Abstract
Provided is a die trim section with a recess adapted to retain slugs in a stamping process. The recess may be added to existing die inserts via wire EDM, conventional surface grinding or other suitable methods. The recess extends a distance greater than the die trim punch stroke and the cross-sectional area of the recess decreases along the height of the recess.
Claims
1. A stamping press for a stamping operation, the stamping press including a trim punch and die trim section assembly wherein the trim punch and die trim section assembly retains a stamping slug generated by a stamping operation on a metal sheet, the stamping press comprising: a trim punch and a die trim section; the die trim section comprising a body with a top surface for supporting the sheet and a die trim profile opening extending into the body from the top surface, the die trim profile opening comprising interior trim profile walls and extending along a longitudinal central axis; the trim punch being movable along a punch stroke having a predetermined length and receivable into the die trim profile to contact and drive the stamping slug stamped from the sheet a maximum depth along the longitudinal axis into the trim profile opening; at least one recess along an edge of said die trim profile opening, each at least one recess extending parallel with the longitudinal axis from the top surface of the body along the die trim interior walls and having a height along said interior trim profile walls from a top end of the recess at the top surface of the body to a bottom end of the recess; the height of each at least one recess being at least equal to the maximum depth that the stamping slug is driven into the die trim profile opening by the trim punch during the stamping operation whereby a respective tab attached to the stamping slug created by the stamping operation remains in the at least one recess when the stamping slug has reached the maximum depth into the die rim profile opening; and each at least one recess has a respective cross-sectional area in a plane perpendicular to the longitudinal axis along the height of the recess, the cross-sectional area continuously decreasing along the height of the recess from the top of the recess to the maximum depth the stamping slug is driven into the recess.
2. The stamping press of claim 1 wherein a cross sectional area of each at least one recess is bounded by a respective surface extending along a radius of each at least one recess that tapers from the top end of the recess to the bottom end of the recess.
3. The stamping press of claim 1 wherein a cross-sectional area of each at least one recess is defined by a surface extending along a portion of a circle, the circle having a center disposed in the die trim profile opening.
4. The stamping press of claim 3 wherein the center of each cross-sectional area of the recess is disposed increasingly closer to the longitudinal axis of the die trim profile opening in a direction extending from the top end of the recess to the bottom end of the recess.
5. The stamping press of claim 1 wherein each cross sectional area of each at least one recess is defined by a surface extending along a portion of a circle, the circle having a radius, the radius continuously decreasing from the top end of the recess to the bottom end of the recess.
6. The stamping press of claim 1 wherein the cross sectional area of each at least one recess is defined by a surface extending along a portion of a circle, the circle having a radius, the radii of the cross-sectional areas being constant from the top end of the recess to the bottom end of the recess.
7. The stamping press of claim 1 wherein each at least one recess is shaped by a conical extruder having a central axis defined at an angle relative to said interior trim profile walls, wherein a side of said conical extruder is positioned parallel to said interior trim profile walls.
8. The stamping press of claim 1 wherein each at least one recess is shaped by a conical extruder having a central axis defined at an angle relative to said interior trim profile walls, wherein a side of said conical extruder is positioned at an angle relative to said interior trim profile walls.
9. The stamping press of claim 1 wherein each at least one recess is shaped by a cylindrical extruder having a central axis defined at an angle relative to said interior trim profile walls, wherein said cylindrical extruder central axis is positioned at said angle.
10. The stamping press of claim 1, wherein each at least one recess is created on an existing, previously used die trim section.
11. The stamping press of claim 1 wherein each at least one recess is created in a new die trim section.
12. The stamping press of claim 1 wherein said die trim profile opening comprises at least one substantially rounded profile wall.
13. The stamping press of claim 1 wherein said die trim profile opening comprises at least one substantially planar profile wall.
14. The stamping press of claim 1 further comprising a taper relief below and spaced from the bottom end of each at least one recess.
15. The stamping press of claim 1 comprising a stamping slug from a prior stamping operation being retained in the die trim profile opening.
16. The stamping press of claim 1 comprising a metal sheet on the top surface of the body and covering the die trim profile opening for cutting a slug from the sheet.
17. The stamping press of claim 1 wherein each at least one recess has a respective depth dimension extending from the die trim profile walls to a floor of the recess, the depth of each recess decreasing as the recess extends from the top end of the recess to the bottom end of the recess whereby the floor extends closer to the slug as the slug is driven into the trim profile opening.
