FLAT TOP METAL GAINER
A method of forming a metal part that includes placing a metal blank in a stamping apparatus having a first die including a plurality of metal gainers and a second die including a plurality of recesses that correspond to the plurality of metal gainers, and compressing the metal blank such that the metal gainers and the corresponding recesses provide the metal blank with regions of localized stretching. Each of the metal gainers and recesses includes a flat surface such that during the compressing of the metal blank to provide the metal blank with the regions of localized stretching, a strain exerted on the metal blank by the metal gainers and recesses is less than a strain exerted on the metal blank by metal gainers and recesses that do not include the flat surface.
The present disclosure relates to a stamping method and system that uses a metal gainer having a flat top for providing additional material before a flanging operation is conducted.
BACKGROUNDMany manufacturing processes are available to form sheet metal blanks into parts in a wide variety of industries. For example, drawing and deep drawing of sheet metal blanks is a process in which the metal blank is drawn between an upper die and a lower die to take a shape that initially resembles the shape of the finished part. Additional manufacturing process might also take place after the drawings. For example, flanging can bend an end region of the metal blank to form a flange. When these flanges are formed, however, there may be residual stress in regions of the flange that can distort the final shape of the part due to the stretching and bending of the metal to form the flange.
In addition, when the metal blank is formed from an advanced high strength metal such as an ultra-high strength steel or a 7000 series aluminum alloy, the metal blank may have poor ductility and/or formability. The reduced formability of these newer materials may result in cracks, necking, or other imperfections during the flanging process. Any of these imperfections may compromise the integrity of the finished part, and are simply not acceptable in commercial products, including automotive applications.
SUMMARYThe present disclosure provides a method of forming a metal part that includes placing a metal blank in a stamping apparatus having a first die including a plurality of metal gainers and a second die including a plurality of recesses that correspond to the plurality of metal gainers, and stretching the metal blank such that the metal gainers and the corresponding recesses provide the metal blank with regions of localized stretching; and subjecting the metal blank including the regions of localized stretching to a stretch-flanging process; wherein each of the metal gainers and recesses includes a flat surface surrounded by a side surface such that during the stretching of the metal blank to provide the metal blank with the regions of localized stretching, a combined strain exerted on the metal blank by the metal gainers and recesses that include the flat surface in combination with the stretch-flanging process is less than a combined strain exerted on the metal blank by traditional metal gainers and recesses that do not include the flat surface in combination with the stretch-flanging process.
The present disclosure also provides a method of forming a metal part that includes placing a metal blank in a stamping apparatus having a first die including a plurality of metal gainers and a second die including a plurality of recesses that correspond to the plurality of metal gainers, and stretching the metal blank such that the metal gainers and the corresponding recesses provide the metal blank with regions of localized stretching; and subjecting the metal blank including the regions of localized stretching to a stretch-flanging process; wherein each of the metal gainers and recesses includes a flat surface surrounded by a side surface such that during the stretching of the metal blank to provide the metal blank with the regions of localized stretching, a curve that graphically represents the strains exerted on the metal blank at the regions of localized stretching exhibits a pair of peaks at different locations rather than a single peak when the metal blank is stretched between metal gainers and recesses that do not have the flat surface.
Lastly, the present disclosure provides a stamping press that includes a first die including a plurality of protrusions; and a second die including a plurality of recesses that correspond to the plurality of protrusions, wherein the plurality of protrusions in combination with the plurality of protrusions are configured to provide a metal blank with regions of localized stretching when the metal blank is stretched between the plurality of protrusions and the plurality of recesses, and wherein each of the protrusions and each of the recesses includes a flat surface surrounded by a side surface such that during the stretching of the metal blank to provide the metal blank with the regions of localized stretching, a curve that graphically represents the strains exerted on the metal blank at the regions of localized stretching exhibits a pair of peaks at different locations rather than a single peak when the metal blank is compressed between metal gainers and recesses that do not have the flat surface.
Further areas of applicability of the teachings of the present disclosure will become apparent from the detailed description, claims and the drawings provided hereinafter, wherein like reference numerals refer to like features throughout the several views of the drawings. It should be understood that the detailed description, including disclosed embodiments and drawings referenced therein, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application or uses. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.
A stamped metal part may become dimensionally unstable or undesirable for later use in a vehicle assembly due to stresses that can be a byproduct of the metal stamping process. Depending on the function of the metal part and its location in the vehicle, the dimensional defect can cause vehicle build issues and can be visibly undesirable to the driver or customer. This undesirability may occur in a flange of a stamped part. Stretch-flanging is an operation in which a part of the metal part, such as an edge of the metal part, is bent with respect to the body. Some example regions of the vehicle body with a flanged edge include a fender door line, a roof line, a fender wheel opening, a cowling, and a liftgate outer roof line.
In order to suppress cracking or splitting of the metal blank during formation of flange 18, a metal blank 20 is subjected to a stamping process where the metal material of the metal blank 20 is stretched before conducting the flanging process.
