Negative rake angle micro-texture cutting tool

Abstract

The invention belongs to the field of cutting machining, and discloses a negative front angle micro-texture cutter which can greatly reduce the under-plane damage distance of a CFRP (Carbon Fiber Reinforced Plastics) preset machining surface during cutting machining, obviously reduce the abutting influence on a nearby carbon fiber strip and avoid debonding of a matrix and / or breakage of carbon fibers, so that the service life of the CFRP is obviously prolonged. The micro-texture is located on the front cutter face and provided with a micro-texture groove, the micro-texture groove is provided with a bending part, a top stopping face and a cutting part which are sequentially continuous, the micro-texture is continuous with the rear cutter face through the main cutting edge, the cutting part is parallel to the main cutting edge, and when the cutter conducts cutting machining in the cutting direction, burr strips generated by machining of the preset machining face enter the micro-texture groove, and the burr strips are cut off. The burr strip is bent by the bending part, so that the connection strength of the burr strip is reduced, and then the burr strip is cut off by the cutting part.

Description

Technical Field

[0001] The invention belongs to the field of cutting processing, and in particular relates to a negative rake angle micro-texture cutting tool. Background Art

[0002] CFRP (Carbon Fiber Reinforced Polymer, the same below) is a two-phase composite material with high specific strength and high specific modulus carbon fiber as the reinforcement phase and anti-fatigue and corrosion-resistant resin as the matrix phase. It is widely used in various fields such as aerospace, military, and medical.

[0003] Carbon fiber reinforced composite materials are typical difficult-to-process materials due to their high hardness, high strength, and poor thermal conductivity. The surface quality of the workpiece after processing is poor and the tool wear is serious. Among them, the reinforcement phase is formed by the superposition of multiple carbon fiber layers, and the adjacent fiber orientation angles are different, so that the overall CFRP has good tensile and compressive properties in all directions. These fiber orientation angles are divided into four types: 0°, 45°, 90°, and 135°. Therefore, for the same cutting process, the maximum number of fiber orientation angles that can be matched is four.

[0004] Thus, if Figures 1 to 4 As shown in the figure, due to the different mutual forces generated by the cutting force under the working conditions of four fiber orientation angles, different mutual forces correspond to different subsurface damage distances. When the fiber orientation angle is 135°, the subsurface damage distance is the largest, and the impact of burrs and debris on the nearby carbon fiber strips is the most obvious, which can easily lead to debonding of the matrix and / or breakage of the carbon fiber, thereby reducing the service life of CFRP. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a negative rake angle micro-texture cutting tool, which can greatly reduce the subsurface damage distance of the predetermined processing surface of CFRP during cutting, and significantly reduce the impact of the top impact on the nearby carbon fiber strips, avoiding debonding of the matrix and / or breakage of the carbon fiber, thereby significantly increasing the service life of CFRP.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A negative rake angle micro-texture cutting tool, wherein the rake angle surface and the back angle surface intersect to form a main cutting edge, the main cutting edge is used to cut a predetermined processing surface of CFRP, and is characterized in that: wherein the rake angle of the cutting tool is a negative value, the micro-texture is located on the rake face, and has a micro-texture groove, the micro-texture groove has a bending portion, a top stop surface and a cutting portion that are continuous in sequence, the micro-texture is continuous with the back face through the main cutting edge, and the cutting portion is parallel to the main cutting edge, when cutting, the burr strip generated by the processing enters the micro-texture groove, the bending portion bends the burr strip, and then the cutting portion cuts the burr strip.

[0008] Preferably, the micro-texture groove also has a wedge-shaped surface in the groove, the wedge-shaped surface in the groove, the bending portion, the top stop surface and the cutting portion are continuous in sequence, the wedge-shaped surface in the groove is inclined toward the main cutting edge and is closest to the main cutting edge, there are multiple micro-texture grooves, and the multiple micro-texture grooves are distributed in sequence through the cutting portion, so that the micro-texture is a multi-tooth serrated type extending toward the predetermined processing surface.

[0009] Furthermore, the cutting portion is a linear edge and all the cutting portions are parallel to each other, the main cutting edge and all the cutting portions are located in the plane where the front cutting surface is located, the bending portion is bent at an acute angle, and the extension length of the micro texture is less than or equal to the maximum feed amount of the cutting tool.

