Draw die assembly and method

Abstract

A draw die assembly includes a lower die shoe and an upper die shoe vertically moveable relative to the lower die shoe. A draw punch vertically protrudes from the lower die shoe. The upper die shoe defines a cavity for receiving the work piece and draw punch such that downward movement of the upper die shoe causes the work piece to be compressed between the draw punch and the cavity. A slip flange form is positioned adjacent to the binder segment. The upper die shoe has an edge that is approximately aligned with an edge of the slip flange form such that downward movement of the upper die shoe causes an edge of the work piece to be pinched between the edge of the upper die shoe and the edge of the slip flange form.

Description

DRAW DIE ASSEMBLY AND METHODCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This PCT International Patent Application claims the benefit of and priority to U.S. Provisional Patent Application Serial No. 63 / 602,029 filed on November 22, 2023, and titled “Draw Die Assembly And Method,” the entire disclosure of which is hereby incorporated by reference.BACKGROUND OF THE DISCLOSURE1. Field of the Disclosure

[0002] The present disclosure relates to draw die assemblies for cold forming metal parts, and methods of using draw die assemblies.2. Related Art

[0003] This section provides background information related to the present disclosure which is not necessarily prior art.

[0004] Draw die assemblies are known for cold-forming products from metal work pieces. As shown in FIG. 1, a conventional draw die assembly 1 includes a lower die shoe 2, and an upper die shoe 3 that is positioned above the lower die shoe 2. A gap is located between the lower and upper die shoes 2, 3 for receiving the work piece 6. The upper die shoe 3 is vertically moveable toward and away from the lower die shoe 2 via action from a press ram 4. The upper die shoe 3 defines a draw cavity 5 that faces the work piece 6. A draw punch 7 protrudes upwardly from the lower die shoe 2. A plurality of binders 8 are configured to support the work piece 6 and vertically move to accommodate downward movement of the upper die shoe 3 against the work piece 6. During use, the work piece 6 is positioned on top of the binders 8 and the draw punch 7. The upper die shoe 3 is moved downwardly against the work piece 6, whichcauses the work piece 6 to be compressed between the draw punch 7 and the draw cavity 5 and thus take a shape which is consistent with that of the drawn punch 7 and draw cavity 5 to provide the final product. After this drawing step, the upper die shoe 3 is retrieved away from the lower die shoe 2, and the resulting product is removed. The binders 8 include one or more beads 9 which project upwardly from the binders 5, and the upper die shoe 3 includes corresponding bead recesses 11 such that the beads 9 pinch and inhibit lateral sliding movement of the work piece 6 during the drawing operation.

[0005] An issue with such conventional die assemblies 1 is a certain amount of lateral sliding of the edges of the work piece 6 is typically required, especially at a bottom of the stroke of the upper die 3 to prevent splitting of the work piece 6, while near total locking of the work piece 6 is required through most of the compression stroke. It is known to adjust a size of the beads 9 and recesses 11 to modify the sliding characteristics, but there remains a need for continued improvements to draw die assemblies 1.SUMMARY OF THE DISCLOSURE

[0006] According to an aspect of the disclosure, a draw die assembly is provided for forming a finished part from a work piece. The draw die assembly includes a lower die shoe. An upper die shoe is spaced from the lower die show in a vertical direction. At least one of the upper and lower die shoes is vertically moveable relative to the other of the upper and lower die shoes. A draw punch vertically protrudes from the lower die shoe. The upper die shoe defines a cavity for receiving the work piece and draw punch such that movement of the upper and lower die shoes relative to one another causes the work piece to be compressed between the draw punch and the cavity of the upper die shoe such that the work piece takes a shape which is consistent with that of the draw punch and the cavity. At least one slip flange form is provided. The upperdie shoe has at least one edge that is approximately aligned with at least one edge of the at least one slip flange form in a horizontal direction such that downward movement of the upper die shoe causes at least one edge of the work piece to be pinched between the at least one edge of the upper die shoe and the at least one edge of the at least one slip flange form to inhibit movement of the work piece during the forming process while the work piece is vertically aligned with the edge of the slip flange form.

