JP2023109027A - Striking-out device and striking-out method - Google Patents

Abstract

To provide a two tier striking-out part in a plate.SOLUTION: A striking-out device 60 includes a punch 62 and a die 64. The punch 62 has a body 68 and a protruding part 70 protruding from a tip of the body 68. The die 64 has: a first recessed part 72 having an inner diameter larger than an outer diameter of the body 68; and a second recessed part 74 formed at a bottom part of the first recessed part 72 and having an inner diameter which is smaller than the outer diameter of the body 68 and larger than an outer diameter of the protruding part 70.SELECTED DRAWING: Figure 6

Description

The present invention relates to a launching device and a launching method.

For example, the following technology is known as a stamping device having a punch and a die (see Patent Document 1, for example). That is, in the known technology, the punch has a main body and a projection projecting from the tip of the main body, and the die has an inner diameter smaller than the outer diameter of the main body and a diameter larger than the outer diameter of the projection. also has a recess with a large inner diameter.

JP-A-2-59134 JP 2017-19015 A JP 2019-187140 A

However, with the known technique described above, even if the punch is moved toward the die while the plate material is set in the die, only one step of the stamped portion can be formed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a striking device and a striking method capable of forming a two-stage stamped portion (hereinafter referred to as a two-stage stamped portion) in a plate material. and

A punching device according to a first aspect of the present invention is a punching device comprising a punch and a die, wherein the punch has a main body and a projection projecting from the tip of the main body, and the die comprises: a first recess having an inner diameter larger than the outer diameter of the main body; and a bottom of the first recess having an inner diameter smaller than the outer diameter of the main body and larger than the outer diameter of the projection. and a second recess.

According to this stamping device, the die is formed in the first concave portion whose inner diameter is larger than the outer diameter of the body portion, and the bottom portion of the first concave portion, the inner diameter is smaller than the outer diameter of the main body portion, and the outer diameter of the convex portion is formed. and a second recess having an inner diameter larger than the diameter. Therefore, when the plate material is set in the die and the punch is moved to the die side, the plate material is pressed by the body portion, thereby forming the first projecting portion projecting from the plate-like portion of the plate material and protruding. A second protrusion projecting from the top of the first protrusion is formed by pressing the plate member by the portion. In other words, the plate can be formed with a two-stage embossed portion having a first protrusion that protrudes from the plate-like portion of the plate and a second protrusion that protrudes from the top of the first protrusion.

A striking method according to a second aspect of the present invention is a striking method using the striking device according to the first aspect, wherein a plate material is set in the die, and while the punch is moved toward the die, the main body portion and pressing the plate material with the convex portion and pressing the plate material with the body portion to form a first projecting portion projecting from a part of the plate material, and pressing the plate material with the convex portion and forming a second protrusion that protrudes from the tip of the first protrusion.

According to this stamping method, by pressing the plate material with the body portion, the first projecting portion that protrudes from the plate-like portion of the plate material is formed, and by pressing the plate material with the convex portion, the top portion of the first projecting portion is formed. forming a protruding second protrusion; Therefore, it is possible to form the two-stage embossed portion in the plate material, which has the first projection portion projecting from the plate-like portion of the plate material and the second projection portion projecting from the top portion of the first projection portion.

It is a longitudinal section showing an example of a motor. It is a longitudinal cross-sectional view showing an example of a joint structure. It is a longitudinal section showing an example of a joining method. It is a longitudinal section showing an example of a striking device. It is a longitudinal cross-sectional view which shows an example of the 1st operation state of a striking device. FIG. 5 is a vertical cross-sectional view showing an example of a second operating state of the striking device; FIG. 10 is a vertical cross-sectional view showing an example of a third operating state of the striking device; FIG. 11 is a vertical cross-sectional view showing an example of a fourth operating state of the striking device; It is a longitudinal cross-sectional view which shows an example of the 5th operation state of a striking device. FIG. 11 is a vertical cross-sectional view showing an example of a sixth operating state of the striking device; It is a longitudinal cross-sectional view which shows an example of the 7th operating state of a striking device. FIG. 11 is a vertical cross-sectional view showing an example of the eighth operating state of the striking device; It is a longitudinal cross-sectional view showing an example of a ninth operating state of the striking device. It is a longitudinal cross-sectional view which shows an example of the 10th operation state of a striking device.

