole 3a. Thus, by pressing the inner peripheral surface 4a of the central circular hole 3a with the punches 29 and 32 from the lower side and the upper side, the thickness of both side portions of the inner peripheral surface 4a is brought to the center in the thickness direction, and Rounds 7 and 8 are attached to the corners on both sides of the inner peripheral surface 4a.

  FIG. 5 shows the shapes of the tip portions of the bottom punch 29 and the top punch 32. The punch 29 for punching the lower surface indicated by a solid line includes a cylindrical main body portion 29a and a truncated cone-shaped tip portion 29b, and a slightly curved annular step between the main body portion 29a and the tip portion 29b. A surface 29c is formed. The shape of the annular step surface 29c and the outer peripheral surface 29d of the leading end portion 29b that is continuous with the annular step surface 29c is complementary to the shape of the inner peripheral surface with a radius on the back side of the inner peripheral surface 4 of the ring-shaped disc spring 1. Shape. The punch 32 for punching indicated by a one-dot chain line also includes a cylindrical main body portion 32a and a truncated cone-shaped tip portion 32b, and a slightly curved annular step between the main body portion 32a and the tip portion 32b. A surface 32c is formed. The shape of the annular step surface 32c and the outer peripheral surface 32d of the tip portion 32b continuous with the annular step surface 32c is complementary to the inner peripheral surface shape with a rounded surface on the inner peripheral surface 4 of the ring-shaped disc spring 1. Shape.

  Next, as shown in FIG. 3 (a), the steel plate 11 is fed by a fixed pitch, and the circular center hole 3a is subjected to press forming for resizing, and the thickness of the circular center hole 3a on the inner peripheral surface 4a. The center portion in the direction is pushed and widened to give the inner circumferential surface 4 a smooth curved surface portion 9.

  After forming the circular center hole 3 having the inner peripheral surface 4 with the rounded shape in the steel material 11 in this way, as shown in FIG. 3B, the ring-shaped disc spring forming portion 12 is placed on the side of the steel material back surface 11b. Press-molded into a conical shape. Thereafter, as shown in FIG. 3C, the steel material 11 is pressed, and the ring-shaped disc spring material 1a is punched out. A ring-shaped disc spring 1 is obtained by subjecting the punched ring-shaped disc spring material 1a to finishing such as heat treatment and surface treatment.

  Here, a press machine shown in FIG. 6 can be used in the step of pressing (FIG. 3C). In this press machine 40, the clearance between the die 41 and the punch 42 is set to be substantially zero. Further, an annular protrusion 44 is formed on the steel material pressing surface 43 of the die 41. The ring-shaped disc spring forming portion 12 after being press-bent in the steel material 11 is positioned between the die 41 and the punch 42, and the die 41 is lowered to sandwich the steel material 11 between the protrusions 44. Thereafter, the punch 42 is pushed up to punch out the ring-shaped disc spring material 1a. A protrusion 44 is formed in an annular shape on the steel material pressing surface 43 of the die 41, and the protrusion 44 bites into the steel material 11 and is restrained so that the meat of the ring-shaped disc spring forming portion 12 does not escape to the outer peripheral side. In this state, the ring-shaped disc spring material 1a is obtained in a state where the outer peripheral surface is cut smoothly by being punched by the punch 42 having zero clearance. As a result, there is an advantage that it is not necessary to polish the outer peripheral surface.

(Other embodiments)
Although the above explanation relates to the pressing of a ring-shaped disc spring, the method of the present invention is a press-processed product having a circular through hole other than the disc spring, and is formed on the inner peripheral surface of the circular through hole. It can also be applied to the production of items with a round.

It is the top view which shows an example of the ring-shaped disk spring manufactured by this invention, a half sectional view, and a partial expanded sectional view. It is explanatory drawing which shows the main manufacturing processes of a ring shaped disc spring. It is explanatory drawing which shows the manufacturing process of the ring shaped disk spring after a circular center hole was formed. It is explanatory drawing which shows the shape of the punch used for lower preliminary | backup surface strike and upper preliminary | backup surface strike. It is explanatory drawing which shows the shape of the punch used for bottom strike and top strike. It is a schematic block diagram which shows the press used in order to press-release a ring-shaped disk spring raw material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ring-shaped disc spring 2 Ring-shaped part 3 Circular center hole 3a Circular center hole 4 Inner peripheral surface 4a Inner peripheral surface 5 Spring surface 6 Spring back surface 7, 8 R 9 Curved surface part 11 Flat plate material 11a Surface 11b Back surface 14 Extrusion part 21, 24, 27, 30 Press machine 22, 25, 28, 31 Dies 23, 26, 29, 32 Punches 23a, 26a, 29a, 32a Main body portions 23b, 26b, 29b, 32b Tip portions 23c, 26c, 29c, 32c Step surface 29d, 32d Outer peripheral surface 40 Press machine 41 Die 42 Punch 43 Steel material pressing surface 44 Projection

Claims (7)

