JP3986925B2 - Ioning die - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ionizing die that is used when ironing a workpiece by pushing a cup-shaped workpiece into the die, and is suitable for use in molding a DI can.
[0002]
[Prior art]
For example, DI cans for beverages (draw and ironed can) are obtained by punching an aluminum alloy base plate into a circular shape, drawing it to obtain a bottomed cylindrical cup member, and then redrawing and ironing it. Can be produced. As schematically shown in FIG. 5, the DI processing apparatus used in this method has a single redraw die 1 having a circular through hole 1a, and is arranged coaxially with the redraw die 1 to form a circular through hole. Three ironing dies (ioning dies) 3, 5, 7 having 3 a, 5 a, 7 a and a cylindrical shape that can be fitted inside each of the through holes 1 a to 7 a and movable in the axial direction Punch sleeve 9 and a cylindrical cup holder sleeve 11 fitted to the outside of the punch sleeve 9. A pilot ring 13 is arranged behind each of the ionizing dies 3 to 7 (left side in FIG. 5), and the punch sleeve 9 comes into contact with each die by an impact when the can is detached from each die. Is preventing. The redraw die 1 and the ionizing dies 3 to 7 can be supplied with DI coolant for lubrication and cooling.
[0003]
In the redrawing and ironing process by this apparatus, a bottomed cylindrical cup (work) 15 (see FIGS. 5 and 6a) manufactured by a cupping press which is the previous process is placed between the punch sleeve 9 and the redrawing die 1. In this state, the cup holder sleeve 11 and the punch sleeve 9 are advanced. As a result, the cup holder sleeve 11 presses the bottom surface of the cup 15 against the end surface of the redraw die 1 (two-dot chain line in FIG. 5). Next, the punch sleeve 9 pushes the cup 15 into the through-hole 1 a of the redraw die 1 while the cup holder sleeve 11 presses the cup 15. Thus, the cup 15 is redrawn and the cup 15 is formed into an elongated flat bottom can (work) 17 (see FIG. 6b).
[0004]
Since the cup holder sleeve 11 presses the bottom surface of the cup 15 against the end face of the redraw die 1 during the pushing operation of the punch sleeve 9, it is possible to prevent wrinkles from being generated in the flange portion of the cup 15 during molding, and during molding. By applying a tension to the side wall cylindrical portion of the cup 17 (that is, the side wall cylindrical portion of the flat bottom can 17), wrinkles can be prevented from occurring in the bottom conical portion 17a (see FIG. 6b) of the flat bottom can 17.
[0005]
The flat bottom can 17 that has passed through the redraw die 1 further sequentially passes through the through holes 3a to 7a of the ionizing dies 3 to 7, and is gradually ironed to obtain a flat bottom can 19 having a predetermined thickness. (See FIG. 6c). The punch sleeve 9 extrudes the flat bottom can 19 after the ironing process is finished further forward, and presses the bottom of the flat bottom can 19 against a bottom mold (not shown) to form a dome shape, for example. The can body is manufactured.
[0006]
After that, the can body thus obtained is a conventional process: trimming process → cleaning / surface treatment / drying process → outer surface coating / baking drying process → inner surface coating / baking drying process → necking / screw forming After the process → inspection process, it becomes the final product can. Thereafter, the product can is filled with the contents, and a screw cap is wound around the opening of the product can to seal the inside, thereby producing a beverage can.
[0007]
By the way, in the redrawing and ironing process described above, each work of the cup 15, the flat bottom can 17 or the flat bottom can 19 that passes through each die is caused by uneven thickness (partial thickness unevenness) or extension of the side wall of the can body. Due to the difference in nature, the peripheral edge of the cylindrical opening may not be the same distance from the bottom plate (the peripheral edge has a wave shape). When such a workpiece passes through each of the ionizing dies 3 to 7, the peripheral edge of the opening does not come off from the die uniformly, and the peripheral part that finally comes off from the die receives a reaction force from the die and may generate an impact. is there. According to the above-described DI processing apparatus, by arranging the pilot ring 13 behind the respective ionizing dies 3 to 7, the outer periphery of the work comes into contact with the pilot ring 13 immediately after the work passes through the die. This prevents the punch sleeve 9 and the die from being damaged due to the punch sleeve 9 and the die coming into contact with each other due to an impact when the workpiece is detached from the die.