An embodiment of the present invention will be described below.

FIG. 1 shows, as an example, a motor 10 to which a joint structure 30 according to one embodiment of the invention is applied. Motor 10 includes motor shaft 12 , rotor 14 , stator 16 , motor holder 18 , center piece 20 , circuit board 22 , circuit case 24 and heat sink 26 . The motor 10 has the same configuration as the motor disclosed in Patent Document 3 except for the joint structure 30 . The bonding structure 30 is used for bonding the heat sink 26 and the circuit board 22 as an example. As an example, the heat sink 26 is made of metal such as an aluminum alloy, and the circuit board 22 is a printed circuit board made of resin.

An example of the junction structure 30 is shown in FIG. The joint structure 30 is a structure that joins the first plate-shaped portion 32 and the second plate-shaped portion 34 . The first plate-like portion 32 is part of the heat sink 26 and the second plate-like portion 34 is part of the circuit board 22 . Although the first plate-like portion 32 is part of the heat sink 26, it may be part of a member other than the heat sink 26. FIG. Moreover, although the second plate-like portion 34 is a part of the circuit board 22, it may be a part of a member other than the circuit board 22. FIG. Also, the joint structure 30 may be applied to devices or members other than the motor 10 .

The joining structure 30 includes a first projecting portion 36 projecting from the first plate-shaped portion 32 , a second projecting portion 38 projecting from the tip of the first projecting portion 36 , and a through hole formed in the second plate-shaped portion 34 . and a hole 40 . Both the projecting direction of the first projecting portion 36 and the projecting direction of the second projecting portion 38 are directions that match the plate thickness direction of the first plate-shaped portion 32 . The first projecting portion 36 and the second projecting portion 38 are formed by stamping as will be described later, and form a two-stage stamped portion 42 .

The first projecting portion 36 is formed to have a circular cross section. The first protruding portion 36 is hollow by being formed by stamping. A portion of the second projecting portion 38 other than the tip portion is also formed to have a circular cross-section. The first protruding portion 36 is hollow by being formed by stamping. In other words, the portion of the second projecting portion 38 other than the tip portion is formed in a hollow shape. The through hole 40 is formed with a circular cross section.

The tip of the first projecting portion 36 is in contact with the second plate-shaped portion 34 , and the second projecting portion 38 is inserted into the through hole 40 . A tip portion of the second projecting portion 38 protrudes from the through hole 40 , and a crimped portion 44 is formed at the tip portion of the second projecting portion 38 .

As will be described later, the crimped portion 44 is crimped by being compressed from both sides in a direction crossing (perpendicular to, for example) the direction in which the second projecting portion 38 projects. The crimped portion 44 has a crushed shape extending in the longitudinal direction by being compressed from both sides in a direction crossing the projecting direction of the second projecting portion 38 . As shown in the lower diagram of FIG. 2 , both ends 44 A of the crimped portion 44 in the longitudinal direction are engaged with the peripheral edge portion of the through hole 40 when the crimped portion 44 is viewed in cross section.

The first protruding portion 36 and the crimped portion 44 (that is, both end portions 44A in the longitudinal direction) sandwich the second plate-like portion 34 therebetween. The second plate-shaped portion 34 is fixed to the first plate-shaped portion 32 by sandwiching the second plate-shaped portion 34 between the first projecting portion 36 and the crimped portion 44 . The fixing mode of the second plate-like portion 34 to the first plate-like portion 32 may be permanent fixing or temporary fixing. In the case of temporary fixation, the second plate-like portion 34 is sandwiched between the first plate-like portion 32 and another member (not shown), so that the second plate-like portion 34 is fixed to the first plate-like portion 32 . May be fixed.

Next, a joining method according to one embodiment of the present invention will be described.

A crimping device 50 is shown in FIG. The caulking device 50 includes a metal core 52 and a pair of caulking tools 54 . A crimping device 50 is used in a joining method according to an embodiment of the present invention.

A bonding method according to an embodiment of the present invention is a method of bonding the first plate-shaped portion 32 and the second plate-shaped portion 34 . This joining method includes a preparation step and a crimping step. The left diagram of FIG. 3 shows the preparation process, and the right diagram of FIG. 3 shows the caulking process.

