Variable radii sheet metal roll forming tool and methods and systems for forming variable radii sheet metal parts with the same

Abstract

Curved sheet metal parts having variable (multiple) radii may be formed using an adjunct roll forming tool in cooperation with a conventional sheet metal rolling machine without the need to adjust spacing between the forming rolls of the machine during conveyance of the sheet metal blank. The roll forming tool preferably is formed as a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon. The upwardly inclined upper surface forms the curved sheet metal part with variable radii when conveyed through forming rolls of the sheet metal roll forming machine without the need to continually adjust the dimensional spacing between the forming rolls during conveyance therethrough.

Description

FIELD

[0001] The embodiments disclosed herein relate generally to the formation of curved sheet metal parts having variable (multiple) radii. In particular embodiments of the invention, an adjunct tool is provided which allows a curved sheet metal part to be fabricated with variable radii by a conventional sheet metal rolling machine without the need to adjust spacing between the forming rolls (i.e., by maintaining a fixed dimensional gap between the forming rolls).BACKGROUND

[0002] Sheet metal rolling machines are well known in fabrication shops to form curved sheet metal parts from corresponding planar sheet metal blanks. A wide variety of such conventional sheet metal rolling machines employ a pair of spaced apart lower forming rolls, between and above which is positioned an upper forming roll. The upper forming roll may be adjustably positioned relative to the lower forming rolls so as to allow corresponding adjustment of a forming gap between opposed tangential roll planes. The dimension of the forming gap will therefore in practice determine the radius of the curve imparted to the sheet metal blank that is subjected to the roll-forming forces of the upper and lower forming rolls when the blank is fed therebetween.

[0003] It is sometimes necessary to form a sheet metal part with variable (multiple) radii. To accomplish the formation of a variable radii sheet metal part on a conventional machine, the machine operator will need to continually adjust the forming gap manually between the upper and lower forming rolls as the sheet metal blank is fed therebetween. It can be appreciated therefore that such continual manual adjustment of the forming gap of the sheet metal rolling machine can lead to nonuniformity of the variable radii of the curved sheet metal parts. While computer assisted process control algorithms have been employed to alleviate such manual adjustments of the rolling machine and thereby allow for the automatic adjustment of the forming gap between the upper and lower forming rolls, their implementation can be cost-prohibitive for many sheet metal fabricators.

[0004] It would therefore be highly desirable if an adjunct tool could be provided which would preclude the need for continual manual adjustment of a forming gap associated with a conventional sheet metal rolling machine when fabricating curved sheet metal parts with variable radii. It is towards providing such a solution that the embodiments disclosed herein are directed.SUMMARY

[0005] The embodiments disclosed herein are broadly concerned with the fabrication of curved sheet metal parts having variable (multiple) radii using an adjunct roll forming tool in cooperation with a conventional sheet metal rolling machine without the need to continually adjust the dimensional spacing between the forming rolls of the machine during conveyance of the sheet metal blank. The roll forming tool preferably is formed as a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon. The upwardly inclined upper surface forms the curved sheet metal part with variable radii when conveyed through forming rolls of the sheet metal roll forming machine without the need to continually adjust the dimensional spacing between the forming rolls during conveyance therethrough.

[0006] The one piece solid body preferably defines a lower planar surface that coincides with a tangent plane of the lower forming rolls of the roll forming machine when in use. The upwardly inclined upper surface of the one piece solid body may have a continuous upward slope of a constant angle from the leading edge toward the trailing edge thereof. However, the upwardly inclined upper surface may also be provided with discontinuous upward slopes of different angles.

[0007] The one piece solid body is most preferably formed entirely of a pliable thermoplastic or thermoset material, especially thermoplastic or thermoset materials that are capable of being additively manufactured, e.g., via 3D printing processes. The pliable thermoplastic or thermoset material will typically have a Shore A Hardness of between about 80 to about 100, or more specifically between about 85 to about 95. One preferred class of thermoplastic materials that may be usefully employed includes thermoplastic polyurethanes (TPUs). Thermoplastic polyurethanes are desirable since they exhibit the necessary pliability for use as an adjunct roll forming tool and since such a material is capable of being additively manufactured (e.g., by 3D printing) based on the criteria of a computer model of the curvature of the final variable radii curved sheet metal part formed thereby. Thermoset materials may include thermoset resins, such as UV-curable silicone resins, epoxy resins and the like.

