JP2013233574A - Device for molding bottomed container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defective molding from occurring on the wall of the long side of a bottomed container.SOLUTION: On an outer face 22L of the long side of a punch 20, a long side path 27L is structured to raise a workpiece 35 to be molded, between the outer face 22L and the inner face of a cavity 11, and a slidingly contacting face 25L of the long side is formed to make the rising workpiece 35 to be molded contact slidingly. On the outer face 22S of the short side of the punch 20, a short side path 27S is structured to raise the workpiece 35 to be molded, between the outer face 22S and the inner face of the cavity 11, and a slidingly contacting face 25S of the short side is formed to make the rising workpiece 35 contact slidingly. The height of the long side slidingly contacting face 25L on the basis of the bottom pressing face 21 is minimal at both longitudinal ends in the direction of the length of the outer face 22L of the long side and increases toward the center in the direction of the length of the outer face of the long side.

Description

  The present invention relates to an apparatus for forming a bottomed container.

  Patent Document 1 includes a die formed with a cavity for accommodating a molding material, and a punch provided so as to be able to enter the cavity, and the molding material pressed impactively on the bottom surface of the punch, There has been disclosed a molding apparatus for molding a bottomed container having a substantially rectangular bottom shape by plastically deforming so as to rise in a direction opposite to the pressing direction in a gap between the inner side surface of the cavity and the outer side surface of the punch.

Japanese Patent No. 3300266

When forming a bottomed container whose bottom shape is substantially rectangular by raising the material to be molded by the impact pressure of the punch as described above, the long side wall part and the short side wall part constituting the bottomed container Of these, molding defects such as cracks and wrinkles may occur only on the long side wall portion. The occurrence of such molding defects is more remarkable as the wall thickness is thinner.
This invention is completed based on the above situations, Comprising: It aims at preventing generation | occurrence | production of the molding defect in the long side wall part of a bottomed container.

The present invention
A die formed with a cavity having an open top surface for accommodating a molding material;
A punch provided to allow entry into the cavity from above the die,
The bottom material has an approximately rectangular bottom shape by plastically deforming the material to be molded, which has been shockedly pressed by the bottom pressing surface of the punch, while rising in a direction opposite to the pressing direction in the gap between the cavity and the punch. A molding device for molding a bottom container,
The long side side outer surface of the punch forms a long side path for raising the molding material between the inner side surface of the cavity and the long side side where the rising molding material slides. A sliding surface is formed,
The short side of the short side of the punch forms a short side path for raising the molding material between the inner side of the cavity and the short side of the rising material to be slidably contacted A sliding surface is formed,
The height dimension of the long side slidable contact surface with respect to the bottom pressing surface is minimum at both ends in the length direction of the long side outer surface, and at the center in the length direction of the long side outer surface. It has the feature that it is becoming larger.

  The operation and effect of the present invention are as follows. A path that is in sliding contact with the outer surface of the punch while the material to be molded rises during molding includes a long-side path and a short-side path. The cross-sectional area when the two paths are cut at right angles to the rising direction of the material to be molded is that the long side path is larger than the short side path. The sliding resistance generated between the long side path and the short side path is smaller than that of the short side path. The smaller the sliding contact resistance, the smaller the pressure loss of the pressing force applied from the punch to the material to be molded, so the rising speed of the material to be molded becomes faster.

  Therefore, in the conventional molding apparatus, a part of the molding material which is going to rise quickly in the long side path is pulled by the molding material in the short side path whose rising speed is slower than the long side path, and as a result. In the long side path, the rising speed of the molding material becomes non-uniform. This non-uniform rising speed in the long side path is considered to be a cause of forming defects such as cracks and wrinkles only in the long side wall portion of the bottomed container.

  Therefore, in the present invention, the height of the long side sliding contact surface constituting the long side path is lowered at both ends near the short side path, and is increased at the center far from the short side path. Due to the difference in height, the sliding contact resistance when the material to be formed rises up the long-side path was made large at the center and small at both ends. If this setting ignores the influence of the molding material in the short side path and is limited to the long side path, the rising speed of the molding material is the slowest at the center and faster toward both ends. Means that.

