JP7804469B2 - Embossing device and embellishing method - Google Patents

Description

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

For example, the following technology is known as an ejection device equipped with a punch and a die (see, for example, Patent Document 1). In this known technology, the punch has a main body and a protrusion protruding from the tip of the main body, and the die has a recess whose inner diameter is smaller than the outer diameter of the main body and larger than the outer diameter of the protrusion.

Japanese Patent Application Publication No. 2-59134 Japanese Patent Application Laid-Open No. 2017-19015 Japanese Patent Application Laid-Open No. 2019-187140

However, with the above-mentioned known technology, even if the punch is moved toward the die while the sheet material is set in the die, only a single-stage embossed portion can be formed.

The present invention was made in consideration of the above-mentioned problems, and aims to provide an embossing device and embossing method that can form a two-stage embossed portion (hereinafter referred to as a two-stage embossed portion) in a sheet of metal.

The first aspect of the present invention is an impact device comprising a punch and a die, wherein the punch has a main body and a convex portion protruding from the tip of the main body, and the die has a first recess having an inner diameter larger than the outer diameter of the main body, and a second recess formed at the 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 convex portion, wherein the peripheral edge of the tip of the convex portion widens in diameter toward the base end of the convex portion and is formed by a tapered surface that is convexly curved in a vertical cross-sectional view, and the dimension of the convex portion in the protruding direction is shorter than the dimension of the first recess in the depth direction .

With this embossing device, the die has a first recess whose inner diameter is larger than the outer diameter of the main body, and a second recess formed at the bottom of the first recess, whose inner diameter is smaller than the outer diameter of the main body and larger than the outer diameter of the convex portion. Therefore, when a sheet material is set in the die and the punch is moved toward the die, the main body presses the sheet material, forming a first protrusion that protrudes from the plate-shaped portion of the sheet material, and the convex portion presses the sheet material, forming a second protrusion that protrudes from the apex of the first protrusion. In other words, a two-stage embossing portion can be formed in the sheet material, with a first protrusion that protrudes from the plate-shaped portion of the sheet material and a second protrusion that protrudes from the apex of the first protrusion.

An stamping method according to a second aspect of the present invention is an stamping method using the stamping device according to the first aspect, and includes setting a plate material in the die, and pressing the plate material with the main body and the convex portion while moving the punch toward the die, by pressing the plate material with the main body to form a first protrusion protruding from a part of the plate material, and by pressing the plate material with the convex portion to form a second protrusion protruding from the tip of the first protrusion , and the plate material is pressed by the convex portion until the main body begins to press the plate material, so that just before the main body begins to press the plate material, the plate material bends to form a gap between the punch and the plate material from the base end of the convex portion to the tip of the main body.
An stamping method according to a third aspect of the present invention is an stamping method using the stamping device according to the first aspect, and includes setting a plate material in the die, and pressing the plate material with the main body and the convex portion while moving the punch toward the die, forming a first protrusion protruding from a part of the plate material by pressing the plate material with the main body, and forming a second protrusion protruding from a tip of the first protrusion by pressing the plate material with the convex portion, and reducing 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 concave portion by compressing the plate material between the tip of the main body and the bottom of the first concave portion before the convex portion begins to be inserted into the second concave portion.
An stamping method according to a fourth aspect of the present invention is an stamping method using the stamping device according to the first aspect, and includes the steps of setting a plate material in the die, and pressing the plate material with the main body and the convex portion while moving the punch toward the die, and by pressing the plate material with the main body, a first protrusion protruding from a part of the plate material is formed, and by pressing the plate material with the convex portion, a second protrusion protruding from a tip end of the first protrusion is formed, and the plate material is compressed by the outer peripheral surface of the main body and the inner peripheral surface of the first recess, and in a state in which the plate material is compressed by the tip end of the main body and the bottom of the first recess, the plate material is pressed by the convex portion to form the second protrusion.

With this stamping method, a first protrusion protruding from the plate-shaped portion of the plate is formed by pressing the plate material with the main body, and a second protrusion protruding from the apex of the first protrusion is formed by pressing the plate material with the convex portion. Therefore, a two-stage stamped portion can be formed on the plate material, having a first protrusion protruding from the plate-shaped portion of the plate material and a second protrusion protruding from the apex of the first protrusion.

