JPH0839158A - Drawing and ironing equipment - Google Patents

Abstract

PURPOSE:To exactly execute centering by gradually reducing the diameter of a guide part toward a tip and forming a convexed front in the radius direction. CONSTITUTION:The bottom face of a forming body 14 is clamped between the front end 11a of a drawing die 11 and a drawing ear pressing part 16 installed at the tip face of a cup holder 15. When the bottom face of the forming body 14 is depressed in the pressing direction of the drawing die 11, the forming body 14 is applied with the tension due to the friction between the drawing ear pressing part 16 and the front end face 11a. A guide part is composed of a large circular-arc part 17a and 17b, and a small circular-arc part 17c. Then, the guide part 17 is reduced gradually toward the tip along the axis and a convexed front face is formed outside in the radius direction. In such a way, the generation of ears on the forming body can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded body having a bottomed cylindrical shape, which is drawn and ironed while being passed through a drawing die and a plurality of ironing dies by a ram. The present invention relates to a drawing and ironing and forming apparatus for forming a can body having a thinner wall and a smaller diameter.

[0002]

2. Description of the Related Art Conventionally, a drawing and ironing device has been used.
For example, the structure shown in Japanese Patent Publication No. 62-5689 is proposed. This drawing and ironing forming apparatus has a drawing die and a plurality of ironing dies arranged concentrically with each other, and has a cylindrical ram which is inserted into these dies from one direction. Then, by pressing the bottomed cylindrical shaped body whose bottom surface is placed in contact with the front end surface of the drawing die into the die by a ram, drawing and multiple ironing processes are performed when passing through each die. The can body having a smaller diameter and a smaller diameter than the bottomed cylindrical molded body is formed.

In addition, this drawing and ironing and forming apparatus is provided with a cup holder arranged in front of the drawing die. The cup holder is arranged in an inserted state on the inner surface of the molded body to support the molded body to be pushed into the drawing die concentrically with respect to the drawing die in a positioned state. That is, the cup holder has an outer surface consisting of a cylindrical surface that is arranged in close proximity to the inner surface of the molded body, and is provided with a through hole that penetrates the ram in the axial direction, so that the bottom surface of the molded body is narrowed. Support the die so that it is stretched on the front end face. Therefore, when the ram is inserted and the bottom surface of the molded body is pushed into the drawing die, the side wall of the molded body is also moved so as to be dragged by it. It is supported by sliding on the outer surface.

[0004]

By the way, in recent years, from the viewpoint of so-called resource saving or product cost reduction, the thickness of the can body has been reduced, and high-speed drawing and ironing processes have been performed to improve production efficiency. It has come to be realized. As a result, it becomes difficult to maintain high roundness of the open end shape of the molded body formed into a bottomed cylindrical shape due to the thinning of the can body, and the anisotropy of the tough material added to the raw material In consideration of such influences, the opening end shape may be formed into a substantially elliptical shape. Further, due to the necessity of high-speed processing, when performing high-speed conveyance and high-speed positioning, it is conceivable that the molded product positioned on the front end face of the drawing die may be slightly inclined.

In such a case, if a cup holder having an outer surface formed into a cylindrical surface is simply inserted into the molded body, the tip of the cup holder catches the open end of the molded body, a so-called clip. The problem of turning off may occur. In order to avoid the occurrence of such clip-off, it is conceivable that the outer surface of the cup holder is a tapered outer surface whose diameter gradually decreases toward its tip. This ensures a sufficient clearance between the cup holder and the molded body at the time of insertion, and after being inserted to some extent, the outer surface of the cup holder is placed in close proximity to the inner surface of the molded body, and the molded body is squeezed into a drawing die. Will be arranged concentrically with.

However, with the cup holder having such a tapered outer surface, it is possible to avoid the inconvenience that occurs at the time of insertion into the molded body, but on the other hand, as shown in FIG. 5, the molding which is drawn into the drawing die 2 by the ram 1 is performed. A gap will be created between the inner surface 3a of the body 3 and the tapered outer surface 4a of the cup holder 4. That is, the molded body 3 drawn into the drawing die 2 is moved in contact with the corner portions A and B at both ends of the tapered outer surface 4a to form a curved surface that bulges outward, so that the inner surface 3a thereof is moved to the tapered outer surface 4a.
It will be separated from a. Therefore, the molded body 3
Movement of the molded body 3 is not supported by the cup holder 4.
Is allowed to be deformed by the amount of the gap with the cup holder 4, which may cause wrinkles in the drawing process and decrease the forming accuracy.