[0008] In use therefore, a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween may be provided. A sheet metal blank positioned on the upwardly inclined upper surface of the adjunct roll forming tool may then be conveyed in a leading edge-first manner into and through the roll forming gap of the sheet metal roll forming machine while maintaining the fixed dimension of the roll forming gap during such conveyance thereof to cause the upper and lower forming rolls to form the variable radii curved sheet metal part from the sheet metal blank.

[0009] These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[0010] The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:

[0011] FIG. 1 is a schematic side elevational view of a roll forming apparatus to form a variable radii curved sheet metal part using the adjunct tool in accordance with an embodiment of the invention;

[0012] FIGS. 2-5 are schematic perspective views which schematically depict using the adjunct tool in accordance with an embodiment of the invention to form a variable radii curved sheet metal part in a rolling machine; and

[0013] FIG. 6 is a schematic perspective view of a variable radii curved sheet metal part that is fabricated according to the techniques shown in FIGS. 2-5.DETAILED DESCRIPTION OF EMBODIMENTS

[0014] Accompanying FIG. 1 schematically depicts an exemplary sheet metal roll forming apparatus using an adjunct tool 20 according to an embodiment of this invention in combination with a sheet metal rolling machine 12 comprised of an upper forming roll 12a and spaced lower forming rolls 12b, 12c, respectively. The lower forming rolls 12b, 12c are spaced apart from one another in the roll forming machine direction (arrow MD) by a dimension D1 while the upper forming roll 12a is positioned above and between the spaced apart rolls 12b, 12c so as to define a roll forming gap RFG of dimension D2 between parallel planes P1 and P2 that are tangential to the upper forming roll 12a and the lower forming rolls 12b, 12c, respectively.

[0015] As is known, the dimension D2 of the roll forming gap may be adjustably fixed to achieve a desired single radius of curvature for a roll-formed curved sheet metal part. In accordance with the embodiments of the present invention, an adjunct roll forming tool 20 is provided which supports the sheet metal blank as it is being fed in the machine direction MD within the roll forming gap RFG. The use of the adjunct roll forming tool 20 achieves a variable radii curved sheet metal part CP while maintaining a fixed (immovable) dimension D2 of the roll forming gap RFG during a single pass through the sheet metal rolling machine 12 during the roll forming process. Thus, in a single pass through the sheet metal rolling machine 12, an uncurved sheet metal blank (SMB) will be progressively curved from a radius R1 at a forward end thereof (i.e. as shown in solid line in FIG. 1) to a radius R2 at a rear end thereof (i.e., as shown in dashed line in FIG. 1).

[0016] The adjunct roll forming tool 20 is perhaps better seen in FIGS. 2-5. As shown, the tool 20 is most preferably a one-piece (unitary) solid body having a lengthwise dimension between leading and trailing edges 20a, 20b relative to the machine direction MD and a widthwise dimension between lateral side edges 20c, 20d sufficient to fully support a planar (uncurved) sheet metal blank (SMB). In preferred forms, the tool 20 will have a flat planar bottom surface 20f that in use is coincident with a portion of the tangential plane P2. The upper forming surface 20e is upwardly inclined or slanted in a direction from the leading edge 20a to the trailing edge 20b of the tool 20. The upwardly inclined forming surface 20e may be planar and thereby have a uniform slope angle between the leading and trailing edges 20a, 20b, respectively, as may be required in order to impart the variable radii of curvature for the resulting curved sheet metal part CP (see FIG. 6). The upper forming surface 20e may also be non-uniformly inclined, for example, by having planar segments each defining a different slope angle and / or have an upwardly inclined curvature. The thickness of the tool 20 will therefore be less at the leading edge 20a as compared to the trailing edge 20b. Thus, the thickness at the leading edge 20a may be substantially less than the dimension D2 of the roll forming gap RFG while the thickness at the trailing edge 20b may be substantially the same as or even greater than the dimension D2.

[0017] The body of the adjunct roll forming tool 20 may be formed of any material that is sufficiently pliable to allow flexion during the roll forming process yet sufficiently hard so as to resist significant compression during the roll forming process (i.e., so that substantially all of the force of the rolls 12a-12c is exerted onto the sheet metal blank SMB causing curvature thereof). As noted briefly above, preferred materials include thermoplastic or thermoset materials having a Shore A Hardness of between about 80 to about 100, preferably between about 85 to about 95. Particularly preferred materials are thermoplastic polyurethanes (TPUs) since such a material is capable of being additively manufactured (e.g., by 3D printing) based on the criteria of a computer model of the curvature of the final variable radii curved sheet metal part CP. Alternatively, pliable thermoset resins, such as silicone resins, epoxy resins and the like, may be employed.

