JPH07148532A - Curling method - Google Patents

Abstract

PURPOSE:To curl a work without need for a work turning back operation between processes or a driving mechanism on the bed side of a press machine. CONSTITUTION:In a punching process (a first process), a punched hole 2 is formed on a work 1 by pressing from the one direction of a holding punch 14, in a burring process (a second process), a recessed seat 3 is formed by pressing the outer circumference of the punched hole 2 of the work 1 with a burring punch 24 to move in the same direction with the moving direction of the holding punch 14. In such a way, a vertical wall 5 to project to the opposite side to the moving direction of the burring punch 24 on the surrounding periphery of the punching hole 2 of the work 1, in a curling process (a third process), the vertical wall 5 of the work 1 is curved to the outer side with a curling punch 34 to move in the same direction with the moving direction of the burring punch 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curling process (rolling process) of a plate-like work, and more particularly to a curling process method capable of performing machining from one direction in all steps.

[0002]

2. Description of the Related Art The body of an automobile is provided with electrical wiring and piping for connecting various devices. These wirings and pipes are inserted into the wiring or piping holes formed in the body. The wiring and piping holes that are formed in the body of an automobile are punched out by press work, and the edges of the holes are edge-shaped. If inserted, the coating of the electric wire may be damaged. Therefore, in the past, FIG.
15 to 15 are taken.

FIG. 12 shows a wiring hole 202 of a body 201.
The rubber grommet 203 is attached to the peripheral edge of the. In this case, the electric wire 204 is the grommet 20.
Since it comes into contact with the wire 3, the electric wire 204 is prevented from being damaged. In FIG. 13, since the protective tube 205 is covered on the electric wire 204 inserted into the wiring hole 202 of the body 201, only the protective tube 205 is provided in the wiring hole 202.
Therefore, the electric wire 204 is prevented from being damaged. FIG. 14 shows a case where burring is applied to the periphery of the wiring hole 202 of the body 201. The burring portion 206 is a tubular wall portion protruding from the peripheral edge of the wiring hole 202, and the electric wire 204 is protected by the burring portion 206 which is a tubular wall portion. As a prior art related to the burring process, for example, JP-A-56-11783
Japanese Patent Laid-Open No. 6-52124 and Japanese Patent Laid-Open No. 2-52124 are known.

In the case of protecting the electric wire 204 according to FIGS. 12 and 14, it is necessary to mount a grommet 203 in the wiring hole 202 or cover the electric wire 204 with a protective tube 205, which increases the amount of work. Even if the burring portion 206 is formed on the periphery of the wiring hole 202, the tip of the burring portion 206 has an edge shape, so that the electric wire 204
It is difficult to reliably protect. Therefore, as shown in FIG. 15, a curling portion 207 is formed around the periphery of the wiring hole 202 of the body 201 by curling processing (rolling processing).

FIG. 16 shows an example of conventional curling processing. In the first step of FIG. 16, the work (material) 2
01 is pressed against the lower die 211 by the pad 212, and in this state, punching processing is performed by the punch punch 213. Next, in the second step of FIG. 16, the work 201 is pressed against the lower mold 221 by the pad 222. In this state, the burring punch 223 descends and the burring of the peripheral edge of the punched hole 208 of the work 201 is performed. Next, proceeding to the third step of FIG. 16, the work 201 is the pad 2
The lower mold 231 is pressed by 32. In this state, the curling punch 233 rises and the burring portion 209 of the work 201 is pressed by the curling punch 233. As a result, the burring portion 209 is bent outward and the curling portion 210 is formed.

FIG. 17 shows another example of the conventional curling process. The first step of FIG. 17 is the same as the first step of FIG. 16, and the punching by the punching punch 213 is performed. Next, in the second step of FIG. 16, the work 20
1 is pressed against the lower mold 241 by the pad 242. In this state, the burring punch 243 rises and the work 2
Burring processing is performed on the peripheral edge of the punching hole 208 of No. 01. Next, proceeding to the third step of FIG. 17, the work 201 is pressed against the lower mold 251 by the pad 252. In this state, the curling punch 253 descends and the burring portion 209 of the work 201 is pressed by the curling punch 253. As a result, the burring portion 210 is formed.