18. The stamping press of claim 1 wherein each at least one recess has a respective width dimension in a plane perpendicular to the longitudinal axis, the width of each at least one recess continuously decreasing from the top end of the recess to the bottom end of the recess.
19. The stamping press of claim 1 wherein the maximum depth the stamping slug is driven into the die trim profile opening is less that the height of the at least one recess.
Description
BRIEF DESCRIPTIONS OF THE DRAWINGS
(1) FIG. 1 is a top view of a trim section, with a hollow round trim profile having a recess located at one point around the trim profile.
(2) FIG. 2 is a close up top view of the recess on a round trim profile in FIG. 1.
(3) FIG. 3 is a side cross-sectional view of FIG. 1, showing the recess cut into the trim profile of the trim section.
(4) FIG. 4 a side view of the die trim assembly including a sheet of stamping material disposed over a die trim insert and a trim punch therethrough.
(5) FIG. 5 is a side view of a first embodiment of the recess created via a vertical conical extrusion.
(6) FIG. 6 is a front cross-sectional view of the first embodiment of the recess created via a vertical conical extrusion.
(7) FIG. 7 is a close up front view of an embodiment of the recess created via a vertical conical extrusion.
(8) FIG. 8 is a side view of a second embodiment of the disclosed recess created via an angled conical extrusion along a die insert trim wall.
(9) FIG. 9 is a front cross-sectional view of the second embodiment of the disclosed recess created via an angled conical extrusion.
(10) FIG. 10 is a close up view of a front cross-sectional view of the second embodiment of the disclosed recess created via an angled conical extrusion.
(11) FIG. 11 is a side view of a third embodiment of the disclosed recess created via an angled cylindrical extrusion along a die insert trim wall.
(12) FIG. 12 is a front cross-sectional view of the third embodiment of the disclosed recess created via an angled cylindrical extrusion.
(13) FIG. 13 is a close up view of the third embodiment of the disclosed recess created via an angled cylindrical extrusion.
(14) FIG. 14a shows a top view of the two recesses in a rectangular trim profile of a rectangular trim section.
(15) FIG. 14b shows a cross-sectional view of two recesses in a rectangular trim profile of a rectangular trim section.
DETAILED DESCRIPTION
(16) Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the die trim assembly with a recess adapted to retain slugs in a stamping process. For the purposes of presenting a brief and clear disclosure, the preferred embodiment will be discussed as used for die trim section assembly with a recess. The figures are intended for representative purposes only and should not be considered to be limiting in any respect.
(17) Referring now to FIG. 1, there is shown a simplified top view of the die trim insert 20 and the round die trim profile opening 22 with the recess 24. The die trim profile opening 22 is hollow and comprises a longitudinal central axis. The die trim profile opening 22 is adapted to receive a trim punch during a stamping process and retains a slug as the trim punch is withdrawn. The shape of the die trim profile opening 22 substantially matches the trim punch. The size of the die trim profile opening 22 is slightly larger to allow for cutting clearance. The size and shape of the slugs produced during the stamping process is also approximately equal to the die trim profile opening 22. The die trim profile opening 22 is at the die trim insert 20 level, which is the top surface of the die trim insert 20. The die trim profile opening 22 has an interior die trim profile wall 21, which is perpendicular to, and below the surface of the die trim insert 20. The die trim profile wall 21 may include one or more rounded wall surfaces, planar or substantially planar wall surfaces, or a combination thereof to define a desired die trim profile opening. The bottom surface of the die trim profile opening 22 opens into a cavity to allow the slugs to fall out of the bottom of the stamping die after being pushed through the trim profile opening 22. The recess 24 could be semi conical or a semi cylindrical that is approximately as deep horizontally at the top edge as the cutting clearance between the trim punch and the trim profile opening 22. The vertical length of the recess 24 should preferably exceed the depth that the trim punch enters into the die trim profile opening 22.
(18) The recess 24 can be added to an existing die trim profile opening 22 and does not require new parts. The recess 24 may be added to the die trim profile wall 21 using one of various methods, depending upon the embodiment of the recess 24. One of the preferred cutting methods is wire or conventional EDM, which is used to add or retrofit a semi conical embodiment of the recess 24 into a new or existing die trim profile opening 22. For a semi cylindrical embodiment, conventional grinding method, wire EDM, or other suitable method may be used.