FIG. 1 is a vertical cross-sectional view showing an example of a motor. FIG. 2 is a vertical cross-sectional view showing an example of a joining structure. FIG. 10 is a vertical cross-sectional view showing an example of a joining method. FIG. 2 is a vertical cross-sectional view showing an example of a driving device. FIG. 2 is a vertical cross-sectional view showing an example of a first operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of a second operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of a third operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of a fourth operating state of the driving device. FIG. 10 is a vertical cross-sectional view illustrating an example of a fifth operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of a sixth operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of a seventh operating state of the driving device. FIG. 10 is a vertical cross-sectional view showing an example of an eighth operating state of the driving device. FIG. 13 is a vertical cross-sectional view showing an example of a ninth operating state of the driving device. FIG. 19 is a longitudinal cross-sectional view showing an example of a tenth operating state of the driving device.

One embodiment of the present invention is described below.

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

Figure 2 shows an example of a joining structure 30. The joining structure 30 joins a first plate-shaped portion 32 and a second plate-shaped portion 34. The first plate-shaped portion 32 is part of the heat sink 26, and the second plate-shaped portion 34 is part of the circuit board 22. Note that although the first plate-shaped portion 32 is part of the heat sink 26, it may also be part of a member other than the heat sink 26. Furthermore, although the second plate-shaped portion 34 is part of the circuit board 22, it may also be part of a member other than the circuit board 22. Furthermore, the joining structure 30 may be applied to devices or members other than the motor 10.

The joining structure 30 has a first protruding portion 36 protruding from the first plate-shaped portion 32, a second protruding portion 38 protruding from the tip of the first protruding portion 36, and a through hole 40 formed in the second plate-shaped portion 34. The protruding direction of the first protruding portion 36 and the protruding direction of the second protruding portion 38 both coincide with the plate thickness direction of the first plate-shaped portion 32. The first protruding portion 36 and the second protruding portion 38 are formed by stamping, as described below, and form a two-stage stamped portion 42.

The first protrusion 36 is formed to have a circular cross section. The first protrusion 36 is formed to be hollow by being stamped. The second protrusion 38, excluding its tip, is also formed to have a circular cross section. The first protrusion 36 is formed to be hollow by being stamped. In other words, the second protrusion 38, excluding its tip, is formed to be hollow. The through-hole 40 is formed to have a circular cross section.

The tip of the first protrusion 36 abuts against the second plate-shaped portion 34, and the second protrusion 38 is inserted into the through-hole 40. The tip of the second protrusion 38 protrudes from the through-hole 40, and a crimped portion 44 is formed at the tip of the second protrusion 38.

As described below, the crimping portion 44 is crimped by being compressed from both sides in a direction intersecting the protruding direction of the second protruding portion 38 (for example, a direction perpendicular to the protruding direction). The crimping portion 44 has a flattened shape that extends in the longitudinal direction by being compressed from both sides in a direction intersecting the protruding direction of the second protruding portion 38. As shown in the lower diagram of Figure 2, when the crimping portion 44 is viewed in cross section, both ends 44A of the crimping portion 44 in the longitudinal direction are engaged with the periphery of the through-hole 40.

The first protrusion 36 and the crimping portion 44 (i.e., both longitudinal end portions 44A) sandwich the second plate-shaped portion 34. The second plate-shaped portion 34 is fixed to the first plate-shaped portion 32 by being sandwiched between the first protrusion 36 and the crimping portion 44. The second plate-shaped portion 34 may be fixed to the first plate-shaped portion 32 either permanently or temporarily. In the case of temporary fixation, the second plate-shaped portion 34 may be fixed to the first plate-shaped portion 32 by being sandwiched between the first plate-shaped portion 32 and another member (not shown).

Next, we will explain the joining method according to one embodiment of the present invention.

Figure 3 shows a crimping device 50. The crimping device 50 includes a core bar 52 and a pair of crimping tools 54. The crimping device 50 is used in a joining method according to one embodiment of the present invention.

A joining method according to one embodiment of the present invention is a method for joining a first plate-shaped portion 32 and a second plate-shaped portion 34. This joining method includes a preparation step and a crimping step. The left side of Figure 3 shows the preparation step, and the right side of Figure 3 shows the crimping step.