[0007]

However, the conventional curling method has the following problems. In the curling processing method of FIGS. 16 and 17, the processing directions of the burring processing in the second step and the curling processing in the third step are opposite. In normal press working, the lower die is fixed to the bed side, the upper die (punching punch, burring punch, curling punch) is attached to the ram side, and only the upper die moves up and down. Therefore, the difference in the processing direction between the respective steps in the curling method requires the installation of a new drive mechanism similar to the ram on the bed side of the press machine. New drive mechanisms include, for example, die cushions, air cylinders, and cam mechanisms that convert downward force from the ram into upward force, but by providing these, the structure of the press machine and press die becomes complicated. However, there is a problem that the cost of the press equipment becomes high.

In the curling method of FIGS. 16 and 17, in order to make the processing directions the same between the respective steps, it is necessary to reverse the work after performing the burring processing. However, in this case, a work reversing step is required, which increases the number of working steps and the apparatus, resulting in high cost.

It is an object of the present invention to perform curling processing without requiring work reversing work between processes or a bed side drive mechanism of a press machine.

[0010]

A curling method according to the present invention for achieving this object is configured as follows. (1) A punching step of forming a punching hole in a work by pressing from one direction of the punching punch, and a burring punch to cut the punching hole of the work from the same direction as the moving direction of the punching punch. A burring step of forming a vertical wall protruding to the opposite side of the burring punch moving direction by pressing the outer periphery to form a recess seat, and the burring punch moving direction during burring processing A curling step of pressing a vertical wall of the work by a curling punch from a direction to bend the vertical wall outward, the curling method. (2) A drawing process for drawing a part of a work into a convex shape by pressing from one direction of the upper die, and a top of the drawing portion of the work is punched from the same direction as the moving direction of the upper die by a punch punch. The punching step of pressing to form a punch in the work, and the piercing portion of the work is pressed by the burring punch from the same direction as the moving direction at the time of punching processing of the punch, and the burring punch is formed around the punching hole of the work. A burring step of forming a vertical wall projecting to the side opposite to the moving direction, and pressing the vertical wall of the work by a curling punch from the same direction as the moving direction at the time of burring processing of the burring punch, and the vertical wall is outward. A curling method comprising: a curling step of bending. (3) A punching step of forming a punching hole in a work by pressing from one direction of the punching punch, and a burring punch from which the punching hole of the work is formed in the same direction as the moving direction of the punching punch. A burring step of pressing the outer periphery to form a vertical wall projecting in the same direction as the moving direction of the burring punch at the periphery of the punching hole, and a work of the work by the restlike punch from the same direction as the moving direction at the time of burring processing of the burring punch. A curling process, comprising: a curling step of pressing the end portion of the vertical wall against the curved surface of the curling die by pressing the outer periphery of the vertical wall to curve the vertical wall outward.

[0011]

In the curling method thus constructed, the following actions are performed.

(1) In the curling method according to the first aspect, a punched hole is formed in the work by the punching step. When the punched hole is formed in the work, the burring punch moves toward the work from the same direction as the moving direction of the punch for punching, and the burring is performed by pressing the burring punch. When burring with this burring punch, the outer periphery of the punching hole is formed into a concave seat by pressing the burring punch, and a vertical wall protruding in the opposite direction to the moving direction of the burring punch is formed at the periphery of the punching hole of the work. To be done. When the burring process is completed, the curling punch moves toward the vertical wall of the workpiece from the same direction as the burring punch moves in the burring process, and the curling punch presses the vertical wall to bend it outward, curling the vertical wall. Is done. Therefore,
At the time of machining a work by punching punch, burring punch and curling punch in each process, all punches move in the same direction with respect to the work, so it is possible to machine the work from only one direction, and the bed side of the press machine The drive mechanism and work reversing work are also unnecessary.

(2) In the curling method according to the second aspect, a part of the work is drawn into a convex shape by the drawing process. When the drawn portion is formed on the workpiece, the top of the drawn portion is punched from one direction by the punch punch in the punching process. When a punched hole is formed in the work, the burring punch moves toward the work from the same direction as the moving direction of the punch for punching.
Burring is performed by a burring punch. In this burring process, the squeezing portion of the work is pressed by the burring punch, and a vertical wall protruding in the opposite direction to the moving direction of the burring punch is formed on the periphery of the punching hole of the work. When this burring process is completed, the curling punch moves toward the vertical wall of the workpiece from the same direction as the moving direction of the burring punch at the time of burring process, and the vertical wall is curved outward by the pressing of the curling punch and Curling is performed. Also in the curling method according to the second aspect, the processing directions in the respective steps are the same, and the drive mechanism on the bed side of the press machine and the work of inverting the work are unnecessary.