[0007] According to another aspect of the disclosure, a method is provided for drawing a work piece to form a finished part. The method includes providing a die assembly that includes a lower die shoe and an upper die shoe that is spaced from the lower die show in a vertical direction. A draw punch vertically protrudes from the lower die shoe. The upper die shoe defines a cavity for receiving the work piece and draw punch. At least one slip flange form is coupled to the lower die shoe. The upper die shoe has at least one edge that is substantially aligned with the at least one edge of the at least one slip flange form in the horizontal direction. The method also includes moving at least one of the upper die shoe and the lower die shoe toward the other of the upper and lower die shoes. The method also includes pinching at least one edge of the work piece between the at least one edge of the upper die shoe and the at least one edge of the at least one slip flange form to inhibit movement of the work piece while the work piece is vertically aligned with the at least one edge of the at least one slip flange. The method also includes compressing the work piece between the draw punch and the upper die shoe in the cavity of the upper die shoe to form the finished part.

[0008] The slip flange form provides a simple and inexpensive manner of securing the work piece in place during the drawing process without requiring the use of beads, while preventing tearing of the work piece. Specifically, lateral movement of the work piece isprevented via pinching of the edge of the work piece between the slip flange form and the upper die shoe, and the edge of the work piece is freed from such pinching once the edge of the slip flange form has been vertically cleared. This also permits a length of the edge of the slip flange form to be tailored to desired characteristics of specific work pieces.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other advantages of the present disclosure will be more readily understood by reference to the following description in combination with the accompanying drawings wherein:

[0010] FIG. l is a side, cross-sectional view of a conventional draw die assembly;

[0011] FIG. 2 is a side, cross-sectional view of a first embodiment of a draw die assembly according to an aspect of the disclosure;

[0012] FIG. 3 is a side, cross-sectional view of the first embodiment of the draw die assembly, illustrating a first step of a draw process;

[0013] FIG. 4 is a side, cross-sectional view of the first embodiment of the draw die assembly, illustrating a second step of a draw process;

[0014] FIG. 5 is a side, cross-sectional view of the first embodiment of the draw die assembly, illustrating a third step of the draw process;

[0015] FIG. 6 is a side, cross-sectional view of the first embodiment of the draw die assembly, illustrating a fourth step of the draw process;

[0016] FIG. 7 is a side, cross-sectional view of the first embodiment of the draw die assembly, with a second embodiment of a slip flange form of the draw die assembly;

[0017] FIG. 8 is a side, cross-sectional view of the first embodiment of the draw die assembly, with a third embodiment of a slip flange form of the draw die assembly; and

[0018] FIG. 9 is a flow diagram of a method for using the draw die assembly, according to an aspect of the disclosure.DETAILED DESCRIPTION OF THE ENABLING EMBODIMENTS

[0019] Example embodiments will now be described more fully with reference to the accompanying drawings. In general, the subject embodiments are directed to draw die assemblies and methods of using the same. However, the example embodiments are only provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0020] Referring to FIGS. 2-7, wherein like numerals indicate corresponding parts throughout the several views, embodiments of a die assembly 10 are shown. The die assembly 10 is for cold-forming products, e.g., automotive or aerospace components, from metal work pieces 12.

[0021] The die assembly 10 includes a lower die shoe 14. A draw punch 16 protrudes from the lower die shoe 12 and extends upwardly in a vertical direction. A top surface 18 of the draw punch 16 has a shape that corresponds with a desired shape of the resulting product.

[0022] One or more binder segments 20 are connected to a top of the lower die shoe 14 and are vertically moveable relative to the lower die shoe 14. The binder segments 20 are configured to support the work piece 12 along with the draw punch 16 during operation of theassembly 10. The binder segments 20 are located on opposing sides of the draw punch such that the draw punch 16 is located in an opening 22 between the binder segments 20. The binder segments 20 may be part of a continuous, or non-continuous binder that surrounds the draw punch such as in a circle, rectangular or square shape. The opening 22 permits the binder segments 20 and draw punch 16 to move independently of one another. One or more adjustable lifting mechanisms 24, such as a series of hydraulic lifts, interconnect the binder segments 24 to the lower die shoe 14 and provides vertical movement of, and a cushioning effect for the binder segments 24.

