JP3317049B2 - Hole edge treatment method for pressed products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to how bending a peripheral edge of the pressed product of the punching holes.

[0002]

2. Description of the Related Art Most of the bodies of automobiles are press-processed products, and each part has several holes. Each hole has a role of penetrating the wire harness and reducing the weight. The hole for wire harness penetration
Burring processing and curling processing are performed to prevent the wire harness (electric wire) from being damaged by burrs generated at the periphery of the punched hole. As an example of the prior art relating to the burring processing of a metal panel, Japanese Unexamined Utility Model Application Publication No. 59-18502 that enables burring in one step and one operation
No. 5 is known.

FIG . 6 shows an example of a conventional burring process. As shown in FIG. 6 , a panel 1 made of a metal material is provided with a punched hole 2, and a cylindrical vertical wall 3 is formed on the periphery of the punched hole 2. The inner diameter of the vertical wall 3 is D _1, the height has a H _3. FIG. 7 shows an example of a conventional curling process. As shown in FIG. 7 , a punched hole 2 is provided in the panel 1, and a cylindrical vertical wall 4 is formed on the periphery of the punched hole 2 by burring. The vertical wall 4 is formed in an inverted truncated cone shape with an angle θ ₂ by curling. Vertical wall 4, the minimum inner diameter of D _1, the height has become H _4.

[0006] The wire harness 6 inserted into the punched hole 2 in FIG . 6 is less likely to come into contact with the end 3 a where burrs are formed due to the formation of the vertical wall 3. Further, in FIG. 7 , since the vertical wall 4 is formed in the shape of an inverted truncated cone that expands rearward, even when the wire harness 6 is inserted obliquely, it does not easily come into contact with the end 4a where burrs occur. FIG. 8 shows the punched hole 5 for reducing the weight formed in the panel 1, but it is not subjected to the burring or the curling shown in FIG . 6 or FIG .

[0005]

However, as shown in FIG. 6 , in the case of burring, the height of the vertical wall needs to be higher than a predetermined value due to the flange height limit at the time of molding, and it is difficult to secure a space. It is difficult to apply to parts. As shown in FIG. 7 , in the case of the curling process, the curling process is performed after the burring process, so that the vertical wall 4 becomes an elongated flange in both the burring process and the curling process. Therefore, at the time of the curling process, there is a problem that the elongation rate of the flange tip of the vertical wall 4 becomes extremely large, and the vertical wall 4 is cracked. As shown in FIG. 8, when the punched hole 5 for reducing the weight is formed in the panel 1, the rigidity around the punched hole 5 becomes small. Therefore, it is desired to increase the rigidity around the punched hole 5 without increasing the weight.

An object of the present invention, while preventing cracking of the vertical wall can reduce the height of the vertical wall, yet provide a hole edge process how things possible pressed product to increase the rigidity of the periphery of the perforations It is in.

[0007]

In order to achieve this object, a method and an apparatus for processing a hole edge of a pressed product according to the present invention are provided.
It is as follows. A punching step of forming a punched hole in a panel, and a burring step of pressing an outer periphery of the punched hole of the panel to form a vertical wall having an inner peripheral edge of the punched hole as an end and the end inclined inward in the radial direction. When the tip end portion of the vertical wall
Bending punch with a tapered surface that becomes smaller in diameter as it approaches
Pressing from the axial direction with the tapered surface, bending the vertical wall so that the axial height becomes small while suppressing the outward fall of the vertical wall end, and burr at the end of the vertical wall.
And a crushing step.

[0008]

In the hole edge processing method of the action The upper Symbol of pressed product,
A punching hole is formed in the panel in the punching step. In the burring step, the outer periphery of the punched hole of the panel is pressed, and a vertical wall having the inner peripheral edge of the punched hole as an end is formed on the panel. In the bending step, since the end of the vertical wall is pressed from the axial direction, the vertical wall is bent by the compressive load so that the height in the axial direction becomes small. In this case, since the vertical wall end is prevented from falling outward, the vertical wall is not excessively stretched and flanged, and the vertical wall is prevented from cracking. Further, since the vertical wall is bent so as to have a small height in the axial direction, it can be applied to a place where securing of space is strict. Further, since the perimeter of the punched hole is reinforced by the bent vertical wall, the rigidity of the perimeter of the punched hole of the panel is increased as compared with a case where the punched hole is simply formed.
You.

[0009]

EXAMPLES 1 to 5 shows the embodiment of the present invention.

FIGS. 1A and 1B show a first press die 20. FIG. The first press die 20 serves both as a punching die and a burring die, and the punching process and the burring process are performed simultaneously by the first press die 20. The first press die 20 includes an upper die 22 as a movable die.
And a lower mold 26 as a fixed mold. The upper die 22 is mounted on a ram side of a press machine (not shown), and the lower die is mounted on a bed side of the press machine. The upper mold 22 can be moved up and down with respect to the lower mold 26.