The present invention has been made in view of the above-mentioned circumstances, and effectively prevents the occurrence of clip-off to accurately center the molded body in the drawing die, and
An object of the present invention is to provide a drawing and ironing molding apparatus capable of reliably supporting the movement of a molded body during drawing and ironing, preventing wrinkles from occurring, and improving molding accuracy.

[0008]

In order to achieve the above-mentioned object, the present invention provides a molded product formed in a cylindrical shape having a bottom while a ram is passed through a drawing die and a plurality of ironing dies by a ram. A drawing and ironing forming apparatus for forming a can body having a smaller diameter and a smaller diameter than the above-mentioned formed body by performing processing and ironing processing, which is arranged concentrically in front of the drawing die and whose bottom surface is brought into contact with the front end surface of the drawing die. The cup holder is placed inside the molded body in a fitted state, and the cup holder penetrates in the axial direction with the wrinkle holding portion that is arranged at the tip of the cup holder and sandwiches the molded body with the front end face of the drawing die. A through-hole that is provided in a state where the ram is inserted, and a guide part that is provided at the tip of the outer peripheral surface and slides the inner surface of the molded body that is pushed into the drawing die by the ram, and the guide part,
A drawing / ironing forming apparatus is proposed in which the diameter is gradually reduced toward the tip in the direction along the axis and the surface shape is convex outward in the radial direction. Further, in this drawing and ironing / molding apparatus, it is effective that the guide portion has a curved surface.

[0009]

According to the drawing and ironing and forming apparatus of the present invention, the guide portion, which gradually decreases in diameter toward the tip, can sufficiently secure the clearance between the cup holder inserted into the formed body and the opening of the formed body. Therefore, the occurrence of clip-off can be avoided. Further, when the cup holder is sufficiently fitted to the molded body, the molded body is accurately centered with respect to the drawing die because the cup holder is arranged concentrically with the drawing die.

When the ram is inserted through the through hole of the cup holder and the bottom surface of the molded body is pushed into the drawing die, the side wall of the molded body is moved by being dragged by the side wall. In this case, since the cup holder sandwiches the molded body with the front end face of the drawing die by the wrinkle holding portion, free deformation of the molded body in that portion is suppressed and wrinkles are avoided. Become.

Further, in this case, since the guide portion is formed in a surface shape which is convex outward in the radial direction along the axial direction, a curved surface is formed between the wrinkle holding portion and the front end surface of the drawing die. The guide portion is arranged in contact with the inner surface of the side wall of the molded body to be pulled in. As a result, the side wall of the molded body is also supported by the guide portion for its movement, so that free deformation is suppressed, and wrinkles and molding precision are reduced.

Further, if the guide portion acting as described above is constituted by a curved surface, it is possible to achieve a smooth metal flow of the molded body which moves while being deformed,
It becomes possible to perform smooth drawing and ironing.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the drawing and ironing and forming apparatus according to the present invention will be described below with reference to FIGS. As shown in FIG. 4, the drawing and ironing forming apparatus 10 of the present embodiment has a drawing die 11 and a plurality of ironing dies 12 arranged concentrically with each other, and a straight circle arranged concentrically with these dies 11. It has a columnar ram 13. And
The drawing process and the ironing process can be performed a plurality of times during one stroke in which the ram 13 is moved in the axial direction and inserted into the dies 11 and 12. Further, in front of the drawing die 11, there is provided a cup holder 15 which is arranged in a fitted state inside a molded body 14 formed in a bottomed cylindrical shape. The cup holder 15 is arranged concentrically with the dice such as the drawing die 11. The drawing and ironing and forming apparatus 10 of this embodiment is common to the conventional drawing and ironing and forming apparatus in these points. But,
The drawing / ironing forming apparatus 10 of the present embodiment is different from the conventional example in the cup holder 15.

As shown in FIG. 3, the cup holder 15 provided in the drawing and ironing and forming apparatus 10 of the present embodiment is formed in a thick cylindrical shape having a through hole 15a penetrating in the axial direction in the center, and has a tip end. Ring-shaped wrinkle retainer 16 having a flat surface
And has a guide portion 17 at the tip of the outer peripheral surface. The wrinkle holding portion 16 is arranged in parallel with the tip end surface 11a of the drawing die 11, and holds the molded body 14 between them.

