JPH0847729A - Method for punching internal circumferential part and external circumferential part - Google Patents

Abstract

PURPOSE:To provide a punching means without projecting burrs on the surface of a metal plate even in the case of punching a hole from the plate and capable of obtaining a correct shape without generating a dull mouth-edge of the hole. CONSTITUTION:A cylindrical face 21, mouth edges 211 and corner parts 212 on the upper and lower sides are formed correctly by embossing a recessed part 24 on the upper face of a work 11 with a punch 11 having a projecting part 12. Next, after forming a shallow cylindrical face 22 by pressing with a punch 18 from the opposite side of the work 11, a hole is drilled by generating a taper-like breaking from the lower end to the corner part 212 of the cylindrical face 22. Burrs are generated on the broken face 23, but are slightly protruded to the cylindrical face 21 side, and does not reach the front surface of the work 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of punching an inner peripheral portion or an outer peripheral portion of a work made of a plate-shaped metal in a state in which burrs or burrs are not exposed on the surface of the plate and no large sagging occurs.

[0002]

2. Description of the Related Art When punching a plate material, burrs or burrs are likely to occur on the plate surface, but as a means for preventing this, the punching portion is half-punched from both sides to form sags on both sides before punching. A method is known, and this method is described, for example, in "Press Technology" Vol. 32, No. 7, pages 20 to 23.

In this prior art, since a relatively large droop remains in the punched portion of the work, the edge of the punched portion cannot be formed into an accurate shape.

[0004]

SUMMARY OF THE INVENTION According to the present invention, when punching a work, burrs and burrs are not generated on the inner peripheral portion or the outer peripheral portion, and a large sag is generated on the edge portion of the inner peripheral portion or the outer peripheral portion. The challenge is to obtain a means for punching without punching.

[0005]

[Means for Solving the Problems] Of the means for solving the above problems, the first means is, as described in claim 1, that one surface of a plate-like work is supported by a flat die and the work is carried out. A step of embossing a first concave portion having a corner portion on the other surface with a first punch; and supporting the other surface on a die having a die hole, and a second hole having a diameter smaller than that of the first punch. A punch presses the work from the opposite side of the first recess to form a shallow second recess, and then the taper surface from the inner peripheral surface of the second recess to the corner of the first recess is broken. It is characterized by comprising the step of:

The second means is such that one surface of a plate-shaped work is supported by a flat die, and the other surface of the work is provided with a first recess having a corner portion with a first punch and a ring shape surrounding the recess. The step of embossing the convex portion, and supporting the other surface on a die having a die hole, and pressing the work from the opposite side of the first concave portion with a second punch having a smaller diameter than the first punch. After the shallow second recess is formed, the step of breaking the tapered surface from the inner peripheral surface of the second recess to the corner of the first recess is ruptured.

The third means is a plate-like work comprising a pair of annular punches having flat opposing surfaces and different central holes of different sizes, and a pair of dies having opposing flat surfaces fitted into the central holes of the punches. Of the two punches, at least the center hole of which has a small diameter to operate to form a thin portion having a corner portion on the outer peripheral side of the work, and the center hole operates to have a large diameter of the punch. And a step of breaking a tapered surface extending from the contact position of the center hole of the punch to the corner portion.

[0008]

According to the means of the first aspect, when the first punch impresses the first concave portion on the loke with the first punch and the second punch having a small diameter pressurizes from the opposite side, the second concave portion is formed. Accurate holes with no sagging are formed on both surfaces of the second concave portion, and then the inner peripheral surface of the second concave portion is tapered to the corner portion of the first concave portion to form a burr on the fracture surface. , It is inside the holes on both sides and does not appear on the surface.

According to the second aspect of the present invention, when the concave portion is impressed on the workpiece by the first punch, the extruded meat flows to the ring-shaped convex portion to form a deep concave portion having a corner. When a second punch having a small diameter is pressed from the opposite side, a second concave portion is formed, and the second concave portion is tapered from the inner peripheral surface to the corner portion of the first concave portion. Does not appear on the surface of.