  Therefore, when considering the influence of the tension by the molding material in the short side path, the rising speed of the molding material at both ends of the long side path during molding is pulled by the molding material of the short side path. As a result, the speed is reduced to substantially the same speed as the rising speed of the material to be molded in the central portion. As a result, the rising speed of the material to be molded in the long side path is substantially uniform over the entire length, thereby preventing the occurrence of molding defects such as cracks and wrinkles in the long side wall portion of the bottomed container.

Sectional drawing showing the state of the moment the punch pressed the molding material in the molding apparatus of Example 1 AA line sectional view of FIG. Sectional view showing the state where the bottomed container has been molded BB sectional view of FIG. CC sectional view of FIG. Sectional drawing showing the state which the punch entered into the cavity in the molding apparatus of Example 2 DD sectional view of FIG. Sectional drawing showing the state which the punch entered into the cavity in the molding apparatus of Example 3 EE sectional view of FIG. Bottom view of punch Side view of the punch of Example 4

In the molding apparatus of the present invention, the bottom pressing surface is open to the long side sliding contact surface but not to the short side sliding contact surface in a region excluding both ends in the long side direction. A recess may be formed.
According to this configuration, when the punch enters the cavity, both ends of the long side direction in which the concave portion is not formed on the bottom pressing surface press the material to be shocked. The material to be molded rises in advance at both ends of the short side path and the long side path near the short side path. Thereafter, the material to be molded rises with a delay in a region of the long side path excluding both ends in the long side direction, that is, a region corresponding to the recess. Thus, by providing a time difference at the start of rising, unevenness of the rising speed of the molding material is alleviated.

In the molding apparatus of the present invention, tapered surfaces that form an obtuse angle with respect to the short side sliding contact surface may be formed at both ends in the long side direction of the bottom pressing surface.
According to this configuration, a part of the molding material pressed by the bottom pressing surface changes the flow direction from the bottom path along the tapered surface to the short side path. In the present invention, since the tapered surface connected to the short side sliding surface of the bottom pressing surface and the short side sliding surface form an obtuse angle, the bottom pressing surface and the short side sliding surface form a right angle. Compared to the case, the change in the flow direction of the molding material is small. Therefore, since the sliding resistance is reduced, the influence of tension exerted on the molding material in the long side path from the molding material in the short side path is reduced. Thereby, the nonuniformity of the rising speed of the molding material in the long side path can be more effectively reduced.

In the molding apparatus according to the present invention, a groove portion may be formed on the bottom pressing surface so as to extend along the long side direction so that both end portions in the long side direction reach the short side sliding surface.
According to this configuration, a part of the molding material pressed by the bottom pressing surface flows from the bottom path along the bottom pressing surface to the short side path along the long side direction. In the present invention, since the groove in the long side direction is formed on the bottom pressing surface, the cross-sectional area perpendicular to the flow in the bottom path is larger than in the case where no groove is formed, and the flow resistance of the molding material in the bottom path is increased. Has been reduced. Thereby, since the influence of the tension from the molding material in the short side path to the molding material in the long side path is reduced, the rise rate of the molding material in the long side path is uneven. It can be reduced more effectively.

<Example 1>
A first embodiment of the present invention will be described below with reference to FIGS. The forming apparatus Ma according to the first embodiment is provided with a die 10 in which a cavity 11 having an open upper surface for accommodating a metal molding material 35 is formed, and an entrance into the cavity 11 from above the die 10. The punch 20 is provided. When forming the bottomed container 30, as shown in FIGS. 1 and 2, the punch 20 is rapidly lowered in a state where the molding material 35 is accommodated in the cavity 11, and the bottom pressing surface 21 of the punch 20 is used. The molding material 35 is shockedly pressed. Then, a part of the molding material 35 that receives the pressing force from the punch 20 is formed in the gap between the inner side surfaces 12L, 12S, 12R of the cavity 11 and the outer side surfaces 22L, 22S, 22R of the punch 20. As shown in FIGS. 3 and 4, the bottomed container 30 is molded while being plastically deformed while rising in the opposite direction (that is, upward) to the pressing direction of the punch 20 (hereinafter referred to as the pressing direction).

