A method for ultrasonic cutting of preformed composite materials

Abstract

This invention belongs to the field of carbon fiber composite material processing technology and discloses a method for ultrasonic cutting of preformed composite materials. This method involves pre-measuring the angle α between the opposite cutting edges and the angle β between the same cutting edges of the blade. During the cutting process, the angle A between the blade's travel direction and the fiber direction is controlled, and the angle between the blade axis and the travel direction is dynamically adjusted from an acute angle to an obtuse angle. For cutting concave arc surfaces, the maximum tilt angle of the blade is controlled to be greater than α / 2, and the cutting edge is made parallel to the tangent at the cutting position to disperse the cutting force. For planar cutting, the maximum tilt angle is controlled to be α / 2, so that the cutting edge fits the plane. This invention effectively reduces the compression of the composite material by conforming to the shape angle during cutting, avoiding problems such as material deformation, step differences, and overcutting.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber composite material processing technology, and in particular to a method for ultrasonic cutting of preformed composite materials. Background Technology

[0002] Carbon fiber composites are a typical high-strength material, and due to their excellent properties, they are widely used in the main load-bearing structural components of civil aircraft, such as fuselages, wings, tail panels, and stringers. Carbon fiber composite preforms consist of multiple layers of uncured carbon fibers and resin. The resin is relatively soft, while the carbon fibers are relatively hard. Cutting these preforms requires addressing the challenge of cutting both the harder carbon fibers and the softer resin between them.

[0003] Currently, ultrasonic straight-blade cutters are used for high-frequency vibration cutting of composite material preforms. However, due to the strength requirements of the ultrasonic straight-blade cutter itself, the blade has a certain thickness and width. When cutting arc areas or inner right-angle areas, if the axis of the cutter body is perpendicular to the placement surface of the lower side of the composite material preform and the cutter body moves horizontally parallel to the placement surface, the composite material preform will be subjected to extrusion deformation. Thus, when processing concave planes, that is, when processing arc areas or inner right-angle areas, the composite material preform will have quality problems such as step difference and tearing. Summary of the Invention

[0004] The purpose of this invention is to provide a method for ultrasonic cutting of preformed composite materials, which solves the problem of tearing and deformation that occurs when cutting on composite materials with the axis of the cutter body perpendicular to the placement surface in the prior art.

[0005] To achieve this objective, the present invention adopts the following technical solution: The present invention provides a method for ultrasonic cutting of preformed composite materials, comprising the following steps:

[0006] S1. Place the composite material on the cutting table. The blade is spiked. Measure the blade parameters. α is the angle between the opposite blade edges, and β is the angle between the same blade edges.

[0007] S2, the blade moves along the plane of the cutting table, and the angle between the direction of the blade's movement and the fiber in the composite material is A, 0°≤A≤90°;

[0008] S3, during the cutting process, the angle between the blade axis and the direction of travel rotates from an acute angle to an obtuse angle.

[0009] Preferably, when the cutting surface is an arc surface, the maximum angle between the axis of the blade body and the direction perpendicular to the cutting table is greater than α / 2.

[0010] Preferably, when the surface to be cut is a concave arc-shaped surface, the cutting edge is parallel to the tangent of the arc-shaped surface at the cutting position.

[0011] Preferably, when the blade body is positioned at the midpoint of the arc-shaped surface, its axis is perpendicular to the cutting table.

[0012] Preferably, when the surface to be cut is a plane, the maximum angle between the axis of the blade and the direction perpendicular to the cutting table is α / 2.

[0013] Preferably, the blade is in contact with the plane of the cutting location.

[0014] Preferably, when the blade body is in the middle position of the plane, the blade axis is perpendicular to the cutting table.

