TWI775072B - Punch structure of stamping die, stamping die and manufacturing method of stamping formed part - Google Patents

Abstract

The invention provides a punch structure, a stamping die, a method for manufacturing a stamped part, and a stamped part, which can effectively prevent repeated punching during the production of a stamped part including a narrow width portion with a narrow width relative to the thickness. The punch structure used is damaged. This punch structure is arranged to protrude from the main body of the press die and is used for punching out a press-formed product including a narrow width portion having a width (w) to thickness (t) ratio (w/t) of 1.5 or less. The structure has a punch front end portion (2), the punch front end portion (2) has a front end surface (T), and at least a part of the front end surface (T) includes a narrow width corresponding to the planar shape of the narrow width portion of the press-formed product. In the web shapes (3) and (4), a part of the side surface (S) of the front end portion (2) of the punch is provided with a reinforcing rib (6) extending along the protruding direction of the punch structure.

Description

Punch structure of stamping die, stamping die and manufacturing method of stamping formed part

The invention relates to a punch structure, a stamping die, a manufacturing method of the stamped part and the stamped part, which are arranged in a stamping die and are used for punching a stamped part of a predetermined shape from a metal plate of a stamped object, and particularly proposes a method for manufacturing a stamping part comprising: A technique that can effectively prevent breakage of the punch structure that is repeatedly used in the punching process when the width is narrower than the thickness of the narrow-width press-formed product.

When manufacturing a connector or a lead frame, the terminal portion is generally formed by press molding in which a metal plate such as a copper alloy, which is a material to be processed, is punched and punched.

In addition, in recent years, with the miniaturization of devices, the connector terminals built in the device have also been miniaturized. In press molding, it is necessary to punch out a fine and complex shape, and the press molding is strictly required. dimensional tolerances.

In this way, as the miniaturization and complication of press-formed parts progress, according to the press-formed parts, there are parts with a narrow width relative to the thickness, and there are even narrow parts in which the ratio of the width w to the thickness t (w/t) is 1.5 or less. condition of the width. In this case, when manufacturing such a press-formed product, for example, it is easy to perform the punching process in a plurality of times so that the one side and the other side of the narrow-width portion are punched in sequence. A so-called tip-over occurs.

In more detail, this overturning occurs because one side is punched out in the previous punching process among the plurality of punching processes, and the other side is punched out in the subsequent punching process. When punching one side part, since the width of the part of the material to be the narrow part is narrow, the part sandwiched between the punch and the die is oriented in a direction opposite to the cross section during the subsequent punching process. side displacement. In the event of tipping over, the stamped parts are dimensionally unstable, making it difficult to meet tight dimensional tolerances. Moreover, as a technique focusing on such a problem, there exists the technique described in patent document 1, for example. prior art literature Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2007-326105

Invention to solve problem

Various countermeasures have been considered for the above-mentioned overturning, and as one of them, a technique of one-piece punching or double-sided punching is effective. According to this technique, since both sides of the narrow portion are simultaneously punched, it does not fall over, and even the narrow portion with a width/thickness ratio of 1.5 or less can be formed into a stable shape.

However, when such integral punching is performed, there is a problem in that since the shape of the front end surface of the punch structure of the punching die needs to be formed to include the same narrow-width shape as the narrow-width portion, the narrow width of the narrow-width portion has the following problem. The shape reduces the strength of the punch structure, thereby causing a problem in that predetermined portions of the punch structure are broken, such as cracks, with use.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a punch structure, a stamping die, a method for producing a stamped product, and a stamped product, which are used in the production of a stamped product including a narrow width portion with a narrow width relative to the thickness. , which can effectively prevent damage to the punch structure that is repeatedly used in its blanking process. solution to the problem

The punch structure of the present invention is arranged to protrude from the main body of the press die, and is used for punching a press-formed product including a narrow width portion having a ratio of width w to thickness t (w/t) of 1.5 or less, and the punch structure has A punch front end portion having a front end surface, at least a part of the front end surface including a narrow width shape corresponding to the planar shape of the narrow width portion of the press-formed product, and provided on a part of the side surface of the punch front end portion There are reinforcing ribs extending along the protruding direction of the punch structure.

The punch structure of the present invention is particularly effective as a punch structure for punching a press-formed part including two narrow-width portions and a connecting portion, the two narrow-width portions being spaced apart from each other and arranged side by side, which The connecting portion connects the narrow width portions to each other. In this case, it is preferable that the front end portion of the punch has a front end surface, and at least a part of the front end surface includes the narrow width portion and the connecting portion of the press-formed product. The flat shape corresponding to the narrow width shape and the connecting shape.

In addition, in this case, it is preferable that the reinforcing rib is located at an end portion of the narrow-width shape of the front end portion of the punch away from the connecting shape.

Also, wherein, preferably, at at least one of the ends of the narrow shape, the reinforcing rib is provided on each of the two sides across the narrow shape.

In the punch structure of the present invention, preferably, the reinforcing rib is continuously provided from the front end surface of the punch front end portion along the protruding direction by a length of 3 to 50 times the thickness t of the narrow width portion.

In addition, in the punch structure of the present invention, preferably, the reinforcing rib has a rectangular cross-sectional shape.

Wherein, preferably, on the cross section of the reinforcing rib, the width of the reinforcing rib parallel to the side edge of the narrow-width shape is expressed as a ratio of the width w of the narrow-width portion, and is 0.3-4.

In addition, preferably, in the cross section of the reinforcing rib, the height of the reinforcing rib orthogonal to the side edge of the narrow-width shape is 0.3-4 expressed as a ratio to the width w of the narrow-width portion.

In addition, in the punch structure of the present invention, preferably, the reinforcing rib is in the protruding direction, and the entire reinforcing rib has a fixed cross-sectional shape.

The punching die of the present invention has any one of the punch structures described above.

The method for producing a press-formed product of the present invention uses a press die having any one of the above-described punch structures to punch out a metal plate to produce a press-formed product.

More specifically, in the method for producing a press-formed product of the present invention, a metal plate can be sequentially subjected to a plurality of punching processes including a pre-process punching process and a subsequent post-process punching process, and the pre-process punching process or the post-process punching process can be performed. In any one of the punching processes, the punch structure in which the reinforcing rib is provided at the front end of the punch is used to form a primary punching part, and in the other punching process, the same as the primary punching part is formed. The portion including the portion where the reinforcing rib penetrates is punched in a crossed manner to form a secondary punched portion.

In this manufacturing method, preferably, the other punching process for forming the secondary punching portion is used as the pre-stage punching process, and the one punching process for forming the primary punching portion is the post-step punching process.

The press-formed product of the present invention includes a narrow-width portion whose ratio (w/t) of the width w to the thickness t is 1.5 or less, and the side surfaces around the narrow-width portion become the punching surface of the press.

On a part of the side surface of the narrow portion, a rib matching portion for dividing the secondary punching surface from the primary punching surface area is formed.

