JP2001200813A - Caulked structure, caulking method, and caulking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase combining force at a caulked part and reduce an extension. SOLUTION: A first recessed part 16 facing from a first member 10 side to a second member 12 side is formed in a caulked part 14, and a second recessed part 18 facing from the second member 12 side to the first member 10 side is formed therein. A junction surface 20 between the outer peripheral surfaces of the first recessed part 16 and the second recessed part 18 is formed generally in S-shape in cross section. The bent part 20A of the junction surface 20 on the first recessed part 16 side is positioned on the first member 10 side of a general junction surface 22, and projected to the inside of the first recessed part 16 (in the direction of arrow A in Fig. 1). A bent part 20B on the second member 12 side is positioned on the second member 12 side of a bottom part junction surface 24, and projected to the outside of the second recessed part 18 (in the direction of arrow B in Fig. 1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a caulking structure, a caulking method and a caulking device, and more particularly to a caulking structure, a caulking method and a caulking device applied to an automobile body or the like.

[0002]

2. Description of the Related Art Conventionally, as an example of a caulking method applied to an automobile body or the like, there is JP-A-9-234528.

As shown in FIG. 8A, in this caulking method, after a first member (material) 72 on the punch 70 side and a second member (material) 76 on the die 74 side are overlapped, The two members 72, 76 are inserted into a die 74 having a die holder 80 and a fixed die 82, and a hole 78 of the die holder 80.
Are arranged so as to close the openings. Also,
As shown in FIG. 8B, the first punch portion 84 of the punch 70 including the first punch portion 84 and the second punch portion 86 is inserted toward the hole 78 to caulk both materials.
As shown in (C), the second punch portion 86 is driven toward both materials, and both materials are fixed to the fixed die 82 and the second punch 8.
6, and the die holder 80 is divided by the upsetting of both members. Further, when the die holder is not divided and swaged by a swaging device, a swaging portion 90 of the first member 72 and the second member 76 is formed as shown in FIG.

[0004]

However, in the example of FIG. 8 in which the die holder 80 is divided, a large load is applied to the die holder 80, the life of the die 74 is shortened, and the crimping force due to insufficient crimping is obtained. May be reduced. Further, in the example of FIG. 9 in which the die holder is not divided, the outer peripheral portion 90 of the caulked portion 90
In A, the engagement allowance M1 of both materials and the thickness M2, M
3 is reduced, and a sufficient bonding force may not be obtained. Further, since the overhang height L1 of the caulking portion 90 is increased, it may interfere with other components.

The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a caulking structure, a caulking method, and a caulking device that can increase the bonding force at the caulked portion and reduce the overhang.

[0006]

According to the first aspect of the present invention, there is provided a caulking structure in which a first member and a second member are connected to each other at a caulking portion without using another member. A first concave portion formed from the first member side toward the second member side; and a caulked portion formed from the second member side toward the first member side. And a second concave portion.

Accordingly, a part of the two members is pushed out to the outer peripheral side of the two concave portions by the bottom of the first concave portion and the bottom of the second concave portion, and the margin of engagement between the two members increases on the outer peripheral side of both the concave portions. In addition, the thickness of both members is also increased. As a result,
The coupling force at the caulked portion between the first member and the second member can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a second aspect of the present invention, there is provided the caulking structure according to the first aspect, wherein the first member and the second member at the outer peripheral portions of the first concave portion and the second concave portion. Has a substantially S-shaped cross section, and the bent portion on the first concave side is closer to the first member than the general joint surface of the first member and the second member. Further, it is characterized in that it protrudes inward of the first recess.

Therefore, in addition to the contents described in claim 1,
The joint surface between the first member and the second member at the outer periphery of the first concave portion and the second concave portion has a substantially S-shaped cross section,
Since the bent portion on the side of the first recess projects from the general joining surface of the first member and the second member toward the first member and inward of the first recess, the first recess is formed. On the outer peripheral side of the two members, the amount of engagement in the direction along the general joint surface and the direction perpendicular to the general joint surface increases, and the thickness of both members at the joint increases. As a result, the first member and the second member
The joining force at the caulked portion with the member can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a third aspect of the present invention, in the caulking structure according to any one of the first and second aspects, the first member is provided at an outer peripheral portion of the first concave portion and the second concave portion. The joint surface between the second member and the second member has a substantially S-shaped cross section, and the bent portion on the second concave side is the first member.
And protruding outward from the second concave portion on the side of the second member from the joint surface between the bottom of the member and the second member.