[0015] Beneficial effects: The cutting direction is at an acute angle to the fiber arrangement direction in the composite material, which can reduce the problem of tearing of the composite material. At the same time, the oscillation of the cutting axis during the cutting process can also reduce the problem of step tearing. Attached Figure Description

[0016] Figure 1 This is a front view of the blade body of the present invention;

[0017] Figure 2 This is a cross-sectional view of the thickness of the blade body of the present invention;

[0018] Figure 3 This is a top view of the process of the blade cutting a right-angled plane according to the present invention;

[0019] Figure 4 This is a top view of the curved surface being cut by the blade of the present invention;

[0020] Figure 5 This is a side view of the cutting right-angled plane of the blade body of the present invention;

[0021] Figure 6 This is a side view of the blade cutting the arc-shaped surface of the present invention.

[0022] In the picture: 1. Blade body; 11. Blade edge. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0024] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0027] In the current technology, composite preforms are composed of multiple layers of uncured carbon fibers and resin. The resin material is relatively soft, while the carbon fiber material is relatively hard. Cutting composite preforms requires cutting the harder carbon fibers while simultaneously cutting the softer resin between the carbon fibers. Currently, ultrasonic straight-blade cutters are used to cut composite preforms using high-frequency vibration. During the cutting process, since the cutter body is parallel to the surface being cut and there is no angle change, the material will deform due to the pressure of the blade and the cutter body. This will result in quality problems such as uneven joints and tearing in the composite material, leading to quality issues in the cut material.

[0028] To solve the above problems, such as Figures 1 to 6 As shown, the present invention provides a method for ultrasonic cutting of preformed composite materials, comprising the following steps:

[0029] S1. Place the composite material on the cutting table. The blade 1 is in the shape of a spike. Measure the parameters of the blade 1. α is the angle between the opposite blades 11 of the blade 1, and β is the angle between the same blades 11 of the blade 1.

[0030] S2, the blade 1 moves along the plane of the cutting table, and the angle between the direction of travel of the blade 1 and the fiber in the composite material is A, 0°≤A≤90°;

[0031] S3, during the cutting process of the blade body 1, the angle between the axis of the blade body 1 and the direction of travel rotates from an acute angle to an obtuse angle.

[0032] First, it is necessary to measure the data parameters of the blade body 1. In particular, it is necessary to clarify that α is the included angle between the opposite blade edges 11 of the blade body 1, and β is the included angle between the same blade edges 11 of the blade body 1. Through the above two sets of data, the angle of swing required for the blade body 1 during subsequent movement can be determined.

[0033] When starting to cut the composite preform in the shape of an inner arc, the axis of the cutter body 1 is tilted in the cutting direction. This allows the material to withstand greater cutting force during the cutting process, making it easier for the cutter body 1 to cut. During the movement, the tilt angle of the cutter body 1 becomes smaller and smaller. When cutting to the middle of the arc surface, the cutter body 1 is in a vertical state. After that, the cutter body 1 tilts to the side away from the cutting direction.

[0034] When the cutting surface is a concave arc-shaped surface, the maximum angle between the axis of the cutter body 1 and the direction perpendicular to the cutting table is greater than α / 2 in the initial and final stages. Simultaneously, the blade-shaped cutting edge 11 forms a certain angle with the surface being cut, with the angle between the cutting edge 11 and the tangent at the cutting position being β / 2. This reduces the compression on the composite material preform. Typically, the blade contacts the arc-shaped surface at the cutting position, reducing pressure on the preform and preventing deformation and step differences during cutting. By changing the angle of the cutter body 1, the compression on the material being cut is reduced, avoiding overcutting and reduced cutting accuracy.

[0035] At the point of contact with the cut surface, the blade 11 must always maintain an angle of β / 2 with the tangent at that point. This allows the blade 11 to cut into the material in a "sliding cut" rather than a "positive pressure" manner, significantly reducing the component force perpendicular to the material surface, thereby greatly reducing the squeezing effect on soft or layered composite preforms. Secondly, it ensures that the blade 11 guides the fiber bundles or fabrics to separate smoothly, rather than pushing or pulling them to deform them. This is crucial for maintaining the smoothness of the cut edge and the continuity of the fibers, effectively avoiding "step differences" or edge burrs caused by material displacement.