(19) The recess 24 is preferably positioned vertically so that the top part of the recess 24 is level with the top surface of the die trim insert 20 and the bottom is below the depth that the trim punch enters the die trim profile opening 22. The bottom end of the recess 24 creates a pinching action and compresses a slug when the slug is pushed down with a trim punch into the die trim profile opening 22 during a stamping process. As a result, the slug is wedged against the die trim profile wall 21 and secured into place. The horizontal depth of recess 24 disposed on the die trim profile wall 21 depends upon the slug size and thickness, the composition of the stamped material, cutting clearance between trim punch and trim profile opening 22, and trim profile opening 22 design. The vertical length of the recess 24 depends upon amount of land in the die trim insert 20 and the distance that the trim punch travels into the trim profile opening 22.
(20) Referring now to FIG. 2, there is shown a close up view of the recess 24 around the die trim profile opening 22 from the top in FIG. 1. The recess 24 is located at the outer edge of the die trim profile opening 22, and is cut into the die trim profile wall 21. The recess 24 creates a small geometrical tab or offshoot on the slug that is progressively pinched, that is, compressed, as it is pushed into the die trim profile opening 22 when a trim punch is stamped through a material, causing the slug to wedge thereagainst the die trim profile wall 21. Friction between the recess 24 and the geometric tab causes the tab to become wedged therein and therefore prevents the slug from being withdrawn from the die trim profile opening when the trim punch is removed. This prevents slugs from adhering to the surface of the trim punch as it is withdrawn from the die trim profile opening 22 and being drawn out of the die trim profile opening 22. The recess 24 can be added to die trim inserts of various shapes and depth.
(21) The size and depth of the recess 24 depends on the size of the slug, the cutting clearance, the stamping material, and the trim punch depth into the die trim insert. For instance, a large slug stamped from a thick stamping material would require a larger recess compared to a recess for a smaller slug stamped from a thin stamping material. Furthermore, the vertical depth of the recess is preferably equal to or greater than the depth with which the slug will travel into the die trim profile opening 22. Thus, the vertical depth of the recess may be substantially equal to or more than the distance that the trim punch travels into the die trim profile opening 22. Additionally, more than one recess may be added to a die trim profile wall 21. The stamping material typically comprises of metal, but the stamping material is not limited only to metal, and the teachings of this disclosure can be used when perforating holes and shapes in other materials.
(22) The recess 24 has a cross sectional area perpendicular to the longitudinal central axis of the die trim profile opening 21. Several cross-sectional areas of the recess 24 are shown in phantom in FIG. 2. The cross sectional area of the recess 24 shown in FIG. 2 decreases with increasing depth of the die trim profile opening 22 from the top surface of the die trim insert 20. A cross section area is defined by a recess surface 24a. The recess surface 24a extends along a portion of a circle having a radius r and a center c. The center c is located in the die trim profile opening 22. Although the radius r associated with the cross sectional area of the recess 22 decreases with increasing depth of the die trim profile opening 22, the center c of any recess cross section area is located within the die trim profile opening 22.
(23) Referring now to FIG. 3, there is shown a cross-sectional view of the die trim insert 20 in FIG. 1. In the illustrated embodiment, the recess is added via an angled cylindrical extrusion. In other embodiments, however, the recess 24 may be added via an angled conical extrusion, or a vertical conical extrusion into the die trim profile wall 21. Below the die trim profile opening 22 is a taper relief 23, which relieves pressure on the slugs, allowing them to fall out of the die trim insert 20. The size and the shape of the recess 24 generally depends on the cutting clearance between the trim punch and the die trim insert opening 22, and the distance that the trim punch travels into the die trim profile opening 22, and the stamping material. Generally, the recess 24 is approximately as deep horizontally into the top edge as the die insert cutting clearance. The vertical length of the recess 24 depends upon land depth and the distance the trim punch enters into the die trim profile opening 22, which is used to determine the angle of the recess into the die trim profile opening 22.
(24) Referring now to FIG. 4, there is shown a side cross-sectional view of the die trim assembly including a sheet of stamping material 26 disposed over a die trim insert 20 and a trim punch 25 positioned in a die trim profile opening 22. The die trim insert 20 and the trim punch 25 are carried by a stamping press (not shown) in a conventional manner. The trim punch 25 is adapted to move along the punch stroke upwards and downwards along a vertical axis. The die trim profile opening 22 is aligned with the trim punch 25 such that the trim punch 25 enters the die trim profile opening 22 when it moves downwards. As the trim punch 25 moves downwards, it punches a hole or a shape through the stamping material 26 positioned over the die trim profile opening 22, creating a slug 27. As the trim punch 25 travels through the die trim profile opening 22, a recess 24 pinches the slug 27 and wedges it against the die trim profile wall 21 to be retained therein. In the illustrated embodiment, the die trim assembly includes two recesses 24, wherein each recess 24 extends below the die trim profile opening 22 and into the taper relief 23. The embodiment and configuration of the recess 24 may vary depending on the application. Alternatively, the slug 27 falls through the taper relief 23, disposed below the die trim profile opening 22. Additionally, the die trim assembly includes a punch stripper 28 that strips the stamping material 26 from the trim punch 25.
