METHOD AND APPARATUS FOR FORMING SHEET METAL

Abstract

A forming tool has an upper portion composed of an upper forming die arranged between a first clamping element and a second clamping element, and a lower portion composed of a lower forming die arranged between a third clamping element and a fourth clamping element. The first clamping element and the third clamping element cooperate to exert a first clamping force on a workpiece; and the second clamping element and the fourth clamping element cooperate to exert a second clamping force on the workpiece. The upper forming die cooperates with the first and second clamping elements and the lower forming die cooperates with the third and fourth clamping elements to exert a lateral force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when a vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Description

Sheet metal forming is a process of transforming a sheet metal workpiece into a three-dimensional (3D) shape. Sheet metal forming may involve various processes where force is applied to a sheet metal workpiece to plastically deform the material into a desired shape, thus modifying its geometry without removing material. Types of sheet metal forming processes may include one or more of bending, roll forming, spinning, deep drawing, and stretch forming.

SUMMARY

The concepts described herein relate to methods, systems, and/or processes for sheet metal forming, e.g., offset feature forming, that achieves dimensional accuracy while minimizing risk of part distortion, wrinkling, tearing, spring back, etc.

The sheet metal forming methods, systems, and/or processes described herein include stretching or shrinking a workpiece in the form of a sheet metal blank coincident with feature forming to achieve offset feature formation and material flow control in a single operation. This operation may minimize risks of part distortion and material tearing. The material of the workpiece may be steel, aluminum, copper, titanium, alloys thereof, or another material without limitation.

An aspect of the disclosure includes a forming tool that has an upper portion composed of an upper forming die arranged between a first clamping element and a second clamping element, and a lower portion composed of a lower forming die arranged between a third clamping element and a fourth clamping element. The first clamping element and the third clamping element cooperate to exert a first clamping force on a workpiece; and the second clamping element and the fourth clamping element cooperate to exert a second clamping force on the workpiece. The upper forming die cooperates with the first and second clamping elements and the lower forming die cooperates with the third and fourth clamping elements to exert a lateral force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when a vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include the upper forming die cooperating with the first and second clamping elements and the lower forming die cooperating with the third and fourth clamping elements to exert a lateral tensile force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include the upper forming die being a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion, and the lower forming die being a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion. The first tool end cooperates with the second tool end to form an offset feature in the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include upper forming die cooperating with the first and second clamping elements, and the lower forming die cooperating with the third and fourth clamping elements to exert a lateral compressive force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include the upper forming die being a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion, and the lower forming die being a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion. The first tool end cooperates with the second tool end to form an offset feature in the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include the upper forming die being a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion. The first clamping element includes a first grip surface and a first angled surface, the second clamping element includes a second grip surface and a second angled surface, the first angled surface of the first clamping element interfaces with the first wedge face of the upper forming die, and the second angled surface of the first clamping element interfaces with the second wedge face of the upper forming die.

Another aspect of the disclosure may include the first angled surface of the first clamping element defining a first channel, the second angled surface of the second clamping element defining a second channel, the first wedge face of the upper forming die including a first rail, and the second wedge face of the upper forming die including a second rail. The first channel of the first angled surface of the first clamping element interfaces with the first rail of the first wedge face of the upper forming die, and the second channel of the second angled surface of the second clamping element interfaces with the second rail of the second wedge face of the upper forming die. The first channel in cooperation with the first rail and the second channel in cooperation with the second rail cooperate to guide the upper forming die in relation to the first clamping element and in relation to the second clamping element when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

Another aspect of the disclosure may include the first grip surface and the second grip surface defining a horizontal plane. The first angled surface of the first clamping element and the first wedge face of the upper forming die are arranged at a first angle in relation to the horizontal plane, and the second angled surface of the second clamping element and the second wedge face of the upper forming die are arranged at a second angle in relation to the horizontal plane. The first angle is complementarily opposed to the second angle.

Another aspect of the disclosure may include the first angle and the second angle being complementary acute angles in relation to the horizontal plane.

Another aspect of the disclosure may include the first angle and the second angle being complementary obtuse angles in relation to the horizontal plane.

Another aspect of the disclosure may include the lower forming die being a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion, wherein the third clamping element includes a third grip surface and a third angled surface, wherein the fourth clamping element includes a fourth grip surface and a fourth angled surface, wherein the third angled surface of the third clamping element interfaces with the third wedge face of the lower forming die, and wherein the fourth angled surface of the third clamping element interfaces with the fourth wedge face of the lower forming die.

Another aspect of the disclosure may include the third angled surface of the third clamping element defining a third channel, the fourth angled surface of the fourth clamping element defining a fourth channel, the third wedge face of the lower forming die including a third rail, the fourth wedge face of the lower forming die including a fourth rail, the third channel of the third angled surface of the third clamping element interfacing with the third rail of the third wedge face of the lower forming die, the fourth channel of the fourth angled surface of the fourth clamping element interfacing with the fourth rail of the fourth wedge face of the lower forming die, and the third channel in cooperation with the third rail and the fourth channel in cooperation with the fourth rail cooperating to guide the lower forming die in relation to the third clamping element and in relation to the fourth clamping element when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the lower forming die and the lower forming die.