Further, the guide portion 17 has a taper outer surface 17a having a small taper angle for smoothly connecting to the right cylindrical portion 18 formed at the rear portion of the outer peripheral surface, and the taper outer surface 17a.
A large arc portion 17b having a relatively large radius of curvature R that smoothly connects to the tip side, and a small arc portion that has a radius of curvature r smaller than the large arc portion 17b that smoothly connects to the tip side of the large arc portion 17b. And 17c. As a result, the guide portion 17 as a whole is gradually reduced in diameter in the direction of the axis C toward the tip of the cup holder 15, and is formed in a surface shape that is convex outward in the radial direction.

In the present embodiment, the large arc portion 17b is formed such that the radius of curvature R of the vertical cross section shown in FIG. 2 is substantially equal to the diameter of the cup holder.
That is, the cup holder 1 to be inserted into the molded body 14 that has been drawn into a cylindrical shape having a bottom of 3 inches (about 75 mm).
5, the diameter dimension is about 75 mm that can be inserted into the molded body 14, and the radius of curvature R of the large arc portion 17b is R.
Is also formed to have a thickness of about 75 mm. In addition, it may be formed to have a thickness of about 25 mm for a 1-inch molded body.

The small circular arc portion 17c is formed with a radius of curvature r of about 1 to 2 mm in the vertical cross section shown in FIG. These dimensions are not limited to this and may be any other value. In FIG. 3, reference numeral 1
Reference numeral 9 is a mounting flange for attaching the cup holder 15 to a linear movement mechanism (not shown) for moving the cup holder 15 in the direction of the axis C.

When the drawing and ironing process of the molded body 14 is carried out by the drawing and ironing device 10 thus constructed, the bottom face is brought into contact with the front end face 11a of the drawing die 11 as shown in FIG. The cup holder 15 is inserted from the open end of the molded body 14 arranged in this state. Cup holder 15
As described above, since it is formed in a surface shape in which the diameter gradually decreases toward the tip, the small arc portion 17c arranged at the tip is sufficiently radially inward from the open end of the molded body 14. Will be distributed to. Therefore, even if the molded body 14 is slightly inclined or deformed into an elliptical shape, the cup holder 1
It is possible to prevent a problem such as a clip-off from occurring when inserting 5.

Then, as the insertion of the cup holder 15 into the molded body 14 progresses, the outer peripheral surface of the cup holder 15 approaches the inner surface of the molded body 14, and the cup holder 15 is fitted into the molded body 14. Will be distributed. As a result, the inclination of the molded body 14 and the deformation of the opening end are corrected, and the molded body 14 is aligned with the cup holder 15 arranged concentrically with the dies 11 and 12. as a result,
The molded body 14 is accurately centered with respect to the dies 11 and 12.

In this state, the wrinkle pressing portion 16 provided on the tip end surface of the cup holder 15 holds the bottom surface of the molded body 14 between it and the front end surface 11a of the drawing die 11, as shown in FIG. As a result, when the ram 13 is advanced to press the bottom surface of the molded body 14 in the direction of pushing it into the drawing die 11, the molded body 14 causes the frictional force generated between the wrinkle holding portion 16 and the front end surface 11a of the drawing die 11. Appropriate tension is applied by. Therefore, the molded body 14 is restrained from freely deforming, and is thus supported so that wrinkles do not occur.

When the ram 13 is further advanced, the molded body 14 is also moved by being dragged by it. In this case, when the molded body 14 is deformed to a shape that contacts the outer peripheral surface of the cup holder 15, after that, the molded body 14 is moved while sliding on the outer peripheral surface of the cup holder 15.

That is, the molded body 14 has a large arc portion 17b.
When the small circular arc portion 17c is sharply curved and drawn between the wrinkle holding portion 16 and the drawing die 11, the cup holder 15 moves while forming a curved surface that bulges outward in the radial direction. However, the drawing and ironing and forming apparatus 10 of the present embodiment is
Since the cup holder 15 has the guide portion 17 having a surface shape that is convex outward in the radial direction along the direction of the axis C, the guide portion 17 is arranged along the inner surface of the molded body 14 and The movement of the molded body 14 is supported in the contact state.