  As shown in FIGS. 3 and 4, the bottomed container 30 is a bottom wall portion 31 that has a substantially rectangular shape in the width direction (left and right direction), and before and after rising at a right angle from the long side of the outer peripheral edge of the bottom wall portion 31. A pair of long side wall portions 32 </ b> L and a pair of left and right short side wall portions 32 </ b> S rising from the short side of the outer peripheral edge of the bottom wall portion 31 are provided. The bottomed container 30 is symmetrical in the front-rear direction and has a symmetrical shape. The bottomed container 30 is used as a case for housing a secondary battery such as a hybrid vehicle, an electric vehicle, or an electronic device.

  When forming the bottomed container 30 whose bottom shape is substantially rectangular by raising the material to be molded 35 with the impact pressure of the punch 20 as described above, the inner surface of the cavity 11 and the outer surface of the punch 20 are formed. The long side wall part 32L and the short side wall part 32S are formed by the molding material 35 rising from the gap. Conventionally, only the long side wall part 32L of the long and short side wall parts 32L, 32S has cracks, wrinkles, etc. In some cases, molding defects occurred. Therefore, in this embodiment, means for preventing the occurrence of molding defects in the long side wall portion 32L is taken. Hereinafter, a detailed description of the molding apparatus Ma and a means for preventing molding defects will be described. In the following description, the forward / backward direction and the vertical direction of the punch 20 with respect to the cavity 11 are used synonymously, the width direction and the horizontal direction are used synonymously, and the depth direction and the front / back direction are used synonymously.

  The cavity 11 has a shape in which the upper surface of the die 10 is recessed, and the upper surface is open to allow the punch 20 to enter. In the cavity 11, a molding material 35 that is a molding material of the bottomed container 30 is accommodated. The planar shape (opening shape) of the cavity 11 is a substantially rectangular shape elongated in the width direction (left-right direction).

  As shown in FIG. 5, the inner side surfaces 12L, 12S, and 12R of the cavity 11 are a pair of left and right planar short inner surfaces 12L and a pair of left and right planar short sides that are perpendicular to the long side inner side surface 12L. The side-side inner surface 12S, and two pairs of arc-shaped inner surfaces 12R that smoothly connect the long-side inner surface 12L and the short-side inner surface 12S. These inner side surfaces 12L, 12S, and 12R are parallel to the pressing direction. These inner side surfaces 12L, 12S, and 12R come into sliding contact when the molding material 35 rises, and generate sliding resistance against the rise of the molding material 35.

  As shown in FIGS. 1 and 2, the bottom surface of the cavity 11 serves as a pressure receiving surface 13 for placing the molding material 35 and receiving a pressing force (impact) from the punch 20. The pressure receiving surface 13 is a horizontal flat surface perpendicular to the advance / retreat direction (pressing direction) of the punch 20. As shown in FIGS. 1 to 4, the pressure receiving surface 13 and the inner side surfaces 12 </ b> L, 12 </ b> S, 12 </ b> R are smoothly connected by a spherical inner surface 14.

  The punch 20 has a block shape as a whole. A portion of the punch 20 on the bottom side (lower end portion side) that contributes to the molding of the bottomed container 30 has a substantially rectangular shape whose left-right dimension is larger than the front-rear dimension. The bottom surface of the punch 20 is a horizontal flat bottom pressing surface 21 that is perpendicular to the pressing direction. As shown in FIG. 5, the outer surfaces 22L, 22S, 22R of the punch 20 include a pair of front and rear long side outer surfaces 22L, a pair of left and right short side outer surfaces 22S, a long side outer surface 22L, and a short side. An arcuate outer surface 22R that smoothly connects the side outer surface 22S. As shown in FIGS. 1 to 4, the outer side surfaces 22 </ b> L, 22 </ b> S, 22 </ b> R and the bottom pressing surface 21 are smoothly connected by a spherical outer surface 23.