[0036] Tool holder clamping devices typically possess rotational degrees of freedom in two directions, enabling simultaneous changes in the yaw and tilt of the tool body 1 during feed. Its control logic receives path curvature data from a 3D model or sensors and calculates the optimal orientation of the tool body 1's axis based on preset α and β parameters. When cutting concave arc surfaces, a faster system response results in a smoother cutting plane, preventing cutting force fluctuations caused by abrupt angle changes.

[0037] Composite preforms typically have interlaminar strength lower than the strength of the fibers themselves and are extremely sensitive to transverse compression. The deformation angle cutting method described in this application disperses the concentrated normal pressure into shear force along the tangential direction, which is in line with the mechanical properties of such materials.

[0038] This method significantly improves the surface finish of complex curved preforms, eliminating the need for secondary edge trimming and allowing direct use in subsequent part manufacturing processes, thus reducing waste and time. Secondly, by avoiding improper material deformation, the preform fits better in the mold, aiding in the control of final component dimensional accuracy and reducing uneven resin injection or curing deformation caused by preform dimensional errors. Finally, the amount of dust and fiber debris generated during the cutting process is also greatly reduced, improving the working environment and lowering the risk of fine particle contamination at interlayer interfaces.

[0039] Preferably, in addition to concave arc surfaces, for the cutting of preforms of complex components such as convex curved surfaces, S-shaped bends, and irregular reinforcing ribs, it is only necessary to adaptively define the α and β parameters and adjust the tilt angle so that the cutter body 1 can adapt to different cutting methods.

[0040] When the surface being cut is a plane, it is usually a set of four planes with inner right angles. The maximum angle between the axis of the blade body 1 and the direction perpendicular to the cutting table is α / 2, so that when the blade 11 moves to the inner right angle, the tip of the blade 11 can fit with the corner, and the inner walls of the quadrilateral can maintain a 90° perpendicularity.

[0041] The surface of the blade 11 fits against the plane of the cutting position, making the cutting process smoother. When the blade body 1 is in the middle of the cutting plane, the axis of the blade body 1 is perpendicular to the cutting table. As the axis of the blade body 1 swings, it can reduce the excessive pressure on the cutting surface, making the cutting surface smoother and flatter, avoiding step differences, and improving the cutting quality.

[0042] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for ultrasonic cutting of preformed composite materials, characterized in that, When the surface to be cut is curved, the following steps are included: S1, place the composite material on the cutting table, the blade (1) is in the shape of a spike, measure the parameters of the blade (1), α is the angle between the opposite blades (11) of the blade (1), β is the angle between the same blades (11) of the blade (1), the maximum angle between the axis of the blade (1) and the direction perpendicular to the cutting table is greater than α / 2, and the angle between the blade (11) and the tangent of the arc surface at the cutting position is β / 2; S2, the blade (1) moves along the plane of the cutting table, and the angle between the direction of travel of the blade (1) and the fiber in the composite material is A, 0°≤A≤90°; S3, during the cutting process of the blade (1), the angle between the axis of the blade (1) and the direction of travel rotates from an acute angle to an obtuse angle. When the blade (1) is in the middle of the arc surface, the axis of the blade (1) is perpendicular to the cutting table.

2. A method for ultrasonic cutting of preformed composite materials, characterized in that, When cutting four sets of planes with internal right angles, the following steps are included: S1, place the composite material on the cutting table, the blade (1) is in the shape of a spike, measure the parameters of the blade (1), α is the angle between the opposite blades (11) of the blade (1), β is the angle between the same blades (11) of the blade (1), the maximum angle between the axis of the blade (1) and the direction perpendicular to the cutting table is greater than α / 2, and the blade (11) is in contact with the plane of the cutting position; S2, the blade (1) moves along the plane of the cutting table, and the angle between the direction of travel of the blade (1) and the fiber in the composite material is A, 0°≤A≤90°; S3, during the cutting process of the blade (1), the angle between the axis of the blade (1) and the direction of travel rotates from an acute angle to an obtuse angle. When the blade (1) reaches the middle section of the surface to be cut, the axis of the blade (1) is perpendicular to the cutting table.

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