Therefore, in addition to the contents described in either claim 1 or claim 2, the joint surface between the first member and the second member at the outer peripheral portions of the first concave portion and the second concave portion is different from the first concave portion. The cross section is substantially S-shaped, and the bent portion on the side of the second concave portion is closer to the second member than the bottom joint surface between the first member and the second member and outward of the second concave portion. As a result, the engagement margin in the direction along the general joint surface and in the direction perpendicular to the general joint surface of both members increases on the outer peripheral side of the second concave portion, and the thickness of both members at the joint portion increases. Also increase. As a result, the coupling force between the caulked portion of the first member and the second member can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a fourth aspect of the present invention, there is provided a caulking method in which a first member and a second member are joined to each other at a caulking portion without using another member. A first concave portion forming step of forming a first concave portion from the member side toward the second member side;
A second concave portion forming step of forming a second concave portion from the second member side toward the first member side.

Therefore, a part of both members is pushed out to the outer peripheral side of both concave portions by the bottom portion of the first concave portion and the bottom portion of the second concave portion, and the margin of engagement between the two members increases on the outer peripheral side of both concave portions. In addition, the thickness of the meshing portion between the two members also increases. As a result, the coupling force between the caulked portion of the first member and the second member can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a fifth aspect of the present invention, in the caulking structure according to the fourth aspect, an outer peripheral portion of the second concave portion is formed by:
The method includes a step of deforming the second concave portion outward.

Therefore, in addition to the contents described in claim 4,
By deforming the outer periphery of the second recess to the outside of the second recess, the first member and the second member at the outer periphery of the second recess are deformed.
Because the meshing allowance with the members and the thickness of both members are effectively increased, the coupling force can be further increased,
The overhang of the second member in the caulked portion can be further reduced.

According to a sixth aspect of the present invention, there is provided a caulking device for connecting a first member and a second member to each other at a caulking portion without using another member, wherein the caulking portion of the first member is provided. A punch that guides the punch, a die that is driven into the caulking portion of the second member, and a die guide that guides the die.

Accordingly, the punch is driven into the swaged portion of the first member, a recess is formed in the first member, the die is driven into the swaged portion of the second member, and the recess is formed in the second member. You. As a result, by the bottom of the first recess and the bottom of the second recess, a part of both members is pushed out to the outer peripheral side of both concaves, and the engagement margin of both members increases on the outer peripheral side of both concaves, In addition, the thickness of the meshing portion between the two members also increases. For this reason, the joining force of the caulked portion between the first member and the second member can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a seventh aspect of the present invention, in the caulking device according to the sixth aspect, the die is wider than the punch and a tip portion has a substantially mountain shape.

Therefore, in addition to the contents described in claim 6,
Since the die is wider than the punch and has a substantially mountain-shaped tip, the meshing allowance of the two members can be effectively increased, and the thickness of both members can also be effectively increased.

According to an eighth aspect of the present invention, there is provided the caulking device according to the sixth aspect, further comprising a second die disposed on an outer peripheral portion of the die and driven into the caulking portion of the second member. It is characterized by the following.

Therefore, in addition to the contents described in claim 6,
Since the second die arranged on the outer peripheral portion of the die is driven into the caulked portion of the second member, the meshing allowance of both members can be effectively increased, and the thickness of both members can also be effectively increased. .

According to a ninth aspect of the present invention, in the caulking device according to the eighth aspect, the second die has a tapered surface whose diameter increases from a tip end toward a root.

Therefore, in addition to the contents described in claim 8,
Since each member moves along the tapered surface that expands in diameter from the tip portion formed on the second die toward the root portion, the meshing allowance of both members can be effectively increased, and the thickness of both members is also reduced. Can be increased effectively.