(25) Referring now to FIG. 5, there is shown a side view of a first embodiment of the disclosed recess, wherein the recess is created via a vertical conical extrusion. More specifically, the recess is cut with a conical shape from an angle perpendicular to the cutting edge of the die trim insert 20 such that the side of the conical extruder is aligned with a vertical axis and parallel to the die trim profile wall 21. The recess has a larger diameter at an upper portion of the recess 24, and a smaller diameter at the lower end of the recess 24. The upper portion of the recess 24 is level with the cutting edge of the die trim insert 20 and the narrower lower end of the recess 24 extends below the lower end of the die trim profile opening 22 and into the taper relief 23. Accordingly, the length of the recess 24 extends through the die trim insert 20. The die trim insert 20 is above the die trim support block 29. Die trim support block 29 has an opening that is larger than die trim profile opening 22, which allows the slugs to fall out of the die after the slugs have been pushed through the die trim insert 20 by the trim punch 25. Additionally, the diameter of the recess 24 increases as it reaches the cutting edge of the die trim insert 20, and the diameter of the recess 24 decreases as it nears the taper relief 23 and the die trim support block 29 disposed below the die trim profile opening 22. The illustrated embodiment of the recess may be added to the existing die trim profile opening 22 by wire EDM. The recess pinches loose slugs as the slug is pushed down into the die trim profile opening 22.
(26) Referring now to FIG. 6, there is shown a front cross-sectional view of the first embodiment of the recess 24 located on the die trim profile wall 21. In the illustrated embodiment, the recess 24 is aligned vertically and perpendicular to the top edge of the die trim insert 20. The tapered end of the recess 24 wedges a slug in the die trim profile opening 22 as it is driven towards the bottom of the land, stopping above the taper relief 23 by a trim punch. The recess 24 creates a lug on the side of the slug that becomes a pressure point on the slug that keeps it tight in the die trim profile opening 22, allowing the trim punch to withdraw and the slug to stay in the die trim profile opening 22, therefore allowing the die trim assembly to run unobstructed by loose slugs.
(27) Referring now to FIG. 7, there is shown a close up front view of the first embodiment of the disclosed recess. The recess forms a substantially V-shape when viewed from the front such that the widest part of the V is at the die trim insert 20 surface and the narrower part of the V is below the lower end of the die trim profile opening 22 and extends into the taper relief 23. The radius and depth of the recess 24 are dependent upon the size of the slug, cutting clearance, and the distance that the trim punch travels into the die trim profile opening 22. The recess 24 keeps the slug from being drawn upwards above the die trim insert 20 surface, or adhering to the surface of a trim punch when it is withdrawn from the die trim profile opening 22. The recess 24 creates a pinching action on the slug that creates a more positive slug locking pressure and helps to prevent loose slugs from being drawn upwards with the trim punch or tilting sideways after the trim punch is withdrawn. This keeps loose slugs from jamming the in-feeding material or causing the die tooling to break. Accordingly, the disclosed recess keeps the die running more effectively and reduces maintenance costs.
(28) Referring now to FIG. 8, there is shown a side view of a second embodiment of the disclosed recess added via an angled conical extrusion. More specifically, the recess is cut with a side of the conical extruder that is tapered to less depth towards the bottom edge of the trim profile wall 21. In this embodiment, the recess 24 tapers to less depth as it nears the taper relief 23. Alternatively, the recess 24 may taper out at the taper relief 23. Accordingly, the length of the recess 24 is less than, equal to, or greater than the depth of the die trim profile opening 22 and is longer than the distance the trim punch enters the die trim profile opening 22. The angled conical extrusion is added to a new or existing die trim profile opening 22 using wire EDM, or other suitable methods.
(29) Referring now to FIG. 9, there is shown a front cross-sectional view of the second embodiment of the recess 24 located on the die trim profile wall 21. The second embodiment of the recess 24 is aligned substantially vertically. The top part of the recess 24 extends over the outer perimeter of the top of the die trim profile opening 22. The recess 24 is widest at the top, which is at the cutting edge of the trim profile wall 21. The recess is narrower towards its lower end, but it tapers out as it reaches the taper relief 23, which is positioned below the die trim profile opening 22. The slugs are retained in the die trim profile opening 22 and prevented from being withdrawn with the trim punch.