Another aspect of the disclosure may include the third grip surface and the fourth grip surface defining a horizontal plane, wherein the third angled surface of the third clamping element and the third wedge face of the lower forming die are arranged at a third angle in relation to the horizontal plane, wherein the fourth angled surface of the fourth clamping element and the fourth wedge face of the lower forming die are arranged at a fourth angle in relation to the horizontal plane, and wherein the third angle is complementarily opposed to the fourth angle.

Another aspect of the disclosure may include the third angle and the fourth angle being complementary acute angles in relation to the horizontal plane.

Another aspect of the disclosure may include the third angle and the fourth angle being complementary obtuse angles in relation to the horizontal plane.

Another aspect of the disclosure may include a metal forming tool that includes a first workpiece gripper and a second workpiece gripper, wherein the first workpiece gripper and the second workpiece gripper are arranged to secure a workpiece, and a first wedge-shaped stamping die and a second wedge-shaped stamping die. The first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a lateral force on the workpiece when a vertical compressive force is exerted on the first wedge-shaped stamping die and the opposed second wedge-shaped stamping die.

Another aspect of the disclosure may include the first wedge-shaped stamping die including a first tool end, and the second wedge-shaped stamping die including a second tool end. The first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a tensile lateral force on the workpiece and wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the vertical compressive force is exerted on the first wedge-shaped stamping die and the opposed second wedge-shaped stamping die.

Another aspect of the disclosure may include the first wedge-shaped stamping die including a first tool end, and the second wedge-shaped stamping die including a second tool end. The first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a lateral compressive force on the workpiece and wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the vertical compressive force is exerted on the first wedge-shaped stamping die and the opposed second wedge-shaped stamping die.

Another aspect of the disclosure may include a method for forming a metallic workpiece that includes inserting a sheet metal workpiece into a metal forming tool including an upper forming die and a lower forming die; exerting, via a first workpiece gripper and a second workpiece gripper, a lateral force on the workpiece and coincidently executing a vertical compressive force upon the upper forming die and the lower forming die, wherein the upper forming die includes a first tool end, and wherein the lower forming die includes a second tool end; and forming, via the first tool end and the second tool end, an offset feature in the workpiece.

Another aspect of the disclosure may include exerting, via the first workpiece gripper and the second workpiece gripper, a tensile lateral force on the workpiece.

The above summary is not intended to represent every possible embodiment or every aspect of the present disclosure. Rather, the foregoing summary is intended to exemplify some of the novel aspects and features disclosed herein. The above features and advantages, and other features and advantages of the present disclosure, will be readily apparent from the following detailed description of representative embodiments and modes for carrying out the present disclosure when taken in connection with the accompanying drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 schematically illustrates a workpiece processing machine that employs a forming tool for forming a workpiece, in accordance with the disclosure.

FIG. 2 schematically illustrates a detailed cutaway end view of an embodiment of a forming tool, in accordance with the disclosure.

FIG. 3 schematically illustrates a detailed cutaway isometric view of an embodiment of the forming tool described with reference to FIG. 2, in accordance with the disclosure.

FIG. 4 schematically illustrates a detailed cutaway end view of an embodiment of a forming tool, in accordance with the disclosure.

FIG. 5 schematically illustrates a detailed cutaway end view of an embodiment of a forming tool, in accordance with the disclosure.

The appended drawings are not necessarily to scale, and may present a somewhat simplified representation of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes. Details associated with such features will be determined in part by the particular intended application and use environment.

DETAILED DESCRIPTION

The components of the disclosed embodiments, as described and illustrated herein, may be arranged and designed in a variety of different configurations. Thus, the following detailed description is not intended to limit the scope of the disclosure, as claimed, but is merely representative of possible embodiments thereof. In addition, while numerous specific details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed herein, some embodiments may be practiced without some of these details. Moreover, for the purpose of clarity, certain technical material that is understood in the related art has not been described in detail in order to avoid unnecessarily obscuring the disclosure.

Furthermore, the drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, over, above, below, beneath, rear, and front, horizontal, lateral, vertical, etc., may be used with respect to the drawings. These and similar directional terms are not to be construed to limit the scope of the disclosure, and instead are intended only for purposes of description. It should be noted that, when an element is described as being “fixed on” or “disposed on” another element, the element may be placed on the other element directly or by using an intermediate element. When an element is described as being “connected to” or coupled to another element, the element may be connected to the other element directly or by using an intermediate element. Furthermore, the disclosure, as illustrated and described herein, may be practiced in the absence of an element that is not specifically disclosed herein.

The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented herein. Throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

For the sake of brevity, conventional components and techniques and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the disclosure.

The use of ordinals such as first, second and third does not necessarily imply a ranked sense of order, but rather may only distinguish between multiple instances of an act or structure.