Preferably, the press-formed part of the present invention comprises two of the narrow-width parts and a connecting part, the two narrow-width parts are spaced apart from each other and arranged side by side, the connecting part connects the narrow-width parts to each other, and the narrow-width parts are arranged side by side. And the side surface around the connection part becomes the punching surface of the press.

In addition, preferably, in the stamping and forming part of the present invention, the secondary punching surface is located on the side surface of the narrow width portion away from the end portion of the connecting portion.

In addition, preferably, in the stamping-formed part of the present invention, at at least one of the ends of the narrow-width portion, the secondary punching surface is provided on each of the two side surfaces of the narrow-width portion.

Preferably, the secondary punched surface of the stamped part is formed by concave from the primary punched surface.

In this case, preferably, measured along the width direction of the narrow width portion, the amount of depression of the secondary punching surface is 10% to 20% of the width w of the narrow width portion.

Preferably, in the press-formed part of the present invention, the ratio (w1/t) of the width w1 to the thickness t of the narrow width portion at the portion where the secondary blanking surface is formed is 0.5-1.5.

Preferably, in the press-formed part of the present invention, the press-formed part has a sag surface and a burr surface, and in cross section, the surface part of the burr surface is parallel to the sag surface or inclined downward to the right and upward to the right. The area ratio of the larger surface part among the inclined surface parts is 90% or more.

In this case, it is preferable that the inclination angle of the larger surface portion with respect to the sag surface is in the range of 0° to 20° in the cross section. Invention effect

According to the present invention, cracks in a predetermined portion of the punch structure can be suppressed by providing the reinforcing rib extending in the protruding direction of the punch structure on a part of the side surface of the punch tip end portion of the punch structure. Accordingly, even when the punch structure is repeatedly used in punching of a press-formed product including a narrow width portion with respect to the thickness, breakage of the punch structure can be effectively prevented.

Hereinafter, embodiments of the present invention will be described in detail based on the contents shown in the drawings. (Punch structure)

A punch structure 1 according to an embodiment of the present invention is provided in either an upper die or a lower die of a press die body, not shown, such as a sequential operation die, and is used for punching a press-formed product from a metal plate of a press object. The head structure 1 has a columnar shape which is arranged to protrude from the main body of the press die.

More specifically, as illustrated in FIG. 1 , the punch front end portion 2 of the punch structure 1 has a front end surface T that abuts and penetrates the metal plate of the punched object, and the front end surface T is formed as A shape corresponding to the predetermined planar shape of the stamped part.

Here, as an example, as schematically shown in FIG. 2 , the target press-formed product 21 to be finally produced has a substantially “H” shape including two narrow width portions 22 and 23 and a connecting portion 24 in a plan view. The two narrow width portions 22 and 23 are spaced apart from each other and arranged side by side, for example, of different lengths from each other, substantially parallel and extending in a substantially straight line, and the connecting portion 24 is between the narrow width portions 22 and 23, for example, in width The narrow width portions 22 and 23 are connected to each other at an intermediate position in the extending direction of the narrow width portions 22 and 23 while being changed. Furthermore, in this press-molded product 21 , the ratio (w/t) of the width w to the thickness t of the narrow width portions 22 and 23 is 1.5 or less.

Correspondingly, at least a part of the front end surface T of the punch front end portion 2 includes narrow shapes 3 and 4, and the narrow shapes 3 and 4 have a ratio (w/t) of the width w to the thickness t of 1.5 or less. The narrow width shape corresponding to the planar shape of the narrow width portions 22 and 23 is substantially the same as the planar shape of the narrow width portions 22 and 23 , for example. Describing the embodiment of the drawings in detail, the front end surface T of the punch front end portion 2 has a shape including two narrow shapes 3 and 4 and a connecting shape 5, which are substantially the same as the press molding 21. The two narrow shapes 3, 4 are spaced apart from each other and arranged side by side, and this connecting shape 5 connects the narrow width shapes 3, 4 to each other. The narrow shapes 3 and 4 are substantially parallel to each other and extend in a substantially linear shape, and the connecting shape 5 extends while changing the width, and connects the narrow shapes 3 and 4 at an intermediate position in the extending direction of the narrow shapes 3 and 4 .

As described above, the punch structure 1 has the front end surface T of a shape substantially corresponding to the planar shape of the press-formed product 21, so that when the press-formed product 21 is punched from a metal plate, a die and punching template (not shown) are used. Since the narrow width portions 22 and 23 and the connecting portion 24 are integrally punched by pressing both sides of the narrow width portions 22 and 23, the aforementioned problem of dimensional stability due to overturning is unlikely to occur.

On the other hand, since the above-described punch structure 1 enables integral punching of the fine press-molded product 21, the widths of the narrow shapes 3 and 4 and the connecting shape 5 of the front end surface are extremely narrow. Therefore, if the conventional punch structure is repeatedly used, there is a problem that cracks and other damages such as cracks occur at a predetermined portion of the front end face T at an early stage with a small number of shots.

In order to cope with this problem, in the punch structure 1 of the present embodiment, as illustrated in FIG. 1 , for example, a portion of the side surface S of the punch tip portion 2 that is substantially parallel to the projection direction is provided along the projection direction of the punch structure 1 . Extended reinforcing ribs 6 .

According to this configuration, even the front end surface T of the punch front end portion 2 has a fine narrow width shape for punching out the narrow width portions 22 and 23 having a ratio (w/t) of the width w to the thickness t of 1.5 or less In the punch structures 1 of 3 and 4, when the punch structure 1 is used for the punching process, the reinforcing ribs 6 can suppress the force that the punch structure 1 receives from the metal plate of the punched object to have a narrow shape. The displacement of the parts 3 and 4 can effectively prevent damage to the front end surface T.

In order to investigate the cause of the breakage of the front end surface of the punch structure including the narrow shape and the connecting shape on the front end surface as shown in the figure, the position of the reinforcement rib 6 in the front end portion 2 of the punch, its shape, and the For other optimal conditions, studies as described below were carried out.

When the conventional punch structure without the reinforcing rib 6 is repeatedly used, the front end face is broken with a small number of shots. When the breakage of the front end surface was confirmed, it was found that the following cracks existed in the structure of many punches: as shown in FIG. As shown in FIG. 3( b ), such a crack C2 extending from the outer edge side of the middle portion of the longer narrow shape to the inner side is shown.

In addition, based on the results of the investigation of the side surfaces of these punch structures where the front end surface is damaged, it is assumed that the lateral force acting on the side surface of the front end portion of the punch during punching affects the damage of the front end surface. In order to verify this , a simulation was performed in which the lateral force was added as a condition in addition to the punching load.

