Composite material preforming ultrasonic cutting method

Abstract

The invention belongs to the technical field of carbon fiber composite material processing, and discloses a composite material preforming ultrasonic cutting method. According to the method, the included angle alpha of blades on different sides and the included angle beta of blades on the same side of a cutter body are measured in advance, in the cutting process, the advancing direction of the cutter body and the fiber direction are controlled to form an included angle A, the included angle between the axis of the cutter body and the advancing direction is dynamically adjusted to rotate from an acute angle to an obtuse angle, and the maximum inclination angle of the cutter body is controlled to be larger than alpha / 2 for cutting of the inwards-concave arc-shaped face. And for plane cutting, the maximum inclination angle is controlled to be alpha / 2, so that the cutting edge is attached to the plane, extrusion to the composite material is effectively reduced through cutting along with the deformation angle, and the problems of material deformation, step difference, over-cutting and the like are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon fiber composite material processing, and particularly relates to a composite material preform ultrasonic cutting method. BACKGROUND

[0002] Carbon fiber composite material is a typical high specific strength material, and is widely applied to main load-bearing structure members such as fuselage, wing, tail wall plate stringers in civil aircrafts due to excellent performance. The carbon fiber composite material preform is composed of multiple layers of uncured carbon fibers and resin. The resin material is relatively soft, and the carbon fiber material is relatively hard. The cutting of the above-mentioned composite material preform needs to solve the problems of cutting the relatively hard carbon fibers and cutting the relatively soft resin between the carbon fibers.

[0003] At present, the ultrasonic straight blade high-frequency vibration is used to cut the composite material preform. However, due to the strength requirement of the ultrasonic straight blade itself, the blade has a certain thickness and width. During the cutting of the circular arc area or the internal right angle area, if the axis of the blade body is perpendicular to the placement surface of the lower side of the composite material preform, and the blade body moves horizontally parallel to the placement surface, the composite material preform will be extruded and deformed. Therefore, during the processing of the internal concave plane, that is, during the processing of the circular arc area or the internal right angle area, the composite material preform will have quality problems such as step difference and tearing. SUMMARY

[0004] The present application aims to provide a composite material preform ultrasonic cutting method, which solves the problem that the axis of the blade body is perpendicular to the placement surface and cuts the composite material, resulting in tearing and deformation.

[0005] To achieve this purpose, the present application adopts the following technical scheme: the present application provides a composite material preform ultrasonic cutting method, which comprises the following steps:

[0006] S1, placing the composite material on the cutting table, the blade body is in the form of a sharp spike, measuring the parameters of the blade body, alpha is the included angle between the opposite blade edges of the blade body, and beta is the included angle between the same blade edges of the blade body;

[0007] S2, moving the blade body along the plane of the cutting table, the included angle between the advancing direction of the blade body and the fibers in the composite material is A, and 0°≤A≤90°;

[0008] S3, during the cutting movement of the blade body, the included angle between the axis of the blade body and the advancing direction is changed from an acute angle to an obtuse angle.

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

[0010] As preferably, when the cut surface is an arc-shaped surface, the cutting edge is parallel to the tangent of the arc-shaped surface at the cutting position.

[0011] As preferably, the tool body axis is perpendicular to the cutting table at the middle of the arc-shaped surface.

[0012] As preferably, when the cut surface is a plane, the maximum angle between the tool body axis and the direction perpendicular to the cutting table is α / 2.

[0013] As preferably, the cutting edge is tangent to the plane at the cutting position.

[0014] As preferably, the tool body axis is perpendicular to the cutting table at the middle of the plane.

[0015] Beneficial effect: the moving direction of the tool body is distributed at an acute angle with the fiber arrangement direction in the composite material, which can reduce the tearing problem of the composite material, and the tool body axis swings during the cutting process, which can also reduce the step tearing problem. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the main view of the tool body of the present application;

[0017] Figure 2 is the thickness section view of the tool body of the present application;

[0018] Figure 3 is the top view of the tool body cutting a right-angle plane of the present application;

[0019] Figure 4 is the top view of the tool body cutting an arc-shaped surface of the present application;

[0020] Figure 5 is the side view of the tool body cutting a right-angle plane of the present application;

[0021] Figure 6 is the side view of the tool body cutting an arc-shaped surface of the present application.

[0022] In the figure: 1, tool body; 11, cutting edge. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below in conjunction with the drawings and examples. It can be understood that the specific examples described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0024] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0026] In the description of the present embodiment, the terms "up", "down", "right", and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0027] Under the prior art, the composite preform is composed of multiple layers of uncured carbon fibers and resin, the resin material is relatively soft, and the carbon fiber material is relatively hard. Cutting the composite preform needs to solve the problem of cutting the relatively hard carbon fiber and cutting the relatively soft resin between the carbon fibers. At present, an ultrasonic straight blade is used to cut the composite preform at high frequency. During the cutting process, the cutter body itself is parallel to the cutting surface without angle change. During the cutting process, the extrusion material of the blade and the cutter body will deform, which will cause quality problems such as step difference and tearing on the composite material, thus causing quality problems of the cut material.

[0028] In order to solve the above problems, as shown in Figures 1 to 6 The present application provides a composite preform ultrasonic cutting method, comprising the following steps:

[0029] S1, placing the composite material on the cutting table, the cutter body 1 is in the form of a sharp spike, measuring the parameters of the cutter body 1, α is the included angle of the opposite blades 11 of the cutter body 1, and β is the included angle between the same blades 11 of the cutter body 1;

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

[0031] S3, during the movement of the cutter body 1 for cutting, the angle between the axis of the cutter body 1 and the advancing direction is changed from an acute angle to an obtuse angle.