Referring to the drawings, wherein like reference numerals correspond to like or similar components throughout the several Figures, FIG. 1, consistent with embodiments disclosed herein, illustrates a workpiece processing machine 95 that employs a forming tool 10 for forming a workpiece 15 (illustrated in FIG. 2), which are described with reference to a lateral axis (x), a vertical axis (z), and a longitudinal axis (y).

In one embodiment, and as described herein, the workpiece 15 is a sheet metal piece. The material of the workpiece may be steel, aluminum, copper, titanium, alloys thereof, or another material without limitation.

The workpiece processing machine 95 has an upper portion 97 and a lower portion 98, and is configured to accommodate an embodiment of the forming tool 10. In one embodiment, the upper portion 97 accommodates an upper forming die 20 of the forming tool 10, and the lower portion 98 accommodates a lower forming die 50 of the forming tool 10. Details of embodiments of the forming tool 10 are described with reference to FIGS. 2-5. In one embodiment, the upper forming die 20 is arranged as a beading die, and the lower forming die 50 is arranged as a beading punch, although the concepts described herein are not so limited.

The workpiece processing machine 95 may include other elements, systems, and devices, including but not limited to a horizontal blank support plane 96 coordinate guide, workpiece positioning elements, cutting tools, etc.

The workpiece processing machine 95 is arranged to exert, via a first embodiment of forming tool 10, a compressive force 90 in the vertical direction on the workpiece 15 that is positioned between the upper portion 97 and the lower portion 98 to form a finished product. An embodiment of the forming tool 10 is described with reference to FIGS. 2 and 3.

As shown with reference to FIG. 4, a second embodiment of the forming tool 110 employs the vertical compressive force 190 in the vertical direction and compressive force 195 in the lateral direction to form a finished product from the workpiece 15.

Referring again to FIG. 1, an embodiment of workpiece processing machine 95 may instead be oriented in a horizontal arrangement, wherein the compressive force 90 is exerted in the lateral direction or the longitudinal direction on a workpiece that is positioned between the upper portion 97 and the lower portion 98 to form a finished product.

For the sake of brevity, additional technical details related to embodiments of the workpiece processing machine 95 and the individual operating components may not be described in detail herein.

A parameter is defined as a measurable quantity that represents a physical property of a device or other element that is discernible using one or more sensors and/or a physical model. A parameter may be a discrete value (e.g., either “1” or “0”), a percentage (e.g., 0% to 100%), or an infinitely variable value.

Referring now to FIGS. 2 and 3, the first embodiment of the forming tool 10 is described. FIG. 2 schematically illustrates a detailed cutaway end view of the forming tool 10, and FIG. 3 schematically illustrates a detailed cutaway isometric view of the forming tool 10.

The forming tool 10, when employed in an embodiment of the workpiece processing machine 95 of FIG. 1, facilitates sheet metal forming methods, systems, and/or processes that combine a pre-forming step of stretching or shrinking the workpiece 15 with a feature forming function to achieve offset feature formation and material flow control in a single operation. This may serve to minimize risks of part distortion and material tearing. The forming tool 10 is modular and customizable to enable different forming and material flow control capabilities. The forming tool 10 may be applied in both incremental and single stroke forming processes.

The forming tool 10 has an upper portion 11 composed of an upper forming die 20 arranged between a first clamping element 30 and a second clamping element 40, and a lower portion 12 composed of a lower forming die 50 arranged between a third clamping element 60 and a fourth clamping element 70. In one embodiment, the upper forming die 20 is a beading die, and the lower forming die 50 is a beading punch, although the concepts described herein are not so limited.

The upper forming die 20 includes a first tool end 21, and the lower forming die 50 includes a second tool end 51. In operation, a workpiece 15 is arranged between the first tool end 21 and the second tool end 51, and secured in place by the first clamping element 30, the second clamping element 40, the third clamping element 60, and the fourth clamping element 70. When the compressive force 90 is applied to the upper and lower forming dies 20, 50, the first and second tool ends 21, 51 cooperate to form an offset feature in the workpiece 15.

The first clamping element 30 and the third clamping element 60 form a first gripper 14, and cooperate to exert a first clamping force on the workpiece 15. The second clamping element 40 and the fourth clamping element 70 form a second gripper 16, and cooperate to exert a second clamping force on the workpiece 15. The upper forming die 20 cooperates with the first and second clamping elements 30, 40, and the lower forming die 50 cooperates with the third and fourth clamping elements 60, 70 to exert a lateral force on the workpiece 15 when the first and second clamping forces are being exerted on the workpiece 15 and when the vertical compressive force 90 is being exerted upon the upper forming die 20 and the lower forming die 50. In this embodiment, the upper forming die 20 cooperates with the first and second clamping elements 30, 40, and the lower forming die 50 cooperates with the third and fourth clamping elements 60, 70 to exert a lateral tensile or stretching force on the workpiece 15 when the first and second clamping forces are being exerted on the workpiece 15 and when the vertical compressive force 90 is being exerted upon the upper forming die 20 and the lower forming die 50.