(3) In the curling method of the third aspect, punching holes are formed in the work by the punching step. When the punched hole is formed in the work, the burring punch moves toward the work from the same direction as the moving direction of the punch for punching, and the burring punch performs burring. By this burring process, a vertical wall in the same direction as the moving direction of the burring punch is formed on the periphery of the punched hole of the work. Next, the wristlike punch moves toward the work from the same direction as the moving direction of the burring punch during the burring process, and the outer circumference of the vertical wall of the work is pressed. As a result, the end portion of the vertical wall of the work is pressed against the curved surface of the curling die, the vertical wall is curved outward along the curling die, and the vertical wall is curled. Also in the curling method according to the third aspect, the processing directions in the respective steps are the same, and the drive mechanism on the bed side of the press machine and the work reversing work are unnecessary.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the curling method according to the present invention will be described below with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a first embodiment of the present invention.
First, the press die used in each step of this embodiment will be described. The curling method according to this embodiment includes a first step, a punching step, a second step, a burring step, and a third step, a curling step. The press die 11 in the first step includes a lower die cutting edge 12, a pad 13, and a punch punch 14. The lower die cutting edge 12 is attached to the bed side of a press machine (not shown), and the punch punch 14 is attached to the ram side of the press machine. The pad 13 is adapted to interlock with the movement of the ram.

The press die 21 in the second step is the lower die 2
2, pad 23, and burring punch 24 are provided.
The lower die 22 is attached to the bed side of a press machine (not shown). The lower die 22 has an annular recess 22a for forming the work 1 into a truncated cone shape. The burring punch 24 is attached to the ram side of the press machine. Work 1 on the burring punch 24
A ring-shaped convex portion 23a for pressing the outer periphery of the punched hole 2 into the concave portion 22a of the lower die 22 is formed. Pad 2
3 is adapted to be linked to the movement of the ram.

The press die 31 in the third step is the lower die 3
2, pad 33 and curling punch 34 are provided.
The lower die 32 is attached to the head side of a press machine (not shown). The lower die 32 has a recess 32a for holding the truncated cone 3 of the work 1. The curling punch 34 is attached to the ram side of the press machine. On the curling punch 34, the work 1
A curved surface 34a for bending the vertical wall 5 outward is formed. The pad 33 is adapted to interlock with the movement of the ram. The pad 33 is formed with an inclined portion 33 a that presses the concave seat 3 of the work 1 against the lower die 32.

Next, the above-mentioned press dies 11, 21, 3
A curling method in the first embodiment using No. 1 will be described. In the punching step (first step) of FIG. 1, the lower die cutting edge 12 of the press die 11 has a plate thickness of 0.6 to 2.3 m.
The work 1 which is a thin steel plate of m is set. Work 1
When the setting is completed, the ram of the press machine descends and the work 1 is pressed by the pad 13 against the lower cutting edge 12. Further, when the ram descends, the punch 1 punches the work 1 downward, and the punch 1 punches the work 1. As a result, the punched hole 2 is formed in the work 1.

When the punching process is completed, the work 1 is conveyed to the burring process (second process). In the burring process, the work 1 is set on the lower die 22 of the press die 21. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed against the lower die 22 by the pad 23. Further, when the ram descends, the work 1 is pressed downward by the burring punch 24. Since the burring punch 24 is formed with the convex portion 23a, the burring punch 24 presses the work 1 to form the truncated cone-shaped concave seat 3. Also, the recessed seat 3
By the processing described above, a vertical wall 5 is formed on the peripheral edge of the punched hole 2 of the work 1 so as to project to the side opposite to the moving direction of the burring punch 24.

When the burring process is completed, the work 1 is conveyed to the curling process (third process). In the curling process, the work 1 is set on the lower die 32 of the press die 31. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed against the lower die 32 by the pad 33. Further, when the ram descends, the curling punch 34 contacts the vertical wall 5 of the work 1, and the vertical wall 5 is pressed by the curved surface 34 a of the curling punch 34. As a result, the vertical wall of the work 1 is curved outward, and the curling process is completed.

2 and 3 show the cross-sectional shape of the curled workpiece 1. As shown in FIG.
The edge end 5a of the curled vertical wall 5 is located inside the straight line X that connects the starting point 3a of the concave seat 3 and the curved curling portion 5b. As a result, the punched hole 2 of the workpiece 1
Even if an electric wire or a pipe is inserted into, the electric wire or the pipe does not come into contact with the edge end 5a, and the electric wire or the pipe is reliably prevented from being damaged.

