Forming apparatus and method for forming highly contoured composite structures

Patent metadata

Field	Value
Publication number	US-12036754-B2
Application number	US-202117503226-A
Country	US
Kind code	B2
Filing date	Oct 15, 2021
Priority date	Nov 8, 2020
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

There is provided a forming apparatus for constraining a composite charge and forming the composite charge into a highly contoured composite structure. The forming apparatus includes a first die and a second die between which the composite charge is formed. The first die has pairs of first die portions spaced apart to define a die cavity into which the composite charge is formed into a contoured hat section having a cap. The forming apparatus includes a constraining assembly having a constraining device positioned in the die cavity. The constraining device is designed to constrain a cap portion, and to apply an upward resistive force against the cap portion, and against a downward compressive force applied by the second die, to provide wrinkle prevention in the cap as the contoured hat section is formed. The constraining assembly has a retaining element to retain the constraining device.

First claim

What is claimed is:

1. A forming apparatus for constraining a composite charge and forming the composite charge into a highly contoured composite structure, the forming apparatus comprising:
a first die and a second die between which the composite charge is formed, the first die having pairs of first die portions spaced apart to define a die cavity into which the composite charge is formed into a contoured hat section having a cap, the pairs being slidably displaceable with respect to each other, and the second die having a tapered portion designed for at least partial insertion into the die cavity and the second die having a composite charge engagement end with a width; and
a constraining assembly comprising a pneumatic assembly coupled to the first die and having a constraining device comprising an air cylinder coupled to an air cylinder rod, the air cylinder rod having a first end coupled to a cap presser having an engagement surface engaging a cap portion of the composite charge, the air cylinder and the cap presser being removably attached to the die cavity, the cap presser comprising an aluminum bar that is semi-rigid and having a uniform width that is less than a width of the air cylinder and less than the width of the composite charge engagement end of the second die, and the width of the air cylinder being less than the width of the composite charge engagement end of the second die,
the constraining device designed to constrain the cap portion of the composite charge between the engagement surface of the cap presser and the composite charge engagement end of the second die, and the constraining device designed to apply an upward resistive force against the cap portion, and against a downward compressive force applied by the second die, to provide wrinkle prevention in the cap, as the contoured hat section is formed, and the constraining assembly further having a retaining element designed to retain the constraining device, when the second die is retracted after the highly contoured composite structure is formed.

2. The forming apparatus of claim 1 , further comprising a control system for operatively controlling the forming apparatus, including coordinating movements of the first die and the second die with movement of the constraining assembly.

3. The forming apparatus of claim 1 , wherein the highly contoured composite structure comprises one or more of, a stringer, a hat-shaped stringer, an aircraft stringer, a hat-shaped aircraft stringer, a fuselage stringer, a keel stringer, a wing stringer, a stabilizer stringer, a stiffener member, a hat-shaped stiffener member, and a spar.

4. The forming apparatus of claim 1 , wherein the constraining device has a first end engaging, directly or indirectly, with a first surface of the cap portion, to apply the upward resistive force against the first surface of the cap portion, and against the downward compressive force applied by the second die, and to pinch the cap portion against the tapered portion of the second die, during the forming of the composite charge into the highly contoured composite structure.

5. The forming apparatus of claim 1 , wherein during the forming of the composite charge into the highly contoured composite structure, the constraining device is initially in an expanded position in the die cavity to constrain the cap portion against the second die, and when the tapered portion of the second die is fully inserted into the die cavity, the constraining device is in a compressed position, and one or more of the pairs of the first die portions are positioned laterally outward from the constraining device.

6. The forming apparatus of claim 1 , wherein the air cylinder rod of the constraining device comprises a piston rod designed to move from an expanded position to a compressed position, the air cylinder rod having a second end attached to a piston head.

7. The forming apparatus of claim 1 , wherein the cap presser comprising the aluminum bar has a thickness of 0.125 inch.

8. The forming apparatus of claim 1 , wherein the air cylinder of the constraining device comprises a linear actuator that works with compressed air.

9. The forming apparatus of claim 1 , wherein the air cylinder comprises a single acting spring return air cylinder having one air supply line connected between an air supply source and a first port of the single acting spring return air cylinder, the single acting spring return air cylinder comprising a spring inside the air cylinder and fitted around a rod body of the air cylinder rod.

10. The forming apparatus of claim 1 , wherein the air cylinder comprises a double acting air cylinder having a first air supply line and a second air supply line connected between an air supply source and the double acting air cylinder, the first air supply line coupled, via a first port, to a lower bore located within the double acting air cylinder, and the second air supply line coupled, via a second port, to an upper bore located within the double acting air cylinder.

11. The forming apparatus of claim 10 , wherein the retaining element comprises one of,
a spring return and a spring force applied to the air cylinder rod, to retain the air cylinder rod in a compressed position, where the air cylinder comprises a single acting spring return air cylinder;
a pneumatic air pressure application applied to the air cylinder rod, to retain the air cylinder rod in the compressed position, where the air cylinder comprises the double acting air cylinder; and
an actuated rod locking device retaining the air cylinder rod in the compressed position, where the air cylinder comprises a rod lock air cylinder.

12. The forming apparatus of claim 1 , wherein the tapered portion of the second die has the composite charge engagement end with an engagement surface designed to engage with the cap portion of the composite charge, and the width of the cap presser is less than a width of the engagement surface of the tapered portion.

13. The forming apparatus of claim 1 , wherein the air cylinder comprises a rod lock air cylinder having an actuated rod locking device within a cylinder tube of the air cylinder, the actuated rod locking device configured to couple to the air cylinder rod to lock the air cylinder rod in a compressed position.

14. The forming apparatus of claim 13 , wherein the actuated rod locking device comprises an actuator configured to actuate a rod lock to couple to one or more portions of the air cylinder rod to lock the air cylinder rod in the compressed position.

15. A method for constraining a composite charge and forming the composite charge into a highly contoured composite structure, the method comprising the steps of:
positioning the composite charge between, and in contact with, a first die and a second die of a forming apparatus, the first die having pairs of first die portions spaced apart to define a die cavity into which the composite charge is formed into a contoured hat section having a cap, the pairs being slidably displaceable with respect to each other, and the second die having a tapered portion designed for at least partial insertion into the die cavity, and the second die having a composite charge engagement end with a width, and the first die having a constraining assembly with a constraining device positioned in the die cavity, the constraining assembly comprising a pneumatic assembly coupled to the first die and having the constraining device comprising an air cylinder coupled to an air cylinder rod, the air cylinder rod having a first end coupled to a cap presser having an engagement surface engaging a cap portion of the composite charge, the a

Assignees

• Boeing Co

Inventors

• Heath Richard E
• Modin Andrew E
• Prause Richard A
• Shaw Paul D
• Suriyaarachchi Raviendra S

Classifications

• B29L2031/3076

  Aircrafts (blades, propellers B29L2031/08) · CPC title

• B29K2307/04

  Carbon · CPC title

• B29K2105/089

  fabric · CPC title

• B29K2063/00

  Use of {EP, i.e.} epoxy resins {or derivatives thereof}, as moulding material · CPC title

• B29C70/345

  using matched moulds · CPC title