The upper die 22 is formed with a punching punch 23 extending downward. The cross section of the punch 23 is circular. Punch 2 for punching upper die 23
An annular molding groove 24 extending in the circumferential direction is formed on the outer periphery of 3. A burring punch 25 is formed on the outer periphery of the molding groove 24 of the upper die 22. The inner peripheral wall of the burring punch 25 forms the outer peripheral wall of the molding groove 24. The end face of the punch 23 protrudes from the lower end face of the burring punch 25. The outer peripheral surface of the tip of the burring punch 25 is a tapered surface 25a.

The lower die 26 is provided with a die 28 which can enter the molding groove 24 of the upper die 22. A hole 27 is formed in the center of the die 28 so that the punch 23 for punching the upper die 22 can enter. A molding groove 29 into which the burring punch 25 of the upper die 22 can be fitted is formed on the outer periphery of the die 28 of the lower die 26. The outer peripheral wall of the die 28 forms the inner peripheral wall of the forming groove 29. The outer peripheral wall of the forming groove 29 is formed on a tapered surface 29 a parallel to the tapered surface 25 a of the burring punch 25.

In the first press die 20, when the upper die 22 is lowered, first, the burring punch 25 is inserted into the hole 2 of the lower die 26.
7 and then the burring punch 25 is
9 to enter. Burring punch 2
When 5 enters the molding groove 29, as shown in FIG.
A gap S extending in the circumferential direction is formed between the outer peripheral surface of the die 28 and the inner peripheral surface of the burring punch 25.

Next, the operation of FIGS. 1A and 1B will be described. The panel 10 made of a metal material is placed on the lower die 26 while the upper die 22 of the first press die 20 is stationary at the top dead center. Panel 1 placed on lower mold 26
0 is drawn in advance in another step, for example. When the setting of the panel 10 on the lower mold 26 is completed, the upper mold 22
As shown in FIG. 1A, the panel 10 is punched by the pressing of the punch 23, and a punched hole 12 is formed in the panel 10. Further, when the upper mold 22 is lowered, the outer periphery of the punched hole 12 of the panel 10 is pressed by the burring punch 25 as shown in FIG. Thus, a cylindrical vertical wall 14 having the inner peripheral edge of the punched hole 12 as the end 14 a is formed in the panel 10.

In FIG . 1B , the relationship between the upper die 22 and the lower die 26 in the first press die 20 is as shown in FIG. A gap S extending in the circumferential direction is formed between the outer peripheral surface 28b of the die 28 and the inner peripheral surface 25b of the burring punch 25.
Is set to be about 1.7 times the plate thickness T. The reason why the gap S is set to such a value is that the vertical wall 14 of the panel 10
Is tilted inward in the radial direction.

[0016] Next, the present onset AkiraMinoru施例(C), explaining the <br/> configuration of (D). 1C and 1D show a second press die 30. FIG . The second press die 30 is used to bend the vertical wall 14 of the panel 10 formed by the first press die 20. Second press die 30
Is composed of a bending punch 32 as a movable die and a die 34 as a fixed die. The bending punch 32
The die 34 is mounted on the ram side of another press machine (not shown), and the die 34 is mounted on the bed side of the press machine. The bending punch 32 can move up and down with respect to the die 34.

The bending punch 32 has a flat central portion at the tip and a tapered surface 32a having a smaller diameter at the outer periphery toward the tip. A relief hole 35 is formed in a portion of the die 34 facing the flat surface of the bending punch 32. The relief hole 35 is the bending punch 3
It is provided to prevent interference between the die 2 and the die 34. The angle θ ₁ of the tapered surface 32a is set to, for example, 15 °.

Next, the operation of (C) and (D) will be described. When the vertical wall 14 is formed on the panel 10 by the first press die 20, the panel 10 is moved to the first press die 20.
, And conveyed toward the second press die 30. When the panel 10 is set on the die 34 of the second press die 30, the bending punch 32 descends, and FIG.
As shown in (1), the end 14a of the vertical wall 14 is pressed from the axial direction (the direction along the center line A). Thereby, the vertical wall 14
As shown in FIG. 1 (D), the end portion is bent so that the end portion is prevented from falling outward in the radial direction and the height in the axial direction is reduced .