Since the punching punch 14 in the punching process, the burring punch 24 in the burring process, and the curling punch 34 in the curling process shown in FIG. 1 are all driven by the ram of the press machine, the press working direction is the same in all processes. Will be the same. Therefore, it is not necessary to provide a drive mechanism on the bed side of the press machine and it is not necessary to reverse the work 1 as in the conventional case.

Second Embodiment FIG. 4 shows a second embodiment of the present invention. The second embodiment is a modification of the first embodiment, and the punching process and the burring process in the first embodiment can be performed by the same press die. The curling method according to this embodiment includes a first step, a punching step and a burring step, and a second step, a curling step.

The press die 41 in the first step is the lower die 4
2, pad 43, punch punch 44, and burring punch 45. The lower die 42 is attached to the bed side of a press machine (not shown). The burring punch 45 is attached to the ram side of the press machine. The pad 43 is adapted to move with the movement of the ram.
The lower die 42 has a hole 42a for punching the work 1.
And an annular concave portion 4 for forming the concave seat 3 on the work 1.
2b.

The burring punch 45 has an annular convex portion 45 for pressing the work 1 into the concave portion 42b of the lower die 42.
a is formed. A punch punch 44 is attached to the burring punch 45. Punch punch 44
Are attached so as to punch the work 1 before the burring process is started. That is, in the press die 41 of the present embodiment, the punching process is performed before the burring process.

In the second embodiment thus constructed, the lower die 4 of the press die 41 is used in the first step of FIG.
Work 1 is set to 2. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed against the lower die 42 by the pad 43. When the descending amount of the ram increases, the punch 1 punches the work 1 to form the punched hole 2. Further, when the ram descends, the work 1 moves to the burring punch 4
It is pressed by 5, and the recessed seat 3 is formed on the work 1. The vertical wall 5 is formed by forming the concave seat 3 by the burring process.

When the punching process and the burring process are completed, the work 1 is conveyed to the curling process (second process). In the curling process, the work 1 is set on the lower die 32 of the press die 31 as in the first embodiment. When the setting of the work 1 is completed, the ram of the press machine descends and the vertical wall 5 of the work 1 is pressed by the curved surface 34 a of the curling punch 34. As a result, the vertical wall 2 of the work 1 is curved outward, and the curling process is completed.

In the second embodiment, since the punching process and the burring process can be performed by one press die 41,
The number of steps can be reduced by one as compared with the case of the first embodiment, and the number of steps can be shortened.

Third Embodiment FIGS. 5 to 7 show a third embodiment of the present invention.
The curling method according to the present embodiment includes a drawing process which is a first process, a punching process which is a second process, a wrist-like burring process which is a third process, and a curling process which is a fourth process. . The press die 51 in the first step is
It is a diaphragm mold including a lower mold 52 and an upper mold 53. Lower mold 52
Is attached to the bed side of the press machine and
3 is attached to the ram side of the press machine. Lower mold 52
A truncated cone-shaped convex portion 52a is formed on the. Upper mold 5
3 includes a recess 5 matching the shape of the projection 52a of the lower mold 52.
3a is formed. Height H of the convex portion 52a of the lower mold 52
₂ is larger than the height H ₁ of the vertical wall 5 in the three steps described later.

The press die 61 in the second step is the lower die 6
2, pad 63, punch punch 64. The lower die 62 is attached to the bed side of the press machine, and the punch punch 64 is attached to the ram side of the press machine. The lower die 62 has a truncated cone-shaped convex portion 62 a that receives the narrowed portion 4 of the work 1. The pad 63 is adapted to interlock with the movement of the ram of the press machine.

The press die 71 in the third step is the lower die 7
2, pad 73, and burring punch 74.
The lower die 72 is attached to the bed side of the press machine, and the burring punch 74 is attached to the ram side of the press machine. The lower die 72 is provided with a columnar convex portion 72a for performing burring processing.
The burring punch 74 includes a recess 74a for performing burring and a flat portion 74 for performing restrike.
b are formed.