[0018] In use, a flat sheet metal blank SMB may be positioned onto the upper inclined planar forming surface 20e of the tool 20 as shown in FIGS. 2 and 3. The assembly of the sheet metal blank SMB and the tool 20 may optionally be placed within a protective film pouch FP which serves to protect the sheet metal blank from any contaminant that may be present in or on the tool 20, for example, silicone that may leach from the material from which the tool 20 is made. The assembled sheet metal blank SMB on the tool 20 is then fed into the roll forming gap RFG with the leading edge 20a of the tool 20 entering the roll forming gap RFG first. As the rolls 12a-12c rotate in the directions noted in FIGS. 4 and 5, the sheet metal blank SMB and the tool 20 (optionally enveloped by the protective film pouch FP as shown in FIG. 3) will be pulled in the machine direction MD within the roll forming gap RFG between the roll 12a on the one hand and the rolls 12b and 12c on the other hand. Such travel of the sheet metal blank SMB and the tool 20 in the machine direction MD will thus cause bending forces to be applied by the rolls 12a-12c thereby bending the sheet metal blank. A single conveyance progression through the machine 12 will thereby form the final curved sheet metal part CP (see FIG. 6) having variable radii of curvature induced by the inclined surface 20e of the tool 20 as it is pulled through the fixed dimension roll forming gap RFG between the rolls 12a-12c.

[0019] The exemplary variable radii curved sheet metal part CP that may be formed in the manner described above may be formed of virtually any type of sheet metal. For example, in the context of an aviation component, the curved sheet metal part CP may be formed of any aluminum alloy conventionally employed for aviation components. The thickness of the curved sheet metal part P will be dependent upon the particular end use for the part. By way of example, the sheet metal blank SMB and thus the curved part CP formed therefrom may have a thickness of between about 0.010 in. to about 0.080 in. or between about 0.015 in. to about 0.025 in.

[0020] While reference has been made to particular embodiments of the invention, various modifications within the skill of those in the art may be envisioned. Therefore, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.

Examples

Embodiment Construction

[0014]Accompanying FIG. 1 schematically depicts an exemplary sheet metal roll forming apparatus using an adjunct tool 20 according to an embodiment of this invention in combination with a sheet metal rolling machine 12 comprised of an upper forming roll 12a and spaced lower forming rolls 12b, 12c, respectively. The lower forming rolls 12b, 12c are spaced apart from one another in the roll forming machine direction (arrow MD) by a dimension D1 while the upper forming roll 12a is positioned above and between the spaced apart rolls 12b, 12c so as to define a roll forming gap RFG of dimension D2 between parallel planes P1 and P2 that are tangential to the upper forming roll 12a and the lower forming rolls 12b, 12c, respectively.

[0015]As is known, the dimension D2 of the roll forming gap may be adjustably fixed to achieve a desired single radius of curvature for a roll-formed curved sheet metal part. In accordance with the embodiments of the present invention, an adjunct roll forming too...

FIELD

[0001] The embodiments disclosed herein relate generally to the formation of curved sheet metal parts having variable (multiple) radii. In particular embodiments of the invention, an adjunct tool is provided which allows a curved sheet metal part to be fabricated with variable radii by a conventional sheet metal rolling machine without the need to adjust spacing between the forming rolls (i.e., by maintaining a fixed dimensional gap between the forming rolls).BACKGROUND

[0002] Sheet metal rolling machines are well known in fabrication shops to form curved sheet metal parts from corresponding planar sheet metal blanks. A wide variety of such conventional sheet metal rolling machines employ a pair of spaced apart lower forming rolls, between and above which is positioned an upper forming roll. The upper forming roll may be adjustably positioned relative to the lower forming rolls so as to allow corresponding adjustment of a forming gap between opposed tangential roll planes. The dimension of the forming gap will therefore in practice determine the radius of the curve imparted to the sheet metal blank that is subjected to the roll-forming forces of the upper and lower forming rolls when the blank is fed therebetween.