[0010] Furthermore, the micro-texture grooves of the micro-textured edge are continuous with the rake face at a right angle through the cut-off portion.

[0011] Furthermore, the cross-section of the micro-textured groove is a right triangle, and the base-to-height ratio is 2:1.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. Because the front angle of the cutting blade of the present invention is a negative value, the micro-texture is located on the front blade surface, the micro-texture has a micro-texture groove, the micro-texture groove has a bending portion, a top stop surface and a cutting portion that are continuous in sequence, the micro-texture is continuous with the back blade surface through the main cutting edge, and the cutting portion is parallel to the main cutting edge. When the cutting blade cuts along the cutting direction, the burr strips generated by machining the predetermined machining surface enter the micro-texture grooves, the bending portion bends the burr strips, thereby reducing the connection strength of the burr strips, and then the cutting portion cuts off the burr strips, so that no matter what fiber direction angle is used, the length of the generated burr strips can be greatly shortened and become easier to break, so that on the one hand, the shorter burr strips correspond to shorter subsurface damage distances, and on the other hand, shorter and more fragile burr chips have less impact on the impact of the nearby elastic fiber strips. Therefore, the present invention can greatly reduce the subsurface damage distance of the predetermined machining surface of CFRP during cutting, and significantly reduce the impact of the impact on the nearby carbon fiber strips, avoid debonding of the matrix and / or breakage of the carbon fiber, thereby significantly increasing the service life of CFRP.

[0014] 2. Because the micro-texture groove of the present invention also has a wedge-shaped surface in the groove, the wedge-shaped surface in the groove, the bending portion, the top stop surface and the cutting portion are continuous in sequence, the wedge-shaped surface in the groove is inclined toward the main cutting edge and is closest to the main cutting edge, there are multiple micro-texture grooves, and the multiple micro-texture grooves are continuously distributed in sequence through the cutting portion, so that the micro-texture is a multi-tooth sawtooth type extending toward the predetermined processing surface. In the continuous process of the cutting tool cutting along the cutting direction, the burr strip is conveniently and centrally introduced into the bending portion for bending through the wedge-shaped surface in the groove, and the multiple micro-texture grooves can cut the burr strip into multiple sections of burr short strips, and each section of the burr short strip is easy to break, and the fragile burr short strip slides down through the wedge-shaped surface in the groove. Since the burr short strip is smaller in size and lighter in weight, it overflows from the front cutting surface of the cutting portion of the micro-texture groove at both ends under the obstruction of the carbon fiber layer in the cutting direction. Therefore, the present invention further avoids debonding of the matrix and / or breakage of the carbon fiber, thereby increasing the service life of the CFRP.

[0015] 3. Because the cutting portion of the present invention is a linear blade and all the cutting portions are parallel to each other, and the main cutting edge and all the cutting portions are located in the plane where the front blade face is located, the bending portion is bent at an acute angle, and the extension length of the micro-texture is less than or equal to the maximum feed amount of the cutting tool. Therefore, the present invention can not only more conveniently cut the burr strip into multiple sections through multiple cutting portions in the same plane, but also take into account the structural strength of the front blade face of the cutting tool and the optimal implementation of the micro-texture for the extension length of the micro-texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the contact interface formed between the cutting tool and the CFRP surface when the limiting direction angle is 0°;

[0017] Figure 2 Schematic diagram of the contact interface formed between the cutting tool and the CFRP surface when the limiting direction angle is 45°;

[0018] Figure 3 Schematic diagram of the contact interface formed between the cutting tool and the CFRP surface when the limiting direction angle is 90°;

[0019] Figure 4 Schematic diagram of the contact interface formed between the cutting tool and the CFRP surface when the limiting direction angle is 135°;

[0020] Figure 5 is a schematic diagram of a negative rake angle micro-textured cutting tool according to an embodiment of the present invention;

[0021] Figure 6 for Figure 5 A partial schematic diagram of the middle part;

[0022] Figure 7 for Figure 6 Side view of

[0023] Figure 8 The first cutting process of the negative rake angle micro-texture cutting tool of the embodiment of the present invention;

[0024] Fig. 9 This is the second cutting process of the negative rake angle micro-texture cutting tool according to an embodiment of the present invention.