The press die 81 in the fourth step is the lower die 8
2, pad 83, and curling punch 84.
The lower die 82 is attached to the bed side of the press machine, and the curling punch 84 is attached to the ram side of the press machine. In the present embodiment, the squeezing portion 4 of the work 1 is restriked flat by the burring punch 74 in the third step, so that the upper surface of the lower die 82 is flat. Work 1 on the curling punch 84
A curved surface 84a for bending the vertical wall 5 outward is formed. The pad 83 is adapted to interlock with the movement of the ram of the press machine.

Next, the above-mentioned press dies 51, 61, 7
A curling method in the third embodiment using Nos. 1 and 81 will be described. In the drawing step (first step) of FIG. 5, the work 1 is set in the lower die 52 of the press die 51. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed against the lower mold 52 by the upper mold 53. As a result, a part of the work 1 is molded into the truncated conical drawing portion 4.

When the draw forming in the first step is completed,
The work 1 is conveyed to the punching process (second process). In the punching process, the work 1 is the lower die 62 of the press die 61.
Is set to. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed by the pad 63 against the lower die 62. Further, when the ram descends, the work 1 is punched by pressing the punching punch 64, and the punching hole 2 is formed at the top of the drawing portion 4 of the work 1. This punched hole 2 is, as shown in 3 steps of FIG.
The drawing length l ₁ and the burring length l ₀ are l
It is processed so that ₀ ≈ l ₁ .

When the punching process is completed, the work 1 is conveyed to the rest-like burring process (third process).
In the wrist-like burring process, the work 1 is set on the lower die 72 of the press die 71. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1
Is pressed against the lower die 72 by the pad 73. When the ram further descends, the burring punch 74 presses the narrowed portion 4 of the work 1. As a result, the narrowed portion 4 is restriced flat, and the inner portion of the narrowed portion 4 is burred by the convex portion 72a of the lower die 72 and the concave portion 74a of the burring punch 74, so that the punched hole 2 of the work 1 is pierced. Burring punch 74 on the periphery
A vertical wall 5 is formed so as to project to the side opposite to the moving direction of the.

When the restlike burring process in the third step is completed, the work 1 is conveyed to the curling step (fourth step). In the curling process, the work 1 is set on the lower die 82 of the press die 81. Work 1
When the setting is completed, the ram of the press machine descends, and the outer periphery of the punched hole 2 of the work 1 is pressed by the pad 83 against the lower die 82. Further, when the ram descends, the vertical wall 5 of the work 1 bends the curved surface 84a of the curling punch 84.
Pressed by. As a result, the vertical wall 5 of the work 1 is curved outward, and the curling process is completed.

6 and 7 show the sectional shape of the work 1 formed by the curling method of the third embodiment. As shown in FIG. 7, the curled vertical wall 5
The edge end 5a is curved sufficiently outward so that the wire or the pipe does not come into contact with the edge end even if the wire or the pipe is inserted into the punching hole 2 of the work 1.

Fourth Embodiment FIG. 8 shows a fourth embodiment of the present invention. The fourth embodiment is a modification of the third embodiment, and the punching process and the restlike burring process in the third embodiment can be performed by the same press die. The curling method of the present embodiment includes a first step that is a drawing step, a second step that is a punching step and a rest-like burring step, and
It is composed of a curling process and a third process.

The press die 91 in the second step is the lower die 9
2, pad 93, punch punch 94, and burring punch 95. The lower die 92 is attached to the bed side of the press machine, and the burring punch 95 is attached to the ram side of the press machine. The pad 93 is
It is designed to work with the movement of the ram. Lower die 9
A hole 92a for punching out the work 1 and a convex portion 92b for burring are formed in 2.

The burring punch 95 has a recess 95a for burring and a flat portion 95b for flattening the narrowed portion 4 of the work 1. A punch punch 94 is attached to the burring punch 95. The punch punch 94 is attached so as to punch the work 1 before the restlike and burring processes are started. That is, in this embodiment,
In the press die 91, punching is performed prior to restriking and burring.

In the thus constructed fourth embodiment, the work 1 is set in the lower die 52 of the press die 51 in the first step of FIG. When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed against the lower mold 52 by the upper mold 53. As a result, a frustoconical drawing portion 4 is formed on the work 1.

When the draw forming in the first step is completed,
The work 1 is conveyed to the second step. In the second step, the work 1 is set on the lower die 92 of the press die 91.
When the setting of the work 1 is completed, the ram of the press machine descends and the work 1 is pressed by the pad 93. When the descending amount of the ram increases, the punch 1 punches the work 1 to form the punched hole 2 in the work 1. Further, when the ram descends, the work 1 is pressed by the burring punch 95. Thereby, the diaphragm 4
Is flat-stretched, and a vertical wall 5 is formed on the periphery of the punched hole 2 of the work 1 so as to project in the opposite direction to the moving direction of the burring punch 95.