In the preparation step, the tip of the first projecting portion 36 projecting from the first plate-shaped portion 32 is brought into contact with the second plate-shaped portion 34 . A second projecting portion 38 projecting from the tip portion of the first projecting portion 36 is inserted into the through hole 40 . In this state, the tip portion of the second protrusion 38 protrudes from the through hole 40 . A metal core 52 is inserted inside the first projecting portion 36 . The tip (that is, the lower end) of the cored bar 52 contacts the bottom of the first protrusion 36 , and the outer peripheral surface of the cored bar 52 contacts the inner peripheral surface of the first protrusion 36 .

In the caulking process, the tip of the second protrusion 38 protruding from the through-hole 40 is compressed by a pair of caulking tools 54 from both sides in a direction crossing (perpendicular to, for example) the direction in which the second protrusion 38 protrudes. . A crimping portion 44 is formed at the tip of the second projecting portion 38 by being compressed by a pair of crimping tools 54 .

Next, a stamping method for manufacturing the two-step stamped portion 42 according to one embodiment of the present invention will be described.

A launching device 60 is shown in FIG. The stamping device 60 is a device for manufacturing the two-stage stamping part 42 . The stamping device 60 comprises a punch 62 , a die 64 and a presser die 66 .

The punch 62 has a body portion 68 and a convex portion 70 projecting from the tip of the body portion 68 . The die 64 has a first recess 72 with an inner diameter larger than the outer diameter of the body portion 68 and a second recess 74 formed in the bottom of the first recess 72 . The first recessed portion 72 and the second recessed portion 74 have shapes corresponding to the above-described first projecting portion 36 and second projecting portion 38, and are each formed to have a circular cross section. The inner diameter of the second concave portion 74 is smaller than the outer diameter of the body portion 68 and larger than the outer diameter of the convex portion 70 . A hole 76 is formed in the pressing die 66 and the punch 62 is housed in the hole 76 . The projecting dimension (that is, height H) of the convex portion 70 with respect to the tip portion of the main body portion 68 is set smaller than the plate thickness dimension (that is, thickness T) of the later-described plate member (see FIG. 5). . In FIG. 4, the clearance between the body portion 68 and the pressing die 66 is exaggerated, and in reality the clearance between the body portion 68 and the pressing die 66 is infinitesimally small.

A peripheral edge portion 68A of the distal end portion of the main body portion 68 has a tapered shape that increases in diameter toward the base end portion (not shown) of the main body portion 68, i.e., the side away from the die 64, and curves convexly in a vertical cross-sectional view. formed by faces. A peripheral edge portion 70A of the distal end portion of the convex portion 70 is formed by a tapered surface that increases in diameter toward the base end portion 70B side of the convex portion 70 and curves convexly in a vertical cross-sectional view. A base end portion 70B of the convex portion 70 is formed by a tapered surface that increases in diameter toward the main body portion 68 and curves concavely in a vertical cross-sectional view. The tapered surface is a concept that includes an R shape.

A peripheral edge portion 72A of the opening of the first recess 72 is formed by a tapered surface that increases in diameter toward the bottom side of the first recess 72 and curves convexly in a vertical cross-sectional view. A peripheral edge portion 74A of the opening of the second recess 74 is formed by a tapered surface that increases in diameter toward the bottom side of the second recess 74 and curves convexly in a vertical cross-sectional view. The striking device 60 configured as described above is used in a striking method according to an embodiment of the present invention.

A stamping method according to an embodiment of the present invention is a method of manufacturing a two-step stamped portion 42 . FIGS. 5 to 14 show how the two-step embossing part 42 is manufactured by this embossing method.

In this stamping method, a plate material 80 is set on a die 64 as shown in FIG. The plate material 80 corresponds to, for example, the heat sink 26 before the two-step embossed portion 42 is formed. The plate material is pressed by a pressing die 66 from the opposite side of the die 64 . Then, as shown in FIGS. 5 to 14 , the plate material 80 is pressed by the body portion 68 and the convex portion 70 while the punch 62 moves toward the die 64 . The punch 62 moves toward the die 64 until the two-stage punched portion 42 is formed.

Although the details will be described later, the body portion 68 presses the plate member 80 to form the first projecting portion 36 that protrudes from a portion of the plate member 80 as shown in FIG. 14 . A portion of the plate member 80 corresponds to the first plate-shaped portion 32 . Further, the plate member 80 is pressed by the convex portion 70 to form the second projecting portion 38 projecting from the tip portion of the first projecting portion 36 . Dots attached to the plate material 80 shown in FIGS. 5 to 14 indicate the distribution of stress acting on the plate material 80 in the stamping process. Darker dots indicate higher stress. 5 to 14, the shape of the plate member 80 is exaggerated based on the stress distribution.

