DEVICE AND METHOD FOR HOT STAMPING

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This U.S. Non-Provisional patent application claims the benefit of and priority to U.S. Provisional Application Ser. No. 63/663,375 filed Jun. 24, 2024, the entire disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to a device and method for hot stamping a steel component, such as a door for a vehicle.

2. Related Art

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

Components formed from steel are often desired for use in vehicles. The method of manufacturing the component can include hot forming a steel blank to achieve a predetermined shape. The hot forming processes typically includes heating the blank in a furnace, and then transferring the heated blank to a forming device. The hot forming process next includes forming the blank in a die of the forming device while the blank is at a temperature ranging from 950° C. to 1250° C. followed by quenching the hot formed component in the die. The forming step preferably includes applying sufficient pressure to the component to achieve the desired shape and material properties. The quenching step preferably includes contacting the hot formed component with sections of the die which are cooled by a fluid, such as water cooling, to also achieve the desired material properties.

However, in some cases, the desired shape and/or material properties of the component require the die to present an angled forming surface that would create a backdraft condition, preventing the component from being removed from the forming device. In order to allow for removal of the component after the hot forming process, the die is designed for convenient removal of the component, but then post forming or secondary operations on the component are required outside of the forming device in order to achieve the desired shape and/or material properties. Thus, improvements to the forming device and method are desired.

SUMMARY

One aspect of the disclosure provides a forming device for hot forming a component. The forming device includes an upper cam slide and a lower fill slide which form a desired shape of the component therebetween. The shape of the upper cam slide and lower fill slide allow for desired material properties to be obtained in the forming device, so that no post-forming or secondary operation outside of the forming device is required. The lower fill slide is capable of retracting after forming the component to the desired shape, so that the component can be removed from the forming device and a backdraft situation is avoided.

Another aspect of the disclosure provides a method of hot forming a component. The method includes forming a blank between an upper cam slide and a lower fill slide of a forming device. The upper cam slide and lower fill slide are designed to form a desired shape of the component therebetween. The shape of the upper cam slide and lower fill slide also allow the method to include obtaining desired material properties in the forming device, so that no post-forming or secondary operation outside of the forming device is required. The method further includes retracting the lower fill slide after forming the component to the desired shape, so that the component can be removed from the forming device and a backdraft situation is avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 illustrates a component formed by a forming device and method according to an example embodiment;

FIG. 2 is another view of the component according to the example embodiment;

FIG. 3 is a view of a portion of the component and a portion of the forming device according to an example embodiment;

FIG. 4 is another view of the component according to the example embodiment;

FIG. 5 is a view of a portion of the component and a portion of the forming device according to an example embodiment;

FIG. 6 is a view of a portion of the component according to an example embodiment;

FIG. 7 illustrates the forming device in an closed position according to an example embodiment; and

FIG. 8 illustrates the forming device in an open position according to an example embodiment.

DESCRIPTION OF THE ENABLING EMBODIMENT

One aspect of the disclosure provides a forming device 10 for forming a component 12, and typically for hot forming a component 12 from a blank made of steel. The component 12 is typically designed for use in a vehicle, such as a door panel for an automotive vehicle. An example wherein the component 12 is the door panel is shown in FIGS. 1, 2, and 4. Portions of the example component are shown in FIGS. 3 and 5-8. The shape of the example component 12 includes a plurality of walls having complex shapes. At least two opposing walls of the component 12 are disposed at an angle that creates an undercut area 14. According to an example embodiment, the two walls form an angle ranging from 10 to 20 degrees, such as 15 degrees. This undercut area 14 could create a backdraft condition in a conventional die, preventing the component 12 from being removed from the die. Alternatively, if the conventional die were designed for convenient removal of the component 12, post forming or secondary operations outside of the conventional die would be required to achieve the desired shape and/or material properties. However, the forming device 10 disclosed herein is advantageously designed to avoid the backdraft condition and allow for convenient removal of the component 12, while also achieving the desired shape and material properties in the component, without post-forming or secondary operations outside of the forming device 10.

As best shown in FIGS. 7 and 8, the forming device 10 includes an upper cam slide 16 which extends from an upper die and a lower fill slide 18 disposed above a lower die. The upper cam slide 16 presents an upper forming surface 16a and the lower fill slide 18 presents a lower forming surface 18a which together form the component 12 having the desired shape and material properties. In the example embodiments, the upper forming surface 16a presents a corner or pointed edge extending outward and toward the lower fill slide 18. The lower fill slide 18 presents a lower forming surface 18a facing the upper forming surface 16a and receiving the lower forming surface 18a when the forming device 10 is in a closed position. The lower forming surface 18a extends inward and away from upper cam slide 16. In other words, in the example embodiments, the lower forming surface 18a presents a ledge, and the corner or pointed edge of the upper forming surface 16a rests on the ledge. The shapes of the surfaces 16a, 18a correspond to one another. As shown in FIG. 7, the direction of motion of the upper cam slide 16 during the forming process extends at an angle of about 30 to about 50 degrees, for example 40 degrees, relative to a line extending in a vertical direction (perpendicular to the ground). Also shown in FIG. 7, the direction of motion of the lower fill slide 18 during the forming process extends at an angle of about 20 to about 40 degrees, for example 30 degrees, relative to a line extending in a vertical direction (perpendicular to the ground).

The upper cam slide 16 and the lower fill slide 18 include a plurality of cooling holes for conveying a cooling fluid therethrough. The forming device 10 also include a saw tooth driver 20 disposed beneath the lower fill slide 18 and an upper pad 22 adjacent the upper cam slide 16. The upper pad 22 also presents a pad surface 22a which engages the component 12 and helps to form the component 12 into the desired shape.

The forming device 10 is preferably used to hot form the steel blank into the component 10 having the desired shape and material properties. The hot forming process includes heating the blank, typically in a furnace, or another location outside of the forming device 10. The method next includes transferring the heated blank to the forming device 10, and forming the heated blank between the upper forming surface 16a of the upper cam slide 16 and the lower forming surface 18a of the lower fill slide 18 while the blank is at a high temperature, such as a temperature ranging from 950° C. to 1250° C. The upper cam slide 16 and the lower fill slide 18 are desired with dimensions that cause the component 12 to achieve the desired shape and/or material properties. The upper cam slide 16 and the lower fill slide 18 also apply a sufficient pressure to the component 12 which allows the component 12 to achieve the desired shape and/or material properties. The upper and lower forming surfaces 16a, 18a of the upper cam slide 16 and lower fill slide 18 are designed at angles that depend on the desired shape of the component 12. In the example embodiment, wherein the component 12 is the door panel, the upper cam slide 16 and the lower fill slide 18 are able to create the undercut area 14 in the component 12.

The method next includes quenching the hot formed component 12 between the upper cam slide 16 and the lower fill slide 18. This step includes conveying the cooling fluid, such as water, through the cooling holes of the upper cam slide 16 and the lower fill slide 18. The quenching step preferably includes contacting the hot formed component 12 with certain sections of the upper cam slide 16 and the lower fill slide 18 which are cooled by the cooling fluid and at a sufficient pressure to achieve the desired material properties.

Due to the design of the forming device 10, the component 12 can be easily removed from the forming device 10 after the hot forming process. The lower fill slide 18, which forms the undercut area 14, as well as the saw tooth driver 20, retract from the upper cam slide 18 after the forming process, as shown in FIG. 8, so that the component 12 can be released from contact with the upper cam slide 18 and thus can be removed from the forming device 10.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings and may be practiced otherwise than as specifically described while within the scope of the disclosure.