When the punching process and the wrist-like burring process in the second process are completed, the work 1 is conveyed to the curling process (third process). In the curling process,
The work 1 is set in the lower die 82 of the press die 81 as in the third embodiment. When the setting of the work 1 is completed, the ram of the press machine descends and the vertical wall 5 of the work 1 is pressed by the curved surface 84 a of the curling punch 84. As a result, the vertical wall 5 of the work 1 is curved outward, and the curling process is completed.

In the fourth embodiment, the punching process and the wrist-like burring process can be performed by one press die 91, so that the number of steps can be reduced by one compared with the case of the third embodiment. The process can be shortened.

Fifth Embodiment FIGS. 9 and 10 show a fifth embodiment of the present invention. The curling method according to this embodiment includes a first step, a punching step, a second step, a burring step, and a third step.
The process consists of a curling process. Since the press die 11 in the first step is the same as that in the first embodiment, its explanation is omitted.

The press die 101 in the second step has the same structure as the conventional press die for performing the burring process shown in FIG. 15, and includes a lower die 102, a pad 103, and a burring punch 104. The lower die 102 is attached to the bed side of the press machine, and the burring punch 104 is attached to the ram side of the press machine. The pad 103 is adapted to interlock with the movement of the ram of the press machine. The lower end of the burring punch 104 can enter the lower die 102.

The press die 111 used in the third step includes a curling die 112, a pad 113, and a wrist-like punch 11.
It is equipped with 4. The curling die 112 is attached to the bed side of the press machine, and the restrike punch 114 is attached to the ram side of the press machine. The pad 113 is adapted to move with the movement of the ram of the press machine. The curling die 112 is formed with a convex portion 112a protruding toward the wrist-like punch 114 side. A curved surface 112b is formed on the outer periphery of the convex portion 112a of the curling die 112.

The surface of the wrist-like punch 114 facing the curling die 112 is formed as a curved surface 114b having a recess 114a at the center. Curling dice 1
12 and the center of the convex portion 112a and the wrist-like punch 114
The centers of the concave portions 114a of the two are aligned. When the ram of the press machine descends, the curved surface 1 of the wristlike punch 114
14b presses the outer periphery of the vertical wall 5 of the work 1, and the vertical wall 5 of the work 1 is curved outward along the curved surface 112b of the curling die 112.

Next, a curling method in the fifth embodiment will be described. In the punching step (first step) of FIG. 9, the work 1 is set in the lower die 12 of the press die 11. When the setting of the work 1 is completed, the ram of the press machine descends, the work 1 is punched by the punch punch 14, and the punch hole 2 is formed in the work 1.

When the punching process is completed, the work 1 is conveyed to the burring process (second process). In the burring process, the work 1 is set on the lower die 102 of the press die 101. When the setting of the work 1 is completed, the ram of the press machine descends, and the work 1 is pressed against the lower die 102 by the pad 103. Further, when the ram descends, the outer periphery of the punching hole 2 of the work 1 is pressed by the burring punch 104, and a vertical wall 5 protruding in the same direction as the moving direction of the burring punch 104 is formed at the peripheral edge of the punching hole 2 of the work 1. To be done.

When the burring process in the second step is completed, the work 1 is conveyed to the curling step (third step). In the curling process, the work 1 is a press die 111.
The curling die 112 is set. When the work 1 is set, the protrusion 112a of the curling die 112 enters the punching hole 2 of the work 1. Work 1
When the setting is completed, the ram of the press machine descends, and the outer peripheral portion of the work 1 is pressed against the curling die 112 side by the pad 113.

When the ram further descends, the outer periphery of the vertical wall 5 of the work 1 is pressed by the strike punch 114. Since the curved surface 112b is formed on the outer periphery of the convex portion 112a of the curling die 112, the vertical wall 5 of the work 1 is curved outward along the curved surface 112b of the curling die 112. In this state, the peripheral edge of the punched hole 2 of the work 1 is slightly depressed by the pressing of the wrist-like punch 114.