The upper forming die 20 has a trapezoidal cross-sectional shape that includes the first tool end 21 that is opposite to base 22, and opposite to sides that include a first angled surface 24 and a second angled surface 26. In one embodiment and as shown, the upper forming die 20 has an isosceles trapezoidal cross-sectional shape. First angle 23 is defined by the junction of the base 22 and the first angled surface 24, and also defined by the junction of the base 22 and the second angled surface 26. A plurality of rail portions 25 are formed on the first angled surface 24 and the second angled surface 26, and traverse either the first angled surface 24 or the second angled surface 26 between the first tool end 21 and the base 22. In this embodiment, the linear width of the base 22 is greater than the linear width of the first tool end 21 in the lateral direction, and thus the first angle 23 is an acute angle.

The first clamping element 30 has a right trapezoidal cross-sectional shape that includes a first grip surface 31 and third angled surface 32, which are joined at second angle 33, wherein second angle 33 is equivalent to the first angle 23 associated with the upper forming die 20. The third angled surface 32 interfaces with the first angled surface 24 of the upper forming die 20. The third angled surface 32 also includes a plurality of countersunk first channels 35 that traverse the third angled surface 32 between the first grip surface 31 and a top portion 36.

The second clamping element 40 has a right trapezoidal cross-sectional shape that includes a second grip surface 41 and fourth angled surface 42, which are joined at third angle 43, wherein third angle 43 is equivalent to the first angle 23 associated with the upper forming die 20. The fourth angled surface 42 interfaces with the second angled surface 26 of the upper forming die 20. The fourth angled surface 42 also includes a plurality of countersunk second channels 45 that traverse the fourth angled surface 42 between the second grip surface 41 and the top portion 46.

The third angle 43 is equivalent to and complementarily opposed to the second angle 33. A first linear distance 57 is defined between the first clamping element 30 and the second clamping element 40 at the angle apexes.

The rail portions 25 and the first and second channels 35, 45 are arranged as a moveable tongue and groove joint in one embodiment.

The rail portions 25 and the first and second channels 35, 45 are arranged as a moveable dovetail junction in one embodiment.

The lower forming die 50 has a trapezoidal cross-sectional shape that includes the second tool end 51 that is opposite to base 52, and opposite to sides that include a fifth angled surface 54 and a sixth angled surface 56. In one embodiment and as shown, the lower forming die 50 has an isosceles trapezoidal cross-sectional shape. Fourth angle 53 is defined by the junction of the base 52 and the fifth angled surface 54, and also defined by the junction of the base 52 and the sixth angled surface 56. A plurality of rail portions 55 are formed on the fifth angled surface 54 and the sixth angled surface 56, and traverse either the fifth angled surface 54 or the sixth angled surface 56 between the second tool end 51 and the base 52. In this embodiment, the linear width of the base 52 in the lateral direction is greater than the linear width of the second tool end 51, and thus the fourth angle 53 is an acute angle.

The third clamping element 60 has a right trapezoidal cross-sectional shape that includes a third grip surface 61 and seventh angled surface 62, which are joined at fifth angle 63, wherein the fifth angle 63 is equivalent to the fourth angle 53 associated with the lower forming die 50. The seventh angled surface 62 interfaces with the fifth angled surface 54 of the lower forming die 50. The seventh angled surface 62 also includes a plurality of countersunk second channels 65 that traverse the seventh angled surface 62 between the third grip surface 61 and a bottom portion 66.

In one embodiment, and as shown, the third clamping element 60 is a mirror image of the first clamping element 30.

Alternatively, the fifth angle 63 and the sixth angle 73 are asymmetric to the second angle 33 and the third angle 43.

The fourth clamping element 70 has a right trapezoidal cross-sectional shape that includes a fourth grip surface 71 and eighth angled surface 72, which are joined at sixth angle 73, wherein sixth angle 73 is equivalent to the fourth angle 53 associated with the lower forming die 50. The eighth angled surface 72 interfaces with the sixth angled surface 56 of the lower forming die 50. The eighth angled surface 72 also includes a plurality of countersunk second channels 75 that traverse the eighth angled surface 72 between the fourth grip surface 71 and the bottom portion 66.

The first, second, third and fourth grip surfaces 31, 41, 61 and 71 are advantageously roughened or patterned to increase friction using sandblasting, serration features, etc.

In one embodiment, and as shown, the fourth clamping element 70 is a mirror image of the second clamping element 40.

Alternatively, the sixth angle 73 of the fourth clamping element 70 may differ from, i.e., be greater than or less than, the second angle 33 of the second clamping element 40.