By the simulation with the addition of the lateral force, the following results were obtained: the part where the tensile stress concentrated was the part of the connecting shape between the narrow shapes and the outer edge of the middle part of the longer narrow shape. Since this corresponds to the damaged portions of the above-mentioned cracks C1 and C2 on the front end surface, it can be seen that the lateral force at the time of punching largely affects the damage of the front end surface.

That is, it can be considered that, at the time of punching, in the punch structure, not only a punching load oriented parallel to the protruding direction is applied, but also, as shown in FIGS. As shown by the arrow in the figure, a lateral force also acts from the lateral side of the extended portion of the web shape. As shown in Fig. 4(a), when a lateral force acts from the side of the shorter narrow shape, that is, from the inner edge side to the outer edge side, the tensile stress concentrates on the connecting shape as indicated by the dotted line in the figure. Near the part of the long narrow shape. On the other hand, as shown in Fig. 4(b), when a lateral force acts from the outer edge side to the inner edge side, as shown by the dotted line in the figure, the tensile stress is concentrated in the central part of the connected shape, and the long and narrow The outer edge of the central portion of the web shape, so that cracks are generated at these stress concentration locations.

Therefore, in order to suppress the stress concentration caused by the lateral force as described above, the reinforcing rib 6 is provided on a part of the side surface S of the punch tip portion 2 to resist the lateral force, which is effective in preventing breakage.

Specifically, as shown in FIG. 1 , the reinforcing rib 6 is preferably arranged at the ends of the narrow shapes 3 and 4 of the punch tip 2 away from the connecting shape 5 . This is because the ends of the narrow shapes 3 and 4 are greatly displaced by the lateral force during punching. Therefore, by arranging the reinforcing ribs 6 at the ends to suppress the displacement, it is possible to effectively prevent the tensile stress from spreading to the The concentration of the predetermined part, and then effectively prevent the occurrence of cracks. In the example shown in FIG. 1 , reinforcing ribs 6 are arranged at both ends of the long narrow shape 3 and both ends of the short narrow shape 4 .

In addition, in this case, it is preferable to provide reinforcing ribs 6 on both sides S across the narrow shapes 3 and 4 at at least one end of the narrow shapes 3 and 4, that is, to strengthen the The ribs 6 are provided so as to sandwich the ends of the narrow shapes 3 and 4 from both side surfaces S sides. As a result, the ends of the narrow shapes 3 and 4 that are largely displaced during punching are restrained from both sides by the reinforcing ribs 6, thereby further enhancing the effect of preventing cracks. However, in the punch structure 1 as shown in FIG. 1, only the end of the extended portion of the long narrow shape 3 is separated from the end of the extended portion of the long narrow shape 3 due to restrictions on the arrangement space of the reinforcing ribs 6 and other reasons. The reinforcing ribs 6 are provided on both sides of the end portion, and the reinforcing ribs 6 are provided on only one side of the outer edge side of the other end portion. In addition, as illustrated in FIG. 5 , the reinforcing ribs 6 may be provided on only one side of all the ends of the narrow shapes 3 and 4 .

Regarding the size and shape of the reinforcing rib 6, according to the analogy results, it is preferable that the reinforcing rib 6 is protruded from the front end surface T of the punch front end portion 2 toward the base side in the narrow width portion 22 of the press-formed product 21 to be produced. The lengths of 3 times to 50 times the thickness t of 23 are provided continuously. If the length Lr in the protruding direction of the reinforcing rib 7 is made larger than 50 times the thickness t of the narrow portions 22 and 23 , the cutting edge may become insufficient in strength (warped, skewed, etc.). In addition, as in other examples to be described later, when the reinforcing rib extends from the base side to the front of the front end surface, there is a possibility that the reinforcing rib apex portion (for example, the contact between the side surface of the front end portion of the punch and the acute angle portion of the triangular rib) seams) damaged.

In addition, according to the analogy results, it is preferable that the reinforcing rib 6 has a rectangular cross-sectional shape, and it is particularly preferable that the reinforcing rib 6 has a rectangular cross-sectional shape that forms a fixed area in the entire protruding direction as shown in FIGS. 1 and 5. Corner column. This is because such a quadrangular columnar reinforcing rib 6 can more effectively suppress deformation of the punch tip end portion 2 due to the stress in the direction indicated by the arrow in FIG. 4 , as compared with the triangular rib described later.

Further, as shown in FIG. 6 , in the cross section of the reinforcing rib 6 perpendicular to the protruding direction, the width Wr of the reinforcing rib 6 parallel to the side edges of the narrow shapes 3 and 4 is equal to the width Wr of the narrow parts 22 and 23 . The ratio of the width w of , is preferably 0.3 to 4. If the width Wr of the reinforcing rib 6 is too narrow relative to the width w of the narrow portions 22 and 23, the reinforcing effect may be reduced. When it is wide, it cannot be denied that there is a possibility of breakage from the joint between the reinforcing rib 6 and the side surface S of the punch tip end portion 2 .

In addition, as shown in FIG. 6, in the cross section of the reinforcing rib 6, the height Hr of the reinforcing rib 6 orthogonal to the side edges of the narrow shapes 3 and 4 is a ratio of the width w of the narrow parts 22 and 23. represents, preferably 0.3 to 4. If the height Hr of the reinforcing rib 6 is too low relative to the width w of the narrow width portions 22 and 23, there is a possibility that the reinforcing effect may be reduced, and if the height Hr of the reinforcing rib 6 is too high relative to the width w of the narrow width portions 22 and 23 , there is a fear of damage from the joint between the reinforcing rib 6 and the side surface S of the punch tip end portion 2 .

However, the reinforcing rib may have a size and shape as shown in FIG. 7 , for example.

In the example shown in FIG. 7( a ), the reinforcing rib 6 a is formed into a substantially right-angled triangle shape in side view, and its cross-sectional shape is a rectangle whose area gradually decreases from the base side of the punch structure 1 toward the front end surface T side. (triangular rib). And the reinforcing rib 6a of such a shape is arrange|positioned so that it may extend from the base part side until it does not reach the intermediate position in the protruding direction of the front end surface T. As shown in FIG.

In the example shown in FIG. 7( b ), on the outer surface of the short narrow shape 4 , reinforcing ribs of the same shape are also provided between the reinforcing ribs 6 a respectively provided at both ends of the narrow shape 4 . 6a, other than that, it is the same as the example shown in Fig. 7(a).

In the example shown in Fig. 7(c), all the reinforcing ribs 6a in Fig. 7(a) are replaced with the reinforcing ribs 6b extending up to the front end surface T longer than the reinforcing ribs 6b. The example shown in Figure (a) is the same.

Depending on the shape of the front end surface T of the punch front end portion 2 and other conditions, the size and shape as illustrated in FIG. 7 may be preferable in some cases.