FIG. 10 shows a curled workpiece 1
The cross-sectional shape of is shown. As shown in FIG. 10, since the edge end 5a of the curled vertical wall 5 is sufficiently curved outward, even if an electric wire, a pipe or the like is inserted into the punched hole 2,
These electric wires and pipes do not come into contact with the edge end 5a, and the electric wires and pipes are reliably prevented from being damaged.

Sixth Embodiment FIG. 11 shows a sixth embodiment of the present invention. The sixth embodiment is a modification of the fifth embodiment, in which the hole diameter accuracy of the punched hole 2 after the curling processing of the work 1 is improved. The curling method of the present embodiment includes a drawing process which is a first process, a punching process which is a second process, a third process which is a burring process which is a third process, and a curling process which is a fourth process. It consists of

The press die 121 in the first step is the lower die 122.
And an upper die 123. The lower die 122 is attached to the bed side of the press machine, and the upper die 123 is attached to the ram side of the press machine. The lower die 122 is formed with a truncated cone-shaped convex portion 122a. In the upper mold 123,
Concave portion 123 that matches the shape of the convex portion 122a of the lower die 122
a is formed.

The press die 131 in the second step comprises a lower die 132, a pad 133, and a punch punch 134. The lower die 132 is attached to the bed side of the press machine, and the punch punch 134 is attached to the ram side of the press machine. The lower die 132 has a truncated cone-shaped convex portion 132 that receives the convex drawn portion 6 of the work 1.
a is formed. The pad 133 is adapted to interlock with the movement of the ram of the press machine.

The press die 141 in the third step comprises a lower die 142, a pad 143 and a burring punch 144. The lower die 142 is attached to the bed side of the press machine, and the burring punch 144 is attached to the ram side of the press machine. The lower die 142 has a truncated cone-shaped convex portion 1 that receives the narrowed portion 6 of the work 1.
42a is formed. The lower end of the burring punch 144 can enter the lower die 142. Since the press die 111 in the fourth step is the same as that in the fifth embodiment, its explanation is omitted.

Next, the curling method in the sixth embodiment will be explained. In the drawing process (first step) of FIG. 11, the work 1 is set in the lower die 122 of the press die 121. When the setting of the work 1 is completed, the ram of the press machine descends, and the work 1 is pressed by the upper mold 123 against the lower mold 122. As a result, the work 1 is drawn, and a frustoconical drawing portion 6 is formed on the work 1.

When the drawing process in the first step is completed,
The work 1 is conveyed to the second step. In the second step, the work 1 is set in the lower die 132 of the press die 141. When the setting of the work 1 is completed, the ram of the press machine descends, and the outer periphery of the work 1 is moved to the lower mold 13 by the pad 133.
Pressed to 2. When the ram further descends, the punching punch 134 punches the top of the narrowed portion 6 of the work 1 to form the punched hole 2 in the work 1.

When the punching process in the second step is completed, the work 1 is conveyed to the third step. In the third step,
The work 1 is set in the lower mold 142 of the press mold 141. When the setting of the work 1 is completed, the ram of the press machine descends, and the outer peripheral portion of the work 1 is pressed against the lower die 142 by the pad 143. Further, when the ram descends, the outer periphery of the punching hole 2 of the work 1 becomes burring punch 1
A vertical wall 5 that is pressed by 44 and projects in the same direction as the moving direction of the burring punch 144 is formed on the peripheral edge of the punched hole 2 of the work 1.

When the burring process in the third step is completed, the work 1 is conveyed to the fourth step. In the fourth step, the work 1 is set in the curling die 112 of the same press die 111 as in the fifth embodiment. In the work 1 set on the curling die 112, the vertical wall 5 is curved outward by pressing the wristlike punch 114 as in the fifth embodiment. In this embodiment, since the drawing portion 6 is formed in the work 1 in the first step prior to the punching process in the second step, the line length when forming the vertical wall 5 can be preliminarily obtained, and the curling can be performed. It is possible to prevent expansion of the diameter of the punched hole 2 after processing.

The punching hole 2 of the work 1 is necessary for inserting an electric wire or the like, but in the body of an automobile, the punching hole 2 may be closed by a lid for noise prevention after the electric wire is inserted. If the precision of the hole diameter is poor, the lid cannot be fitted into the punched hole 2. Therefore, by forming the narrowed portion 6 in the first step, it is possible to improve the accuracy of the hole diameter of the punched hole 2 after curling.

In the first to sixth embodiments,
The punching punch, burring punch, curling punch, and restrike punch, which are the moving parts of the press die, are all mounted on the ram side of the press machine, so the processing directions in each process are the same, and the bed side of the press machine is the same. The curling process can be performed without providing a drive mechanism in the.