The fifth angle 63 is equivalent to and complementarily opposed to the sixth angle 73. A second linear distance 58 is defined between the third clamping element 60 and the fourth clamping element 70 at the angle apexes. The magnitudes of the second angle 33, the third angle 43, the fifth angle 63, the sixth angle 73, the first linear distance 57, and the second linear distance 58 are selected to achieve a desired material tension in the workpiece 15 when the upper forming die 20 and the lower forming die 50 are subjected to the compressive force 90, with the desired material tension being application specific.

In operation, the first clamping element 30 and the third clamping element 60 cooperate to exert a first clamping force on the workpiece 15 that is placed therebetween, and the second clamping element 40 and the fourth clamping element 70 cooperate to exert a second clamping force on the workpiece 15 that is placed therebetween. A vertical compressive force 90 may be exerted on the upper forming die 20 and the lower forming die 50 as part of a metal forming process. The upper forming die 20 cooperates with the first and second clamping elements 30, 40 and the lower forming die 50 cooperates with the third and fourth clamping elements 60, 70 to exert a lateral tensile or stretching force on the workpiece 15 as the vertical movement of the upper forming die 20 causes an outward movement of the first and third clamping elements 30, 60, and the lower forming die 50 causes a corresponding outward movement of the second and fourth clamping elements 40, 70, thus stretching the workpiece 15 during the forming operation caused by the action of upper forming die 20 and the lower forming die 50 on the workpiece 15.

Referring now to FIG. 4, a second embodiment of the forming tool 110 is described. FIG. 4 schematically illustrates a detailed cutaway end view of the forming tool 110. The forming tool 110, when employed in an embodiment of the workpiece processing machine 95 of FIG. 1, facilitates sheet metal forming methods, systems, and/or processes that combine a pre-forming step of stretching or shrinking workpiece 115 with a feature forming function to achieve offset feature formation and material flow control in a single operation. This may serve to minimize risks of part distortion and material tearing. The forming tool 110 is modular and customizable to enable different forming and material flow control capabilities. The forming tool 110 may be applied in both incremental and single stroke forming processes.

The forming tool 110 has an upper portion 111 composed of an upper forming die 120 arranged between a first clamping element 130 and a second clamping element 140, and a lower portion 112 composed of a lower forming die 150 arranged between a third clamping element 160 and a fourth clamping element 170. In one embodiment, the upper forming die 120 is a beading die, and the lower forming die is beading punch, although the concepts described herein are not so limited.

The first clamping element 130 and the third clamping element 160 form a first gripper 114, and cooperate to exert a first clamping force on a workpiece 115. The second clamping element 140 and the fourth clamping element 170 form a second gripper 116, and cooperate to exert a second clamping force on the workpiece 115. The upper forming die 120 cooperates with the first and second clamping elements 130, 140, and the lower forming die 150 cooperates with the third and fourth clamping elements 160, 170 to exert a lateral force on the workpiece 115 when the first and second clamping forces are being exerted on the workpiece 115 and when a vertical compressive force 190 is being exerted upon the upper forming die 120 and the lower forming die 150 and compressive force 195 is being exerted upon the upper forming die 120 and the lower forming die 150 in the lateral direction. In this embodiment, the upper forming die 120 cooperates with the first and second clamping elements 130, 140, and the lower forming die 150 cooperates with the third and fourth clamping elements 160, 170 to exert a lateral tensile or stretching force on the workpiece 115 when the first and second clamping forces are being exerted on the workpiece 115 and when the vertical compressive force 190 is being exerted upon the upper forming die 120 and the lower forming die 150.

The upper forming die 120 has a trapezoidal cross-sectional shape that includes a tool end 121 that is opposite to a base 122, and opposite to sides that include a first angled surface 124 and a second angled surface 126. In one embodiment and as shown, the upper forming die 120 has an isosceles trapezoidal cross-sectional shape. First angle 123 is defined by the junction of the base 122 and the first angled surface 124, and also is defined by the junction of the base 122 and the second angled surface 126. A plurality of rail portions may be formed on the first angled surface 124 and the second angled surface 126, and traverse either the first angled surface 124 or the second angled surface 126 between the tool end 121 and the base 122. In this embodiment, the linear width of the base 122 in the lateral direction is less than the linear width of the tool end 121, and thus the first angle 123 is an obtuse angle.

The first clamping element 130 has a right trapezoidal cross-sectional shape that includes a first grip surface 131 and third angled surface 132, which are joined at second angle 133, wherein second angle 133 is equivalent to the first angle 123 associated with the upper forming die 120. The third angled surface 132 interfaces with the first angled surface 124 of the upper forming die 120. The third angled surface 132 may also include a plurality of countersunk first channels that traverse the third angled surface 132 between the first grip surface 131 and a top portion 136.

The second clamping element 140 has a right trapezoidal cross-sectional shape that includes a second grip surface 141 and fourth angled surface 142, which are joined at third angle 143, wherein third angle 143 is equivalent to the first angle 123 associated with the upper forming die 120. The fourth angled surface 142 interfaces with the second angled surface 126 of the upper forming die 120. The fourth angled surface 142 may also include a plurality of countersunk second channels that traverse the fourth angled surface 142 between the second grip surface 141 and the top portion 146.