In the above description, as shown in FIG. 2 for punching, the two narrow width portions 22 and 23 that are spaced apart from each other and extend side by side, and the narrow width portions 22 and 23 are mutually The press-formed product 21 of the connected connecting portion 24 has been described as including the punch structure 1 including the narrow shapes 3 and 4 and the front end face T of the connecting shape 5 corresponding to the planar shape of the press-formed product 21 , but When punching a stamped part different from this shape, the shape of the punch structure can be appropriately changed according to its plane shape.

For example, the punch structure 31 shown in Fig. 8(a) has a narrow shape 33 and a narrow shape 34 on the front end surface, and has a substantially "L"-shaped plane shape, and the narrow shape 33 extends linearly , the narrow-width shape 34 is connected to one end of the narrow-width shape 33 , and extends linearly with a length shorter than that of the narrow-width shape 33 in a direction substantially orthogonal to the narrow-width shape 33 . Here, reinforcing ribs 36 are provided on both sides of the other end of the long narrow shape 33 .

The punch structure 41 shown in FIG. 8(b) has a front end surface T including two long and short narrow shapes 43 and 44 and a connecting shape 45, the narrow shapes 43 and 44 being parallel to each other in a straight line The connecting shape 45 extends between the two narrow-width shapes 43 and 44 in a direction substantially orthogonal to the two narrow-width shapes 43 and 44 , and connects the middle part of the long narrow-width shape 43 with the short narrow-width shape 43 . One end of the web shape 44 is connected. In this punch structure 41 , reinforcing ribs 46 are provided on both sides of one end of the long narrow shape 43 , and only the other end of the long narrow shape 43 and the other end of the short narrow shape 43 are provided with reinforcing ribs 46 . A reinforcing rib 46 is provided on the outer side of one side.

In the punch structure 51 shown in FIG. 8( c ), the part from the connecting shape 55 to the other end side of the long narrow shape 53 is removed, and the other end of the long narrow shape 53 and the short narrow shape 53 are removed. One end portion of the shape 54 is connected by the connecting shape 55 , and the rest has substantially the same configuration as that of the punch structure 41 in FIG. 8( b ). (Manufacturing method of press-formed parts)

By punching out the metal plate using a punching die having the punch structure 1, 31, 41, or 51 as described above, a predetermined punch-formed product can be produced. The punching die is incorporated into a sequential action die or the like, and other structures other than the punch structure and its related structures can be used as existing structures, so detailed description and illustration are omitted here.

Hereinafter, the manufacturing method using the punch structure 1 will be described as an example, but the method using the other punch structures 31 , 41 , or 51 and the like can be performed in substantially the same manner.

Since the punch structure 1 is provided with the reinforcing ribs 6, depending on the arrangement of the reinforcing ribs 6, there may be cases in which the part of the metal plate penetrated by the reinforcing ribs 6 also occurs when the punch structure 1 is used to punch a metal plate. After being punched out, the portion corresponding to the reinforcing rib 6 on the side surface of the formed product thus formed is inevitably formed with a convex portion corresponding to the cross-sectional shape of the reinforcing rib 6 .

In order to cope with the above-mentioned situation, it is preferable to sequentially perform the punching process of a plurality of steps including the pre-process punching process and the subsequent post-process punching process on the metal plate.

Specifically, for example, first, as shown in FIG. 9( a ), the metal plate 61 is punched using the punch structure 1 provided with the reinforcing ribs 6 . Thereby, the semi-finished product 62 shown in FIG. 9(b) can be formed by punching and shaping|molding from the metal plate 61. FIG. As a result of forming the semi-finished product 62 using the punch structure 1 described above, as shown in FIG. 9( b ), a portion on the side surface corresponding to the reinforcing rib 6 of the punch structure 1 (in this example, a narrow width shape The protruding portion 63 protruding from the side surface and having a shape such as a rectangle corresponding to the cross-sectional shape of the reinforcing rib 6 is formed. The entire side surface of the semi-finished product 62 including the convex portion 63 becomes the primary punching portion Sp1. In addition, here, the punching process using the punch structure 1 is a pre-process punching process performed before the punching process to be described later.

Next, in order to remove the above-mentioned convex portion 63 of the semi-finished product 62 , as shown in FIG. 9( c ), punch structures 1 a to 1 e different from the punch structure 1 are used so as to intersect the primary punching portion Sp1 of the semi-finished product 62 . The punching process is performed on the site|part including the site|part where the reinforcement rib 6 mentioned above penetrates and the convex part 63 is formed. By this punching, as shown in FIG. 9( d ), a press-molded product 71 in which the secondary punching portion Sp2 is formed in the portion where the convex portion 63 exists can be obtained. In this case, the punching process by the punch structures 1a to 1e is later than the above-mentioned pre-process punching process in time, and thus becomes a post-process punching process.

In addition, the semi-finished product 62 may be punched simultaneously by using all the punch structures 1a to 1e, or at least one of the punch structures 1a to 1e may be used staggered from the remaining punch structures, thereby sequentially performing the punching process . That is, the post-process punching process can be further divided into a plurality of processes.

In this embodiment, each of the punch structures 1a to 1e is slightly wider than each of the convex portions 63 and punched so as to be slightly recessed into the narrow width portion of the semi-finished product 62 in plan view, thereby forming a press-molded product. In 71, the portion of the side surface where the convex portion 63 once existed is slightly recessed, and a matching portion serving as a boundary between the primary punching portion Sp1 and the secondary punching portion Sp2 is formed near both sides of the portion. However, although the drawing is omitted, the convex portion 63 may be punched by punch structures 1a to 1e so as to be slightly spaced apart from the narrow width portion of the semi-finished product 62. The protrusion from the side surface is caused by the remaining part of the part 63 . Details of the press-formed part 71 will be described later.

In this way, by using the punch structure 1 to manufacture the press-formed part 71 and providing the reinforcing ribs 6 as described above, the front end face of the punch structure 1 can be prevented from being damaged, and the ratio of the width w to the thickness t can be efficiently manufactured ( The press-formed product 71 of the narrow width part with w/t) being 1.5 or less.

Alternatively, the press-molded product 71 can also be produced as shown in FIG. 10 .

In this embodiment, first, as shown in FIG. 10( a ), as a pre-step punching process, the metal plate 61 is punched using punch structures 1 a to 1 e , as shown in FIG. 10( b ) , on the metal plate 61, a secondary punching portion Sp2 that becomes a cavity corresponding to each of the punch structures 1a to 1e is formed. At this time, the punching process by the punch structures 1a to 1e is performed at the following positions: in the post-process punching process described later, the primary punching part Sp1 by the post-process punching process and the secondary punching process The cutting portion Sp2 intersects and includes the position of the portion where the reinforcing rib 6 of the punch structure 1 used in the subsequent punching process is to penetrate.

In addition, all the punching processes performed by the punch structures 1a to 1e may be performed at the same time, or at least one of them may be performed at a time staggered.