According to the third aspect of the present invention, a punch having a small central hole is used alone or in combination with a punch having a large central hole to form a thin-walled portion having a corner portion on the outer periphery of the work. When only the large-diameter punch is operated, the taper surface from the working surface of the large-diameter punch to the corner portion is broken, but the burr of the fracture surface does not project to both sides of the work.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Hit 1 ₁ to 1 ₅ in a work consisting of plate-shaped metal 1, FIG. 1 (a) to (d) are those punched inner peripheral portion of the workpiece, FIG. 1 (e) the outer peripheral portion The one that is pulled out is shown.

The hole 2 in FIG. 1 (a) has smooth shallow cylindrical holes 2 ₁ and 2 ₂ which are recessed from both upper and lower surfaces of the work 1 ₁ and an intermediate tapered rough fracture surface 2 ₃ . (B) hole 3
Form a cylindrical surface 3 ₁ , a tapered surface 3 _{2 from} the lower surface, and a cylindrical surface 3 ₃ from the upper surface. These surfaces 3 ₁ , 3 ₂ , 3 ₃ are smooth, and the tapered surface 3 ₂ and the cylindrical surface 3 3 Between the faces 3 ₃ has a tapered rough fracture surface 3 ₄ .

In the hole 4 of FIG. 1C, a ring-shaped convex portion 4 ₁ is provided on the lower portion, and the inner cylindrical surface 4 ₂ and the upper cylindrical surface 4 4 are formed.
₃ is smooth but has a tapered rough fracture surface 4 ₄ in the middle. In the hole 5 of FIG. 1D, a ring-shaped convex portion 5 ₁ is provided at the bottom, a cylindrical surface 5 ₂ is formed on the inner surface thereof, a tapered surface 5 ₃ is formed on the inner surface thereof, and a shallow cylindrical surface 5 ₄ is formed on the upper portion thereof. , These surfaces 5 ₂ , 5 ₃ , 5 ₄ are smooth and have a tapered rough fracture surface 5 ₅ in the middle of the surfaces 5 ₃ and 5 ₄ .

[0014] Work 1 ₅ in FIG. 1 (e) is, which was punched outer peripheral portion, the lower and upper smooth cylindrical surface 6 _1, 6 ₂ are formed on the outer circumferential surface 6, intermediate the tapered Rough fracture surface 6
Holds ₃ .

When each of the works 1 ₁ to ₁₅ is processed in this way, even if burrs are generated on the fracture surface, they do not reach the plate surface of the works 1 ₁ to ₁₅ and the shapes of the cylindrical surface and the rim are small. Be accurate. For example, even if superposed plate-like member A to the upper or lower surface of the workpiece 1 ₁ of FIG. 1 (b) burrs without developing gap for back like does not protrude, and the cylindrical surface 2 ₁ is accurately formed by a punch Therefore, even if the pipe B is press-fitted, the fitting can be reliably performed.

FIG. 2 and subsequent figures show a means for processing the works ₁₁ to ₁₅ shown in FIGS. 2 (a) is shown in FIG.
In the first step for the work 1 _{1 in} (a), the flat die 1
0 and a punch 11 having a convex portion 12 at the tip thereof are provided, and the punch 11 presses the surface of the work 1 ₁ to form a concave portion 2 ₄ . Meat recess 2 ₄ fills the mold space to flow outwardly,
The upper and lower rims 2 ₁₁ and corners 2 ₁₂ of the cylindrical surface 2 ₁ are the punch 1
It is molded into a precise shape equal to the outer surface shape of 1. 2 ₅ is a protrusion of the workpiece 1 ₁ occurring on the outer peripheral side of the punch 11.