  As shown in FIGS. 2, 4, and 5, the depth dimension of the punch 20 in the front-rear direction (short side direction) is smaller than the dimension of the cavity 11 in the front-rear direction (interval between the long side inner surfaces 12L). This dimensional difference corresponds to the thickness dimension of the long side wall portion 32L. As shown in FIGS. 1, 3 and 5, the width dimension of the punch 20 in the left-right direction (long side direction) is smaller than the dimension in the left-right direction of the cavity 11 (interval between the short side inner surfaces 12 </ b> S). The dimensional difference corresponds to the thickness dimension of the short side wall portion 32S. 3 and 4, in the state where the punch 20 is positioned at the lowermost end in the forward / backward stroke, the bottom pressing surface 21 of the punch 20 is located higher than the pressure receiving surface 13 of the cavity 11, and this height difference Corresponds to the thickness dimension of the bottom wall portion 31.

  As shown in FIGS. 1-4, the lower end part area | region (namely, area | region of the front side in a press direction) connected with the bottom part press surface 21 among 22 L of long side outer sides of the punch 20 is compared with the area | region above it. Thus, the long-side land portion 24L is projected in a step shape in the front-rear direction. The long-side land portion 24L is formed in the left-right direction over the entire length in the left-right direction of the long-side outer surface 22L. The lower end edge of the long side land portion 24L is smoothly connected to the bottom pressing surface 21 via the arc-shaped outer surface 22R. The outer surface of the long side land portion 24L is a long side sliding contact surface 25L that is a plane parallel to the pressing direction.

  Further, the region above the long side sliding surface 25L of the long side outer surface 22L is a long side non-sliding surface 26L. As shown in FIGS. 2 and 4, the front-rear dimension of the punch 20 in the formation region of the long-side slidable contact surface 25L is larger than the front-rear dimension in the formation region of the long-side non-slidable contact surface 26L. When the molding material 35 rises due to the pressing of the punch 20, the long side sliding contact surface 25 </ b> L causes sliding contact resistance against the rising by bringing the molding material 35 into sliding contact. The molding material 35 does not contact the contact surface 26L.

  In order to prevent the occurrence of molding defects in the long side wall portion 32L, the height of the long side sliding contact surface 25L with respect to the bottom pressing surface 21 is as shown in FIG. The minimum height dimension Hb is set at both end portions of 22L (that is, both end portions in the length direction of the long side outer surface 22L) and is set to increase toward the center of the long side outer surface 22L in the left-right direction. Yes. The height of the long side sliding contact surface 25L with respect to the bottom pressing surface 21 is the maximum height dimension Ha at the center in the left-right direction. The upper edge of the long side sliding surface 25L (boundary with the long side non-sliding surface 26L) has a curved shape so as to swell upward as a whole. Further, both end portions of the upper edge of the long side sliding contact surface 25L are substantially horizontal (substantially perpendicular to the pressing direction). The long side slidable contact surface 25L is symmetric in the front-rear direction and is symmetric in the left-right direction.

  The maximum height dimension Ha of the long side sliding contact surface 25L with respect to the bottom pressing surface 21 is set to be smaller than the depth dimension D of the cavity 11 in the pressing direction. Therefore, as shown in FIGS. 3 and 4, in the state where the punch 20 has entered the cavity 11 most deeply and the molding of the bottomed container 30 is completed, the highest widthwise central portion of the long side sliding surface 25L. Is lower than the upper end of the cavity 11 (the upper surface of the die 10) (that is, inside the cavity 11).