Then, as shown in FIG. 10( b ), as a subsequent punching process, the metal plate 61 having the secondary punching portion Sp2 formed thereon is punched using the punch structure 1 provided with the reinforcing ribs 6 . As a result, as shown in FIG. 10( c ), the scrap metal plate 61 in which the cavities penetrating the front and back surfaces are formed at the primary punching site Sp1 and the secondary punching site Sp2 can be obtained, and as shown in FIG. 10 (d) The press-formed part 71 shown in the above is substantially the same.

In the manufacturing method shown in FIG. 10, the punching process for forming the secondary punching portion Sp2 by the punch structures 1a to 1e is used as the pre-step punching process, and the punch structure 1 provided with the reinforcing ribs 6 is used. The punching process for forming the primary punching portion Sp1 is performed as a post-process punching process, and thereby, compared with the manufacturing method shown in FIG. 9 , there is an advantage that the generation of scrap can be suppressed. In the manufacturing method shown in FIG. 9, since the size of the punched shape in the step of FIG. 9(c) is small, it cannot be denied that there is a possibility that scraps are likely to be generated. Therefore, the manufacturing method shown in FIG. 10 is preferable to the method shown in FIG. 9 .

In the manufacturing method shown in FIG. 9 or FIG. 10, you may change a part and implement it.

As a modification thereof, although illustration is omitted, for example, punching by at least one of the punch structures 1 a to 1 e can be considered before or after punching by the punch structure 1 . That is, in this modification, first, punching is performed by at least one of the punch structures 1a to 1e, then, punching is performed by the punch structure 1, and then the punch structure 1a is performed. The remaining blanking process of ~1e.

In addition, although the planar shape of the punch structures 1a-1e is a substantially "L" shape in embodiment of a figure, you may change it into a rectangle, a square, or other shape.

Such various changes and improvements can be appropriately performed according to the shape of the press-molded product to be produced, the form of the mold, and other conditions.

In addition, in the above description, the terms "primary" and "secondary" in the primary punching site Sp1 and the secondary punching site Sp2 only refer to sites formed using different punch structures 1 and punch structures 1a to 1e. The same applies to the primary punching surface and the secondary punching surface of the press-formed product to be described later. (Stamping and forming parts)

As shown in FIGS. 11( a ) and ( b ), the press-formed product 71 manufactured as described above has narrow width portions 72 and 73 having a ratio (w/t) of width w to thickness t of 1.5 or less, including The entire side surfaces of the press-molded product 71 on the side surfaces of the narrow width portions 72 and 73 are punched and punched surfaces. In particular, when the ratio (w/t) of the width w to the thickness t of the narrow width portions 72 and 73 is 1.0 or less and further 0.8 or less, the narrow width shape 3 of the punch structure 1 for molding the narrow width portions 72 and 73 , 4 become fine, displacement easily occurs during punching, and the problem of breakage becomes significant, therefore, the application of the present invention will be more effective. In addition, the ratio (w/t) of the width w to the thickness t of the narrow width parts 72 and 73 is usually 1.0 or more in many cases.

In addition, as shown in FIG. 11( b ), the punched surface generally includes one or more shear surface regions and fracture surface regions that extend side by side in the extending direction of the side surface (left-right direction in the same figure). The shear plane region is considered to be formed by friction with a punch or die when the metal plate is stretched in the thickness direction by punching, and becomes a smooth surface having some linear patterns in the thickness direction. On the other hand, the fractured surface region is considered to be formed by being pulled off the scrap discharged after drawing by punching, and is clearly different from the sheared surface region, and is a pit-shaped surface having irregularities.

The press-molded product 71 of this embodiment is composed of two narrow width portions 72 and 73 and a connecting portion 74 which are spaced apart from each other and are arranged side by side, and the connecting portion 74 connects the narrow width portions 71 to each other. The parts 72 and 73 are connected to each other, and one narrow-width part 72 has an extension part extending longer than the other narrow-width part 73 on one end side thereof.

This press-molded product 71 is manufactured by the method described above, whereby the entire side surfaces of the narrow width portions 72 and 73 and the connecting portion 74 are constituted by the primary punching surface Fp1 and the secondary punching surface Fp2, and the narrow width portion is Parts of the side surfaces of 72 and 73 are formed with matching portions Mr for ribs extending in the thickness direction and dividing the secondary punching surface Fp2 from the primary punching surface Fp1 .

The rib matching portion Mr exists in the primary punching surface Fp1 formed by the punch structure 1 having the reinforcing rib 6, and the shearing surface region and the fracture surface formed by the punch structures 1a to 1e and the primary punching surface Fp1 In many cases, the transition position between the secondary punching surfaces Fp2 having different surface properties in the region is a corner shape convex outward as a cut shape as shown in the embodiment shown in the figure.

In addition, in this embodiment, on the primary punching surface Fp1 and the secondary punching surface Fp2 divided by the rib matching portion Mr, as shown in FIG. 11(b), the shear plane area and the fracture plane area are The formation positions are upside down in the thickness direction of the press-molded product 71 and are mutually opposite. This is due to the fact that the punching process for forming the primary punching surface Fp1 and the punching process for forming the secondary punching surface Fp2 are arranged in opposite positions up and down.

The secondary punching surface Fp2 sandwiched by the rib matching portion Mr in the extending direction of the side surface is formed in the narrow shape 3, Since the reinforcing ribs 6 are provided at the ends of the 4 , in the embodiment shown in the drawings, they are located on the respective side surfaces of the ends of the narrow width portions 72 and 73 away from the connecting portion 74 .

In addition, in this embodiment, as described above, corresponding to the arrangement position of the reinforcing rib 6 on the punch structure 1 , two of the ends of the extended portion of the long narrow-width portion 72 of the press-molded product 71 are formed in two portions. The secondary punching surface Fp2 is located on each of the two side surfaces across the narrow width portion 72 .

Also, here, as described above, punching is performed so that the punch structures 1a to 1e are slightly recessed into the narrow-width portion, whereby in the press-formed product 71, any secondary punching surface Fp2 is formed from the The primary punching surface Fp1 is recessed and formed.

In this case, as shown in FIG. 12, the amount of depression D of the secondary punching surface Fp2 is measured along the width direction of the narrow width portions 72 and 73 (the vertical direction in the same drawing), and it is preferably a narrow width within the range of 10% to 20% of the width w of the parts 72 and 73 . This is because, when the amount of depression D of the secondary punching surface Fp2 is less than 10% of the width w of the narrow width portions 72 and 73, there is a possibility that a defect (burr, etc.) may occur when the punching position is displaced, and On the other hand, when the dent amount D of the secondary punching surface Fp2 is larger than 20% of the width w of the narrow width portions 72 and 73 , there is a fear of the width obtained by subtracting the dent amount D from the width w of the narrow width portions 72 and 73 . The narrow width portion is deformed as w1 becomes small.

However, although illustration is abbreviate|omitted, you may make at least one of the secondary punching surfaces protrude from the primary punching surface in accordance with the punching method of the punch structures 1a-1e, etc.,.