In the preparation process, the tip of the first protrusion 36 protruding from the first plate-shaped portion 32 abuts against the second plate-shaped portion 34. Furthermore, the second protrusion 38 protruding from the tip of the first protrusion 36 is inserted into the through-hole 40. In this state, the tip of the second protrusion 38 protrudes from the through-hole 40. A core metal 52 is inserted inside the first protrusion 36. The tip (i.e., the lower end) of the core metal 52 abuts against the bottom of the first protrusion 36, and the outer peripheral surface of the core metal 52 contacts the inner peripheral surface of the first protrusion 36.

In the crimping process, the tip of the second protrusion 38 protruding from the through hole 40 is compressed by a pair of crimping tools 54 from both sides in a direction intersecting the protrusion direction of the second protrusion 38 (for example, a direction perpendicular to the protrusion direction). Then, the tip of the second protrusion 38 is compressed by the pair of crimping tools 54 to form a crimped portion 44.

Next, we will explain the embossing method for manufacturing the two-stage embossed portion 42 according to one embodiment of the present invention.

Figure 4 shows the embossing device 60. The embossing device 60 is a device for manufacturing the two-stage embossed portion 42. The embossing device 60 includes a punch 62, a die 64, and a presser die 66.

The punch 62 has a main body 68 and a protrusion 70 protruding from the tip of the main body 68. The die 64 has a first recess 72 whose inner diameter is larger than the outer diameter of the main body 68, and a second recess 74 formed at the bottom of the first recess 72. The first recess 72 and the second recess 74 have shapes corresponding to the first protrusion 36 and the second protrusion 38 described above, and are each formed with a circular cross section. The inner diameter of the second recess 74 is smaller than the outer diameter of the main body 68 and larger than the outer diameter of the protrusion 70. The pressing die 66 has a hole 76 formed therein, and the punch 62 is housed in the hole 76. The protrusion dimension (i.e., height H) of the protrusion 70 relative to the tip of the main body 68 is set to be smaller than the thickness dimension (i.e., thickness T) of the plate material (see Figure 5) described below. Note that in Figure 4, the clearance between the main body 68 and the presser die 66 is exaggerated; in reality, the clearance between the main body 68 and the presser die 66 is extremely small.

The peripheral edge 68A at the tip of the main body 68 increases in diameter toward the base end (not shown) of the main body 68, i.e., the side away from the die 64, and is formed by a tapered surface that is convexly curved in a vertical cross section. The peripheral edge 70A at the tip of the convex portion 70 increases in diameter toward the base end 70B of the convex portion 70, and is formed by a tapered surface that is convexly curved in a vertical cross section. The base end 70B of the convex portion 70 increases in diameter toward the main body 68, and is formed by a tapered surface that is concavely curved in a vertical cross section. The term "tapered surface" includes an R-shape.

A peripheral edge 72A of the opening of the first recess 72 is tapered so that its diameter decreases toward the bottom of the first recess 72 and is formed by a tapered surface that is convexly curved in a vertical cross section. A peripheral edge 74A of the opening of the second recess 74 is tapered so that its diameter decreases toward the bottom of the second recess 74 and is formed by a tapered surface that is convexly curved in a vertical cross section. The embossing device 60 having the above configuration is used in a embossing method according to one embodiment of the present invention.

The embossing method according to one embodiment of the present invention is a method for manufacturing a two-stage embossed portion 42. Figures 5 to 14 show how the two-stage embossed portion 42 is manufactured using this embossing method.

In this embossing method, as shown in Figure 5, a plate material 80 is set in the die 64. The plate material 80 corresponds to, for example, the heat sink 26 before the two-stage embossment portion 42 is formed. The plate material is pressed down by a presser die 66 from the side opposite the die 64. Then, as shown in Figures 5 to 14, the punch 62 moves towards the die 64, while the main body portion 68 and the protrusion portion 70 press down on the plate material 80. The punch 62 moves towards the die 64 until the two-stage embossment portion 42 is formed.

As will be described in more detail below, when the plate material 80 is pressed by the main body portion 68, a first protrusion 36 is formed that protrudes from a portion of the plate material 80, as shown in FIG. 14. This portion of the plate material 80 corresponds to the first plate-shaped portion 32. When the plate material 80 is pressed by the convex portion 70, a second protrusion 38 is formed that protrudes from the tip of the first protrusion 36. The dots on the plate material 80 shown in FIGS. 5 to 14 indicate the distribution of stress acting on the plate material 80 during the stamping process. The darker the dots, the higher the stress. Furthermore, in FIGS. 5 to 14, the shape of the plate material 80 is exaggerated based on the stress distribution.

