KR20140114591A

KR20140114591A - Press die

Info

Publication number: KR20140114591A
Application number: KR1020130029031A
Authority: KR
Inventors: 강태훈; 안연성; 남기주
Original assignee: 삼성전자주식회사
Priority date: 2013-03-19
Filing date: 2013-03-19
Publication date: 2014-09-29

Abstract

The present invention provides a press die. The press die includes a die on which an object to be processed is placed, and a punch for cutting the object. The press die is characterized in that the press die includes a scrap rising prevention part on either or both of the die and the punch for preventing a scrap and the punch from rising at the same time. The press die prevents the scrap from rising without additional devices, thus reducing defection of products during a manufacturing process and a loss caused by pausing the manufacturing process.

Description

PRESS DIE {PRESS DIE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press die, and more particularly, to a press die having at least one of a die and a punch having a scrap rising prevention portion for preventing scrap from rising together with the punch.

In general, the operation of the press mold is made up of the following three steps.

A plastic deformation step in which plastic deformation is initiated beyond the elastic limit of the workpiece as the punch touches the workpiece, and a shearing step in which the punch enters the workpiece and shear after pressing due to bending occurs. Finally, as the shear deformation progresses, there is a cutting step in which the stress concentration of the punch and the die end causes the material to be cut and the material is divided.

At the end of the cutting step, the punch rises with the rise of the press, where the scrap must fall down but may rise with the punch.

If the scrap rises, the automatic machining will not be smooth, resulting in a delay in the working time and causing defects. As a cause of the rise of scrap, there is typically an increase in adhesion between punch and scrap due to compressed air, and a suction action. Several methods have been used to prevent such scrap rise. Separate compulsory devices or processing methods affecting the shape of the product require a reduction in dimensional accuracy and a separate connection device. Further, there is a need to connect and disassemble each time the mold is exchanged.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a press mold which can prevent the scrap from rising by modifying the structure of at least one of dies and punches.

The press die of the present invention includes a die on which a workpiece is placed and a punch for cutting the workpiece, and a scrape-up prevention portion for preventing scrap from rising together with the punch is provided on at least one of the die and the punch .

The punch may have at least one protrusion on the bottom surface for deformation of the scrap.

The punch may have at least one groove on the bottom surface for reducing the contact area with the scrap.

The die may have at least one groove for discharging compressed air to the denting side.

The die may be characterized by having multiple clearances for discharging compressed air to the denting side.

The multiple clearances may have different clearances in the first and third quadrants and the second and fourth quadrants of the cross section perpendicular to the longitudinal direction of the die.

The die may have a multi-stage inclination for inducing a scraping phenomenon on the scraper side.

The die may be characterized by having multiple clearances and multi-step inclination on the denting side.

The multi-stage inclination may be characterized by having a two-step inclined clearance divided into a single-stage scraper portion to which the workpiece is cut and a two-stage scraper portion to sandwich the scrap.

Application of the shape proposed by the present invention can prevent scrap rise after shearing the product, thereby reducing defects during production and loss due to stopping time during operation.

Further, since there is no need for a separate additional device, it is possible to apply the present invention regardless of the size and shape of various sheaves without inconveniencing the connection and disassembly when changing the mold.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an operating state of a press die according to an embodiment of the present invention. Fig.
Fig. 2 is a view showing a punch having the projection shown in Fig. 1; Fig.
3 illustrates a punch having a groove according to one embodiment of the present invention.
Figure 4 illustrates a die having grooves according to one embodiment of the present invention.
Figure 5 illustrates a die having multiple clearances in accordance with one embodiment of the present invention.
Figure 6 illustrates a die having a multi-tapered incline according to one embodiment of the present invention.
Figure 7 illustrates a die having multiple clearances and multi-step slopes in accordance with one embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing an operating state of a press die according to an embodiment of the present invention, and FIG. 2 is a view showing a punch having the protrusion shown in FIG.

The press mold 1 is a device for producing a product by molding a material by placing a tool on a press machine that reciprocates linearly. The press die 1 is constituted by a press for applying pressure to a material by up and down movement in the axial direction, a punch 20 attached to the press, and a die 10 placed on the lower part of the punch to seat the material.

The punch 20 cuts the workpiece 30. The die 10 includes a flat portion on which the workpiece 30 is seated and a die inner side 100 where the punch 20 passes through the die 10. The punch 20 has a cylindrical shape when machining a circular hole with a different shape depending on the shape to be machined.

The scrap is a workpiece cut by the punch 20 and is generally referred to as excluding the product. The scrap is dropped from the punch 20 as the punch 20 is lowered to the inner side of the die 100 and stacked on the bottom portion of the die inner side 100 to be processed separately from the product.

However, there are cases where the scrap is lifted together with the punch 20 without falling down to the punch 20 due to the punch and the attracting force. Rising scrap will fall on the finished product and cause the product to fail or stick to the punch, making subsequent processing difficult.

In order to prevent such a scrap rise, the present invention uses a punch 20 having a projection 22.

The projections 22 are formed so as to be convex downward on the bottom surface 21 where the punch 20 meets the workpiece. In FIG. 2, projections are formed on the bottom surface 21 away from the cutting portion 23 to form a flat portion 222 convex to the slanting line 220.