[0065]

According to the present invention, the following effects can be obtained. (1) In the curling method according to any one of claims 1 to 3, since the machining directions in each process are all the same, it is not necessary to reverse the work between the processes as in the conventional case, and the productivity is improved. it can. Further, since the processing directions are the same in each process, it is not necessary to provide a new drive mechanism on the bed side of the press machine, and the cost of the press equipment can be reduced. (2) In the curling method according to claim 4, before the punching step, a drawing step for drawing the portion to be punched into a convex portion is provided. Can be sufficiently secured in advance. Therefore, the hole diameter of the punched hole after curling can be prevented from increasing, and the hole diameter accuracy of the punched hole can be improved.

[Brief description of drawings]

FIG. 1 is a process drawing showing a curling method according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a cross section of a work processed by the curling method of FIG.

FIG. 3 is a partially enlarged sectional view of FIG.

FIG. 4 is a process drawing showing the curling method according to the second embodiment of the present invention.

FIG. 5 is a process drawing showing the curling method according to the third embodiment of the present invention.

6 is a perspective view showing a cross section of a work processed by the curling method of FIG.

FIG. 7 is a partially enlarged sectional view of FIG.

FIG. 8 is a process drawing showing the curling method according to the fourth embodiment of the present invention.

FIG. 9 is a process drawing showing the curling method according to the fifth embodiment of the present invention.

10 is a perspective view showing a cross section of a work processed by the curling method of FIG.

FIG. 11 is a process drawing showing the curling method according to the sixth embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a mounted state of an electric wire protection grommet.

FIG. 13 is a cross-sectional view showing a mounted state of a wire protection tube.

FIG. 14 is a cross-sectional view of a wire protection burring.

FIG. 15 is a cross-sectional view of a wire protection curling.

FIG. 16 is a process chart showing an example of a conventional curling method.

FIG. 17 is a process drawing showing another example of the conventional curling method.

[Explanation of symbols]

 1 Work 2 Punching Hole 3 Recessed Seat 4 Drawing Part 5 Vertical Wall 6 Drawing Part 14 Drawing Punch 24 Burling Punch 34 Curling Punch 44 Punching Punch 45 Burring Punch 53 Upper Die 64 Punching Punch 74 Burring Punch 84 Curling Punch 94 Punching Punch 95 Burring punch 104 Burring punch 114 Restlike punch 123 Upper mold 134 Hole punching punch 144 Burling punch

Claims (4)

[Claims] 1. A punching step of forming a punching hole in a work by pressing from one direction of the punching punch, and the punching of the work by a burring punch from the same direction as the moving direction of the punching punch. A burring step of forming a vertical wall on the periphery of the punched hole by pressing the outer periphery of the hole so as to project to the opposite side to the moving direction of the burring punch, and a moving direction of the burring punch during burring processing. And a curling step of pressing the vertical wall of the work by a curling punch from the same direction as the above and curving the vertical wall outward. 2. A drawing process for drawing a part of a work into a convex shape by pressing from one direction of the upper die, and punching the top of the drawing portion of the work from the same direction as the moving direction of the upper die. A punching step in which a punch is pressed to form a punch in the work, and the squeezing portion of the work is pressed by a burring punch from the same direction as the moving direction of the punching punch,
A burring step of forming a vertical wall projecting to the opposite side to the moving direction of the burring punch at the periphery of the punching hole of the work, and a vertical wall of the work by a curling punch from the same direction as the moving direction at the time of burring processing of the burring punch. A curling process, comprising: a curling step of pressing and curving the vertical wall outward. 3. A punching step of forming a punching hole in a work by pressing from one direction of the punching punch, and the punching of the work with a burring punch from the same direction as the moving direction of the punching punch. A burring process of pressing the outer periphery of the hole to form a vertical wall projecting in the same direction as the moving direction of the burring punch at the periphery of the punching hole, and by a restlike punch from the same direction as the moving direction of the burring punch during burring processing. A curling process comprising: a curling step of pressing the outer periphery of the vertical wall of the work to press the end portion of the vertical wall against the curved surface of the curling die to curve the vertical wall outward. . 4. A drawing process is provided before the punching process, in which a portion of the workpiece to be punched is drawn into a convex shape by pressing an upper die that moves in the same direction as the punching punch. The curling method described in 3.