[0008]
[Problems to be solved by the invention]
However, since the DI processing apparatus described above has a separate pilot ring arranged behind each ioning die, the punch sleeve does not come into contact with each die due to the impact when the can is detached from each die. Although it was possible to prevent the deterioration of the quality of the product can due to a portion (gloss difference portion) where a slight difference in gloss on the surface of the can is caused by the collision of the can with the pilot ring, the can cannot be prevented. Further, since the distance between the dies is increased by the thickness of the pilot ring, the degree of freedom in setting the distance between the dies is reduced. In addition, since the stroke of the punch sleeve becomes longer, the processing time becomes longer correspondingly, and further, the processing of a short can size could not be performed.
The present invention was made in view of the above situation, the can collides with the pilot ring, can prevent the product can deteriorate due to the difference in gloss, and can reduce the distance between the dies, An object of the present invention is to provide an ionizing die that can increase the degree of freedom in setting the distance between the dies, shorten the processing time, and can also process a short can size.
[0009]
[Means for Solving the Problems]
To achieve the above object, an ionizing die according to claim 1 of the present invention is such that a die is supported on a holder and a bottomed cylindrical workpiece is extrapolated to the tip of a punch sleeve arranged coaxially with the die. In the ionizing die in which the punch sleeve is advanced toward the die and the workpiece is pressed into the die to squeeze the workpiece, the holder has an inner diameter substantially the same as the through hole of the die. A pilot ring having a coaxial through hole on the outlet side of the die in the pushing direction, and the holder has a large-diameter hole coaxial with the punch sleeve on one surface and the other surface on the other side. A small-diameter hole on the same axis that communicates with the large-diameter hole and the stepped portion as a boundary, and the die is fitted into the large-diameter hole by bringing the stepped portion into contact with the surface on the outlet side in the pushing direction, Before the small diameter hole Characterized in that it was fitting the pilot ring.
[0010]
In this ionizing die, the pilot ring is provided on the die exit side of the holder, so that the pilot ring can be provided close to the die. As a result, even if the can collides with the pilot ring due to the uneven thickness of the can and the can collides with the pilot ring, and the gloss difference portion is formed, that position should be the upper end of the can (trimming allowance) Can be cut off by trimming in a later process.
Furthermore, by fitting the pilot ring into a small-diameter hole that has been provided in the past to form a step for preventing die detachment, the thickness of the pilot ring that has been separate from the holder can be reduced. Can do. Thereby, the freedom degree of setting of the distance between the dies arranged in tandem can be increased. Further, by reducing the thickness of the pilot ring, the stroke of the punch sleeve is shortened, the processing time can be shortened, and further, the processing of a short can size becomes possible.
[0011]
The ionizing die according to claim 2 is the ionizing die according to claim 1, wherein the pilot ring is an arc formed by removing a corner portion at a peripheral edge of the through hole of the pilot ring in the pushing direction. It has a surface .
[0013]
The ionizing die according to claim 3 is the ionizing die according to claim 1 or 2, wherein the position of the minimum inner diameter portion of the through hole provided in the pilot ring is piloted from the entrance side of the through hole in the pushing direction. The range is up to 1/3 of the thickness of the ring.
[0014]
In this ionizing die, the position of the smallest inner diameter portion of the through hole provided in the pilot ring, that is, the position in the axial direction of the through hole of the portion where the inner diameter of the through hole is the smallest is from the inlet side in the pushing direction of the through hole. Since the pilot ring is formed so as to be in the range up to 1/3 of the thickness of the pilot ring, the position where the gloss difference portion is formed is on the upper end side of the can. Thereby, the trimming allowance can be reduced in the step of cutting the gloss difference portion by trimming.