The rail portions and the first and second channels are arranged as a moveable tongue and groove joint in one embodiment.

The rail portions and the first and second channels are arranged as a moveable dovetail junction in one embodiment.

The lower forming die 150 has a trapezoidal cross-sectional shape that includes a second tool end 151 that is opposite to a base 152, and opposite to sides that include a fifth angled surface 154 and a sixth angled surface 156. In one embodiment and as shown, the lower forming die 150 has an isosceles trapezoidal cross-sectional shape. Fourth angle 153 is defined by the junction of the base 152 and the fifth angled surface 154, and also defined by the junction of the base 152 and the sixth angled surface 156. A plurality of rail portions may be formed on the fifth angled surface 154 and the sixth angled surface 156, and traverse either the fifth angled surface 154 or the sixth angled surface 156 between the second tool end 151 and the base 152. In this embodiment, the linear width of the base 152 in the lateral direction is less than the linear width of the second tool end 151, and thus the fifth angle 163 is an obtuse angle.

The third clamping element 160 has a right trapezoidal cross-sectional shape that includes a third grip surface 161 and seventh angled surface 162, which are joined at fifth angle 163, wherein the fifth angle 163 is equivalent to the fourth angle 153 associated with the lower forming die 150. The seventh angled surface 162 interfaces with the fifth angled surface 154 of the lower forming die 150. The seventh angled surface 162 may also include a plurality of countersunk second channels that traverse the seventh angled surface 162 between the third grip surface 161 and a bottom portion 166.

In one embodiment, and as shown, the third clamping element 160 is a mirror image of the first clamping element 130.

Alternatively, the fifth angle 163 and the sixth angle 173 are asymmetric to the second angle 133 and the third angle 143.

The fourth clamping element 170 has a right trapezoidal cross-sectional shape that includes a fourth grip surface 171 and eighth angled surface 172, which are joined at sixth angle 173, wherein sixth angle 173 is equivalent to the fourth angle 153 associated with the lower forming die 150. The eighth angled surface 172 interfaces with the second angled surface 156 of the lower forming die 150. The eighth angled surface 172 may also include a plurality of countersunk second channels that traverse the eighth angled surface 172 between the fourth grip surface 171 and the bottom portion 166.

In one embodiment, and as shown, the fourth clamping element 170 is a mirror image of the second clamping element 140.

In operation, the first clamping element 130 and the third clamping element 160 cooperate to exert a first clamping force on the workpiece 115 that is placed therebetween, and the second clamping element 140 and the fourth clamping element 170 cooperate to exert a second clamping force on the workpiece 115 that is placed therebetween. A vertical compressive force 190 may be exerted on the upper forming die 120 and the lower forming die 150 as part of a metal forming process. The upper forming die 120 cooperates with the first and second clamping elements 130, 140 and the lower forming die 150 cooperates with the third and fourth clamping elements 160, 170 to exert a lateral compressive force 195 on the workpiece 115 as the vertical movement of the upper forming die 120 causes an inward movement of the first and third clamping elements 130, 160, and the lower forming die 150 causes a corresponding inward movement of the second and fourth clamping elements 140, 170, thus compressing the workpiece 115 during the forming operation caused by the action of upper forming die 120 and the lower forming die 150 on the workpiece 115.

The third angle 143 is equivalent to and complementarily opposed to the second angle 133.

A first linear distance 157 is defined between the first clamping element 130 and the second clamping element 140 at the angle apexes.

The fifth angle 163 is equivalent to and complementarily opposed to the sixth angle 173.

A second linear distance 158 is defined between the third clamping element 160 and the fourth clamping element 170 at the angle apexes.

The magnitudes of the second angle 133, the third angle 143, the fifth angle 163, the sixth angle 173, the first linear distance 157, and the second linear distance 158 are selected to achieve a desired material compression in the workpiece 115 when the first tool end 121 and the second tool end 151 are subjected to the vertical compressive force 190 and the lateral compressive force 195, with the desired material tension being application specific.

FIG. 5 schematically illustrates a detailed cutaway end view of an embodiment of the forming tool 10 that is described with reference to FIGS. 2 and 3. The forming tool 10 may also include a guiding component 94 including a position monitoring sensor and/or a loading component 92 that includes a control sensor, which may provide position and load feedback, respectively, to the workpiece processing machine 95 to control the linear position and the compressive force 90 being applied via the forming tool 10 to the workpiece 15. The loading component 92 is an additional loading component driven by spring force as illustrated, or by other driven mechanisms such as hydraulic, pneumatic, or magnetic forces to provide additional force to control the position and assist the movements of elements 30, 40, 60, 70 or 130, 140, 160, 170.

Components such as the loading component 92 are important to return the shrinking/stretching wedges to their neutral positions. The guiding component 94 ensure the slide angle is maintained. A single guide was included in the illustration. The guiding component 94 may be in addition or alternative to the rail portions 25, 125 that are illustrated with reference to FIG. 3.