According to a tenth aspect of the present invention, in the caulking device according to the sixth aspect, a tapered surface is formed on an inner peripheral portion of the tip end of the punch guide, the diameter of which decreases from the tip end toward the root. It is characterized by having.

Therefore, in addition to the contents described in claim 6,
Since each member moves along a tapered surface that is reduced in diameter from the distal end portion formed on the inner peripheral portion of the distal end of the punch guide toward the root portion, the meshing allowance of both members can be effectively increased, and both members can be increased. Can be effectively increased.

According to an eleventh aspect of the present invention, in the caulking device according to the sixth aspect, a tapered surface is formed on the inner peripheral portion of the tip end of the die guide, the diameter of which is reduced from the tip end toward the root. It is characterized by having.

Therefore, in addition to the contents described in claim 6,
Since each member moves along a tapered surface that is reduced in diameter from the tip portion formed at the tip inner peripheral portion of the die guide toward the root portion, the meshing allowance of both members can be effectively increased, and both members can be increased. Can be effectively increased.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention is shown in FIGS.
It will be described according to.

As shown in FIG. 1, in the caulking structure of the present embodiment, the first member 10 and the second member 12 are connected to each other at the caulking portion 14 without using other members.

In the caulking portion 14, the first member 10
From the side toward the second member 12 side, the first member is substantially circular
Are formed, and a second concave portion 18 having a substantially circular shape in a plan view is formed from the second member 12 side to the first member 10 side.

The joining surface 2 between the first member 10 and the second member 12 at the outer periphery of the first concave portion 16 and the second concave portion 18
0 has a substantially S-shaped cross section, and the bent portion 20A on the first concave portion 16 side is closer to the first member 10 than the general joint surface 22 between the first member 10 and the second member 12. And protrudes inward (in the direction of arrow A in FIG. 1) of the first recess 16.

On the other hand, the bent portion 20B on the second concave portion 12 side
Is a bottom joint surface 2 between the first member 10 and the second member 12.
4 and protrudes outward from the second concave portion 18 (in the direction of arrow B in FIG. 1) on the second member 12 side.

Next, the caulking device of this embodiment will be described.

As shown in FIG. 2, the caulking device 28 of the present embodiment is provided with a punch guide 30 and a die guide 32 for holding the first member 10 and the second member 12 in an overlapping state. . The punch guide 30 is formed in a cylindrical shape, and a punch 34 driven into the caulked portion of the first member 10 is relatively movable in the axial direction (the direction of arrow C and the direction of arrow D in FIG. 2). It is arranged.
On the other hand, the die guide 32 is also formed in a cylindrical shape, and a die 36 that is driven into a caulked portion of the second member 12 moves relative to the die guide 32 in the axial direction (the direction of arrow E and the direction of arrow F in FIG. 2). It is arranged as possible. In addition, die 3
6 is larger than the shaft diameter V1 of the punch 34 (V
2> V1).

The die 36 is composed of a first die 38 forming a central portion of the die 36 and a second die 40 forming an outer peripheral portion of the die 36. Second die 40
Has a tapered surface 40C whose diameter increases from the distal end portion 40A toward the root portion 40B side, and the distal end portion of the die 36 has a substantially mountain shape. Further, a tapered surface 30C whose diameter is reduced from the distal end portion 30A toward the root portion 30B side is formed on the inner peripheral portion of the distal end of the punch guide 30.

Next, a caulking method according to this embodiment will be described.

In this embodiment, as shown in FIG. 2, in a state where the first member 10 and the second member 12 are overlapped, the members 10 and 12 are moved between the punch guide 30 and the die guide 32. Set to. Thereafter, as shown in FIG. 3, a punch 34 is driven into the caulking portion of the first member 10 from the first member side 10 toward the second member 12 to form the first concave portion 16 (the first concave portion 16). 1 recess forming step). At this time, the tip of the first die 38 and the tip of the second die 40 coincide with each other, the tip of the die 36 has a substantially mountain shape, and the shaft diameter V2 of the die 36 is equal to the shaft diameter of the punch 34. Since V1 is larger than V1 (V2> V1), both members 10 and 12 are deformed without their respective thicknesses being too thin.