[0015]
The ionizing die according to claim 4 is the ionizing die according to claim 3, wherein the pilot ring has a tapered surface that gradually increases in diameter toward the outlet direction on the outlet side in the pushing direction of the through hole. It is characterized by.
[0016]
In this ionizing die, the pilot ring has a tapered surface that gradually increases in diameter toward the exit direction on the exit side of the through-hole in the pushing direction. Less interference. Further, even when the workpiece comes into contact with the pilot ring, the tapered surface becomes a relief surface, and the reaction force that the workpiece receives from the pilot ring can be reduced.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of an ionizing die according to the present invention will be described below in detail with reference to the drawings.
1 is a cross-sectional view of a principal part of a DI processing apparatus provided with an ionizing die according to the present invention, FIG. 2 is a cross-sectional view of the ionizing die of FIG. 1, FIG. 3 is an enlarged view of a portion A in FIG. FIG. 3 is a partially enlarged view of a pilot ring 2.
[0018]
As shown in FIG. 1, the DI processing apparatus includes one redraw die 31 having a circular through hole 31a and three pieces having circular through holes 33a to 37a arranged coaxially with the redraw die 31. An ironing die (ioning die) 33 to 37, a cylindrical punch sleeve (not shown) that can be fitted in each of the through holes 31a to 37a and can be moved in the axial direction, and the punch sleeve And a cylindrical cup holder sleeve (not shown) fitted to the outside. The redraw die 31 and the ionizing dies 33 to 37 can be supplied with DI coolant for lubrication and cooling.
[0019]
The redrawing die 31 is screwed to the redrawing holder 41 via a clamp ring 43. A first ironing portion 45 is disposed in close contact with the outlet side of the redraw holder 41 in the pushing direction. On the outlet side of the first ironing portion 45 in the pushing direction, an intermediate ironing portion 47 and a final ironing portion 49 are sequentially arranged. Each of the first ironing portion 45, the intermediate ironing portion 47, and the final ironing portion 49 includes a centering ring 51 that aligns the axes of the ironing portions, a washer 53 that is fitted to the inner periphery of the centering ring 51, and the washer 53. The above-mentioned ionizing dies 33 to 37 are in contact with each other.
[0020]
Between the first ironing part 45 and the intermediate ironing part 47 and between the intermediate ironing part 47 and the final ironing part 49, an annular leuplicator 55 and a bronze bushing 57 are sequentially inserted in the pushing direction. .
[0021]
Next, the ionizing dies 33 to 37 provided in each of the first ironing portion 45, the intermediate ironing portion 47, and the final ironing portion 49 will be described. Since the ionizing dies 33 to 37 have substantially the same configuration, the ionizing die 33 will be described as a representative example.
As shown in FIG. 2, the ionizing die 33 has a die 63 fitted and held in a holder 61. In addition, the holder 61 includes a pilot ring 65 having a through hole 65 a having the same inner diameter as that of the through hole 33 a of the die 63 on the same axis and fitted on the outlet side of the die 63 in the pushing direction.
[0022]
The holder 61 has a large-diameter hole 67 shown in FIG. 3 coaxial with the punch sleeve on one surface (surface in the pushing direction inlet side), and the large-diameter hole 67 on the other surface (in the pushing direction outlet side). And a coaxial small-diameter hole 71 communicating with the stepped portion 69 as a boundary. The holder 61 is fitted by shrink-fitting the die 63 into the large-diameter hole 67 with the stepped portion 69 in contact with the surface on the outlet side in the pushing direction of the die 63. The structure in which the die 63 is abutted and fitted to the stepped portion 69 is the same as the conventional one.
[0023]
On the other hand, the pilot ring 65 is fitted in the small diameter hole 71 of the holder 61. The pilot ring 65 can be fitted into the small diameter hole 71 by shrink fitting, for example, like the die 63. Further, the pilot ring 65 is prevented from coming off twice by the surface on the outlet side in the pushing direction coming into contact with the replicator 55 shown in FIG. The pilot ring 65 is not subjected to a large pulling direction force during ironing as compared with the die 63.