As a result, the molded body 14 is moved while being slidably supported on the inner surface of the cup holder 15, so that the outer peripheral surface of the cup holder 15 is free to be deformed similarly to the wrinkle pressing portion 16. It will be suppressed and maintained without wrinkles. In particular, in the present embodiment, since the guide portion 17 is formed by the curved surface having the relatively large radius of curvature R in the large arc portion 17b, a smooth metal flow can be generated during the deformation and the deformation can be performed without difficulty. . Further, as a result, it becomes possible to improve the processing accuracy of the drawing process and the ironing process.

In the present embodiment, the guide portion 17 is constituted by smoothly connecting the tapered surface 17a having a small taper angle, the large arc portion 17b and the small arc portion 17c, respectively. By smoothly connecting a plurality of tapered surfaces having different taper angles with a curved surface, it is possible to form the guide portion 17 having a surface shape that gradually decreases in diameter toward the tip and is convex outward in the radial direction. However, in order to generate a smooth metal flow, it is desirable to reduce the taper surface as much as possible and to form a plurality of curved surfaces.

[0025]

As described above in detail, the drawing and ironing molding apparatus according to the present invention is a bottomed cylindrical molding which is disposed concentrically in front of the drawing die and whose bottom surface is brought into contact with the front end face of the drawing die. A cup holder that fits inside the body, a wrinkle holding part that is placed at the tip of the cup and sandwiches the molded body with the front end surface of the drawing die, and a through hole that is provided in the axially penetrating state and through which a ram is inserted. , A guide portion that is provided at the outer peripheral surface tip portion and slides on the inner surface of the molded body that is pushed into the drawing die by the ram, and the guide portion gradually decreases in diameter in the direction along the axis and has a radius. Since the surface is formed to be convex outward in the direction, it is possible to correct the slight inclination of the molded body and the deformation of the opening end, and to perform the reliable centering without causing the clip-off. Further, since the inner surface of the molded body pushed into the drawing die by the ram is slidably supported by the guide portion having the surface shape that is convex outward in the radial direction, the free deformation of the molded body together with the wrinkle holding portion is suppressed, It is possible to prevent wrinkles from being generated.

Further, in the above-mentioned drawing and ironing forming apparatus, when the guide portion is constituted by a curved surface, a smooth metal flow is generated in the formed body which is pushed into the drawing die by the ram and moved along the guide portion. ,
The effect of being able to deform reasonably and improving the forming accuracy of the manufactured can body is produced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view in the vicinity of a drawing die for explaining drawing in an embodiment of a drawing and ironing forming apparatus according to the present invention.

FIG. 2 is a partially cutaway vertical sectional view showing a sectional shape of a cup holder of the drawing and ironing / molding apparatus of FIG.

FIG. 3 is a vertical sectional view showing the cup holder of FIG.

FIG. 4 is a vertical cross-sectional view showing the overall configuration of the drawing and ironing forming apparatus of FIG.

FIG. 5 is a vertical sectional view in the vicinity of a drawing die for explaining a drawing process by a conventional drawing and ironing and forming apparatus.

[Explanation of symbols]

 10 Drawing and Ironing Machine 11 Drawing Die 11a Front End Surface 12 Ironing Die 13 Ram 14 Molded Body 15 Cup Holder 15a Through Hole 16 Wrinkle Holding 17 Guide C C-axis

Claims (2)

[Claims] 1. A can having a smaller thickness and a smaller diameter than that of the molded body by performing a drawing process and an ironing process while passing a molded product formed in a bottomed tubular shape into a drawing die and a plurality of ironing dies by a ram. A drawing and ironing forming device for forming a body, which is arranged concentrically in front of the drawing die and is fitted into the inside of a formed body whose bottom face is brought into contact with the front end face of the drawing die. A cup holder, which is provided at the tip of the cup holder and sandwiches the molded body between the cup holder and the front end surface of the drawing die; and a through hole which is axially penetrated and through which the ram is inserted. A guide portion provided at the tip of the outer peripheral surface and sliding on the inner surface of the molded body pushed into the drawing die by a ram, the guide portion being gradually reduced in diameter in the direction along the axis toward the tip. Radial direction An squeezing and ironing forming apparatus, which is characterized in that it has a surface shape that is convex outward. 2. The drawing and ironing and forming apparatus according to claim 1, wherein the guide portion has a curved surface.