Composite material shell with embedded pendant and preparation method thereof

Abstract

A composite material housing with an embedded hanger and its preparation method include an insulation layer, a wrapping layer, an embedded curved plate, spikes, and a hanger. The wrapping layer is disposed outside the insulation layer, the embedded curved plate is disposed within the wrapping layer, and one end of a plurality of spikes is fixedly mounted on the embedded curved plate, while the other ends of the spikes pass through the wrapping layer and are fixedly connected to the hanger. The hanger is attached within the wrapping layer, eliminating the need to waste material and increase wrapping thickness to install the hanger, thus reducing negative weight. Furthermore, only one curing step is required, significantly shortening the production cycle. Except for a protrusion at the hanger, the housing is a uniform cylindrical surface, resulting in low wind resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material solid rocket engines, and particularly relates to a composite material shell with an embedded hanger and a preparation method thereof. Background Art

[0002] Modern tactical missiles generally require wings and attachment points. For metal shells, welding can be used to connect the attachments to the missile's outer shell, but for missiles using advanced composite solid rocket motors, this approach is more challenging. While bonding can be used for very low load-bearing requirements, it's more challenging for projects with high load-bearing requirements. The combustion chamber shell of a composite solid rocket motor is typically part of the missile's outer shell. Composite combustion chamber shells are made using a winding process using ultra-high-strength fiber materials such as carbon fiber or aramid. Currently, to attach load-bearing attachments to composite shells, the process begins by winding the shell to a minimum thickness, as required by the shell's pressure-bearing requirements. An additional thickness is then added to allow for machining margins. After the shell solidifies, a mounting groove is machined for the attachment. The attachment's wings are then glued into the groove and wound circumferentially around the wings. The attachment disrupts the winding continuity, resulting in a less smooth outer shell surface and increased flight drag. The restraining force on the attachment primarily comes from the circumferential fibers wrapped around the wings and the side surfaces of the mounting groove. Because the wrapping thickness cannot be increased too much, the load-bearing capacity of the pendant is low. The wrapping portion added specifically to accommodate the pendant is considered a negative mass of the rocket. In particular, milling the slots in the shell can easily damage the fibers that make up the shell's basic wrapping thickness, rendering the shell scrapped due to insufficient pressure bearing capacity. Summary of the Invention

[0003] The present invention aims to provide a composite shell with an embedded hanger and a method for its preparation. This addresses the problem of existing hangers disrupting winding continuity, resulting in a less smooth shell surface and increased flight resistance. The restraining force on the hanger primarily comes from the circumferential fibers wrapped around the hanger's wings and the side surfaces of the mounting slot. However, since the winding thickness cannot be increased significantly, the hanger's load-bearing capacity is low.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A composite material shell with an embedded hanger comprises an insulating layer, a winding layer, an embedded curved plate, sharp nails and a hanger; the winding layer is arranged on the outside of the insulating layer, the embedded curved plate is arranged inside the winding layer, one end of a plurality of sharp nails is fixedly arranged on the embedded curved plate, and the other ends of the sharp nails pass through the winding layer and are fixedly connected to the hanger.

[0006] Furthermore, the winding layer includes an early winding layer and a late winding layer; the early winding layer is laminated on the insulating layer, the embedded arc plate is arranged on the early winding layer, and the late winding layer covers the early winding layer and the embedded arc plate.

[0007] Furthermore, the thermal insulation layer is provided on the core mold of the fiber placement machine.

[0008] Furthermore, the spike and the embedded curved plate, as well as the spike and the hanging piece are connected by welding.

[0009] Furthermore, the curvature radius of the inner arc surface of the arc-shaped plate of the insert is equal to the radius of the outer shell surface when pasted, and the thickness of the four sides of the arc-shaped plate of the insert is gradually thinner.

[0010] Furthermore, one end of the spike is a cone with an acute angle, and the other end is a cylinder. A countersunk hole is provided on the arc-shaped plate of the insert, and one end of the spike cone is provided in the countersunk hole and welded into one piece.

[0011] Furthermore, the spikes are arranged in multiple rows and columns, and the axes of all the spikes are parallel to each other.

[0012] Furthermore, a method for preparing a composite material shell embedded with a pendant comprises the following steps:

[0013] First, make the embedded parts and external parts according to the outer diameter of the shell and the load-bearing requirements of the hanger;

[0014] The shell is then wound using a cylindrical fiber placement machine with a wrapper. When the wrapping thickness reaches the designed preliminary wrapping layer, the insert is placed on the surface of the shell fiber using a positioning tool and wrapped around it. After the insert is fixed, the positioning tool is removed and the hoop winding is continued.