[0023] An upper die shoe 26 is spaced from the lower die shoe 14 in the vertical direction. A press ram 28 is positioned above the upper die shoe 26 for vertically moving the upper die shoe 26 toward and away from the lower die shoe 14. The upper die shoe 26 defines a cavity 30 that is aligned with the draw punch 16 for receiving the draw punch 16 and work piece 12 which is positioned on top of the draw punch 16. Like the die punch 16, the cavity 30 has a shape that corresponds with the desired shape of the resulting product.

[0024] During use, the upper die shoe 26 is configured to move vertically downwardly toward the lower die shoe 14 in response to actuation from the press ram 28, which causes the work piece 12 to be compressed between the draw punch 16 and the draw cavity 30, and take a shape which is consistent with that of the draw punch 16 and draw cavity 30 to form the final part. The binder segments 20 vertically move to support the work piece 12 while accommodating the vertical movement of the upper die shoe 26. The binder segments 20 are independently moveable relative to the draw punch 16 to accommodate changes in the shape of the work piece 12 during forming. According to other embodiments, the lower die shoe 26 could move relativeto the upper die shoe 26, or both the upper and lower die shoes 26, 14 could move simultaneously.

[0025] As shown in FIGS. 2-6, one or more slip flange forms 32 are each disposed adjacent to one of the binder segments 20. Any number of slip flange forms 32 could be used. According to embodiments, one or more continuous slip flange forms 32 could be used, e.g., in a continuous circular or rectangular shape. The slip flange forms 32 each have an axial portion 34 that extends vertically, and a flange portion 36 that extends in a horizontal direction from the axial portion 34 to define a void 38 beneath the flange portion 36 and along the flange portion 36. The flange portion 36 presents an edge 37 toward the draw punch 16 that has a vertical length L.

[0026] The upper die shoe 26 has one or more edges 40 that are each substantially aligned with one of the edges 37 of the flange portions 36 of the slip flange forms 32 in the horizontal direction such that downward movement of the upper die shoe 26 causes at least one edge of the work piece 12 to be pinched between the edge 40 of the upper die shoe 26 and the edge 37 of the slip flange form 32 to inhibit movement of the work piece 12 during the forming process (FIGS. 4-5) until work piece 12 has passed the length L of the edge 37 of the flange portion 36. The presence of the void 38 beneath the flange portion 36 causes the edge of the work piece 12 to only be pinched along the vertical length of the edge 37 of the flange portion 26 of the slip flange form 32. As shown in FIG. 6, once the edge of the work piece 12 has vertically passed the edge 37 of the flange portion 26, the edge of the work piece 12 has entered the void 38 which relieves tension on the work piece 12 and prevents splitting of the work piece 12 during continued compression of the work piece 12.

[0027] A method 100 of using the die assembly is schematically presented in FIG. 9. As illustrated in FIG. 2, the method 100 includes 102 positioning the work piece 12 on top of the press ram 28 and binder segment 20. As shown, while in this position, an edge of the work piece 12 extends slightly beyond the binder segment 20 and upper die shoe 26. As shown in FIGS. 3-5, the method continues with 104 moving the upper die shoe 26 downwardly toward the lower die shoe 14, which causes the edges 12 of the work piece 12 to be pinched between the edges 37 of the flange portions 36 of the slip flange forms 32 and the upper die shoe 14. This inhibits lateral sliding of the work piece 12 through most of the down stroke of the upper die shoe die 14 (along a length of the edges 37 of the slip flange forms 32). As shown in FIG. 6, once the edges of the work piece 12 have vertically moved past the edges 37 of the flange portions 36 of the slip flange forms 32 beyond the length of the edges 37, the method includes 106 relieving lateral tension on the work piece 12 by permitting the work piece 12 to enter the voids 38 of the slip flange forms 32. This allows final compression of the work piece 12 without splitting the work piece 12. The method then includes 108 raising the upper die shoe 26 to permit the resulting product to be removed from the die assembly 10.

[0028] The vertical length L of the edge 37 of the flange portion 36 of the slip flange forms 32 can be adjusted to provide a desired length at which the work piece 12 is pinched. Furthermore, the edge 37 of the slip flange form 32 extends parallel to the edge 40 of the upper die shoe in FIGS. 2-6, but as shown in FIGS. 7 and 8, the edge 37A, 27B may have other shapes, e g., it may taper outwardly or inwardly, to vary the pinching strength as the work piece 12 moves along the length L of the flange portion 36, in order to provide different operational characteristics.