FIG. 7 shows a state immediately before the body portion 68 starts pressing the plate member 80 . More specifically, in the present striking method, as shown in FIG. 7, in a state immediately before the main body portion 68 starts to press the plate member 80, the plate member 80 is curved, so that the base end portion 70B of the convex portion 70 is moved from the main body portion 68. A gap 82 is formed between the punch 62 and the plate over the tip of the punch (that is, the lower surface of the main body 68). In this manner, the plate member 80 is pressed by the convex portion 70 so that the gap 82 is formed until the body portion 68 starts to press the plate member 80 .

FIG. 10 shows a state immediately before the protrusion 70 begins to be inserted into the second recess 74 . In this hammering method, more specifically, as shown in FIG. 10, before the projection 70 starts to be inserted into the second recess 74, the tip of the main body 68 and the bottom of the first recess 72 compress the plate material 80. be done. By compressing the plate material 80 between the tip of the main body part 68 and the bottom part of the first recess 72 , the plate material 80 is acted on between the outer peripheral surface of the main body part 68 and the inner peripheral surface of the first recess 72 . Tensile force F2 is reduced.

10 to 14, the plate member 80 is compressed by the outer peripheral surface of the main body portion 68 and the inner peripheral surface of the first concave portion 72, and the tip of the main body portion 68 is compressed. The plate member 80 is pressed by the convex portion 70 while the plate member 80 is compressed by the portion and the bottom portion of the first concave portion 72 , thereby forming the second projecting portion 38 .

Next, the effect of one embodiment of the present invention will be described.

As described in detail above, according to the joint structure 30 according to one embodiment of the present invention, as shown in FIG. are formed by being compressed from both sides in a direction crossing (perpendicular to, for example) the projecting direction of the . Therefore, when the first plate-like portion 32 and the second plate-like portion 34 are joined together, it is possible to suppress the stress acting on the second plate-like portion 34 in the thickness direction. Accordingly, deformation of the second plate-like portion 34 (eg, a portion of the circuit board 22) can be suppressed.

Further, as shown in FIG. 2 , the first projecting portion 36 and the crimped portion 44 sandwich the second plate-shaped portion 34 , so that the first projecting portion 36 and the crimped portion 44 cause the second plate-shaped portion 34 to can be fixed (for example, temporarily fixed or permanently fixed) to the first plate-shaped portion 32 .

Moreover, as shown in FIG. 3, the first projecting portion 36 and the second projecting portion 38 are formed in a hollow shape. Therefore, the first projecting portion 36 and the second projecting portion 38 can be formed by stamping.

Further, as shown in FIG. 4, according to the stamping device 60 according to one embodiment of the present invention, the die 64 has a first recess 72 whose inner diameter is larger than the outer diameter of the body portion 68, and the first recess 72. A second concave portion 74 is formed in the bottom portion and has an inner diameter smaller than the outer diameter of the main body portion 68 and larger than the outer diameter of the convex portion 70 . Therefore, as shown in FIGS. 5 to 14, when the plate material 80 is set in the die 64 and the punch 62 is moved toward the die 64, the body portion 68 presses the plate material 80, thereby causing the plate material 80 to move. A first projecting portion 36 projecting from a portion of the first projecting portion 36 is formed, and the plate member 80 is pressed by the projecting portion 70 to form a second projecting portion 38 projecting from the tip portion of the first projecting portion 36 . That is, it is possible to form the plate material 80 with the two-stage embossed portion 42 having the first projecting portion 36 projecting from a portion of the plate material 80 and the second projecting portion 38 projecting from the tip portion of the first projecting portion 36 . .

A base end portion 70B of the convex portion 70 is formed by a tapered surface that increases in diameter toward the main body portion 68 and curves concavely in a vertical cross-sectional view. Therefore, as shown in FIG. 7, in a state immediately before the main body portion 68 starts to press the plate member 80, the base end portion 70B of the convex portion 70, which is a tapered surface, suppresses the flow of the material of the plate member 80. The plate member 80 is curved such that a gap 82 is formed between the punch 62 and the plate member 80 from the proximal end portion 70B of the portion 70 to the distal end portion of the body portion 68 . As a result, the timing at which the tensile force F1 acts on the plate member 80 due to the pressure from the convex portion 70 can be delayed compared to, for example, the case where the base end portion 70B of the convex portion 70 is not formed with a tapered surface.