Figure 7 shows the state immediately before the main body 68 begins to press against the sheet material 80. In this punching method, more specifically, as shown in Figure 7, immediately before the main body 68 begins to press against the sheet material 80, the sheet material 80 bends, forming a gap 82 between the punch 62 and the sheet material from the base end 70B of the convex portion 70 to the tip end of the main body 68 (i.e., the underside of the main body 68). In this way, until the main body 68 begins to press against the sheet material 80, the sheet material 80 is pressed by the convex portion 70 so as to form the gap 82.

Figure 10 shows the state immediately before the protrusion 70 begins to be inserted into the second recess 74. More specifically, in this striking method, as shown in Figure 10, before the protrusion 70 begins to be inserted into the second recess 74, the plate material 80 is compressed between the tip of the main body 68 and the bottom of the first recess 72. Then, by compressing the plate material 80 between the tip of the main body 68 and the bottom of the first recess 72, the tensile force F2 acting on the plate material 80 between the outer peripheral surface of the main body 68 and the inner peripheral surface of the first recess 72 is reduced.

More specifically, in this striking method, as shown in Figures 10 to 14, the plate material 80 is compressed by the outer peripheral surface of the main body 68 and the inner peripheral surface of the first recess 72, and in this state, the plate material 80 is pressed by the convex portion 70, thereby forming the second protrusion 38.

Next, we will explain the effects of one embodiment of the present invention.

As described above in detail, according to the joining structure 30 of one embodiment of the present invention, as shown in FIG. 3, the crimping portion 44 formed at the tip of the second protrusion 38 is formed by compression from both sides in a direction intersecting the protrusion direction of the second protrusion 38 (for example, a direction perpendicular to the protrusion direction). Therefore, when joining the first plate-shaped portion 32 and the second plate-shaped portion 34, stress acting in the plate thickness direction on the second plate-shaped portion 34 can be suppressed. This makes it possible to suppress deformation of the second plate-shaped portion 34 (for example, a part of the circuit board 22).

Furthermore, as shown in FIG. 2, the first protrusion 36 and the crimping portion 44 sandwich the second plate-shaped portion 34, allowing the second plate-shaped portion 34 to be fixed (e.g., temporarily or permanently fixed) to the first plate-shaped portion 32 by the first protrusion 36 and the crimping portion 44.

Furthermore, as shown in FIG. 3, the first protrusion 36 and the second protrusion 38 are hollow. Therefore, the first protrusion 36 and the second protrusion 38 can be formed by stamping.

4, in an embossing device 60 according to one embodiment of the present invention, the die 64 has a first recess 72 having an inner diameter larger than the outer diameter of the main body 68, and a second recess 74 formed at the bottom of the first recess 72, the second recess 74 having an inner diameter smaller than the outer diameter of the main body 68 and larger than the outer diameter of the protrusion 70. Therefore, as shown in FIGS. 5 to 14, when a sheet material 80 is set in the die 64 and the punch 62 is moved toward the die 64, the main body 68 presses the sheet material 80, forming a first protrusion 36 that protrudes from a portion of the sheet material 80, and the protrusion 70 presses the sheet material 80, forming a second protrusion 38 that protrudes from the tip of the first protrusion 36. In other words, a two-stage embossing portion 42 can be formed in the sheet material 80, including the first protrusion 36 that protrudes from a portion of the sheet material 80 and the second protrusion 38 that protrudes from the tip of the first protrusion 36.

The base end 70B of the convex portion 70 is formed with a tapered surface that increases in diameter toward the main body portion 68 and is concavely curved in a vertical cross section. Therefore, as shown in FIG. 7 , just before the main body portion 68 begins to press against the sheet material 80, the tapered surface of the base end 70B of the convex portion 70 suppresses the flow of the material of the sheet material 80, causing the sheet material 80 to bend so that a gap 82 is formed between the punch 62 and the sheet material 80 from the base end 70B of the convex portion 70 to the tip of the main body portion 68. This allows for a delay in the timing at which a tensile force F1 acts on the sheet material 80 due to the pressing by the convex portion 70, compared to when the base end 70B of the convex portion 70 does not have a tapered surface.