[0003] It is sometimes necessary to form a sheet metal part with variable (multiple) radii. To accomplish the formation of a variable radii sheet metal part on a conventional machine, the machine operator will need to continually adjust the forming gap manually between the upper and lower forming rolls as the sheet metal blank is fed therebetween. It can be appreciated therefore that such continual manual adjustment of the forming gap of the sheet metal rolling machine can lead to nonuniformity of the variable radii of the curved sheet metal parts. While computer assisted process control algorithms have been employed to alleviate such manual adjustments of the rolling machine and thereby allow for the automatic adjustment of the forming gap between the upper and lower forming rolls, their implementation can be cost-prohibitive for many sheet metal fabricators.

[0004] It would therefore be highly desirable if an adjunct tool could be provided which would preclude the need for continual manual adjustment of a forming gap associated with a conventional sheet metal rolling machine when fabricating curved sheet metal parts with variable radii. It is towards providing such a solution that the embodiments disclosed herein are directed.SUMMARY

[0005] The embodiments disclosed herein are broadly concerned with the fabrication of curved sheet metal parts having variable (multiple) radii using an adjunct roll forming tool in cooperation with a conventional sheet metal rolling machine without the need to continually adjust the dimensional spacing between the forming rolls of the machine during conveyance of the sheet metal blank. The roll forming tool preferably is formed as a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon. The upwardly inclined upper surface forms the curved sheet metal part with variable radii when conveyed through forming rolls of the sheet metal roll forming machine without the need to continually adjust the dimensional spacing between the forming rolls during conveyance therethrough.

[0006] The one piece solid body preferably defines a lower planar surface that coincides with a tangent plane of the lower forming rolls of the roll forming machine when in use. The upwardly inclined upper surface of the one piece solid body may have a continuous upward slope of a constant angle from the leading edge toward the trailing edge thereof. However, the upwardly inclined upper surface may also be provided with discontinuous upward slopes of different angles.

[0007] The one piece solid body is most preferably formed entirely of a pliable thermoplastic or thermoset material, especially thermoplastic or thermoset materials that are capable of being additively manufactured, e.g., via 3D printing processes. The pliable thermoplastic or thermoset material will typically have a Shore A Hardness of between about 80 to about 100, or more specifically between about 85 to about 95. One preferred class of thermoplastic materials that may be usefully employed includes thermoplastic polyurethanes (TPUs). Thermoplastic polyurethanes are desirable since they exhibit the necessary pliability for use as an adjunct roll forming tool and since such a material is capable of being additively manufactured (e.g., by 3D printing) based on the criteria of a computer model of the curvature of the final variable radii curved sheet metal part formed thereby. Thermoset materials may include thermoset resins, such as UV-curable silicone resins, epoxy resins and the like.

[0008] In use therefore, a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween may be provided. A sheet metal blank positioned on the upwardly inclined upper surface of the adjunct roll forming tool may then be conveyed in a leading edge-first manner into and through the roll forming gap of the sheet metal roll forming machine while maintaining the fixed dimension of the roll forming gap during such conveyance thereof to cause the upper and lower forming rolls to form the variable radii curved sheet metal part from the sheet metal blank.

[0009] These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[0010] The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:

[0011] FIG. 1 is a schematic side elevational view of a roll forming apparatus to form a variable radii curved sheet metal part using the adjunct tool in accordance with an embodiment of the invention;

[0012] FIGS. 2-5 are schematic perspective views which schematically depict using the adjunct tool in accordance with an embodiment of the invention to form a variable radii curved sheet metal part in a rolling machine; and

[0013] FIG. 6 is a schematic perspective view of a variable radii curved sheet metal part that is fabricated according to the techniques shown in FIGS. 2-5.DETAILED DESCRIPTION OF EMBODIMENTS

[0014] Accompanying FIG. 1 schematically depicts an exemplary sheet metal roll forming apparatus using an adjunct tool 20 according to an embodiment of this invention in combination with a sheet metal rolling machine 12 comprised of an upper forming roll 12a and spaced lower forming rolls 12b, 12c, respectively. The lower forming rolls 12b, 12c are spaced apart from one another in the roll forming machine direction (arrow MD) by a dimension D1 while the upper forming roll 12a is positioned above and between the spaced apart rolls 12b, 12c so as to define a roll forming gap RFG of dimension D2 between parallel planes P1 and P2 that are tangential to the upper forming roll 12a and the lower forming rolls 12b, 12c, respectively.