Further, as shown in FIG. 10, before the protrusion 70 starts to be inserted into the second recess 74, the plate member 80 is compressed by the tip of the main body 68 and the bottom of the first recess 72, thereby The tensile force F2 acting on the plate material 80 between the outer peripheral surface of the first recess 72 and the inner peripheral surface of the first recess 72 is reduced. As a result, the tensile force F2 acting on the plate member 80 due to the pressing by the peripheral edge portion 68A of the tip end portion of the main body portion 68 can be reduced, so breakage of the plate member 80 can be suppressed.

10 to 14, the plate material 80 is compressed by the outer peripheral surface of the body portion 68 and the inner peripheral surface of the first recess 72, and the tip portion of the body portion 68 and the bottom portion of the first recess 72 are compressed. The second projecting portion 38 is formed by pressing the plate member 80 with the convex portion 70 while the plate member 80 is compressed by . Therefore, when the second projecting portion 38 is formed, the material of the plate member 80 flows toward the second projecting portion 38, so that the hollow second projecting portion 38 can be formed while suppressing breakage of the plate member 80. can be done.

A peripheral edge portion 68A of the distal end portion of the main body portion 68 is formed by a tapered surface that increases in diameter toward the base end portion side of the main body portion 68 and curves convexly in a vertical cross-sectional view. Therefore, as shown in FIGS. 8 to 11 , when the plate member 80 is pressed by the body portion 68 to form the first projecting portion 36 , along the peripheral edge portion 68A of the tip portion of the body portion 68, Since the material of the plate member 80 flows smoothly, it is possible to form the hollow first projecting portion 36 while suppressing breakage of the plate member 80 .

A peripheral edge portion 72A of the opening of the first recess 72 is formed by a tapered surface that increases in diameter toward the bottom side of the first recess 72 and curves convexly in a vertical cross-sectional view. Therefore, as shown in FIGS. 8 to 11, when the plate member 80 is pressed by the body portion 68 to form the first projecting portion 36, the peripheral edge portion 72A of the opening portion of the first recess portion 72 is Since the material of the plate member 80 smoothly flows along the groove, the hollow first projecting portion 36 can be formed while suppressing breakage of the plate member 80 .

A peripheral edge portion 70A of the distal end portion of the convex portion 70 is formed by a tapered surface that increases in diameter toward the base end portion 70B side of the convex portion 70 and curves convexly in a vertical cross-sectional view. Therefore, as shown in FIGS. 11 to 14 , when the plate member 80 is pressed by the convex portion 70 to form the second projecting portion 38 , along the peripheral edge portion 70A of the tip portion of the convex portion 70 , Since the material of the plate member 80 flows smoothly, it is possible to form the hollow second projecting portion 38 while suppressing breakage of the plate member 80 .

A peripheral edge portion 74A of the opening of the second recess 74 is formed by a tapered surface that increases in diameter toward the bottom side of the second recess 74 and curves convexly in a vertical cross-sectional view. Therefore, as shown in FIGS. 11 to 14, when the plate member 80 is pressed by the projection 70 to form the second projecting portion 38, the peripheral edge portion 74A of the opening of the second recess 74 is Since the material of the plate member 80 smoothly flows along the groove, the hollow second projecting portion 38 can be formed while suppressing breakage of the plate member 80 .

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that various modifications can be made in addition to the above without departing from the scope of the invention. is.

In addition, the following additional remarks are further disclosed regarding one embodiment of the technology disclosed in the present application described above.