Next, as shown in FIG.
2 from the second member side 12 to the first member 10
The first die 38 is driven toward the
Is formed (second concave portion forming step). At this time, the second die 40 is not moved. As a result, the outer peripheral portions of the first concave portion 16 and the second concave portion 18 in the two members 10 and 12 move along the inner peripheral surface of the die guide 32 toward the second die 40 (in the direction of arrow J in FIG. 4). Go to).

Next, as shown in FIG.
2 from the second member side 12 to the first member 10
The second die 40 is driven toward the side, and the second die 40
(Step of deforming the outer peripheral portion of the second concave portion to the outside of the second concave portion).

At this time, the tapered surface 40C of the second die 40
Since both materials move in the directions indicated by arrows P and Q in FIG.
As shown in FIG. 1, the joining surface 20 of the first member 10 and the second member 12 at the outer peripheral portions of the first concave portion 16 and the second concave portion 18 has a substantially S-shaped cross section. The bent portion 20A on the side is closer to the first member 10 than the general joint surface 22 between the first member 10 and the second member 12 and inside the first recess 16 (in the direction of arrow A in FIG. 1). The bent portion 20 </ b> B on the side of the second concave portion 12 is located on the second member 12 side from the bottom joint surface 24 between the first member 10 and the second member 12, and is located outside the second concave portion 18. (In the direction of arrow B in FIG. 1).

Next, the operation of the present embodiment will be described.

In the present embodiment, as shown in FIG. 1, in the caulking portion 14 between the first member 10 and the second member 12, the joining surface 20 of the two members 10, 12 has a substantially S-shaped cross section. The bent portion 20 </ b> A on the first concave side is closer to the first member 10 than the general joint surface 22 between the first member 10 and the second member 12, and inward of the first concave portion 16. (In the direction of the arrow A in FIG. 1), and the bent portion 20B on the second concave side is closer to the second member 12 than the bottom joint surface 24 between the first member 10 and the second member 12. And the second recess 18
(In the direction of arrow B in FIG. 1). Therefore, on the outer peripheral side of the first recess 16, both members 10, 1
2, both the meshing allowance S1 in the direction along the general joining surface 22 and the meshing allowance S2 in the direction perpendicular to the general joining surface 22 increase. Furthermore, the minimum thicknesses M1 and M2 of the two members 10 and 12 at the joint surface 20 also increase. As a result, the first member 1
It is possible to increase the bonding force of the caulking part 14 between the 0 and the second member 12.

In this embodiment, the bent portion 20A on the first concave side projects obliquely in the direction of arrow A in FIG.
Since the bent portion 20B on the second concave side projects obliquely in the direction of arrow B in FIG. 1, the height D1 of the protrusion 10A of the first member and the height of the protrusion 12A of the second member 12 in the caulking portion 14. D2 can be reduced. As a result, interference between the overhangs 10A and 12A in the caulking portion 14 and other components can be reduced.

In the above, the present invention has been described in detail with respect to a specific embodiment. However, the present invention is not limited to such an embodiment, and various other embodiments are included in the scope of the present invention. It is clear to a person skilled in the art that is possible. For example, in the above-described embodiment, the dice 36 is made up of the first dice 38 forming the axial center of the dice 36 and the dice 3.
6 and the second die 40 constituting the outer peripheral portion,
Instead, as shown in FIG.
May be constituted by one part having a substantially mountain shape having a tapered surface 40C at the tip. In this case, as in the above-described embodiment, as shown in FIG.
A joining surface 20 having a substantially S-shaped cross section can be formed in the caulked portion 14 between the member 10 and the second member 12.

In this embodiment, as shown in FIG. 3, a tapered surface 30C whose diameter is reduced from the distal end portion 30A toward the root portion 30B is formed on the inner peripheral portion of the distal end of the punch guide 30. 7A instead of the tapered surface 30C.
As shown in (2), a configuration in which a tapered surface 32C whose diameter is reduced from the distal end portion 32A toward the root portion 32B side may be formed on the inner peripheral portion of the distal end of the die guide 32. Also in this case, as in the above embodiment, as shown in FIG. 7B, the swaged portion 1 of the first member 10 and the second member 12 is formed.
4, a joining surface 20 having a substantially S-shaped cross section can be formed.