[0015] As is known, the dimension D2 of the roll forming gap may be adjustably fixed to achieve a desired single radius of curvature for a roll-formed curved sheet metal part. In accordance with the embodiments of the present invention, an adjunct roll forming tool 20 is provided which supports the sheet metal blank as it is being fed in the machine direction MD within the roll forming gap RFG. The use of the adjunct roll forming tool 20 achieves a variable radii curved sheet metal part CP while maintaining a fixed (immovable) dimension D2 of the roll forming gap RFG during a single pass through the sheet metal rolling machine 12 during the roll forming process. Thus, in a single pass through the sheet metal rolling machine 12, an uncurved sheet metal blank (SMB) will be progressively curved from a radius R1 at a forward end thereof (i.e. as shown in solid line in FIG. 1) to a radius R2 at a rear end thereof (i.e., as shown in dashed line in FIG. 1).

[0016] The adjunct roll forming tool 20 is perhaps better seen in FIGS. 2-5. As shown, the tool 20 is most preferably a one-piece (unitary) solid body having a lengthwise dimension between leading and trailing edges 20a, 20b relative to the machine direction MD and a widthwise dimension between lateral side edges 20c, 20d sufficient to fully support a planar (uncurved) sheet metal blank (SMB). In preferred forms, the tool 20 will have a flat planar bottom surface 20f that in use is coincident with a portion of the tangential plane P2. The upper forming surface 20e is upwardly inclined or slanted in a direction from the leading edge 20a to the trailing edge 20b of the tool 20. The upwardly inclined forming surface 20e may be planar and thereby have a uniform slope angle between the leading and trailing edges 20a, 20b, respectively, as may be required in order to impart the variable radii of curvature for the resulting curved sheet metal part CP (see FIG. 6). The upper forming surface 20e may also be non-uniformly inclined, for example, by having planar segments each defining a different slope angle and / or have an upwardly inclined curvature. The thickness of the tool 20 will therefore be less at the leading edge 20a as compared to the trailing edge 20b. Thus, the thickness at the leading edge 20a may be substantially less than the dimension D2 of the roll forming gap RFG while the thickness at the trailing edge 20b may be substantially the same as or even greater than the dimension D2.

[0017] The body of the adjunct roll forming tool 20 may be formed of any material that is sufficiently pliable to allow flexion during the roll forming process yet sufficiently hard so as to resist significant compression during the roll forming process (i.e., so that substantially all of the force of the rolls 12a-12c is exerted onto the sheet metal blank SMB causing curvature thereof). As noted briefly above, preferred materials include thermoplastic or thermoset materials having a Shore A Hardness of between about 80 to about 100, preferably between about 85 to about 95. Particularly preferred materials are thermoplastic polyurethanes (TPUs) since such a material is capable of being additively manufactured (e.g., by 3D printing) based on the criteria of a computer model of the curvature of the final variable radii curved sheet metal part CP. Alternatively, pliable thermoset resins, such as silicone resins, epoxy resins and the like, may be employed.

[0018] In use, a flat sheet metal blank SMB may be positioned onto the upper inclined planar forming surface 20e of the tool 20 as shown in FIGS. 2 and 3. The assembly of the sheet metal blank SMB and the tool 20 may optionally be placed within a protective film pouch FP which serves to protect the sheet metal blank from any contaminant that may be present in or on the tool 20, for example, silicone that may leach from the material from which the tool 20 is made. The assembled sheet metal blank SMB on the tool 20 is then fed into the roll forming gap RFG with the leading edge 20a of the tool 20 entering the roll forming gap RFG first. As the rolls 12a-12c rotate in the directions noted in FIGS. 4 and 5, the sheet metal blank SMB and the tool 20 (optionally enveloped by the protective film pouch FP as shown in FIG. 3) will be pulled in the machine direction MD within the roll forming gap RFG between the roll 12a on the one hand and the rolls 12b and 12c on the other hand. Such travel of the sheet metal blank SMB and the tool 20 in the machine direction MD will thus cause bending forces to be applied by the rolls 12a-12c thereby bending the sheet metal blank. A single conveyance progression through the machine 12 will thereby form the final curved sheet metal part CP (see FIG. 6) having variable radii of curvature induced by the inclined surface 20e of the tool 20 as it is pulled through the fixed dimension roll forming gap RFG between the rolls 12a-12c.

[0019] The exemplary variable radii curved sheet metal part CP that may be formed in the manner described above may be formed of virtually any type of sheet metal. For example, in the context of an aviation component, the curved sheet metal part CP may be formed of any aluminum alloy conventionally employed for aviation components. The thickness of the curved sheet metal part P will be dependent upon the particular end use for the part. By way of example, the sheet metal blank SMB and thus the curved part CP formed therefrom may have a thickness of between about 0.010 in. to about 0.080 in. or between about 0.015 in. to about 0.025 in.