FIG. 3 shows that the vertical wall 14 has a small height in the axial direction.
Shows a process of bent manner. (A) of FIG.
As shown in FIG. 3, since the end 14a of the vertical wall 14 is inclined inward in the radial direction, the vertical wall 14 is pressed by the bending punch 32, as shown in FIGS. Buckle in a U-shape. Furthermore, when the descending amount of the bending punch 32 becomes large, the vertical wall 14 is completely bent in the axial direction as shown in FIG. In the bending process shown in FIG.
4 is deformed in the contraction (compression) direction, thereby preventing the vertical wall 14 from cracking due to an increase in the elongation of the vertical wall 14.
In this embodiment, since the contraction (compression) direction of deformation of the vertical wall 14, it is possible to burring limit shown in FIG. 1 (B) is a two-stage bending flanging limit, to reduce the required hole diameter.

FIGS. 4A and 4B show the vertical wall 14 shown in FIG.
Shows the relationship of the forces acting on. In FIG. 4, F represents the force acting on the vertical wall 14, F ₂ and F ₃ represents the component forces F. μ ₂ F ₂ indicates a frictional force between the tapered surface 32 a of the bending punch 32 and the vertical wall 14. F ₄ is,
The reaction force against the frictional force between the panel 10 and the die 34 is shown. As shown in FIG. 4, the vertical wall 14 is weakest at the central portion in the axial direction against bending. Therefore, as shown in FIG. 4B, the central portion of the vertical wall 14 has a component force F ₂ , buckled by F _3, it is folded-shaped vertical wall 14 foil.

FIG. 5 shows the shape of the vertical wall 14 which has been bent by the second press die 30. As shown in FIG. 5, the outer periphery of the punched hole 12 is bent in a plurality of steps, and has a substantially S-shaped cross section. A wire harness 18 is inserted into the punched hole 12. Since the end of the vertical wall 14 is squeezed by the tapered surface 32a of the bending punch 32, the burr generated on the end 14a of the vertical wall 14 is also crushed, and the wire harness 18 is prevented from being damaged by the burr. Further, since the height H ₁ of the vertical wall 14 is significantly lower than the height H ₃ of the vertical wall 3 in FIG. 10, it can be applied to a place where securing of space is strict.

In each of the above embodiments, the hole punching step shown in FIG. 1A and the burring step shown in FIG. 1B are performed only by the first press die 20. It may be configured to be performed by a mold. Further, in each of the above embodiments,
Since punching, burring, and bending can be performed by processing from the same direction, the panel 10 does not need to be turned over, and productivity can be increased.

[0023]

According to 請 Motomeko 1 according to the present invention, by piercing process,
A punched hole is formed in the panel, and in a burring process, an outer periphery of the punched hole of the panel is pressed to form a vertical wall having an inner peripheral edge of the punched hole as an end. The vertical wall is bent so that the height in the axial direction is small while suppressing the falling of the end of the vertical wall to the outside, so that the vertical wall can be prevented from cracking and the vertical wall can be prevented. Height can be made small, and it can be applied to places where securing of space is strict. In addition, since the perimeter of the punched hole is reinforced by the bent vertical wall,
The rigidity of the outer periphery of the punched hole of the panel can be increased as compared with the case where the punched hole is simply formed. Therefore, it is possible to reduce the weight of the panel by the punched holes while maintaining the rigidity of the panel. In the bending process, since the end of the vertical wall is pressed from the axial direction, the burr generated at the end of the vertical wall can be crushed, and the burr of an inserted object such as a wire harness inserted into the punched hole can be used. Ru can <br/> is possible to prevent damage.

[Brief description of the drawings]

FIG. 1 is a process chart showing a processing order in a method for processing a hole edge of a pressed product according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of FIG.

FIG. 3 is a cross-sectional view showing a transition of deformation of a vertical wall in a bending step of FIG.

FIG. 4 is a schematic view showing a force relationship acting on a vertical wall in a bending step of FIG. 3;

FIG. 5 is an enlarged cross-sectional view of a vertical wall bent by the bending step of FIG. 3;

FIG. 6 is an enlarged sectional view showing an example of a conventional vertical wall formed only by burring.

FIG. 7 is an enlarged sectional view showing an example of a conventional vertical wall formed by burring and curling.

FIG. 8 is a perspective view of a conventional panel having punched holes for reducing weight.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 panel 12 punching hole 14 vertical wall 14 a vertical wall end 20 first press die 23 punch for punching 25 burring punch 30 second press die 32 bending punch 34 die

Claims (1)

(57) [Claims] 1. A punching step of forming a punched hole in a panel, and a vertical wall which presses an outer periphery of the punched hole of the panel, and has an inner peripheral edge of the punched hole as an end and the end tilts inward in a radial direction. A burring step of forming a taper whose diameter becomes smaller as the end of the vertical wall approaches the tip
Face and pressed from the axial direction by the tapered surface of the bending punch having, together with falling axial height of the vertical wall while preventing outward of the vertical end wall is bent bent such that the small
Crushing the burrs at the end of the vertical wall .