  The lower end region (that is, the region on the front side in the pressing direction) connected to the bottom pressing surface 21 of the short-side outer surface 22S of the punch 20 protrudes in a step shape in the front-rear direction compared to the region above it. The short side land portion 24S is formed. The formation range of the short-side land portion 24S in the front-rear direction extends over the entire length of the short-side outer surface 22S in the front-rear direction. Further, the lower end edge of the short side land portion 24S is smoothly connected to the bottom pressing surface 21 via the arc-shaped outer surface 22R. The outer surface of the short side land portion 24S is a short side sliding contact surface 25S made of a plane parallel to the pressing direction.

  Moreover, the area | region above the short side slidable contact surface 25S among the short side outer surface 22S becomes the short side non-slidable surface 26S. As shown in FIGS. 1 and 3, the left-right dimension in the formation region of the short-side slidable contact surface 25S of the punch 20 is larger than the left-right dimension in the formation region of the short-side non-slidable contact surface 26S of the punch 20. When the material to be molded 35 rises due to the pressing of the punch 20, the short side sliding surface 25 </ b> S causes a sliding resistance against the rising by bringing the material 35 into sliding contact. The molding material 35 does not contact the contact surface 26S.

  The height Hb of the short side sliding contact surface 25S with respect to the bottom pressing surface 21 is constant over the entire length in the front-rear direction. And in order to prevent the generation | occurrence | production of the shaping | molding defect in the long side side wall part 32L, the height dimension Hb of the short side sliding surface 25S is made the same height as the minimum height dimension Hb of the long side sliding surface 25L. Yes. The short side slidable contact surface 25S is symmetric in the front-rear direction and in a bilaterally symmetric form.

  In the pressing process in which the punch 20 enters the cavity 11, the inner surfaces 12 </ b> L and 12 </ b> S of the cavity 11 until the molding of the bottomed container 30 is completed after the punch 20 starts pressing the molding material 35. , 12R and the outer surface 22L, 22S, 22R of the punch 20, when the pressed molding material 35 rises, there is a rising path that guides the molding material 35 while forming the molding material 35 to a predetermined thickness. It is formed. The rising path includes a long side path 27L corresponding to the long side sliding surface 25L in the left-right direction (long side direction) and the vertical direction, and a short side sliding surface 25S in the front and back direction (short side direction) and the vertical direction. And corresponding short side paths 27S.

  In the bottomed container 30 of the present embodiment, the thickness dimension of the long side wall part 32L and the short side wall part 32S is 0.7 mm, and the thickness dimension of the bottom wall part 31 is 1.1 to 1.2 mm. . The ratio between the thickness dimension of the side wall portions 32L and 32S of the bottomed container 30 and the width dimension along the long side is about 1: 200. The ratio of the width dimension along the long side and the depth dimension along the short side of the bottomed container 30 is about 6: 1. The ratio of the maximum height dimension Ha to the minimum height dimension Hb of the long side sliding contact surface 25L of the punch 20 is about 12: 1. The ratio of the maximum height dimension Ha of the long side sliding contact surface 25L and the width dimension along the long side of the punch 20 is about 1:12. In addition, the dimension ratio in each drawing has the part deformed for convenience, and these parts are not consistent with each said ratio.

  Next, the form in which the molding material 35 moves while being plastically deformed by the pressing force of the punch 20 will be described. When the punch 20 is lowered, a bottom path 28 is formed between the bottom pressing surface 21 of the punch 20 and the pressure receiving surface 13 of the cavity 11. The height dimension of the bottom path 28 decreases as the punch 20 descends. Therefore, in the bottom path 28, the material 35 to which the pressing force is applied from the punch 20 is plastically deformed so as to be crushed between the bottom pressing surface 21 and the pressure receiving surface 13, and from the center toward the outer peripheral edge. Move horizontally. Then, the molding material 35 whose movement direction is changed from the horizontal direction to the upper side at the outer peripheral edge of the bottom path 28 enters the long side path 27L and the short side path 27S.

  In the long side path 27L, the molding material 35 rises while sliding while being sandwiched between the long side inner side surface 12L and the long side side sliding contact surface 25L, thereby forming the long side wall portion 32L. . In the short side path 27S, the material 35 to be molded rises while sliding while being sandwiched between the short side inner surface 12S and the short side sliding surface 25S, thereby forming the short side wall portion 32S. .