Furthermore, as shown in FIG. 10 , before the projection 70 begins to be inserted into the second recess 74, the plate material 80 is compressed between the tip of the main body 68 and the bottom of the first recess 72, thereby reducing the tensile force F2 acting on the plate material 80 between the outer peripheral surface of the main body 68 and the inner peripheral surface of the first recess 72. This reduces the tensile force F2 acting on the plate material 80 due to pressure from the peripheral edge 68A of the tip of the main body 68, thereby preventing breakage of the plate material 80.

Furthermore, as shown in Figures 10 to 14, the plate material 80 is compressed by the outer peripheral surface of the main body portion 68 and the inner peripheral surface of the first recessed portion 72, and in this state, the plate material 80 is pressed by the convex portion 70, thereby forming the second protruding portion 38. Therefore, when the second protruding portion 38 is formed, the material of the plate material 80 flows toward the second protruding portion 38, making it possible to form the hollow second protruding portion 38 while preventing the plate material 80 from breaking.

Furthermore, the peripheral edge 68A at the tip of the main body 68 increases in diameter toward the base end of the main body 68 and is formed by a tapered surface that is convexly curved in a longitudinal cross section. Therefore, as shown in Figures 8 to 11, when the plate material 80 is pressed by the main body 68 to form the first protrusion 36, the material of the plate material 80 flows smoothly along the peripheral edge 68A at the tip of the main body 68, making it possible to form the hollow first protrusion 36 while preventing the plate material 80 from breaking.

Furthermore, the peripheral edge 72A of the opening of the first recess 72 is tapered so that the diameter decreases toward the bottom of the first recess 72 and is curved convexly in a vertical cross section. Therefore, as shown in Figures 8 to 11, when the plate material 80 is pressed by the main body 68 to form the first protrusion 36, the material of the plate material 80 flows smoothly along the peripheral edge 72A of the opening of the first recess 72, so that the hollow first protrusion 36 can be formed while preventing the plate material 80 from breaking.

Furthermore, the peripheral edge 70A at the tip of the convex portion 70 increases in diameter toward the base end 70B of the convex portion 70 and is formed by a tapered surface that is convexly curved in a vertical cross section. Therefore, as shown in Figures 11 to 14, when the plate material 80 is pressed by the convex portion 70 to form the second protrusion 38, the material of the plate material 80 flows smoothly along the peripheral edge 70A at the tip of the convex portion 70, making it possible to form the hollow second protrusion 38 while preventing the plate material 80 from breaking.

Furthermore, the peripheral edge 74A of the opening of the second recess 74 is tapered so that the diameter decreases toward the bottom of the second recess 74 and is curved convexly in a vertical cross section. Therefore, as shown in Figures 11 to 14, when the plate material 80 is pressed by the convex portion 70 to form the second protrusion 38, the material of the plate material 80 flows smoothly along the peripheral edge 74A of the opening of the second recess 74, so that the hollow second protrusion 38 can be formed while preventing the plate material 80 from breaking.

The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that various modifications and variations are possible within the scope of the gist of the present invention.

The following supplementary notes are also provided regarding one embodiment of the technology disclosed in the present application described above.

(Appendix 1)
A joining structure for joining a first plate-shaped portion and a second plate-shaped portion,
a first protruding portion protruding from the first plate-shaped portion;
a second protruding portion protruding from a tip end portion of the first protruding portion;
a through hole formed in the second plate-shaped portion;
and
a tip end of the first protrusion abuts against the second plate-shaped portion,
the second protrusion is inserted into the through hole,
a tip end of the second protrusion protrudes from the through hole,
A crimping portion is formed at the tip end of the second protrusion, the crimping portion being compressed from both sides in a direction intersecting the protruding direction of the second protrusion.
Joint structure.
(Appendix 2)
The first protruding portion and the crimping portion sandwich the second plate-shaped portion.
2. The joining structure of claim 1.
(Appendix 3)
The first protrusion and the second protrusion are formed hollow.
3. The joining structure according to claim 1 or 2.
(Appendix 4)
A joining method for joining a first plate-shaped portion and a second plate-shaped portion, comprising:
a tip end of a first protruding portion protruding from the first plate-shaped portion abutting against the second plate-shaped portion;
a second protruding portion protruding from a tip end of the first protruding portion is inserted into a through hole formed in the second plate-shaped portion;
a crimping portion is formed at a tip end of the second protruding portion protruding from the through hole, the crimping portion being compressed from both sides in a direction intersecting the protruding direction of the second protruding portion;
A bonding method comprising:

10...motor, 12...shaft, 14...rotor, 16...stator, 18...holder, 20...center piece, 22...circuit board, 24...circuit case, 26...heat sink, 30...joint structure, 32...first plate-shaped portion, 34...second plate-shaped portion, 36...first protrusion, 38...second protrusion, 40...through hole, 42...two-stage embossed portion, 44...crimping portion, 50...crimping device, 5 2...Core metal, 54...Crimping tool, 60...Ejection device, 62...Punch, 64...Die, 66...Pressing die, 68...Main body, 68A...Periphery of the tip of the main body, 70...Convex portion, 70A...Periphery of the tip of the convex portion, 70B...Base end of the convex portion, 72...First recess, 72A...Periphery of the opening of the first recess, 74...Second recess, 74A...Periphery of the opening of the second recess, 76...Hole

Claims (8)

An embossing device including a punch and a die,
The punch is
a main body;
a protrusion protruding from a tip end of the main body;
and
The die is
a first recess having an inner diameter larger than an outer diameter of the main body;
a second recess formed at a bottom of the first recess, the second recess having an inner diameter smaller than an outer diameter of the main body and larger than an outer diameter of the protrusion;
and
a peripheral edge portion of the tip end of the convex portion is formed by a tapered surface that increases in diameter toward the base end side of the convex portion and is curved convexly in a vertical cross section,
a dimension of the protruding portion in a protruding direction is shorter than a dimension of the first recess in a depth direction;
Launching device. The base end of the protrusion is formed by a tapered surface that increases in diameter toward the main body and is curved concavely in a vertical cross section.
The embossing device according to claim 1 . The peripheral edge of the tip end of the main body portion is formed by a tapered surface that increases in diameter toward the base end of the main body portion and is curved convexly in a vertical cross section.
The embossing device according to claim 1 or 2. a peripheral edge portion of the opening of the first recess portion is formed by a tapered surface that is tapered in diameter toward the bottom of the first recess portion and is curved convexly in a vertical cross section;
The driving device according to any one of claims 1 to 3. a peripheral edge portion of the opening of the second recess portion is formed by a tapered surface that is tapered toward the bottom of the second recess portion and is convexly curved in a vertical cross section;
The embossing device according to any one of claims 1 to 4. A method for striking using the striking device according to any one of claims 1 to 5,
A plate material is set in the die,
While moving the punch toward the die, the plate material is pressed by the main body portion and the protrusion portion,
The plate material is pressed by the main body portion to form a first protrusion protruding from a part of the plate material,
a second protruding portion protruding from a tip end of the first protruding portion is formed by pressing the plate material with the convex portion;
This includes:
the plate material is pressed by the convex portion until the main body portion starts to press the plate material, such that a gap is formed between the punch and the plate material from the base end of the convex portion to the tip end of the main body portion by bending the plate material immediately before the main body portion starts to press the plate material;
Launch method. A method for striking using the striking device according to any one of claims 1 to 5,
A plate material is set in the die,
While moving the punch toward the die, the plate material is pressed by the main body portion and the protrusion portion,
The plate material is pressed by the main body portion to form a first protrusion protruding from a part of the plate material,
a second protruding portion protruding from a tip end of the first protruding portion is formed by pressing the plate material with the convex portion;
This includes:
Before the protrusion begins to be inserted into the second recess, a tensile force acting on the plate material between the outer peripheral surface of the main body portion and the inner peripheral surface of the first recess is reduced by compressing the plate material between the tip end of the main body portion and the bottom of the first recess.
Launch method. A method for striking using the striking device according to any one of claims 1 to 5,
A plate material is set in the die,
While moving the punch toward the die, the plate material is pressed by the main body portion and the protrusion portion,
The plate material is pressed by the main body portion to form a first protrusion protruding from a part of the plate material,
a second protruding portion protruding from a tip end of the first protruding portion is formed by pressing the plate material with the convex portion;
This includes:
the plate material is compressed by the outer peripheral surface of the main body and the inner peripheral surface of the first recess, and the plate material is compressed by the tip end of the main body and the bottom of the first recess, and in this state, the plate material is pressed by the convex portion, thereby forming the second protrusion.
Launch method.