[0025] In the figure: 10, negative rake angle micro-texture cutting tool, D1, cutting direction, 1, rake angle surface, α, rake angle, 2, back angle surface, 2a, main cutting edge, β, back angle, 3, micro texture, 31, micro texture groove, 311, wedge surface in the groove, D2, knife thickness direction, 312, bending part, 313, top stop surface, 314, cutting part, P, blade cutting surface, S, predetermined processing surface, C, burr strip, C1, burr short strip. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following examples and drawings specifically illustrate the negative rake angle micro-texture cutting tool of the present invention. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0027] like Figure 5 As shown, the negative rake angle micro-texture cutting blade 10 in this embodiment, specifically, the negative rake angle micro-texture cutting blade 10 has a blade thickness direction D.

[0028] like Figure 6 and Figure 7 As shown, the negative rake angle micro-texture cutting tool 10 has a rake angle surface 1, a back angle surface 2 and a micro-texture 3. The rake angle surface 1 and the back angle surface 2 intersect to form a main cutting edge 2a. The main cutting edge 2a is used to cut the predetermined processing surface S of the CFRP along the cutting direction D1. Specifically, the rake angle surface 1 is continuous with the micro-texture 3 and the back angle surface 2. In this embodiment, the main cutting edge 2a is a cutting edge with a bending radius of 3um.

[0029] The rake angle α of the negative rake angle micro-texture cutting tool 10 is a negative value. The micro-texture 3 is located on the rake face 1 . The micro-texture 3 has micro-texture grooves 31 . In this embodiment, the rake angle α is -5°.

[0030] There are multiple micro-texture grooves 31, which are continuously distributed in sequence through the cutting portion toward the predetermined processing surface, and the extension length of the micro-texture 31 is less than or equal to the maximum feed amount of the cutting tool 31 in the CFRP. In this embodiment, there are three micro-texture grooves 31.

[0031] The micro-textured groove 31 has a groove inner wedge surface 311 , a bending portion 312 , a top stop surface 313 and a cut-off portion 314 which are continuous in sequence.

[0032] The cross-section of the micro-texture groove 31 along the knife thickness direction D2 is a right triangle, and the base-to-height ratio is 2:1. Specifically, the micro-texture groove 31 is formed by laser burning. The bottom of the right triangle corresponds to the slot width of the micro-texture groove 31, and the height corresponds to the deepest depth of the micro-texture groove 31. In the present embodiment, the slot width of the micro-texture groove 31 is 40um, and the deepest depth is 20um.

[0033] The groove wedge surface 311 of each micro-textured groove 31 is inclined toward the main cutting edge 2 a and is closest to the main cutting edge 2 a.

[0034] The bending portion 312 is bent at an acute angle. Specifically, the bending extension direction of the bending portion 312 is the blade thickness direction D2. Specifically, the bending radius of the bending portion 312 is 3 um, which is approximately equivalent to a straight line extending along the blade thickness direction D2.

[0035] Specifically, the top stop surface 313 corresponds to a right-angled side of the right-angled triangle of the cross section of the micro-textured groove 31 .

[0036] The cutting portion 314 is a linear edge along the blade thickness direction D2, and the cutting portion 314 is parallel to the main cutting edge 2a, all the cutting portions 314 are parallel to each other, and the main cutting edge 2a and all the cutting portions 314 are located in the plane where the rake face 1 is located. Specifically, the plane where the rake face 1 is located is Figure 7 As shown in the blade cutting surface P, in this embodiment, the cutting portion 314 extends along the blade thickness direction D2, and the cutting portion 314 is a cutting edge line with a bending radius of 3um.

[0037] The micro-texture groove 31 at one end edge of the micro-texture 3 is continuous with the rake face 1 at right angles via the cut portion 314 of the micro-texture groove 31 , and the groove inner wedge surface 311 of the micro-texture groove 31 at the other end edge of the micro-texture 3 is continuous with the flank face 2 via the main cutting edge 2 a .

[0038] The plurality of micro-texture grooves 31 are sequentially and continuously distributed through the cut portion 314 , so that the micro-texture 3 has a multi-tooth sawtooth shape extending toward the predetermined processing surface S.