As described above, when the secondary punching surface Fp2 is in a concave shape or a protruding shape, when the widths of the narrow width portions 72 and 73 change slightly, the narrow width portion 72 is formed at the portion where the secondary punching surface Fp2 is formed. The ratio (w1/t) of the width w1 of the 73 to the thickness t is preferably 0.5 to 1.5. The width w1 of the narrow portions 72 and 73 at the location where the secondary punching surface Fp2 exists becomes too small, and when the ratio (w1/t) becomes smaller than 0.5, the narrow portions may be deformed (overturned) sex. Therefore, the ratio (w1/t) is more preferably 1.0 to 1.5.

However, as shown in the cross-sectional view of the narrow-width portions 72, 73 and the connecting portion 74 in FIG. 13, the stamped part 71 has a sag surface 75 and a burr surface 76, and the sag surface 75 may exist facing the stamped part. The burr surface 76 may have a burr protruding from the surface formed on the burr surface 76 with a curved sag curved in a direction in which the thickness gradually decreases. Usually, the surface adjacent to the shear surface region side of the shear surface region and the fracture surface region of the side surface is the sag surface 75 , and the surface adjacent to the fracture surface region side of the side surface, which is the back side, is the burr surface 76 .

Furthermore, since the above-described press-molded product 71 is manufactured by integral punching, the direction of inclination of most of the burr surface 76 is the same as the direction of inclination of the sag surface 75 when viewed in cross-section. Further, in this case, since the majority of the burr surface 76 is in contact with a single die or punch, there is a case where the polishing marks of the front end face of the single die or punch are transferred so as to have a single surface roughness .

Specifically, in the cross section, the area ratio AR of the larger one of the surface portion of the burr surface 76 that is parallel to the sag surface 75 or the surface portion that slopes downward to the right and the surface portion that slopes upward to the right is preferable. above 90%. That is, it can be said that it is preferable that 90% or more of the surface portion of the burr surface 76 has the same inclination orientation with respect to the sag surface 75, since it is manufactured by integral punching and dimensionally stable. More preferably, the area ratio AR of the larger surface portion of the burr surface 76 is 95% or more.

Here, the area ratio AR is measured as follows.

First, as shown in FIG. 14 , the press-molded product 71 is fixed with the clip 151 , and the entire periphery of the press-molded product 71 is fixed by the resin material 152 in this state. Next, as shown by the arrow in FIG. 14( b ), the resin material 152 is cut or polished until it reaches the cross-sectional position to be observed. Also, the polished surface including the section of the press-formed part 71 thus exposed is finished by polishing. Then, the cross-sectional shape is photographed with an observation device such as a microscope, and the area ratio AR is measured.

As for the cross-sectional shape photographed with the observation device, as illustrated in FIG. 15 , first, except for the sag portions (non-fixed portions) at both ends of the sag surface 75 , the two boundary points Bp1 and Bp2 with the respective sags will pass through first. The straight line is used as the reference line RL. Then, the reference line RL is moved in parallel to the burr surface 76 side as indicated by the arrow in FIG. 15, and compared with the burr surface 76 (a portion other than the burr portion when a burr occurs in a corner). Here, in the width direction of the cross section, the surface portion of the measurement burr surface 76 that is parallel to the reference line RL or the surface portion that is inclined downward to the right, and the orientation of the surface portion inclined at the transition point Tp are changed and The length of the surface part inclined upward to the right, and the length of the longer of them is taken as the area ratio AR. In the example shown in FIG. 15( a ), substantially the entire burr surface 76 is parallel to and coincident with the reference line RL, so the area ratio AR is a value close to 100%. On the other hand, in the case of an oblique cross-sectional shape as shown in Fig. 15(b), the length L1 of the surface portion substantially parallel to the reference line RL is measured, and the surface inclined upward to the right with respect to the reference line RL is measured. For the length L2 of the part, the longer length L2 of these lengths L1 and L2 is used as the area ratio AR.

Further, the inclination angle of the larger surface portion of the burr surface 76 with respect to the sag surface 75 is preferably within a range of 0° to 20°. When the inclination angle is larger than 20°, there is a fear that the narrow-width portions 72 and 73 serving as pins may be skewed (pin deviation) at the time of processing in the next step. The inclination angle of the larger surface portion of the burr surface 76 with respect to the sag surface 75 is more preferably 0° to 10°.

The inclination angle of the larger surface portion of the burr surface 76 with respect to the sag surface 75 is as described above, and by moving the reference line RL of the sag surface 75 in parallel to the burr surface 76 side in the cross-sectional view, and The inclination of the approximate straight line obtained by the least squares method of the contour line of the surface portion with respect to the reference line RL is obtained and measured.

On the other hand, the press-formed product of the reference example shown in Fig. 16 is not integrally punched, but as described in the item of the prior art, by sequentially aligning the respective side portions of one side and the other side of the narrow portion It is formed by punching, and the punched product after the overturning occurs. In the press-formed part of Fig. 16, as shown in the same figure, the burr surface (the surface on the lower side in the same figure) is mainly composed of a surface portion that is inclined upward to the right with respect to the sag surface (the surface on the upper side). , and a downward-facing sloped surface portion occupying the same degree of area as the surface portion is constituted, and the above-mentioned area ratio is reduced. In addition, since the polishing traces of the front end surfaces of two or more types of dies or punches are transferred to these surface portions, there are cases in which the surface roughness thereof differs greatly.

In the above description, the press-molded product 71 having the two narrow width portions 72 and 73 having different lengths and the connecting portion 74 connecting the two narrow width portions at the intermediate position has been described as an example. The present invention can be applied to press-formed parts of various shapes including a press-formed part having a narrow width portion whose ratio (w/t) of width w to thickness t is 1.5 or less.

As a specific example thereof, for example, a press-formed product in which the narrow width portions 82 and 83 shown in FIGS. 17( a ), ( b ) and ( c ) are connected to each other in a substantially “L” shape can be mentioned. 81; The long and short two narrow width portions 92 and 93 are at the end position of the short narrow width portion 93 and the middle position of the long narrow width portion 92, and are connected to each other by a connecting portion 94 that is perpendicular to it. The shape of the press-molded part 91 ; The two long and short narrow width portions 102 and 103 staggered from each other in the longitudinal direction are at the end position of the short narrow width portion 103 and the end position of the long narrow width portion 102, and are mutually connected by the connecting portion 104 which is orthogonal to them. The press-molded product 101 etc. of the connected shape. (Example)

Next, the punch structure of the present invention was trial-produced, and the effect thereof was confirmed, so the following description will be given. However, the descriptions herein are for illustrative purposes only, and are not intended to limit the present invention. (Test Example 1)

As a comparative example, as shown in FIG. 18, a punch structure having no reinforcing ribs was used, and a metal plate having a width of 8.0 mm and a thickness of 0.12 mm was repeatedly punched. The minimum width of the connecting portion of the press-formed product to be produced is 0.07 mm, and in the punching process, the stroke is set to 13 mm, and the number of continuous strokes that can be performed in one minute, that is, the continuous stroke amount, is from the start to 200,000 injections. 500 spm, 800 spm from 200,000 injections to 3 million injections, and 1000 spm from 3 million injections to 5 million injections.