Thus, the sheet metal forming methods, systems, and/or processes described herein include stretching or compressing a sheet metal workpiece coincident with feature forming to achieve offset feature formation and material flow control in a single operation. This operation may minimize risks of part distortion and material tearing.

Variables such as the location, size, texture of effective areas of the first, second, third and fourth grip surfaces 31, 41, 61 and 71 are advantageously roughened or patterned to increase friction using sandblasting, serration features, etc.

The sliding angles may be customized to control material flow so that no material fault and/or distortion occur during or after the feature forming process of the workpiece 15.

The stretching or shrinking effects introduced by the top and lower wedge sets may be asymmetric to enable uneven deformation on the top and bottom surfaces of the workpiece to generate intentional deformation. Different directions and degrees of material flow/deformation may be employed to counteract the distortion induced by feature forming.

The positions, movements, and pressures/loads of the stretching/shrinking wedges and the feature forming blocks may be adjusted dependently or independently via associated or dissociated mechanical, hydraulic, magnetic, or pneumatic controls.

The stretching or shrinking wedge set for each center block includes two or more pieces, which enables material flow control within local stretching/shrinking areas through tool design.

The forming tool is modular allowing different stretching or shrinking wedges to be assembled with different feature forming block sets to enable various combinations of forming/material flow control capabilities.

The offset feature forming tool described herein integrates multiple forming functions, including the formation of a feature such as a stiffening bead and concurrent stretching/shrinking outside the feature area for material flow control. This integrated tool consists of 1) a set of forming blocks (beading blocks, e.g.,) in the center with a punch and a die, and 2) two sets of wedges to enable stretching or shrinking of the top and bottom surfaces of the sheet metal.

Stretching/shrinking wedges may be assembled with the forming blocks via different connection methods that enable guided movements of the pieces. Examples of such connection methods are internal sliding channels/slots, constraining plate connections, sleeves, or cartridges. Positions and load controls of individual pieces of the tool assembly may be dependent or independent, driven by mechanical, hydraulic, magnetic, or pneumatic controls.

The construction of the integrated tool assembly is modular and customizable by users. The forming blocks may be designed to achieve different feature geometries. The shrinking/stretching wedges may be designed in terms of sizes, effective areas, sliding angles, surface pattern/texture of the working surfaces, and number of wedge pieces to tune the direction and amount of local metal flow and deformation that affects the distortion compensation capability. In addition, the upper and lower wedge sets may be different to facilitate an asymmetric deformation on the top and bottom surfaces of sheet metal, which provides additional capabilities to tune the distortion.

The detailed description and the drawings or figures are supportive and descriptive of the present teachings, but the scope of the present teachings is defined solely by the claims. While some of the best modes and other embodiments for carrying out the present teachings have been described in detail, various alternative designs and embodiments exist for practicing the present teachings defined in the claims.

Claims

1. A forming tool, comprising:

an upper portion composed of an upper forming die arranged between a first clamping element and a second clamping element;

a lower portion composed of a lower forming die arranged between a third clamping element and a fourth clamping element;

wherein the first clamping element and the third clamping element cooperate to exert a first clamping force on a workpiece; and

wherein the second clamping element and the fourth clamping element cooperate to exert a second clamping force on the workpiece;

wherein the upper forming die cooperates with the first and second clamping elements and the lower forming die cooperates with the third and fourth clamping elements to exert a lateral force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when a vertical compressive force is being exerted upon the upper forming die and the lower forming die.

2. The forming tool of claim 1, wherein the upper forming die cooperates with the first and second clamping elements and the lower forming die cooperates with the third and fourth clamping elements to exert a lateral tensile force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

3. The forming tool of claim 2, comprising:

the upper forming die being a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion;

the lower forming die being a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion; and

wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

4. The forming tool of claim 1, wherein the upper forming die cooperates with the first and second clamping elements and the lower forming die cooperates with the third and fourth clamping elements to exert a lateral compressive force on the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

5. The forming tool of claim 4, comprising:

the upper forming die being a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion;

the lower forming die being a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion; and

wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

6. The forming tool of claim 1,

wherein the upper forming die is a wedge-shape die having a first tool end, a first wedge face, a second wedge face, and a first base portion;

wherein the first clamping element includes a first grip surface and a first angled surface;

wherein the second clamping element includes a second grip surface and a second angled surface;

wherein the first angled surface of the first clamping element interfaces with the first wedge face of the upper forming die; and

wherein the second angled surface of the first clamping element interfaces with the second wedge face of the upper forming die.

7. The forming tool of claim 6:

wherein the first angled surface of the first clamping element defines a first channel;

wherein the second angled surface of the second clamping element defines a second channel;

wherein the first wedge face of the upper forming die includes a first rail;

wherein the second wedge face of the upper forming die includes a second rail;

wherein the first channel of the first angled surface of the first clamping element interfaces with the first rail of the first wedge face of the upper forming die;

wherein the second channel of the second angled surface of the second clamping element interfaces with the second rail of the second wedge face of the upper forming die; and

wherein the first channel in cooperation with the first rail and the second channel in cooperation with the second rail cooperate to guide the upper forming die in relation to the first clamping element and in relation to the second clamping element when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the upper forming die and the lower forming die.