  A portion of the molding material 35 that passes through the long side path 27L (the long side sliding contact surface 25L) and rises to a height corresponding to the long side non-sliding contact surface 26L is formed on the long side inner side surface 12L. Although it is in sliding contact, it does not come into contact with the punch 20 and continues to stand up while being spaced from the long side non-sliding contact surface 26L. Therefore, a large slidable contact resistance does not act on the region above the long side path 27L of the material to be molded 35.

  Further, the portion of the molding material 35 that passes through the short-side path 27S (short-side sliding surface 25S) and rises to a height corresponding to the short-side non-sliding surface 26S is the short-side inner surface. Although it is in sliding contact with 12S, it does not come into contact with the punch 20 and continues to rise in a state of being spaced from the short side non-sliding contact surface 26S. Therefore, a large sliding contact resistance does not act on the region above the short side path 27 </ b> S of the material to be molded 35.

  Next, generation prevention of molding defects in the long side wall portion 32L will be described. The molding material 35 at the time of molding slides on the long side sliding surface 25L and the short side sliding surface 25S of the punch 20 while rising in the long side path 27L and the short side path 27S. As shown in FIG. 5, when the two rising paths 27L and 27S are cut at right angles to the rising direction of the molding material 35, the long side path 27L has a longer cross section than the short side path 27S. large. Therefore, the sliding contact resistance generated between the workpiece 35 that rises and the punch 20 has a long side path 27L (long side sliding surface 25L) and a short side path 27S (short side sliding surface 25S). Is smaller than As the slidable contact resistance is smaller, the pressure loss of the pressing force applied from the punch 20 to the molding material 35 becomes smaller, so that the rising speed of the molding material 35 becomes faster.

  Therefore, in the conventional molding apparatus, a part (both end portions) of the molding material 35 that is about to rise quickly in the long side path 27L is in the short side path 27S where the rising speed is slower than that of the long side path 27L. As a result, the rising speed of the molding material 35 in the long side path 27L becomes uneven in the left-right direction (direction perpendicular to the rising direction), and is fast at the center in the left-right direction. Slower at both ends in the left-right direction. This non-uniform rising speed in the long side path 27L is considered to be the cause of forming defects such as cracks and wrinkles only in the long side wall portion 32L of the bottomed container 30.

  Therefore, in the first embodiment, the height dimension of the long side sliding contact surface 25L with respect to the bottom pressing surface 21 is set to both end portions (that is, the short side in the length direction of the long side outer surface 22L). It is set to be the smallest in the area close to the side path 27S and to increase toward the center in the left-right direction (that is, the distance from the short side path 27S). Due to this height difference, the sliding resistance when the molding material 35 rises up the long side path 27L is large at the central portion far from the short side path 27S, and small at both end portions near the short side. In this setting, if the influence of the molding material 35 in the short side path 27S is ignored and limited within the long side path 27L, the rising speed of the molding material 35 is the slowest at the center and at both ends. It means faster as you go.

  Therefore, in consideration of the influence of the tension by the molding material 35 in the short side path 27S, the rising speed of the molding material 35 at both ends in the left and right direction of the long side path 27L during molding is the same as that of the short side path 27S. By being pulled by the material to be molded 35, the speed is lowered to a speed that is approximately the same as the rising speed of the material to be molded 35 in the central portion in the left-right direction. Thereby, since the rising speed of the molding material 35 in the long side path 27L becomes substantially uniform over the entire length, occurrence of molding defects such as cracks and wrinkles in the long side wall portion 32L of the bottomed container 30 occurs. Is prevented.

<Example 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. In the molding apparatus Mb of the second embodiment, the bottom shape of the punch 40 is different from that of the first embodiment. Since other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and descriptions of the structure, operation, and effects are omitted.