In the punch structure of the comparative example, it was confirmed that the connection shape in the front end surface of the punch front end portion was broken at the time of 2,000,000 injections.

As an example, using the punch structures shown in FIGS. 1 , 5 , and 7 ( a ) to ( c ), respectively, punching was repeatedly performed under the same conditions as in the above-described comparative example. As a result, the number of shots until breakage was confirmed on the front end face of the punch tip portion was 4 million shots in the punch structure shown in FIG. 1 and 3 million shots in the punch structure shown in FIG. 5 . The jets are 1.5 million jets in the punch configuration shown in Fig. 7(a), 2 million jets in the punch configuration shown in Fig. 7(b), and 2 million jets in the punch configuration shown in Fig. 7(c) 2.5 million jets in the punch structure. (Test example 2)

In the punch structure shown in FIG. 1, the punch structure was repeatedly punched under the same conditions as in Test Example 1 using a punch structure in which the ratio of the length Lr of the reinforcing rib to the thickness t of the narrow portion was changed as shown in Table 1. cutting. The reinforcing rib is made to extend from the front end face. The results, examination, and evaluation are shown in Table 1.

As can be seen from Table 1, in particular, when the magnification of the length of the reinforcing rib is in the range of 3 to 50, the number of injections until the breakage occurs greatly increases. (Table 1) Multiplier of rib length Punch breakage jet quantity investigation, results Evaluation 2 - Insufficient strength of other components occurs because the tip is too short. Parts machining is not possible. × 3 1.5 million In the same way as above, the strength of other parts needs to be improved ⇒ Extend the length of the rib △ 20 4000000 Longest shot count. If mass production is considered, it is desirable to increase the magnification slightly ◎ 40 2.5 million It is a nose length suitable for mass production, but the number of shots is reduced compared to 20 times ○ 50 3.5 million If the rib length is slightly shortened, it is expected to improve the effect ○ 55 500000 Lifting/skewing of the punch occurs due to the rib being too long × (Test Example 3)

In the punch structure shown in FIG. 1, using a punch structure in which the ratio of the width Wr of the reinforcing rib 6 to the width w of the narrow portion was changed as shown in Table 2, punching was repeated under the same conditions as in Test Example 1. cutting. The results, examinations, and evaluations are shown in Table 2.

From the contents shown in Table 2, it is understood that if the ratio of the width Wr of the reinforcing rib 6 is in the range of 0.3 to 4, breakage can be prevented more effectively. (Table 2) Ratio of rib width Punch breakage jet quantity investigation, results Evaluation 0.2 100,000 The width is too small. Fig. 10(a) shows small blanking chips and parts are damaged × 0.3 1000000 Need to improve the strength of the above parts ⇒ increase the ratio of the rib width △ 1 3.5 million The longest number of injections in the examples. The balance with Hr is important ◎ 3.8 1.5 million Cracked seams. The number of injections is halved compared to 1 ○ 4.5 200,000 Broken from the seam ⇒ Too wide, with a load applied × (Test Example 4)

In the punch structure shown in FIG. 1, using the punch structure in which the ratio of the height Hr of the reinforcing rib 6 to the width w of the narrow portion was changed as shown in Table 3, punching was repeated under the same conditions as in Test Example 1. cutting. The results, examinations, and evaluations are shown in Table 3.

As can be seen from Table 3, when the ratio of the height Hr of the reinforcing rib 6 is in the range of 0.3 to 4, breakage can be further suppressed, and punching with a larger number of shots can be performed. (table 3) Ratio of Rib Height Punch breakage jet quantity investigation, results Evaluation 0.2 100,000 Insufficient reinforcement due to small thickness × 0.3 1000000 Compared to 0.2, strengthening is improved, but further thickening is better △ 1 3.5 million The longest number of injections in the examples. Balance with Wr is important ◎ 3.8 1000000 Cracked seams. The number of injections is halved compared to 1 ○ 4.5 50000 Broken from the seam ⇒ Too wide, with a load applied × (Test Example 5)

In order to confirm the difference in the cross-sectional shape of the press-formed product obtained by the integral blanking processing and the segment blanking processing, respectively, as the integral blanking processing, the processing shown in Fig. 10 (a) and (b) was carried out as a trial production. The press-formed product thus formed was a trial production of a press-formed product formed by performing the processing shown in FIG. 19 as a step punching process.

As a result, it is also described in Table 4 that the cross-section of the press-formed product formed by the integral blanking process is substantially 100% in area ratio, and has a shape that is equal to the left and right and beautiful as shown in Fig. 20(a). On the other hand, as shown in Fig. 20(b), the cross-section of the press-formed product formed by the sectional punching process has a low area ratio, and has a slanted shape. (Table 4) punching method Processing order Results (bridge area ratio, shape) Evaluation One-piece blanking Figure 10 ((a)→(b)) The area ratio is basically 100%. The right and left are equal and beautiful shape ◎ Sectional blanking Figure 18 (①→②→③) Area ratio is low and overturning occurs. Skewed shape → large size deviation × (Test Example 6)

For the press-formed product manufactured in the manner of the above-mentioned Test Example 5, the inclination angle of the surface portion of the burr surface consisting of a single surface roughness with respect to the sag surface is in the range of 0° to 20°, and the inclination Press-formed products with an angle of 30° or more are each subjected to a 90° bending process by embedding one end of the narrow portion in the resin product as shown in Fig. 21 in the next step after that. As a result, as shown in Table 5, the press-formed product with an inclination angle in the range of 0° to 20° was within the dimensional standard with little variation, and the 90° bending portion of the side surface was also stable. On the other hand, the inclination of the press-formed product with an inclination angle of 30° or more is large, and the deviation of the 90° bending portion of the side surface is also large. (table 5) slope Deflection standard after bending ±0.1 result Evaluation 0°～20° 0.02～0.05 Within the size standard and the deviation is small. 90° bending on the side is also stable ◎ Above 30° 0.12～0.15 Big skew. The deviation of the 90° bending in the lateral direction is also large. × (Test Example 7)

As shown in Fig. 22, two different moldings having a thickness t of 0.2 mm and a width w of 0.14 and 0.32 were repeatedly produced using a punch without reinforcing ribs. The results are shown in Table 6.