In the next step of FIG. 2B, a die 13 having a center hole 14 and a die 15 having a stepped center hole 16 are formed.
The punch 18 fixed to the pressure plate 17 is used, and the die 1
A spring 20 is interposed between the press plate 5 and the push plate 17. The work 1 ₁ is turned upside down from the step (a) and the dies 13, 1
And depresses the punch 18 is held between the 5, the stress on the corners 2 ₁₂ of the cylindrical surface 2 ₁ are concentrated, after shallow cylindrical surface 2 ₂ on the upper surface is formed, the lower end of the cylindrical surface 2 ₂ To the corner 2 ₁₂ along the taper surface, the workpiece 1 ₁ is broken,
A fracture surface 2 ₃ with a rough surface is formed. This fracture surface 2 ₃
Is rough because hardly contact with the punch 18, but the downward burr direction of action of force is generated, it such as the length of the burrs exceed short cylindrical surface 2 ₁ reaches the workpiece outer surface Absent.

[0018] Next will be described the processing means with respect to the workpiece 1 ₂ in FIG. 1 (b) in FIG. In FIG. 3A, the flat die 10
And a punch 21 having a convex portion 22 are used. The convex portion 22 is provided with a tapered surface 23, and the tapered surface 23 forms the tapered surface 3 ₂ and the corner portion 3 _{21 on the} work 1 _2. .

[0019] Turn the Figure 3 workpiece 1 ₂ molded by (a), FIG. 2 (b) the same die 13, when using a punch 19 punched as shown in FIG. 3 (b), the surface After shallow cylindrical surface 3 ₃ are formed, a breaking stress from the inner end reaches the corner 3 ₂₁ tends to concentrate occurs, tapered fracture surface 3
₄ is formed.

[0020] processing means for the workpiece 1 ₃ in FIG. 1 (c) is shown in Figure 4, the workpiece 1 ₃ is being stamped in a flat die 10 and the punch 25 of FIG. 4 (a), the punch 25 the recess 26 and the ring groove 27 is provided, thereby the ring convex portion 4 _1, the cylindrical surface 4 _2, corner portions 4 ₂₁ is formed.

In the next step of FIG. 4B, the ring-shaped convex portion 4 is formed.
_A stepped die 28 and punch 19 for receiving ₁ are used,
The recess of the workpiece 1 ₃ is broken at the lower end of the cylindrical surface 4 ₃ tapered fracture surface 4 ₄ leading to the corners 4 _21.

The processing means on the workpiece 1 ₄ in FIG. 1 (d) is shown in Figure 5, the convex portion 31 and the ring groove 33 with a tapered surface 32 is provided in the punch 30 of FIG. 5 (a), the workpiece 1 _4, the convex portion 5 ₁ is embossed with the punch 30, the tapered surface _3, corners 5 ₃₁ and the like are formed. Next, as shown in FIG. 5B, it is inverted and placed on the die 28, and the punch 19
By pressurizing, a tapered rough fracture surface 5 ₅ from the shallow cylindrical surface 5 ₄ to the corner portion 5 ₃₁ is formed.

Next, FIGS. 6 and 7 are both shown in FIG.
This is a means for removing the outer circumference of the die 35 with a flat tip.
And a punch 36, a die 37 and a punch 38 are provided so as to face each other, and the dies 35 and 37 have a circular planar shape.
The blade portion is formed on the inner peripheral side in the form of a 6,38 ring. The radii of the blades of the lower die 35 and punch 36 are slightly smaller than those of the upper die, as indicated by the difference r. As shown in FIG. 6 (a), the work 1 ₅ is attached to the die 3
The outer peripheral portion of the work 15 is punched by sandwiching it with ₅ , 37.
When the pressure is applied at 38, the outer peripheral portion is compressed to form the thin portion 6 _{4 and the} cylindrical surfaces 6 ₁ and 6 ₂ and the corner portions 6 ₁₁ and 6 ₂₁ are formed.

Next, as shown in FIG. 6B, the lower punch 3
When 6 is lowered and the thin portion 6 ₄ is pressed by the upper punch 38,
Both corners 6 ₁₁ since the stress to the corner 6 _11, 6 ₂₁ is concentrated,
Tapered fracture surface 6 ₃ is formed between 6 _21.