  On the bottom pressing surface 41 of the punch 40, a recess 42 is formed in which a region excluding both ends in the long side direction is recessed. The recess 42 is open to the long side sliding contact surface 25L (long side path 27L), but not open to the short side sliding contact surface 25S (short side path 27S). The bottom pressing surface 41 includes a pair of symmetrical first pressing surfaces 43 positioned at both ends in the long side direction, a pair of second pressing surfaces 44 symmetrically positioned at both ends in the long side direction of the recess 42, and a recess. 42, one third pressing surface 45 located between the pair of second pressing surfaces 44.

  The first pressing surface 43 and the third pressing surface 45 are flat surfaces perpendicular to the pressing direction of the punch 40. The second pressing surface 44 is inclined with respect to the first pressing surface 43 and the third pressing surface 45. The ratio of the length dimension of the first pressing surface 43 and the second pressing surface 44 in the long side direction is about 1: 1. The ratio of the length dimension of the first pressing surface 43 and the third pressing surface 45 in the long side direction is about 1:14. The ratio of the length dimension of the first pressing surface 43 in the long side direction to the height difference dimension of the first pressing surface 43 and the third pressing surface 45 is about 4: 1.

  When the punch 40 enters the cavity 11, both the long side direction end portions (first pressing surfaces 43) in which the concave portions 42 are not formed in the bottom pressing surface 41 press the material 35 to be shocked. The material to be molded 35 rises in advance at the short side path 27S near both ends in the long side direction and at both ends of the long side path 27L near the short side path 27S. Thereafter, in the long side path 27L, in the region excluding both ends in the long side direction in the long side direction and corresponding to the second pressing surface 44 of the recess 42, the molding material 35 rises with a delay. Thereafter, in the region corresponding to the third pressing surface 45 in the long side direction in the long side path 27L, the molding material 35 rises with a further delay.

  In the second embodiment, the rising start timing of the molding material 35 in the long-side path 27L is set at both ends in the long-side direction (that is, the region close to the short-side path 27S where the rising speed of the molding material 35 is relatively slow ), And at the center in the long side direction (region where the rising speed of the molding material 35 is higher than at both ends in the long side direction). Thus, by providing a time difference at the start of rising, unevenness of the rising speed of the molding material 35 in the long side direction of the long side path 27L is alleviated.

<Example 3>
Next, a third embodiment of the present invention will be described with reference to FIGS. In the molding apparatus Mc of the third embodiment, the bottom shape of the punch 50 is different from that of the first embodiment. Since other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and descriptions of the structure, operation, and effects are omitted.

  The bottom pressing surface 51 of the punch 50 has a ship bottom shape as a whole. That is, the bottom pressing surface 51 is lowest at the center in the front-rear direction and highest at the front edge and the rear edge connected to the long side sliding contact surface 25L. Moreover, the taper surface 52 which makes an obtuse angle with respect to the short side side sliding contact surface 25S is formed in the both ends in the left-right direction (long side direction) of the bottom part press surface 51. As shown in FIG.

  A part of the molding material 35 (not shown) pressed by the bottom pressing surface 51 moves substantially horizontally along the bottom path 53 along the tapered surface 52, and then moves upward toward the short side path 27S. change. Here, since the taper surface 52 and the short side slidable contact surface 25S form an obtuse angle, as compared with the case where the bottom pressing surface 21 and the short side slidable contact surface 25S form a right angle as in the first embodiment. The change in the flow direction of the molding material 35 is small. Therefore, the sliding contact resistance in the short side path 27S is reduced, so that the influence of tension exerted on the molding material 35 in the long side path 27L from the molding material 35 in the short side path 27S is reduced. The Thereby, the nonuniformity of the rising speed of the molding material 35 in the long side path 27L is more effectively reduced.

<Example 4>
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the molding apparatus Md according to the fourth embodiment, the bottom shape of the punch 60 is different from that of the first embodiment. Since other configurations are the same as those in the first embodiment, the same reference numerals are given to the same configurations, and descriptions of the structure, operation, and effects are omitted.