[0032] Firstly, the data parameters of the cutter body 1 need to be measured, wherein it is particularly necessary to determine that α is the angle between the opposite cutting edges 11 of the cutter body 1, and β is the angle between the same-side cutting edges 11 of the cutter body 1. Through the above two groups of data, the angle which the cutter body 1 needs to swing in the subsequent movement can be determined.

[0033] When starting to cut the composite preform in the form of an inner arc line, the axis of the cutter body 1 is inclined to the cutting direction, so that the material can withstand greater cutting force during the cutting opening process, and the cutter body 1 is convenient for cutting. During the movement, the inclination angle of the cutter body 1 becomes smaller and smaller. When cutting to the middle position of the arc surface, the cutter body 1 is in a vertical state. Then the cutter body 1 is inclined to the side away from the cutting direction.

[0034] When the cutting surface is an inner concave arc 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 at the beginning and end stages, and a certain angle is formed between the sheet-shaped cutting edge 11 and the cutting surface. The angle between the cutting edge 11 and the tangent line of the cutting position is β / 2. In this way, the extrusion on the composite preform can be reduced, which is usually in contact with the arc surface of the cutting position. The pressure on the composite preform can be reduced, the deformation of the composite preform can be avoided, and the problem of step difference in the cutting process can be avoided. By changing the angle of the cutter body 1, the extrusion on the cutting material can be reduced, and the problems of overcutting and reduced cutting precision can be avoided.

[0035] The sheet-shaped cutting edge 11 needs to always maintain an angle of β / 2 with the tangent line at the contact point with the cutting surface. It makes the cutting edge 11 cut into the material in a "sliding cutting" rather than a "normal pressure" manner, significantly reducing the component force perpendicular to the material surface, thereby greatly reducing the extrusion effect on the soft or layered composite preform. Secondly, it ensures that the cutting edge 11 guides the fiber tows or fabrics to separate smoothly rather than being pushed or pulled to deform, which is crucial for maintaining the flatness of the cutting edge and the continuity of the fiber, effectively avoiding "step difference" or edge burrs caused by material displacement.

[0036] The tool holder clamping device often has two directions of rotational freedom, which can change the deflection and tilt of the tool body 1 synchronously during feeding. Its control logic receives path curvature data from a three-dimensional model or a sensor, and calculates the optimal direction of the tool body 1 axis according to the preset α and β parameters. When cutting the inner concave curved surface, the faster the response speed of the system, the smoother the cutting plane, which prevents the cutting force fluctuation caused by angle jump.

[0037] The composite preform has an interlaminar strength generally lower than the strength of the fibers itself, and is extremely sensitive to transverse extrusion. The variable-angle cutting method described in the application disperses the concentrated normal pressure into shear force along the tangent direction, which is consistent with the mechanical properties of such materials.

[0038] Using this method to cut complex curved surface preforms, the cutting surface finish is significantly improved, and the edge does not need to be trimmed again, which can be directly used in subsequent part manufacturing processes, reducing waste and working hours. Secondly, due to the avoidance of improper deformation of the material, the preform fits better in the mold, which helps to control the size accuracy of the final component and reduces the uneven resin infusion or solidification deformation caused by the size error of the preform. Finally, the dust and fiber debris generated during the cutting process are also greatly reduced, improving the working environment and reducing the risk of fine particle pollution of the interlaminar interface.

[0039] As a preferred, in addition to the inner concave curved surface, for the cutting of preforms of complex components such as outward convex curved surface, S-shaped elbow, special-shaped reinforcing rib, etc., only need to adaptively define the α and β parameters and adjust the tilt angle, so that the tool body 1 can adapt to different cutting methods.

[0040] When the surface to be cut is a plane, usually four groups of planes with internal right angles, the maximum angle between the tool body 1 axis and the direction perpendicular to the cutting table is α / 2, so that the tip of the cutting edge 11 can be fitted with the edge angle when the cutting edge 11 moves to the internal right angle, and the internal walls of the quadrilateral can maintain 90° perpendicularity.

[0041] The surface of the cutting edge 11 is fitted with the plane of the position to be cut, making the cutting process smoother. When the cutting table is perpendicular to the tool body 1 axis at the middle position of the cutting plane, the transition extrusion to the cutting surface can be reduced by the swing of the tool body 1 axis, so that the cutting surface can be smoother, the step difference can be avoided, and the cutting quality can be improved.

[0042] Obviously, the above embodiments of the present application are merely exemplary but not intended to limit the embodiments of the present application. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. It is not necessary or possible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for ultrasonic cutting of preformed composite materials, characterized in that, Includes the following steps: 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); 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.

2. The ultrasonic cutting method for preforming composite materials according to claim 1, characterized in that, When the cutting surface is an arc surface, the maximum angle between the axis of the blade (1) and the direction perpendicular to the cutting table is greater than α / 2.

3. The ultrasonic cutting method for preforming composite materials according to claim 2, characterized in that, When the surface being cut is a concave arc surface, the cutting edge (11) is parallel to the tangent of the arc surface at the cutting position.

4. The ultrasonic cutting method for preforming composite materials according to claim 2, characterized in that, When the blade body (1) is in the middle position of the arc-shaped surface, the axis of the blade body (1) is perpendicular to the cutting table.

5. The ultrasonic cutting method for preforming composite materials according to claim 1, characterized in that, When the surface being cut is a plane, the maximum angle between the axis of the blade (1) and the direction perpendicular to the cutting table is α / 2.

6. The ultrasonic cutting method for preforming composite materials according to claim 5, characterized in that, The blade (11) is in contact with the plane of the cutting position.

7. The ultrasonic cutting method for preforming composite materials according to claim 5, characterized in that, When the blade (1) is in the middle position of the plane, the axis of the blade is perpendicular to the cutting table.

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