FIG. 7 uses the same apparatus as in FIG. 6,
Shows a means to machine the same work by slightly changing the operation,
FIGS. 7 (a) die 37 and the punch 38 of the upper die in sandwiching the workpiece 1 ₅ with the lower die of the die 35 to tip as coplanar. When the lower die punch 36 is pushed up, a cylindrical surface 6 ₁ and a corner portion 6 ₁₁ are formed on the lower side.

Next, when the upper punch 38 is pushed down, a shallow cylindrical surface 6 ₂ is formed on the upper surface, and then the corner portion 6 _{11 is} broken to form a tapered fracture surface 6 ₃ .

[0027] FIG 6, even if the outer circumferential vent of Figure 7, burrs produced in the fracture surface is hardly projecting the cylindrical surface ₆₁ side, not naturally protrude in the plate surface.

[0028]

As described above, according to the means of claim 1, since the burr or the burr does not project on both surfaces of the work, other members can be brought into close contact with each other even if the deburring work is omitted. Since a smooth and accurate shape can be obtained without sagging at the rim, there is an advantage that a pipe or the like can be closely fitted.

According to the second aspect of the present invention, the ring-shaped protrusion that surrounds the hole is projected on one surface of the work, and the inner surface thereof is formed into a smooth and long cylindrical surface. Therefore, another member such as a pipe is closely fitted. It is convenient to let

Further, according to the means of claim 3, since the burrs or burrs on the outer periphery do not project to the surface of the work, it is possible to omit the deburring work when it is used as a member to be brought into close contact with another member. Have.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of various works in which the present invention is implemented.

FIG. 2 is an explanatory view of a machining process of the work of FIG.

FIG. 3 is an explanatory view of a machining process of the work of FIG.

FIG. 4 is an explanatory view of a machining process of the work of FIG.

FIG. 5 is an explanatory diagram of a machining process of the work of FIG.

FIG. 6 is an explanatory view of a machining process of the work of FIG.

FIG. 7 is an explanatory diagram of another processing step of the work of FIG.

[Explanation of symbols]

1 ₁ to ₁₅ ... Work 2, 3, 4, 5
... Holes 2 ₁ , 2 ₂ , 3 ₁ , 3 ₃ , 4 ₂ , 4 ₃ , 5 ₂ , 5 ₄ , 6 ₁ , 6 ₂
… Cylindrical surface 2 ₃ , 3 ₄ , 4 ₄ , 5 ₅ , 6 ₃ … Fracture surface

Claims (3)

[Claims] 1. A step of supporting one surface of a plate-shaped work on a flat die and embossing a first recess having a corner portion with a first punch on the other surface of the work, and the other surface of the work. The work is supported on a die having a die hole, a second punch having a smaller diameter than the first punch presses the work from the opposite side of the first recess to form a shallow second recess, and then the second recess is formed. A step of breaking the taper surface from the inner peripheral surface of the concave portion to the corner portion of the first concave portion, and the punching method of the inner peripheral portion. 2. A plate-like work is supported on one surface by a flat die, and the other surface of the work is provided with a first recess having a corner portion by a first punch and a ring-shaped projection surrounding the recess. A step of pressing, the other surface is supported on a die having a die hole, and a second punch having a diameter smaller than that of the first punch pressurizes the work from the opposite side of the first concave portion to a shallow second After the recess is formed, the step of breaking the taper surface from the inner peripheral surface of the second recess to the corner portion of the first recess is included, and the punching method for the inner peripheral portion is characterized by the following steps. 3. A plate-shaped workpiece is sandwiched by a pair of annular punches having flat facing surfaces and different central holes having different sizes, and a pair of dies having flat facing surfaces fitted in the central holes of the punches. Of the two punches, a step of forming a thin-walled portion having a corner portion on the outer peripheral side of the work by activating a punch having a small diameter at the center hole; And a step of breaking the taper surface from the contact position to the corner portion.