[0015] Then continue to complete the unfinished longitudinal and circumferential later winding layers; after the laying and winding is completed, wipe off the resin on the surface of the protruding part of the insert spike, align the hanger with the insert so that the insert spike is inserted into the corresponding hole of the hanger, press the hanger tightly, and use a laser welder or pulse welder to melt and weld the tip of the spike and the edge of the hanger hole into one piece;

[0016] After the hangers are welded, the shell is placed in a curing furnace for heating and rotation curing, and after demoulding, a fiber-wound shell with hangers is obtained.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] The pendant of the present invention is connected within the winding layer, eliminating the need to waste material and increase winding thickness in order to install the pendant, thereby not increasing negative weight. Furthermore, only one curing step is required, significantly shortening the production cycle. The outer shell has a uniform cylindrical surface except for a protrusion at the pendant, resulting in low wind resistance.

[0019] All the curved plates of the insert of the present invention are covered with longitudinal and circumferential fibers, and the hanging part has a large bearing capacity;

[0020] The present invention uses a cylindrical yarn laying machine with a wrapper to wind the shell, which not only ensures the stability of the tension of the longitudinal yarn during the laying and winding process, but also greatly improves the production efficiency compared with using a winding machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A longitudinal anatomical diagram of a composite hair-fixing shell embedded in a pendant;

[0022] Figure 2 A transverse anatomical diagram of a composite hair-fixing shell embedded in a pendant;

[0023] Figure 3 A longitudinal anatomical diagram of the entangled insert;

[0024] Figure 4 A schematic diagram of the transverse anatomy of the entangled insert;

[0025] Among them: 1 - insulation layer, 2 - early winding layer, 3 - late winding layer, 4 - embedded curved plate, 5 - spikes, 6 - hanging parts, 7 - welding points. DETAILED DESCRIPTION

[0026] The present invention is further described below with reference to the accompanying drawings:

[0027] See also Figures 1 to 4 A design and manufacturing method for a composite hair-fixing shell embedded with a hanger. First, the insert and hanger are designed and manufactured according to the outer diameter of the shell and the load-bearing requirements of the hanger. The shell is then wound using a cylindrical fiber laying machine with a wrapper. When the wrapping thickness reaches the designed preliminary wrapping layer, the insert is placed on the surface of the shell fiber using a positioning tool and wrapped around it. After the insert is fixed, the positioning tool is removed and the hoop wrapping is continued. The remaining longitudinal and hoop wrapping layers are then completed according to the wrapping process. After the wrapping is completed, the resin on the surface of the protruding portion of the insert spike is wiped off. The hanger is aligned with the insert so that the insert spike is inserted into the corresponding hole of the hanger. The hanger is pressed and a laser welder or pulse welder is used to instantly melt and weld the tip of the spike and the edge of the hanger hole into one piece. After all the hangers are welded, the shell is placed in a curing oven for heating and rotational curing. After demolding, the fiber-wound shell with the hanger is completed.

[0028] The curvature radius of the inner arc surface of the embedded part is equal to the radius of the outer shell surface when pasted, and the thickness of the four sides of the embedded part is gradually thinner.

[0029] One end of the spike of the insert is a cone with an acute angle, and the other end is a cylinder. The hole on the arc plate of the insert is a countersunk hole. The arc plate of the insert is placed on a special positioning fixture, the spike is inserted, and then a laser welder and a pulse welder are used to instantly melt and weld the tip of the spike and the edge of the hole of the arc plate into one.

[0030] The spikes on the insert are arranged in multiple rows and columns, and the axes of all the spikes are parallel to each other.

[0031] Example 1:

[0032] A design and fabrication method for a composite hair-fixing shell embedded with a hanger. First, the embedded and external hangers are designed and fabricated based on the shell's outer diameter and the hanger's load-bearing requirements. Both are woven from high-strength metal. The radius of curvature of the embedded component's inner arc surface equals the radius of the shell surface when attached, and the thickness of the embedded component's four sides gradually decreases. The hanger's inner arc surface has a radius of curvature equal to the radius of curvature of the fiber surface wrapped around the embedded component.

[0033] One end of the spike of the insert is a cone with an acute angle, and the other end is a cylinder. The hole on the arc plate of the insert is a countersunk hole. The arc plate of the insert is placed on a special positioning tool, the spike is inserted, and then a laser welder or pulse welder is used to instantly melt and weld the tip of the spike and the edge of the hole of the arc plate into one.

[0034] A cylindrical laying machine with a wrapper is used to wind the shell. The cylindrical laying machine is used as the winding equipment mainly because the cylindrical laying machine can lay one layer of yarn in the longitudinal direction each time and all longitudinal yarns always have constant tension, which can ensure that the tension of the longitudinal yarn remains stable during the winding after the insert is added.

