Tooling assembly and method for explosively forming features in a thin-walled cylinder

Patent metadata

Field	Value
Publication number	US-11628485-B2
Application number	US-202117320523-A
Country	US
Kind code	B2
Filing date	May 14, 2021
Priority date	May 14, 2021
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

The present invention provides a method of explosively forming a helical tube from at least one thin-walled cylinder using a tooling assembly. The method includes inserting the at least one thin-walled cylinder into a die of the tooling assembly. The die surrounds the at least one thin-walled cylinder and includes an interior surface that defines a helical thread pattern. The method further includes surrounding the at least one thin-walled cylinder and the die with a casing of the tooling assembly. A cavity is defined by the casing and the thin-walled cylinder. The method further includes positioning an explosive charge within the cavity. The method additionally includes at least partially submerging the tooling assembly. The method further includes detonating the explosive charge. As a result, the at least one thin-walled cylinder is formed into a helical tube that corresponds with helical thread pattern of the interior surface of the die.

First claim

What is claimed is:

1. A method of explosively forming a helical tube from at least one thin-walled cylinder using a tooling assembly, the method comprising the steps of:
inserting the at least one thin-walled cylinder into a die of the tooling assembly, the die surrounding the at least one thin-walled cylinder and comprising an interior surface that defines a helical thread pattern having peaks and valleys, wherein a taper axis is defined between two peaks of the thread pattern, and wherein the taper axis diverges radially outwardly as the die extends axially outwardly;
surrounding the at least one thin-walled cylinder and the die with a casing of the tooling assembly, wherein a cavity is defined by the at least one thin-walled cylinder and extending along an axial centerline of the tooling assembly;
positioning an explosive charge within the cavity;
at least partially submerging the tooling assembly; and
detonating the explosive charge, whereby the at least one thin-walled cylinder is formed into a helical tube that corresponds with helical thread pattern of the interior surface of the die.

2. The method as in claim 1 , wherein the at least one thin-walled cylinder comprises an inner thin-walled cylinder and an outer thin-walled cylinder that are concentric with one another, and wherein detonating the explosive charge results in both the inner thin-walled cylinder and the outer thin-walled cylinder being simultaneously formed into an inner helical tube and an outer helical tube that both correspond with the helical thread pattern of the interior surface of the die.

3. The method as in claim 2 , further comprising:
separating the inner helical tube from the outer helical tube after detonating the explosive charge by rotating one of the inner helical tube or the outer helical tube relative to the other of the inner helical tube or the outer helical tube.

4. The method as in claim 1 , wherein the casing comprises a die support extending between a first end and a second end, a base plate, and a tube sealing plate.

5. The method as in claim 4 , wherein the surrounding step further comprises:
positioning the second end of the die support on the base plate;
placing the die and the at least one thin-walled cylinder onto the base plate and into the die support; and
positioning the tube sealing plate on the first end of the die support.

6. The method as in claim 5 , further comprising:
installing a plurality of bolts and fasteners through the tube sealing plate, the die support, and the base plate.

7. The method as in claim 4 , further comprising:
positioning at least one annular gasket between die support and one of the base plate and the tube sealing plate.

8. The method as in claim 1 , further comprising:
removing, via one or more vacuum sealing ports extending through the casing, air within an annular plenum defined between the at least one thin-walled cylinder, the casing, and the die.

9. The method as in claim 1 , further comprising:
placing an annular U-shaped gasket onto an end of the at least one thin-walled cylinder.

10. A tooling assembly for explosively forming a helical tube from at least one thin-walled cylinder, the tooling assembly defining an axial, radial, and circumferential direction, the tooling assembly comprising:
a casing that surrounds the at least one thin-walled cylinder, the casing including a die support that extends from a first end to a second end and a tube sealing plate coupled to the first end of the die support, wherein the tube sealing plate converges radially inward in the axial direction, and wherein the at least one thin-walled cylinder defines a cavity extending along an axial centerline of the tooling assembly; and
a die positioned within the casing, the die having a radially outer surface in contact with the die support of the casing and a radially inner surface that defines a helical thread pattern having peaks and valleys, wherein a taper axis is defined between two peaks of the thread pattern, and wherein the taper axis diverges radially outwardly as the die extends axially outwardly.

11. The tooling assembly as in claim 10 , wherein the radially inner surface of the die tapers radially outward in the axial direction.

12. The tooling assembly as in claim 11 , wherein the radially inner surface of the die forms an angle with the axial direction that is up to 10°.

13. The tooling assembly as in claim 10 , wherein the tube sealing plate includes a radially inner surface having a portion that tapers radially inward in the axial direction such that the tube sealing plate at least partially defines a frustoconical shape.

14. The tooling assembly as in claim 10 , wherein the distance between a peak and a valley of the thread pattern is between 0.25 inches and 1 inches.

15. The tooling assembly as in claim 10 , wherein the casing further comprises a base plate coupled to the second end of the die support.

16. The tooling assembly as in claim 15 , wherein both the base plate and the tube sealing plate extend radially inward of the die support.

17. The tooling assembly as in claim 10 , further comprising a plurality of bolts circumferentially spaced apart from one another and extending generally axially through the casing.

18. The tooling assembly as in claim 10 , wherein an annular plenum is defined between the at least one thin-walled cylinder, the die, and the casing, and wherein a vacuum sealing port extends through the casing and is in fluid communication with the annular plenum.

Assignees

• Battelle Savannah River Alliance Llc

Inventors

• Eberl Kurt R
• Housley William M
• Shuler James M
• Blanton Paul S
• Flach Joshua P

Classifications

• B21D26/08 Primary

  generated by explosives, e.g. chemical explosives · CPC title

• B21D51/10

  conically or cylindrically shaped objects · CPC title

• B21D51/24

  high-pressure containers, e.g. boilers, bottles · CPC title