[0029] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in that particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0030] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or later, or intervening element or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0031] Although the terms first, second, third, etc. may be used herein to described various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms may be onlyused to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0032] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0033] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in any embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

CLAIMSWhat is claimed is:

1. A draw die assembly for forming a finished part from a work piece, comprising: a lower die shoe; an upper die shoe spaced from the lower die shoe in a vertical direction and vertically moveable relative to the lower die shoe; a draw punch vertically protruding from the lower die shoe; the upper die shoe defining a cavity for receiving the work piece and draw punch such that downward movement of the upper die shoe causes the work piece to be compressed between the draw punch and the cavity of the upper die shoe and to take a shape which is consistent with that of the draw punch and cavity; at least one slip flange form; and the upper die shoe having at least one edge substantially aligned with the at least one slip flange form in a horizontal direction such that downward movement of the upper die shoe causes at least one edge of the work piece to be pinched between the at least one edge of the upper die shoe and at least one edge of the at least one slip flange form to inhibit movement of the work piece during the forming process while the work piece is vertically aligned with the at least one edge of the at least one slip flange form.

2. The draw die assembly as set forth in claim 1, wherein the at least one slip flange form has an axial portion extending vertically and a flange portion extending in a horizontal direction from the axial portion to define a void beneath the flange portion, and wherein the at least one edge of the slip flange form is located along the flange portion such that the work pieceis only pinched between the at least one edge of the upper die shoe and the at least one edge of the at least one slip flange form along a vertical length of the flange portion of the at least one slip flange form.

3. The draw die assembly as set forth in claim 2, wherein the at least one edge of the at least one slip flange form extends substantially parallel to the at least one edge of the upper die shoe.

4. The draw die assembly as set forth in claim 2, wherein the at least one edge of the at least one slip flange form extends at an angle relative to the at least one edge of the upper die shoe.

5. The draw die assembly as set forth in claim 1, further including at least one binder segment for supporting the work piece positioned vertically above the lower die shoe and moveably connected to the lower die shoe, and wherein the at least one slip flange form is disposed adjacent to the at least one binder segment.

6. The draw die assembly as set forth in claim 5, wherein the at least one binder segment includes a plurality of binder segments that are arranged to surround the draw punch.

7. A method for drawing a work piece to form a finished part, comprising: providing a die assembly including a lower die shoe, an upper die shoe spaced from the lower die show in a vertical direction and vertically moveable relative to the lower die shoe, adraw punch vertically protruding from the lower die shoe, the upper die shoe defining a cavity, at least one slip flange form coupled to the lower die shoe, and the upper die shoe having at least one edge substantially aligned with at least one edge of the at least one slip flange form in the horizontal direction; moving the upper die shoe downwardly against the lower die shoe to cause the lower die shoe to move downwardly; pinching at least one edge of the work piece between the at least one edge of the upper die shoe and the at least one edge of the at least one slip flange form to inhibit movement of the work piece; and compressing the work piece between the draw punch and the upper die shoe in the cavity of the upper die shoe to form the finished part.

9. The method as set forth in claim 8, further including relieving tension on the work piece after the edge of the work piece has vertically passed the at least one edge of the at least one slip flange form.

10. The method as set forth in claim 8, wherein the at least one slip flange form has an axial portion that extends vertically, and a flange portion that extends in the horizontal direction from the axial portion to define a void beneath the flange portion, and wherein the method further includes vertically moving the upper die shoe toward the lower die shoe to a point where the at least one edge of the work piece passes the at least one edge of the flange portion of the slip flange form and is released into the void of the slip flange form to relieve tension on the work piece.

11. The method as set forth in claim 8, wherein the at least one edge of the at least one slip flange form extends parallel to the at least one edge of the upper die shoe.

12. The method as set forth in claim 8, wherein the at least one edge of the at least one slip flange form extends at an angle relative to the at least one edge of the upper die shoe.

13. The method as set forth in claim 8, further including at least one binder segment for supporting the work piece positioned vertically above the lower die shoe and moveably connected to the lower die shoe.

14. The draw die assembly as set forth in claim 13, wherein the at least one binder segment includes a plurality of binder segments that are arranged to surround the draw punch.

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