(Appendix 1)
A joint structure for joining the first plate-shaped portion and the second plate-shaped portion,
a first projecting portion projecting from the first plate-shaped portion;
a second protrusion that protrudes from the tip of the first protrusion;
a through hole formed in the second plate-shaped portion;
has
a tip portion of the first projecting portion is in contact with the second plate-shaped portion;
The second projecting portion is inserted into the through hole,
a tip portion of the second projecting portion projects from the through hole,
A crimped portion that is compressed from both sides in a direction that intersects the projecting direction of the second projecting portion is formed at the tip of the second projecting portion,
junction structure.
(Appendix 2)
The first protruding portion and the crimped portion sandwich the second plate-shaped portion,
The joint structure according to appendix 1.
(Appendix 3)
The first projecting portion and the second projecting portion are formed in a hollow shape,
The joint structure according to appendix 1 or appendix 2.
(Appendix 4)
A bonding method for bonding a first plate-shaped portion and a second plate-shaped portion,
a tip portion of a first projecting portion projecting from the first plate-shaped portion is brought into contact with the second plate-shaped portion;
inserting a second projecting portion projecting from a tip portion of the first projecting portion into a through hole formed in the second plate-shaped portion;
Forming a crimped portion compressed from both sides in a direction crossing the projecting direction of the second projecting portion at a tip portion of the second projecting portion projecting from the through hole,
method of joining, including

DESCRIPTION OF SYMBOLS 10... Motor, 12... Shaft, 14... Rotor, 16... Stator, 18... Holder, 20... Center piece, 22... Circuit board, 24... Circuit case, 26... Heat sink, 30... Joining structure, 32... First plate shape Part 34... Second plate-shaped part 36... First projecting part 38... Second projecting part 40... Through hole 42... Two-stage projecting part 44... Crimping part 50... Crimping device 52... Core bar , 54... Crimping tool, 60... Ejecting device, 62... Punch, 64... Die, 66... Pressing die, 68... Main body part, 68A... Peripheral edge part of tip of main body part, 70... Convex part, 70A... Convex part Peripheral edge of distal end 70B Base end of convex portion 72 First recess 72A Peripheral edge of opening of first recess 74 Second recess 74A Peripheral edge of second recess , 76 ... hole

Claims (10)

A stamping device comprising a punch and a die,
punch is
a main body;
a convex portion protruding from the tip portion of the main body portion;
has
The die is
a first recess having an inner diameter larger than the outer diameter of the main body;
a second recess formed in the bottom portion of the first recess and having an inner diameter smaller than the outer diameter of the main body portion and an inner diameter larger than the outer diameter of the protrusion;
having
launching device. A base end portion of the convex portion is formed by a tapered surface that expands in diameter toward the main body portion and curves concavely in a vertical cross-sectional view,
A stamping device according to claim 1. The peripheral edge of the tip of the projection is formed by a tapered surface that expands in diameter toward the base end of the projection and curves convexly in a vertical cross-sectional view,
A stamping device according to claim 1 or claim 2. The peripheral edge portion of the distal end portion of the main body portion is formed by a tapered surface that expands in diameter toward the base end portion side of the main body portion and curves convexly in a vertical cross-sectional view,
A stamping device according to any one of claims 1 to 3. The peripheral edge of the opening of the first recess is formed by a tapered surface that expands in diameter toward the bottom side of the first recess and curves convexly in a vertical cross-sectional view.
A stamping device according to any one of claims 1 to 4. The peripheral edge of the opening of the second recess is formed by a tapered surface that expands in diameter toward the bottom side of the second recess and curves convexly in a vertical cross-sectional view.
A stamping device according to any one of claims 1 to 5. A striking method using the striking device according to any one of claims 1 to 6,
A plate material is set on the die,
While moving the punch toward the die, the plate member is pressed by the body portion and the convex portion;
forming a first projecting portion projecting from a portion of the plate member by pressing the plate member with the body portion;
Forming a second projecting portion projecting from a tip portion of the first projecting portion by pressing the plate material with the projecting portion;
Launch method including. In a state immediately before the main body portion starts to press the plate material, a gap is formed between the punch and the plate material from the base end portion of the convex portion to the tip end portion of the main body portion due to the bending of the plate material. pressing the plate with the convex portion until the body portion begins to press the plate so as to be formed;
The hitting method according to claim 7. Before the protrusion starts to be inserted into the second recess, the tensile force acting on the plate material between the outer peripheral surface of the main body and the inner peripheral surface of the first recess is applied to the front end of the main body. reducing by compressing the plate with the bottom of the first recess;
The hitting method according to claim 7 or 8. The plate member is compressed by the outer peripheral surface of the main body portion and the inner peripheral surface of the first recess, and the plate member is compressed by the tip portion of the main body portion and the bottom portion of the first recess. forming the second projecting portion by pressing the plate material with
The hitting method according to any one of claims 7 to 9.