Now referring to
Now referring to
The regions or bubbles 24 of localized stretching of metal blank 20 are provided by placing metal blank 20 in a stamping apparatus or stamping press die 28. An example stamping press die 28 is illustrated in
As noted above, due to the localized stretching of metal blank 20 at bubbles 24 that are formed by metal gainers 34, the material of metal blank 20 is less prone during stretch-flanging to stretch to an extent that causes the material of metal blank 20 to crack or split. As shown in
More specifically,
As can be seen in
As can be seen in
Metal gainers 34 do not necessarily need to be oval-shaped, as shown in
Regardless of the shape of metal gainer 34, the important aspect of the present disclosure is to provide metal gainer 34 and recesses 36 with first flat surface 38 and second flat surface 40. First and second flat surfaces 38 and 40 may have a similar shape as that of metal gainer 34 and recess 36 as shown in
The surface area of first and second flat surfaces 38 and 40 may also be variable. For example, the surface area of flat surfaces 38 and 40 of metal gainers 34 and recesses 36 can range between 40% to 90% of the surface area of metal gainers 34 and recesses 36, more preferably between 50% to 75% of the surface area, and most preferably 60% to 70% of the surface area.
Lastly, first and second flat surfaces 38 and 40 are not necessarily planar surfaces. In contrast, as noted above, the important aspect to keep in mind is that first and second flat surfaces 38 and 40 can be designed or engineered such that metal gainers 34 and recesses 36 allow for management of the locations of the strain peaks that indicate the locations of the strains exerted on metal blank 20 in the manner shown in
Claims
1. A method of forming a metal part, comprising:
- placing a metal blank in a stamping apparatus having a first die including a plurality of metal gainers and a second die including a plurality of recesses that correspond to the plurality of metal gainers, and forming the metal blank such that the metal gainers and the corresponding recesses provide the metal blank with regions of localized stretching, the regions of localized stretching being located along a trim line of the metal blank that corresponds to a region of the metal blank that will be trimmed from the metal blank;
- after providing the metal blank with the regions of localized stretching, trimming the metal blank along the trim line such that portions of regions of localized stretching remain along the trim line; and
- after trimming the metal blank along the trim line, subjecting the metal blank including the regions of localized stretching to a stretch-flanging process that forms a flange at the trim line;
- wherein each of the metal gainers and recesses includes a flat surface surrounded by a side surface such that during the forming of the metal blank to provide the metal blank with the regions of localized stretching, a combined strain exerted on the metal blank by the metal gainers and recesses that include the flat surface in combination with the stretch-flanging process is less than a stretch limit of a material of the metal blank.
2. The method according to claim 1, wherein a surface area of the flat surfaces of the metal gainers and the recesses ranges between 40% to 90% of a total surface area of the metal gainers and the recesses.
3. The method according to claim 1, wherein the metal gainers and recesses are at least one of oval-shaped, triangular-shaped, diamond- or square-shaped, or round.
4. The method according to claim 3, wherein a shape of the flat surface of each of the metal gainers and recesses is the same as an overall shape of the metal gainer and recess.
5. The method according to claim 3, wherein a shape of the flat surface of each of the metal gainers and recesses is different from an overall shape of the metal gainer and recess.
6. The method according to claim 1, wherein the metal blank is formed of an advanced high strength metal.
7. A method of forming a metal part, comprising:
- placing a metal blank in a stamping apparatus having a first die including a plurality of metal gainers and a second die including a plurality of recesses that correspond to the plurality of metal gainers, and forming the metal blank such that the metal gainers and the corresponding recesses provide the metal blank with regions of localized stretching, the regions of localized stretching being located along a trim line of the metal blank that corresponds to a region of the metal blank that will be trimmed from the metal blank;
- after providing the metal blank with the regions of localized stretching, trimming the metal blank along the trim line such that portions of regions of localized stretching remain along the trim line; and
- after trimming the metal blank along the trim line, subjecting the metal blank including the regions of localized stretching to a stretch-flanging process that forms a flange at the trim line;
- wherein each of the metal gainers and recesses includes a flat surface surrounded by a side surface such that during the forming of the metal blank to provide the metal blank with the regions of localized stretching.
8.-9. (canceled)
10. The method according to claim 7, wherein a surface area of the flat surfaces of the metal gainers and the recesses ranges between 40% to 90% of a total surface area of the metal gainers and the recesses.
11. The method according to claim 7, wherein the metal gainers and recesses are at least one of oval-shaped, triangular-shaped, diamond- or square-shaped, or round.
12. The method according to claim 11, wherein a shape of the flat surface of each of the metal gainers and recesses is the same as an overall shape of the metal gainer and recess.
13. The method according to claim 11, wherein a shape of the flat surface of each of the metal gainers and recesses is different from an overall shape of the metal gainer and recess.
14. The method according to claim 7, wherein the metal blank is formed of an advanced high strength metal.
15. A stamping press comprising:
- a first die including a plurality of protrusions; and
- a second die including a plurality of recesses that correspond to the plurality of protrusions,
- wherein the plurality of protrusions in combination with the plurality of protrusions are configured to provide a metal blank with regions of localized stretching when the metal blank is formed between the plurality of protrusions and the plurality of recesses, and
- wherein each of the protrusions and each of the recesses includes a flat surface surrounded by a side surface such that during the forming of the metal blank to provide the metal blank with the regions of localized stretching; and
- wherein a shape of the flat surface of each of the protrusions and recesses is the same as an overall shape of the protrusions and recesses.
16. The stamping press according to claim 15, wherein a surface area of the flat surfaces of the protrusions and the recesses ranges between 40% to 90% of a total surface area of the protrusions and the recesses.
17. The stamping press according to claim 15, wherein the protrusions and recesses are at least one of oval-shaped, triangular-shaped, diamond-or square-shaped, or round.
18.-19. (canceled)
Type: Application
Filed: Aug 6, 2020
Publication Date: Feb 10, 2022
Inventors: Dajun Zhou (Troy, MI), Chunlei Wang (Rochester Hills, MI), Robert D Miller (Lake Orion, MI)
Application Number: 16/986,449