When the w/t was 1.6, the punch was not damaged even by continuous punching of 3 million jets, but when the w/t was 0.7, the punch was damaged soon after the continuous operation. (Table 6) w/t Punch structure result Evaluation 0.7 No ribs The punch was broken shortly after continuous operation × 1.6 No ribs The punch is not broken even with 3 million continuous jets ◎

1, 1a~1e, 31, 41, 51: punch structure 2, 32, 42, 52: the front end of the punch 3, 4, 33, 34, 43, 44, 53, 54: Narrow shapes 5, 35, 45, 55: Connecting Shapes 6, 6a, 6b, 36, 46, 56: Reinforcing ribs 21, 71, 81, 91, 101: Stamping and forming parts 22, 23, 72, 73, 82, 83, 92, 93, 102, 103: Narrow parts 24, 74, 94, 104: Links 75: slump side 76: Burr surface 61: sheet metal 62: Semi-finished product 63: convex part T: front face S: side w: width w1: width t: thickness C1, C2: Cracks Lr: length Wr: width Hr: height Sp1: One punching part Sp2: Secondary punching part Fp1: One punched face Fp2: Secondary blanking surface Mr: Matching part for rib AR: Area Rate RL: Baseline Bp1, Bp2: boundary points

[ Fig. 1 ] is a perspective view showing a punch tip portion of a punch structure according to an embodiment of the present invention. [Fig. 2] is a perspective view schematically showing a press-formed product to be formed using the punch structure of Fig. 1. [Fig. [FIG. 3] It is a partial plan view which shows the damage of the front-end|tip surface of the conventional punch structure. [FIG. 4] is a plan view schematically showing the deformation form of the front end surface and the concentrated portion of the tensile stress during punching. [ Fig. 5 ] is a perspective view showing another example of arrangement of the reinforcing ribs of the punch structure shown in Fig. 1 . [ Fig. 6 ] is a cross-sectional view of a punch tip end portion of the punch structure shown in Fig. 1 . [FIG. 7] It is a perspective view which shows the modification of the reinforcement rib of the punch structure shown in FIG. 1, and another example of arrangement|positioning. [ Fig. 8 ] is a perspective view showing a punch tip portion of a punch structure according to another embodiment. [ Fig. 9 ] is a plan view showing a method for producing a press-formed product according to an embodiment of the present invention. [ Fig. 10 ] is a plan view showing a method of manufacturing a press-molded product according to another embodiment. [ Fig. 11 ] is a plan view and a side view showing a press-formed product according to an embodiment of the present invention. [ Fig. 12 ] is an enlarged plan view of an end portion of the narrow width portion of the press-formed product shown in Fig. 11 . [ Fig. 13 ] is a cross-sectional view of the narrow portion and the connecting portion taken along the lines a-a, b-b, and c-c in Fig. 11(a). [ Fig. 14 ] is a plan view showing a method of measuring the area ratio, and a side view showing the state before and after polishing. [ Fig. 15 ] is a cross-sectional view of a press-formed product showing a method of measuring the area ratio. [ Fig. 16 ] is a cross-sectional view of a narrow portion and a connecting portion of a press-formed product of a reference example. [ Fig. 17 ] is a plan view showing a press-formed product according to another embodiment. [ FIG. 18 ] is a perspective view showing a punch tip portion of a punch structure of a comparative example of Test Example 1. [ FIG. [ FIG. 19 ] is a plan view showing a method for producing a press-formed product by segment punching in Test Example 5. [ FIG. [ Fig. 20 ] is a cross-sectional view of a press-formed product formed by integral punching and segment punching in Test Example 5, respectively. [ FIG. 21 ] is a front view and a side view showing a state in which the molded article of Test Example 6 is embedded in a resin material and bent. [ FIG. 22 ] is a plan view showing the T-shaped molded article of Test Example 7. [ FIG.

1: Punch structure

2: Front end of punch

3, 4: Narrow shape

5: Connecting Shapes

6: Reinforcing ribs

T: front face

S: side

Lr: length

Claims (13)

A punch structure of a stamping die, characterized in that: The punch structure is configured to protrude from the main body of the punch die, and is used for punching out a punch-formed part including a narrow-width portion with a width (w) to thickness (t) ratio (w/t) of 1.5 or less, The punch structure has a front end portion of the punch, the front end portion of the punch has a front end surface, at least a part of the front end surface includes a narrow width shape corresponding to the planar shape of the narrow width portion of the stamped part, and A reinforcing rib extending to the front end surface in the protruding direction of the punch structure is provided on a part of the side surface on the lateral side of the narrow-shaped extension of the punch tip portion. The punch structure of claim 1, wherein, The punch structure punches a stamped-formed part including two narrow width parts and a connecting part, the two narrow width parts are spaced apart from each other and arranged side by side, the connecting part connects the narrow width parts to each other, the punch The front end portion has a front end surface, and at least a part of the front end surface includes a narrow width shape and a connecting shape corresponding to the planar shapes of the narrow width portion and the connecting portion of the stamping part. The punch structure of claim 2, wherein, The reinforcing rib is located at one end of the narrow shape of the front end of the punch away from the connecting shape. The punch structure of claim 3, wherein, At at least one of the ends of the narrow-width shape, the reinforcing rib is provided on each of the two side surfaces of the narrow-width shape. The punch structure of claim 1 or 2, wherein, The reinforcing rib is continuously provided along the protruding direction from the front end surface of the punch front end portion by a length of 3 times to 50 times the thickness (t) of the narrow width portion. The punch structure of claim 1 or 2, wherein, The reinforcing rib has a rectangular cross-sectional shape. The punch structure of claim 6, wherein, In the cross section of the reinforcing rib, the width of the reinforcing rib parallel to the side edge of the narrow-width shape is 0.3 to 4, expressed as a ratio to the width (w) of the narrow-width portion. The punch structure of claim 6, wherein, In the cross section of the reinforcing rib, the height of the reinforcing rib orthogonal to the side edge of the narrow width is 0.3 to 4, expressed as a ratio to the width (w) of the narrow width portion. The punch structure of claim 1 or 2, wherein, In the protruding direction of the reinforcing rib, the entire reinforcing rib has a fixed cross-sectional shape. A stamping die, characterized in that: The punching die has the punch structure as claimed in claim 1 or 2. A method of manufacturing a stamped part, characterized in that: Using a stamping die having a punch structure as claimed in claim 1 or 2, a metal plate is punched to produce a stamped part. The method for manufacturing a stamped-formed part as claimed in claim 11, wherein, The metal plate is subjected to a plurality of punching processes including a pre-process punching process and a subsequent post-process punching process in sequence, In either the pre-stage punching process or the post-process punching process, the punch structure in which the reinforcing rib is provided at the front end of the punch is used to form a primary punching portion, and the other punching process is used for punching. During processing, a portion including a portion where the reinforcing rib penetrates is punched so as to intersect with the primary punched portion to form a primary and secondary punched portion. The method for manufacturing a stamped and formed part as claimed in claim 12, wherein, The other punching process for forming the secondary punching portion is referred to as the pre-process punching process, and the one punching process for forming the primary punching portion is referred to as the post-process punching process.

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