[0035] The fiber winding is carried out on the surface of the core mold or the surface of the core mold with the insulation layer 1 applied. When the shell thickness is wound to the designed insert insertion thickness, that is, the early winding layer 2 is completed, the insert 4 is placed on the surface of the early winding layer 2 by the positioning tool and wrapped around it. After the insert 4 is fixed, the positioning tool is removed, and the circumferential winding is continued. Then, the unfinished longitudinal and circumferential late winding layers 3 are completed according to the winding process; the resin on the protruding part of the surface of the sharp nail 5 of the insert 4 is wiped off, and the hanger 6 is aligned with the insert 4 so that the sharp nail 5 of the insert 4 is inserted into the corresponding hole of the hanger 6, the hanger 6 is pressed and a laser welder or a pulse welder is used to instantly melt the tip of the sharp nail 5 and the edge of the hole of the hanger 6 and weld them into one; after all the hangers 6 are welded, the shell is placed in a curing furnace for heating and rotation curing. After demolding, the fiber-wound shell with the hanger is completed.

[0036] When the load-bearing capacity requirement of the hanger 6 is high or the shape is special, one row of spikes may not be able to meet the load-bearing requirement. In this case, multiple rows and columns of spikes with parallel axes can be used.

[0037] The above description is merely a typical embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The data listed are merely illustrative of the operating principles of the present invention and do not represent essential numerical values. Any equivalent variations or substitutions that can be readily conceived by a person skilled in the art of fiber winding within the technical scope disclosed herein are intended to be encompassed by the claims of the present invention.

Claims

1. A composite material housing with an embedded pendant, characterized in that: The invention comprises a heat-insulating layer (1), a winding layer, an embedded curved plate (4), sharp nails (5) and a hanging piece (6); the winding layer is arranged outside the heat-insulating layer (1), the embedded curved plate (4) is arranged inside the winding layer, one end of a plurality of sharp nails (5) is fixedly arranged on the embedded curved plate (4), and the other end of the sharp nails (5) passes through the winding layer and is fixedly connected to the hanging piece (6); The winding layer comprises an early winding layer (2) and a late winding layer (3); the early winding layer (2) is laminated on the heat insulating layer (1), the embedded curved plate (4) is arranged on the early winding layer (2), and the late winding layer (3) covers the early winding layer (2) and the embedded curved plate (4); The curvature radius of the inner arc surface of the embedded arc plate (4) is equal to the radius of the outer shell surface when pasted, and the thickness of the four sides of the embedded arc plate (4) is gradually thinner.

2. The composite material housing with an embedded pendant according to claim 1, characterized in that: The heat insulating layer (1) is arranged on a core mold of a fiber laying machine.

3. The composite material housing with an embedded pendant according to claim 1, characterized in that: The sharp nail (5) and the embedded arc plate (4), as well as the sharp nail (5) and the hanging piece (6) are all connected by welding.

4. The composite material housing with an embedded pendant according to claim 1, characterized in that: One end of the spike (5) is a cone with an acute angle, and the other end is a cylinder. A countersink is provided on the arc-shaped plate (4) of the insert, and one end of the spike (5) is arranged in the countersink and welded into one body.

5. The composite material housing with an embedded pendant according to claim 1, characterized in that: The spikes (5) are arranged in multiple rows and columns.

6. A method for preparing a composite material shell embedded with a pendant, characterized in that: The composite material housing with embedded pendant according to any one of claims 1 to 5 comprises the following steps: First, the embedded curved plate and the pendant are made according to the outer diameter of the shell and the load-bearing requirements of the pendant; The shell is then wound using a cylindrical fiber placement machine with a wrapper. When the wrapping thickness reaches the designed preliminary wrapping layer, the arc-shaped insert is placed on the surface of the shell fiber using a positioning tool to wrap around it. After the arc-shaped insert is fixed, the positioning tool is removed and the hoop winding is continued. Then continue to complete the unfinished longitudinal and circumferential later winding layers; after the laying and winding is completed, wipe off the resin on the surface of the part where the sharp nails of the embedded curved plate protrude, align the hanger with the embedded curved plate so that the sharp nails of the embedded curved plate are inserted into the corresponding holes of the hanger, press the hanger tightly, and use a laser welder or a pulse welder to melt and weld the tip of the sharp nail and the edge of the hanger hole into one piece; After the hangers are welded, the shell is placed in a curing furnace for heating and rotation curing, and after demoulding, a fiber-wound shell with hangers is obtained.

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