[0024]
The die 63 has an ironing surface 73 having a minimum inner diameter at a substantially central portion in the thickness direction shown in FIG. Centering on this ironing surface 73, the indentation direction entrance side and the indentation direction exit side of the die 63 are tapered surfaces 75, 77 whose diameters are enlarged at predetermined angles θ1, θ2.
[0025]
On the other hand, as shown in FIG. 4, the pilot ring 65 forms an arcuate surface (R) 79 formed by removing a corner at the periphery of the through hole 65 a on the entrance side in the pushing direction, and is continuous with the arcuate surface 79. A minimum inner diameter surface 83 is formed on the inner surface. The inner diameter of the minimum inner diameter surface 83 is substantially the same inner diameter as the ironing surface 73 of the die 63. When the minimum inner diameter surface 83 is formed as a curved surface, the apex of the minimum inner diameter surface 83 is the minimum inner diameter portion 83a. In the minimum inner diameter portion 83a, the inner diameter of the through hole 65a is minimized. With respect to the position where the minimum inner diameter portion 83 a is provided, the position x from the side surface 66 on the inlet side of the through hole 65 a is set to a range of １ ／ of the thickness t of the pilot ring 65. That is, the minimum inner diameter portion 83a is formed so as to satisfy the relationship of 0 <x <t / 3. In this embodiment, when t = 7.865, the position x is provided within the range of 0 <x <2.622. When the minimum inner diameter surface 83 is formed as a flat surface parallel to the axis of the through hole 65a, the entire surface of the minimum inner diameter surface 83 is the minimum inner diameter portion, and the entire surface of the minimum inner diameter surface 83 is within the above range. It is formed.
[0026]
Further, the pilot ring 65 is provided with a tapered surface 81 continuously to the minimum inner diameter surface 83, and the tapered surface 81 gradually increases in diameter toward the outlet direction toward the outlet side in the pushing direction of the through hole 65a. Is formed. The tapered surface 81 is formed at an angle θ3 = 10 degrees. Since the pilot ring 65 has such a tapered surface 81, the interference between the workpiece and the pilot ring 65 due to the fluctuation (runout) of the workpiece after passing through the die is reduced. Even when the workpiece contacts the pilot ring 65, the tapered surface 81 serves as a relief surface, so that the reaction force that the workpiece receives from the pilot ring 65 can be reduced.
[0027]
In the DI processing apparatus having the above-described configuration, a bottomed cylindrical cup (work) (not shown) is disposed between a punch sleeve (not shown) and the redraw die 31 and the punch sleeve is advanced in this state. The workpiece is pushed into the through hole 1a of the redraw die 31. As a result, the work is redrawn and the work is formed into an elongated flat bottom can.
[0028]
The flat bottom can that has passed through the redraw die 31 further passes through the through holes 33a to 37a of the ionizing dies 33 to 37 in order, and is gradually ironed to form a flat bottom can having a predetermined thickness. Is done. In other words, the DI processing apparatus performs redrawing and ironing at once with the redrawing die 31 and the ionizing dies 33 to 37 disposed in tandem, and the can wall height is reduced by reducing the plate thickness by ironing. To make a DI can with a predetermined depth.
[0029]
According to the above ioning dies 33 to 37, the pilot ring 65 is provided on the die outlet side of the holder 61, so that the pilot ring 65 can be provided close to the die 63. As a result, even if the can collides with the pilot ring 65 due to the uneven thickness of the can due to the uneven thickness of the can, and the gloss difference portion is formed, the position is defined as the upper end of the can (trimming allowance). It can be excised by trimming in a later process.
[0030]
In addition, by fitting the pilot ring 65 into the small-diameter hole 71 that has been conventionally provided to form the die 63 for preventing the die from being removed, the thickness of the pilot ring that has been separate from the holder 61 in the past can be obtained. Can be reduced. Thereby, the freedom degree of the setting of the distance between the ionizing dies 33-37 arrange | positioned in tandem can be raised. Further, by reducing the thickness of the pilot ring 65, the stroke of the punch sleeve is shortened, the processing time can be shortened, and further, the processing of a short can size becomes possible.