The caulking structure, the caulking method, and the caulking device of the present invention can be applied to uses other than the automobile body, and can also be applied to a case where three or more members to be connected are connected.

[0047]

According to the first aspect of the present invention, in the caulking structure in which the first member and the second member are connected to each other at the caulking portion without using another member, the first member is attached to the caulking portion. Since there is a first concave portion formed from the side toward the second member side and a second concave portion formed from the second member side to the first member side in the caulked portion, caulking is performed. This has an excellent effect that the joining force at the portion can be increased and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a second aspect of the present invention, in the caulking structure according to the first aspect, a joint surface between the first member and the second member at the outer peripheral portions of the first concave portion and the second concave portion is provided. The cross-section is substantially S-shaped, and the bent portion on the first concave side is closer to the first member and inward of the first concave than the general joint surface between the first member and the second member. Since the protruding portion protrudes, the coupling force at the caulked portion can be increased, and the overhang of the first member and the second member at the caulked portion can be reduced.

According to a third aspect of the present invention, in the caulking structure according to the first or second aspect, the first member and the second member at the outer peripheral portions of the first concave portion and the second concave portion are provided. Has a substantially S-shaped cross section, and the bent portion on the second concave side is closer to the second member than the bottom joint surface between the first member and the second member. Since it protrudes outward from the second concave portion, there is an excellent effect that the coupling force at the caulked portion can be increased and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a fourth aspect of the present invention, there is provided a caulking method in which the first member and the second member are joined to each other at the caulking portion without using another member. Forming a first concave portion from the second member side toward the second member side, and forming a second concave portion from the second member side toward the first member side in the caulked portion. Since the method includes the step of forming the second concave portion, the coupling force at the caulked portion can be increased, and the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a fifth aspect of the present invention, in the caulking structure according to the fourth aspect, the outer peripheral portion of the second concave portion is formed by a second
The step of deforming the concave portion outwardly has an excellent effect that the coupling force at the caulked portion can be further increased and the protrusion of the second member at the caulked portion can be further reduced. It is characterized by the following.

According to a sixth aspect of the present invention, there is provided a caulking device for connecting a first member and a second member to each other at a caulking portion without using another member, wherein the first member and the second member are driven into the caulking portion of the first member. A punch to be guided, a punch guide for guiding the punch, a die driven into a caulked portion of the second member, and a die guide for guiding the die.
Therefore, it is possible to increase the coupling force at the caulked portion, and to provide an excellent effect that the protrusion of the first member and the second member at the caulked portion can be reduced.

According to a seventh aspect of the present invention, in the caulking apparatus according to the sixth aspect, the die is wider than the punch.
In addition, since the tip portion has a substantially angled shape, in addition to the effect described in claim 6, an excellent effect that the meshing allowance of both members can be effectively increased, and the thickness of both members can also be effectively increased. Having.

According to an eighth aspect of the present invention, there is provided the caulking device according to the sixth aspect, wherein the caulking device is provided on an outer peripheral portion of the die.
Since the second die has the second die that is driven into the caulked portion of the second member, in addition to the effect described in claim 6, in addition to the effect described in claim 6, the meshing allowance of both members can be effectively increased. In addition, there is an excellent effect that the thickness of both members can be effectively increased.

According to a ninth aspect of the present invention, in the caulking device according to the eighth aspect, the second die has a tapered surface that increases in diameter from the tip end toward the root. In addition to the effects described above, there is an excellent effect that the meshing allowance of both members can be effectively increased and the thickness of both members can also be effectively increased.

According to a tenth aspect of the present invention, in the caulking device according to the sixth aspect, a taper surface is formed on an inner peripheral portion of the leading end of the punch guide, the diameter of which decreases from the leading end toward the root. Therefore, in addition to the effect described in claim 6,
It has an excellent effect that the meshing allowance of both members can be effectively increased, and the thickness of both members can also be effectively increased.