  The bottom pressing surface 61 of the punch 60 is formed with a groove portion 62 extending in the left-right direction (long side direction) and having both end portions in the left-right direction reaching the short-side slidable contact surface 25S. In the long side direction (left-right direction), the groove part 62 is a form that continues over the entire length of the bottom pressing surface 61. The groove 62 is formed at the center position of the bottom pressing surface 61 in the front-rear direction (short-side direction).

  A part of the molding material 35 (not shown) pressed by the bottom pressing surface 61 flows from the bottom path (not shown) along the bottom pressing surface 61 to the short side path 27S along the long side direction. Here, since the groove 62 along the long side direction is formed on the bottom pressing surface 61, the cross-sectional area perpendicular to the flow in the bottom path is larger than in the case where the groove 62 is not formed. The flow resistance of the molding material 35 is reduced. Thereby, since the influence of the tension exerted on the molding material 35 in the long side path 27L from the molding material 35 in the short side path 27S is reduced, the molding material 35 in the long side path 27L is reduced. Unevenness of the rising speed can be reduced more effectively.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above Examples 1 to 4, the minimum height of the long side sliding surface is the same as the short side sliding surface, but the minimum height of the long side sliding surface is the short side. It may be higher than the side sliding surface and may be lower than the short side sliding surface.
(2) In Examples 1 to 4, the height of the short side sliding surface is constant, but the height of the short side sliding surface is decreased from the center in the short side direction toward both ends. Alternatively, the height may increase from the center in the short side direction toward both ends.
(3) In the first to fourth embodiments, the upper edge of the long side sliding surface has a shape including a smoothly continuous curve. However, the upper edge of the long side sliding surface is composed of only a straight line. It is good also as a shape.
(4) The groove portion of the fourth embodiment may be added to the second and third embodiments.
(5) The tapered surface of the third embodiment may be added to the second and fourth embodiments.
(6) The dimensional ratios set or applied in the above Examples 1 to 4 show an example, and the present invention can be set and applied to dimensions other than those described in the above Examples.

Ma ... Molding device 10 ... Die 11 ... Cavity 20 ... Punch 21 ... Bottom pressing surface 22L ... Long side outer surface 22S ... Short side outer surface 25L ... Long side sliding surface 25S ... Short side sliding surface 27L ... Long side path 27S ... Short side path 30 ... Bottomed container 35 ... Molded material Mb, Mc, Md ... Molding device 40, 50, 60 ... Punch 41, 51, 61 ... Bottom pressing surface 42 ... Concave portion 52 ... Taper Surface 62 ... groove

Claims (4)

A die formed with a cavity having an open top surface for accommodating a molding material;
A punch provided to allow entry into the cavity from above the die,
The bottom material has an approximately rectangular bottom shape by plastically deforming the material to be molded, which has been shockedly pressed by the bottom pressing surface of the punch, while rising in a direction opposite to the pressing direction in the gap between the cavity and the punch. A molding device for molding a bottom container,
The long side side outer surface of the punch forms a long side path for raising the molding material between the inner side surface of the cavity and the long side side where the rising molding material slides. A sliding surface is formed,
The short side of the short side of the punch forms a short side path for raising the molding material between the inner side of the cavity and the short side of the rising material to be slidably contacted A sliding surface is formed,
The height dimension of the long side slidable contact surface with respect to the bottom pressing surface is minimum at both ends in the length direction of the long side outer surface, and at the center in the length direction of the long side outer surface. An apparatus for forming a bottomed container, characterized in that the container becomes larger toward the bottom.   A recess is formed in the bottom pressing surface excluding both ends in the long side direction so as to be opened on the long side sliding contact surface but not on the short side sliding contact surface. The apparatus for forming a bottomed container according to claim 1.   3. The bottomed container according to claim 1, wherein a tapered surface having an obtuse angle with respect to the short side sliding contact surface is formed at both ends in the long side direction of the bottom pressing surface. Molding equipment.   4. The groove according to claim 1, wherein the bottom pressing surface is formed with a groove extending along the long side direction and having both end portions in the long side direction reaching the short side sliding surface. The apparatus for forming a bottomed container according to claim 1.

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