This is a pressing method in which a metal flat plate (11) such as a steel plate is pressed to form a circular through hole (3) having an inner peripheral surface (4) with a radius (7, 8). And
Using the punch (23) having an outer diameter that is slightly smaller than the inner peripheral surface (4) of the circular through hole (3), the formation area of the circular through hole in the flat plate material (11) is defined as the flat plate material. By pushing a predetermined amount in the thickness direction from the front surface (11a) side or the back surface (11b) side of (11), an inner peripheral surface smaller than the inner diameter of the inner peripheral surface (4) of the circular through hole (3) is formed. A first preliminary facing process for forming an extruded portion (14) provided;
Using the punch (26) having an outer diameter slightly smaller than the inner peripheral surface (4) of the circular through hole (3), the extruded portion (14) is moved in the thickness direction of the flat plate material (11). A second preliminary surface punching step of forming a small circular through hole (3a) having an inner diameter slightly smaller than the inner diameter of the circular through hole (3) by extruding and punching in the opposite direction along
By pushing a punch (29) having an outer diameter slightly larger than the inner diameter of the small circular through hole (3a) into the small circular through hole (3a) from one side in the thickness direction, the small circular through hole (1a) a first face hitting step of attaching a radius (8) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By pushing a punch (32) having an outer diameter slightly larger than the inner diameter of the small circular through hole (3a) into the small circular through hole (3a) from the other side in the thickness direction, the small circular through hole A second hitting step of attaching a radius (7) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By adjusting the inner diameter dimension of the central portion in the thickness direction of the inner peripheral surface by pushing a punch into the small circular through hole (3a) with rounds (7, 8) on both side portions in the thickness direction, A resizing step of obtaining the circular through hole (3) having the inner peripheral surface (4). In the press processing method of Claim 1,
In the first preliminary surface placing process and the second preliminary surface placing process,
Using the punches (26, 29) having a conical outer peripheral surface whose outer diameter gradually decreases toward the tip, the meat of the inner peripheral surface portion of the small circular through hole (3a) is flattened (11 ) From the front surface (11a) and back surface (11b) side toward the center in the thickness direction. The press working method according to claim 1 or 2,
In the first and second surface hitting steps,
The inner periphery of the small circular center hole (3a) is formed by using punches (29, 32) having an outer peripheral surface shape that is complementary to the shape of the inner peripheral surface (4) of the circular center hole (3). A press working method characterized by attaching a radius to the surface (4a). A method for producing a ring-shaped disc spring (1) comprising a circular center hole (3) and having a rounded inner peripheral surface (4) of the circular center hole (3),
Using the punch (23) having an outer diameter that is slightly smaller than the inner peripheral surface (4) of the circular center hole (3), the circular center hole is formed in a flat metal plate (11) such as a steel plate. By extruding (12) by a predetermined amount in the thickness direction from the front surface (11a) side or back surface (11b) side of the flat plate material (11), the inner peripheral surface (4) of the circular center hole (3) A first preliminary facing process for forming an extruded portion (14) having an inner peripheral surface smaller than the inner diameter;
Using the punch (26) having an outer diameter slightly smaller than the inner peripheral surface (4) of the circular center hole (3), the extruded portion (14) is moved in the thickness direction of the flat plate material (11). A second preliminary surface punching step of forming a small circular center hole (3a) having an inner diameter slightly smaller than the inner diameter of the circular center hole (3) by extruding and punching in the opposite direction along
By pushing a punch (29) having an outer diameter slightly larger than the inner diameter of the small circular center hole (3a) into the small circular center hole (3a) from one side in the thickness direction, the small circular central hole (1a) a first face hitting step of attaching a radius (8) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
By pushing a punch (32) having an outer diameter slightly larger than the inner diameter of the small circular center hole (3a) into the small circular center hole (3a) from the other side in the thickness direction, the small circular central hole A second hitting step of attaching a radius (7) to the inner peripheral surface portion on the punch pushing side in the thickness direction of the inner peripheral surface (4a) of (3a);
The inner diameter of the inner peripheral surface (4a) is adjusted by pushing a punch into the inner peripheral surface (4a) of the small circular center hole (3a) with rounds (7, 8) on both sides in the thickness direction. A resizing step of forming a circular center hole (3) having the inner peripheral surface (4);
A press bending step of press-molding a ring-shaped portion centering on the circular center hole (3) in the flat plate material (11);
A press-punching step of press-pulling the ring-shaped part that has been press-bent,
A method for producing a ring-shaped disc spring, wherein the ring-shaped disc spring material (1a) is subjected to a finishing process to obtain a ring-shaped disc spring (1). In the manufacturing method of Claim 4,
In the first preliminary surface placing process and the second preliminary surface placing process,
Using a punch (26, 29) having a conical outer peripheral surface whose outer diameter gradually decreases toward the tip, the meat of the inner peripheral surface portion of the small circular center hole (3a) is flattened (11 ) From the front surface (11a) and back surface (11b) side toward the center in the thickness direction. In the manufacturing method of Claim 4 or 5,
In the first and second surface hitting steps,
Using the punches (29, 32) of the outer peripheral surface shape with rounds (7, 8) complementary to the shape of the inner peripheral surface (4) of the circular center hole (3), the small circular center hole ( A method of manufacturing a ring-shaped disc spring (1), characterized by attaching rounds (7, 8) to the inner peripheral surface (4a) of 3a). In the manufacturing method according to any one of claims 4 to 6,
In the pressing process,
The flat plate member (11) is constrained so that the meat on the outer peripheral side surrounding the ring-shaped disc spring forming portion (12) does not move in the plane direction of the flat plate member (11). In this state, the clearance is substantially reduced. A method of manufacturing a ring-shaped disc spring (1), wherein the ring-shaped disc spring forming portion (12) is press-extracted using a zero die (41) and a punch (42).

Images