[0039] The cutting process of the negative rake angle micro-texture cutting tool 100 is described below in conjunction with an embodiment:

[0040] like Figure 8 As shown, cutting process one: when the negative rake angle micro-texture cutting tool 100 cuts the predetermined processing surface S along the cutting direction D1, the negative rake angle micro-texture cutting tool 100 and the predetermined processing surface S move relative to each other, so that the portion cut off by the main cutting edge 2a on the predetermined processing surface S forms a burr strip C. Under the action of the chip force, the burr strip C will bend toward the inside of the micro-texture groove 31, thereby entering the micro-texture groove 31 through the local guidance of the wedge surface 311 in the groove, and finally being stopped by the stop surface 313.

[0041] like Fig. 9 As shown, cutting process 2: the negative rake angle micro-texture cutting tool 100 and the predetermined processing surface S continue to move relative to each other, and the burr strip C is divided into multiple segments and continues to penetrate into the interior of the micro-texture groove 31, and is restricted by the bending portion 312 to form a bend, so that the connection strength of the burr strip C is weakened, and it becomes easy to break. At this time, all the cutting portions 314 simultaneously form a cutting of the burr strip C, and the burr strip C is cut into multiple burr short strips C1. At the same time, the vibration generated by the cutting will cause the burr short strip C1 with weakened connection strength to break again. In each micro-texture groove 31, the burr The short strip C1 or the broken burr short strip C1 slides along the wedge surface 311 in the groove to the intersection of the cut-off portion 314 and the contact interface. Because the burr short strip C1 or the broken burr short strip C1 is smaller in volume and lighter in weight, it overflows from the two ends of the cut-off portion 314 of the micro-textured groove 31 along the blade thickness direction D2 to the front blade surface 1 under the obstruction of the carbon fiber layer in the cutting direction D1, that is, the contact interface. Specifically, the surface of the CFRP to be cut is uneven, and the thickness of the CFRP to be cut is equal to the thickness of the burr strip C, but for the convenience of display and explanation, Figure 8 and Fig. 9 The surface of the CFRP in FIG. 1 is roughly drawn as a plane, and in order to highlight the relevant features of the burr strip C, the thickness of the burr strip C is shown to be much smaller than the thickness of the CFRP to be cut.

[0042] The above-mentioned implementation modes are preferred cases of the present invention and are not used to limit the protection scope of the present invention. Various deformations or modifications that can be made by ordinary technicians in this field without creative work within the scope of the attached claims are still within the protection scope of this patent.

Claims

1. A negative rake angle micro-textured cutting tool, wherein the rake angle surface and the back angle surface intersect to form a main cutting edge, and the main cutting edge is used to cut a predetermined processing surface of CFRP, characterized in that: in, The front angle of the cutting blade is a negative value, the micro-texture is located on the front blade face, and has a micro-texture groove. The micro-texture groove has a bending portion, a top stop surface and a cutting portion that are continuous in sequence. The micro-texture is continuous with the back blade face through the main cutting edge, and the cutting portion is parallel to the main cutting edge. When cutting, the burr strip generated by the processing enters the micro-texture groove, the bending portion bends the burr strip, and then the cutting portion cuts off the burr strip.

2. The negative rake angle micro-textured cutting tool according to claim 1, characterized in that: in, The micro-textured groove further comprises a groove inner wedge surface, wherein the groove inner wedge surface, the bending portion, the top stop surface and the cutting portion are sequentially continuous, and the groove inner wedge surface is inclined toward the predetermined main cutting edge and is closest to the predetermined main cutting edge. The number of the micro-texture grooves is multiple, and the multiple micro-texture grooves are sequentially and continuously distributed through the cutting portion, so that the micro-texture is in a multi-tooth sawtooth shape extending toward a predetermined processing surface.

3. The negative rake angle micro-textured cutting tool according to claim 2, characterized in that: in, The cutting portion is a linear edge and all the cutting portions are parallel to each other, the main cutting edge and all the cutting portions are located in the plane where the front cutting surface is located, the bending portion is bent at an acute angle, and the extension length of the micro texture is less than or equal to the maximum feed amount of the cutting tool.

4. The negative rake angle micro-textured cutting tool according to claim 3, characterized in that: in, The micro-texture grooves of the micro-textured edge are continuous with the rake face at a right angle through the cut-off portion.

5. The negative rake angle micro-textured cutting tool according to claim 3, characterized in that: in, The cross section of the micro-textured groove is a right triangle, and the base-to-height ratio is 2:1.

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