(30) Referring now to FIG. 10, there is shown a close up front view of the second embodiment of the disclosed recess. Radius, depth, and angle relative to the die trim profile opening 22 of the recess 24 are dependent upon the size of the slug, cutting clearance between the trim punch and the die trim profile wall 21, the distance the trim punch travels into the die trim profile 22, the amount of land, as well as the stamping material used. The recess 24 creates a small geometrical tab or lug on the slug that is progressively squeezed as it is pushed into the die trim insert 20. This prevents the slug from being withdrawn out of the die trim profile opening 22. The area of recess 24 decreases as the slug travels deeper into the die trim profile opening 22, compressing the slug and locking it into place, which keeps the in-feeding material from jamming. This also prevents the tooling in the die from breaking and the finished products from being damaged by slugs in the working area of the die.
(31) Referring now to FIG. 11, there is shown a view of the third embodiment of the disclosed recess. The third embodiment is added via an angled cylindrical extrusion. In this embodiment, a cylindrical cut is used to create the recess 24 into the trim profile wall 21. The recess 24 is cut at an angle, wherein the central axis of the conical extruder is at an angle relative to the die trim profile wall 21. The top of the recess 24 cuts deeper into the top cutting edge of the trim profile wall 21 such that the top of the recess 24 extends past the outer perimeter of the die trim profile opening 22. In the illustrated embodiment, the recess 24 extends below the die trim profile opening 22, such that the recess 24 tapers out below the taper relief 23. Additionally, the cut is deeper into the top of the die trim profile wall 21 and is tapered to less depth at the bottom which is tapered out. The angled cylindrical extrusion may also be added to new or existing die trim profile opening 22 using conventional grinding, wire EDM, or other suitable methods.
(32) A cross sectional area of the recess 24 illustrated in FIG. 11, like a cross sectional area of the recess 24 illustrated in FIG. 2, is bounded by a surface of the recess that extends along a portion of a circle. Each cross sectional area of the recess 24 in FIG. 11, however, has the same radius r, that is, the radius r remains constant along the entire recess 24. The depth of the recess 24 into the die trim insert 20 decreases with increasing depth of the die trim profile opening 22 from the top surface of the die trim insert 20. The center c of each cross sectional area of the recess 24 shown in FIG. 11, like the center c of each cross sectional area of the recess 24 shown in FIG. 2, is located within the die trim profile opening 22. However, the centers c associated with the cross-sectional areas of the recess 24 are located closer and closer to the longitudinal central axis of the die trim profile opening 22 in a direction extending from the top end of the recess to the bottom end of the recess.
(33) Referring now to FIGS. 12 and 13, there are shown frontal views of the third embodiment of the disclosed recess created via an angled cylindrical extrusion. The recess 24 assumes the shape of the cylindrical cut, but the width and depth of the recess changes along its length. As such, the recess 24 captures slugs and prevents the slugs from jamming the in-feeding material. The cylindrical cut of the recess 24 has similar features as the previous embodiments. This embodiment also creates a small lug on the slug, which takes the shape of the recess at the top cutting edge. The area of the recess 24 decreases towards the bottom of the recess 24. The slug that is created near the top of the recess 24 is driven to the bottom of the recess 24, where the area of the recess 24 is now smaller. This creates a pinching action on the slug itself.
(34) Referring now to FIGS. 14a and 14b, there are shown an embodiment of the disclosed recess in a rectangular die trim profile opening 22. Two recesses 24 are added to the die trim profile wall 21 at two different points in a rectangular embodiment of the die trim profile opening 22. As discussed above, one or more recess 24 may be added to die trim profile opening 22 of various shapes and sizes. The number of the recess 24 required for the die trim profile opening 22 depends upon the slug size and metal thickness. Generally, more recesses are needed for larger and thicker slugs. Each recess in the disclosed embodiment creates a geometrical tab that allows the configuration of the recess 24 and the die trim profile wall 21 to exert pressure on tabs and the slug to rigidly wedge the slug into the die trim profile wall 21 at the bottom of the trim punch stroke. Eventually, the slugs are pushed free downward and fall out of the bottom of the die trim insert 20.
(35) While multiple embodiments have been disclosed and described in detail, it is understood that this is capable of modification and that the scope of the disclosure is not limited to the precise details set forth but includes modifications obvious to a person of ordinary skill in possession of this disclosure and also such changes and alterations as fall within the purview of the following claims.