[0031]
In addition, by providing the minimum inner diameter portion 83a of the pilot ring 65 in the above-described range, the gloss difference portion formed on the can can be made closer to the upper end side of the can. Thereby, the part cut away by the trimming of a post process can be decreased.
[0032]
【The invention's effect】
As described above in detail, according to the ioning die according to the present invention, the pilot ring having the through hole having substantially the same inner diameter as the through hole of the die is provided on the outlet side in the pushing direction of the die in the holder. Therefore, the pilot ring can be provided close to the die, and even if the can collides with the pilot ring due to the deviation of the can due to the uneven thickness of the can, Can be used as the upper end (trimming allowance) of the can, and can be cut off by trimming in a later step. As a result, quality deterioration of the product can due to the gloss difference portion can be prevented.
By fitting the pilot ring into a conventional small-diameter hole for forming a step portion for preventing die detachment, it is possible to reduce the thickness of the pilot ring that has conventionally been separate from the holder. As a result, in addition to increasing the degree of freedom in setting the distance between the dies, the stroke of the punch sleeve is shortened, so that the processing time can be shortened, and further processing of a short can size is possible.
Also, the ionizing die has a position of the smallest inner diameter portion of the through hole provided in the pilot ring in a range from the inlet side in the pushing direction of the through hole to 1/3 of the thickness of the pilot ring. The formed position can be the upper end portion of the can, and the gloss difference portion can be cut out with a small trimming allowance.
Furthermore, since the ionizing die has a tapered surface that gradually increases in diameter toward the exit direction on the exit side of the through-hole in the pushing direction, interference between the workpiece and the pilot ring due to the blowout of the workpiece after passing through the die. Even when the workpiece contacts the pilot ring, the tapered surface becomes a relief surface, and the reaction force that the workpiece receives from the pilot ring can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a DI processing apparatus provided with an ionizing die according to the present invention.
FIG. 2 is a cross-sectional view of the ionizing die of FIG.
FIG. 3 is an enlarged view of a part A in FIG. 2;
4 is a partially enlarged view of the pilot ring of FIG. 2. FIG.
FIG. 5 is a cross-sectional view of an essential part showing an outline of a conventional DI processing apparatus.
FIG. 6 is a cross-sectional view showing a deformation state associated with DI machining of a workpiece.
[Explanation of symbols]
33, 35, 37 ... ionizing dies 33a, 35a, 37a ... through hole 61 ... holder 63 ... die 65 ... pilot ring 67 ... large diameter hole 69 ... stepped portion 71 ... small diameter hole 79 ... arc surface 81 ... tapered surface

Claims (4)

A die is supported by a holder, a bottomed cylindrical workpiece is extrapolated to the tip of a punch sleeve arranged coaxially with the die, the punch sleeve is advanced toward the die, and the workpiece is moved into the die. In an ionizing die that irons the workpiece by pressing,
The holder includes a pilot ring coaxially having a through hole having substantially the same inner diameter as the through hole of the die on the outlet side in the pushing direction of the die ,
The holder has a coaxial large diameter hole on one surface and a coaxial small diameter hole communicating with the large diameter hole and the step on the other surface, An ionizing die, wherein the die is fitted into the large-diameter hole with the surface on the outlet side in the pushing direction in contact, and the pilot ring is fitted into the small-diameter hole . The ionizing die according to claim 1,
The ionizing die according to claim 1, wherein the pilot ring has an arc surface formed by removing a corner portion at a peripheral edge of the through hole of the pilot ring on a side in a pushing direction . The ionizing die according to claim 1 or 2,
An ionizing die characterized in that the position of the minimum inner diameter portion of the through hole provided in the pilot ring is in the range from the inlet side in the pushing direction of the through hole to 1/3 of the thickness of the pilot ring. . The ionizing die according to claim 3,
The said pilot ring has the taper surface which diameter-expands gradually toward an exit direction in the pushing direction exit side of the said through-hole, The ionizing die characterized by the above-mentioned.

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