According to an eleventh aspect of the present invention, in the caulking device according to the sixth aspect, a taper surface is formed on an inner peripheral portion of the tip end of the die guide so as to decrease in diameter from the tip end toward the root. Therefore, in addition to the effect described in claim 6,
It has an excellent effect that the meshing allowance of both members can be effectively increased, and the thickness of both members can also be effectively increased.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a caulking structure according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing one step of a caulking method using a caulking device according to an embodiment of the present invention.

3 is a side sectional view showing a step following the step shown in FIG. 2 of the swaging method using the swaging apparatus according to the embodiment of the present invention;

FIG. 4 is a side sectional view showing a step following the step of FIG. 3 of the swaging method using the swaging apparatus according to the embodiment of the present invention;

FIG. 5 is a side sectional view showing a step following the step shown in FIG. 4 of the swaging method using the swaging apparatus according to the embodiment of the present invention;

FIG. 6A is a side sectional view showing one step of a caulking method using a caulking device according to another embodiment of the present invention,
(B) is a side sectional view showing a step following (A).

FIG. 7A is a side sectional view showing one step of a caulking method using a caulking device according to another embodiment of the present invention,
(B) is a side sectional view showing a step following (A).

8A is a side cross-sectional view showing one step of a caulking method using a conventional caulking apparatus, FIG. 8B is a side cross-sectional view showing a step subsequent to FIG. FIG.

FIG. 9 is a side sectional view showing a conventional caulking structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 1st member 12 2nd member 14 Caulked part 16 1st recess 16A Bottom of 1st recess 18 2nd recess 18A Bottom of 2nd recess 20 Joint surface in the peripheral part of recess 20A Joint in the joint surface 1 Bent portion on the concave side 20B Bent portion on the second concave side in the bonding surface 22 General bonding surface 28 Caulking device 30 Punch guide 32 Dice guide 34 Punch 36 Dice 38 First die 40 Second die

Claims (11)

[Claims] 1. A caulking structure in which a first member and a second member are connected to each other at a caulking portion without using another member, wherein the caulking portion includes the second member from the first member side. A first concave portion formed toward the first member side; and a second concave portion formed from the second member side toward the first member side in the caulking portion. Swaging structure. 2. A joining surface between the first member and the second member at an outer peripheral portion of the first concave portion and the second concave portion has a substantially S-shaped cross section. The bent portion on the side of the concave portion protrudes from the general joint surface between the first member and the second member toward the first member and toward the inside of the first concave portion. The swaging structure according to claim 1, wherein 3. A joint surface between the first member and the second member at an outer peripheral portion of the first concave portion and the second concave portion has a substantially S-shaped cross section, and Wherein the bent portion on the concave side protrudes from the bottom joint surface between the first member and the second member toward the second member side and outward of the second concave portion. The caulking structure according to claim 1 or 2, wherein 4. A caulking method for connecting a first member and a second member to each other at a caulking portion without using another member, wherein the caulking portion includes the second member from the first member side. Forming a first concave portion toward the first side; and forming a second concave portion from the second member side toward the first member side on the caulked portion. A method for forming a concave portion, comprising: 5. The caulking method according to claim 4, further comprising a step of deforming an outer peripheral portion of the second concave portion to an outside of the second concave portion. 6. A caulking device for connecting a first member and a second member to each other at a caulking portion without using another member, comprising: a punch driven into the caulking portion of the first member; A punch guide that guides the die, a die that is driven into the swaging portion of the second member, and a die guide that guides the die. 7. The caulking device according to claim 6, wherein the die is wider than the punch, and the tip has a substantially mountain shape. 8. The caulking device according to claim 6, wherein said die comprises a first die forming an axial center portion of the die and a second die forming an outer peripheral portion of the die. apparatus. 9. The caulking device according to claim 8, wherein the second die has a tapered surface whose diameter increases from a tip end toward a root. 10. The caulking device according to claim 6, wherein a tapered surface is formed on an inner peripheral portion of the distal end of the punch guide, the diameter of which decreases from the distal end toward the root. 11. The caulking device according to claim 6, wherein a tapered surface is formed on an inner peripheral portion of the tip end of the die guide so as to decrease in diameter from the tip end portion toward the root portion.