When cutting the workpiece with the punch shown in Fig. 2, before the workpiece is cut, the projection 22 touches the portion to be scrapped first, and after the deformation advances, shear-shaping of the workpiece proceeds

Unlike general scrap, scrap after shearing forms curved scrap 42. When pressure is removed from curved scrap 42, a springback shape which is a resilient action to return to the original state is generated. Thereby increasing the surface area of the scrap 42 and preventing the scrap from rising due to the frictional force between the scrap 42 and the die inner side 100.

3 is a view showing a punch 20a having a groove 24 according to an embodiment of the present invention.

The groove 24 is recessed downwardly at the bottom surface 21. In FIG. 3, the center portion 240 is the vertex of the punch on the bottom surface 21, and the groove 24 of the triangular pyramid is expressed based on the cut portion 23.

When cutting the workpiece with the punch 20a shown in FIG. 3, the contact surface between the scrap and the punch is reduced to reduce the attraction force between the scrap and the punch, thereby preventing the scrap from rising. The shape of the product or scrap is the same as that of a general press die.

4 is a diagram illustrating a die 10b having a groove 12 according to an embodiment of the present invention.

The grooves 12 are recessed in the die side surface 110 where the die 10b and the die inner side 100 meet. In FIG. 4, four round fine grooves 12 are shown at intervals of 90 degrees on the denting side surface 110.

When the workpiece is cut using the die 10b shown in Fig. 4, the air inside the die 100, which is compressed by the punch when the punch is lowered, escapes through the groove 12 upward. Accordingly, the attraction force between the scrap and the punch is reduced to prevent the scrap from rising.

Figure 5 is a diagram illustrating a die 10c having multiple clearances in accordance with one embodiment of the present invention.

The clearance is a linear minimum distance between the cut surface of the punch and the inner side surface 110 when the punch enters the inner side of the die 100. That is, the distance between the punch and the die.

The cross section perpendicular to the longitudinal direction of the die 10c is divided into four quadrants, the second and fourth quadrants are denoted by a denting side face 110, the first and third quadrants have diameters larger than the denting side face 110, And the branch has the escape surface 111.

When the workpiece is cut using the die 10c shown in Fig. 5, when the punch is lowered, the air inside the die 100 compressed by the punch escapes upward through the escape surface 111 . Accordingly, the attraction force between the scrap and the punch is reduced to prevent the scrap from rising.

6 is a diagram showing a die 10d having a multi-tilt according to an embodiment of the present invention.

In the case of a general die, the portion to be cut by the punch is narrow, and the portion where the scrap falls on the inner side of the die is made wider so that the scrap is piled up at the die inner bottom portion. The present invention has a two-step inclination that narrows the two-end short-crown portion 17, which is a portion falling from the first short cervical portion 16, which is the portion to be cut.

When the workpiece is cut using the die 10d shown in Fig. 6, the scrap having a large area cut off by the one short cutter 16 is pushed down by the two short cutters 17 by the punch. So that it does not fall down but is engaged with the two short-axis scarf 17 through friction with the inner side of the die, thereby preventing scrap rise. The scrap caught by the two short-axis scarf 17 is piled up one after another and falls to the bottom of the die inner side 100 one by one.

At this time, the feeding amount of the punch (the degree to which the punch is lowered to the die) is applied to not less than the two short-

7 is a diagram showing a die 10e having multiple clearances and multi-step inclination according to an embodiment of the present invention.

5 and FIG. 6, it is possible to reduce the attraction force between the punch and the scrap by allowing the compressed air to escape through the escaping surface 111 and to increase the frictional force between the scrap and the die by using the inclination of the die inner side 100, Thereby preventing scrap from rising.

In the above description, the specific shape has been mainly described in the description of the press die with reference to the accompanying drawings. The detailed dimensions, protrusions, grooves, clearances, the number and shape of the stages are differently applied depending on the shear size and shape, so long as those skilled in the art do not deform the product. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Further, although a press die for manufacturing a hole has been described as an example, this is merely an example, and a molded punch or die for preventing scrap rise according to the present invention may be used for other molding.

Accordingly, the true scope of protection of the present invention should be defined by the claims.

10: die 12: groove of die
20: punch 21: groove of punch
22: projection of punch 30:
42: bent scrap 100: inner die
110: dull side 111: escape surface

Claims

1. A press die having a die on which a workpiece is placed and a punch for cutting a workpiece,
At least one of the die and the punch,
And a scrap rising preventing portion for preventing the scrap from rising together with the punch.

The method according to claim 1,
Wherein the punch has at least one protrusion on a bottom surface for deformation of the scrap.

The method according to claim 1,
Wherein the punch has at least one groove on the bottom surface for reducing the contact area with the scrap.

The method according to claim 1,
Wherein the die has at least one groove for discharging compressed air to the denting side.

The method according to claim 1,
Wherein the die has multiple clearances for discharging compressed air to the die side.

6. The method of claim 5,
Wherein the multiple clearances have clearances different from each other in the first, third and fourth quadrants of the cross section perpendicular to the longitudinal direction of the die.

The method according to claim 1,
Wherein the die has a multistage inclination for inducing a scraping phenomenon of the scrap on the inner side of the die.

The method according to claim 1,
Wherein the die has multiple clearances and multi-step inclination on the denting side.

8. The method of claim 7,
Wherein the multi-stage inclination has a two-stage inclined clearance divided into a single-stage scraper part in which the workpiece is cut and a two-stage scraper part in which the scrap is sandwiched.