8. The forming tool of claim 6, comprising the first grip surface and the second grip surface defining a horizontal plane;

wherein the first angled surface of the first clamping element and the first wedge face of the upper forming die are arranged at a first angle in relation to the horizontal plane;

wherein the second angled surface of the second clamping element and the second wedge face of the upper forming die are arranged at a second angle in relation to the horizontal plane; and

wherein the first angle is complementarily opposed to the second angle.

9. The forming tool of claim 8, comprising the first angle and the second angle being complementary acute angles in relation to the horizontal plane.

10. The forming tool of claim 8, comprising the first angle and the second angle being complementary obtuse angles in relation to the horizontal plane.

11. The forming tool of claim 1,

wherein the lower forming die is a wedge-shaped die having a second tool end, a third wedge face, a fourth wedge face, and a second base portion;

wherein the third clamping element includes a third grip surface and a third angled surface;

wherein the fourth clamping element includes a fourth grip surface and a fourth angled surface;

wherein the third angled surface of the third clamping element interfaces with the third wedge face of the lower forming die; and

wherein the fourth angled surface of the third clamping element interfaces with the fourth wedge face of the lower forming die.

12. The forming tool of claim 11:

wherein the third angled surface of the third clamping element defines a third channel;

wherein the fourth angled surface of the fourth clamping element defines a fourth channel;

wherein the third wedge face of the lower forming die includes a third rail;

wherein the fourth wedge face of the lower forming die includes a fourth rail;

wherein the third channel of the third angled surface of the third clamping element interfaces with the third rail of the third wedge face of the lower forming die;

wherein the fourth channel of the fourth angled surface of the fourth clamping element interfaces with the fourth rail of the fourth wedge face of the lower forming die; and

wherein the third channel in cooperation with the third rail and the fourth channel in cooperation with the fourth rail cooperate to guide the lower forming die in relation to the third clamping element and in relation to the fourth clamping element when the first and second clamping forces are being exerted on the workpiece and when the vertical compressive force is being exerted upon the lower forming die and the lower forming die.

13. The forming tool of claim 11, comprising the third grip surface and the fourth grip surface defining a horizontal plane;

wherein the third angled surface of the third clamping element and the third wedge face of the lower forming die are arranged at a third angle in relation to the horizontal plane;

wherein the fourth angled surface of the fourth clamping element and the fourth wedge face of the lower forming die are arranged at a fourth angle in relation to the horizontal plane; and

wherein the third angle is complementarily opposed to the fourth angle.

14. The forming tool of claim 13, comprising the third angle and the fourth angle being complementary acute angles in relation to the horizontal plane.

15. The forming tool of claim 13, comprising the third angle and the fourth angle being complementary obtuse angles in relation to the horizontal plane.

16. The forming tool of claim 13, further comprising a loading component arranged on one of the upper forming die or the lower forming die, wherein the loading component is arranged to urge the upper forming die or the lower forming die to a neutral position.

17. A metal forming tool, comprising:

a first workpiece gripper and a second workpiece gripper, wherein the first workpiece gripper and the second workpiece gripper are arranged to secure a workpiece; and

a first wedge-shaped stamping die and a second wedge-shaped stamping die;

wherein the first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a lateral force on the workpiece when a vertical compressive force is exerted on the first wedge-shaped stamping die and the second wedge-shaped stamping die.

18. The metal forming tool of claim 17, comprising:

the first wedge-shaped stamping die including a first tool end; and

the second wedge-shaped stamping die including a second tool end;

wherein the first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a tensile lateral force on the workpiece and wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the vertical compressive force is exerted on the first wedge-shaped stamping die and the second wedge-shaped stamping die.

19. The metal forming tool of claim 17, comprising:

the first wedge-shaped stamping die including a first tool end; and

the second wedge-shaped stamping die including a second tool end;

wherein the first wedge-shaped stamping die, the second wedge-shaped stamping die, the first workpiece gripper and the second workpiece gripper cooperate to exert a lateral compressive force on the workpiece and wherein the first tool end cooperates with the second tool end to form an offset feature in the workpiece when the vertical compressive force is exerted on the first wedge-shaped stamping die and the second wedge-shaped stamping die.

20. A method for forming a metallic workpiece, the method comprising:

inserting a sheet metal workpiece into a metal forming tool including an upper forming die and a lower forming die;

exerting, via a first workpiece gripper and a second workpiece gripper, a lateral force on the workpiece and coincidently executing a vertical compressive force upon the upper forming die and the lower forming die, wherein the upper forming die includes a first tool end, and wherein the lower forming die includes a second tool end; and

forming, via the first tool end and the second tool end, an offset feature in the workpiece.