[0020] While reference has been made to particular embodiments of the invention, various modifications within the skill of those in the art may be envisioned. Therefore, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.

Examples

Embodiment Construction

[0014]Accompanying FIG. 1 schematically depicts an exemplary sheet metal roll forming apparatus using an adjunct tool 20 according to an embodiment of this invention in combination with a sheet metal rolling machine 12 comprised of an upper forming roll 12a and spaced lower forming rolls 12b, 12c, respectively. The lower forming rolls 12b, 12c are spaced apart from one another in the roll forming machine direction (arrow MD) by a dimension D1 while the upper forming roll 12a is positioned above and between the spaced apart rolls 12b, 12c so as to define a roll forming gap RFG of dimension D2 between parallel planes P1 and P2 that are tangential to the upper forming roll 12a and the lower forming rolls 12b, 12c, respectively.

[0015]As is known, the dimension D2 of the roll forming gap may be adjustably fixed to achieve a desired single radius of curvature for a roll-formed curved sheet metal part. In accordance with the embodiments of the present invention, an adjunct roll forming too...

Claims

1. An adjunct roll forming tool for forming a variable radii curved sheet metal part in a sheet metal roll forming machine, wherein the tool comprises:a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon, whereinthe upwardly inclined upper surface forms the curved sheet metal part with variable radii when fed through forming rolls of the sheet metal roll forming machine.

2. The adjunct roll forming tool according to claim 1, wherein the one piece solid body defines a lower planar surface.

3. The adjunct roll forming tool according to claim 1, wherein the upwardly inclined upper surface of the one piece solid body has a upward slope from the leading edge toward the trailing edge thereof.

4. The adjunct roll forming tool according to claim 1, wherein the one piece solid body is comprised of a pliable thermoplastic or thermoset material.

5. The adjunct roll forming tool according to claim 4, wherein the thermoplastic or thermoset material has a Shore A Hardness of between about 80 to about 100.

6. The adjunct roll forming tool according to claim 5, wherein the thermoplastic or thermoset material has a Shore A Hardness of between about 85 to about 95.

7. The adjunct roll forming tool according to claim 4, wherein the thermoplastic material is a thermoplastic polyurethane (TPU).

8. The adjunct roll forming tool according to claim 7, wherein the TPU has a Shore A Hardness of between about 80 to about 100.

9. The adjunct roll forming tool according to claim 4, wherein the one piece body is additively manufactured from the thermoplastic material.

10. A method of forming a variable radii curved sheet metal part comprising the steps of:(a) providing a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween;(b) providing the adjunct roll forming tool according to claim 1;(c) positioning a sheet metal blank onto the upwardly inclined upper surface of the adjunct roll forming tool; and(d) conveying the adjunct roll forming tool and the sheet metal blank positioned on the upwardly inclined upper surface thereof into and through the roll forming gap of the sheet metal roll forming machine while maintaining the fixed dimension of the roll forming gap during conveyance thereof to cause the upper and lower forming rolls to form the variable radii curved sheet metal part from the sheet metal blank.

11. The method according to claim 10, wherein step (d) is practiced by conveying the adjunct roll forming tool in a leading edge-first manner into and through the roll forming gap.

12. The method according to claim 11, which further comprises before step (d) a step of placing the adjunct roll forming tool and the sheet metal blank positioned on the upper surface thereof within a pouch.

13. The method according to claim 10, wherein the one piece solid body of the adjunct roll forming tool defines a lower planar surface.

14. The method according to claim 10, wherein the upwardly inclined upper surface of the one piece solid body has a uniform upward slope from the leading edge toward the trailing edge thereof.

15. The method according to claim 10, wherein the one piece solid body is comprised of a pliable thermoplastic material.

16. The method according to claim 15, wherein the thermoplastic material has a Shore A Hardness of between about 80 to about 100.

17. The method according to claim 16, wherein the thermoplastic material has a Shore A Hardness of between about 85 to about 95.

18. The method according to claim 15, wherein the thermoplastic material is a thermoplastic polyurethane (TPU).

19. The method according to claim 18, wherein the TPU has a Shore A Hardness of between about 85 to about 95.

20. A sheet metal roll forming system for forming a variable radii curved sheet metal part comprising:a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween; andthe adjunct roll forming tool according to claim 1.

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