High-efficiency copy milling cutter for curved surface machining

Abstract

The application discloses a high-efficiency copy milling cutter for curved surface machining, which comprises a handle part and a blade part, the handle part is located at the tail end of the cutter, the blade part is located at the front end of the cutter, the handle part is in the shape of a cylinder, and the cylinder radius is the cutter radius. The application is different from the traditional ball-end milling cutter in the end blade part rotary surface structure, the effective cutting width is larger, the effective cutting radius is larger, the effective cutting linear velocity is larger, and the end blade axial length is smaller, so the application is suitable for machining small-curvature flat curved surfaces. The increase of the effective cutting width improves the instantaneous material removal rate of the cutter, improves the machining efficiency and machining quality of the cutter. The increase of the effective cutting linear velocity improves the workpiece surface quality. The reduction of the end blade axial length can reduce the vibration generation in the milling machining, reduce the spindle load, improve the cutter life, and improve the machining surface quality.

Description

Technical Field

[0001] The invention belongs to the technical field of profiling tools, and in particular relates to a high-efficiency profiling milling cutter for curved surface processing. Background Art

[0002] In the current field of mechanical processing, high-quality and efficient processing of mold surfaces has always been an important part of the technical challenge. The design of traditional ball-end milling cutters often focuses on their adaptability and versatility, and it is difficult to meet the requirements of actual processing for processing efficiency and processing quality. During milling, the ball-end milling cutter has low cutting efficiency and is prone to processing errors, which affects the processing quality. At the same time, the low effective cutting linear speed of the ball-end milling cutter is also one of the key factors affecting its cutting performance. The effective cutting linear speed directly determines the tool's ability to remove material per unit time, and when processing small curvature flat surfaces, the low effective cutting linear speed will also lead to a decrease in the quality of the processed surface, and even cause tool failure phenomena such as tool breakage and chipping.

[0003] Therefore, in view of the problems faced by ball end mills, it is necessary to propose and design a tool with high quality and high efficiency to solve the above problems. Summary of the Invention

[0004] The object of the present invention is to provide a high-efficiency profile milling cutter for curved surface machining to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a high-efficiency contour milling cutter for curved surface processing, comprising a shank portion and a blade portion, wherein the shank portion is located at the end of the tool, and the blade portion is located at the front end of the tool, the shank portion is in the shape of a cylinder, and the radius of the cylinder is the radius of the tool, and the blade portion comprises two parts, a peripheral blade portion and an end blade portion, and the rotating surface of the peripheral blade portion is a cylindrical surface.

[0006] Preferably, the blade portion includes an end blade portion rotation surface and a peripheral blade portion rotation surface, and multiple cutting edges are evenly distributed around the peripheral blade portion rotation surface. The peripheral blade portion cutting edges extend spirally along the tool axis in a constant lead manner to the end of the peripheral blade portion rotation surface; the rotation surface of the end blade portion is a parametric surface, and the same number of constant lead cutting edges as the peripheral blade portion are distributed around it.

[0007] Preferably, the end blade portion rotation surface is tangentially connected to the peripheral blade portion rotation surface, and the end blade portion cutting edge and the peripheral blade portion cutting edge on the rotation surface are smoothly tangentially connected and spirally extend along the axis to the apex of the end blade portion rotation surface.

[0008] Preferably, the end blade portion rotation surface includes an end blade portion rotation generatrix rotated around the tool axis, and the end blade portion rotation generatrix, the end blade portion rotation surface and the end blade portion cutting edge equation are all constructed under the tool coordinate system O-XYZ. The tool coordinate system O-XYZ construction process is as follows: the vertex of the end blade portion rotation surface is used as the tool coordinate system origin O, the tool axis is used as the coordinate system Z axis, the direction of the end blade portion vertex pointing to the tool handle is used as the positive direction of the Z axis, the starting direction of the end blade portion cutting edge at the vertex is used as the X axis direction, and the Y axis direction conforms to the right-hand rule. The end blade portion rotation generatrix equation is constructed in the XOZ plane as follows:

[0009]

[0010] Where x and z are the coordinates of the points on the end cutting edge rotation generatrix of the XOZ surface, the tool parameter θ is the angle parameter of the end cutting edge rotation generatrix, and the tool parameters a and b are the width parameter and height parameter of the end cutting edge rotation generatrix, respectively.

[0011] Preferably, the end blade portion rotation generatrix rotates around the tool axis to form an end blade portion rotation surface, and the equation of the end blade portion rotation surface in the tool coordinate system is:

[0012]

[0013] Where x1, y1 and z1 are the coordinates of the points on the rotating surface of the end blade. It is the angle between the radial line of the point on the end blade rotation surface and the XOZ plane,

[0014] Preferably, the rotary surface of the tool end blade changes with the change of tool parameters a and b. The tool parameter a is determined by the tool radius R, and the tool parameter b is determined by the axial length D of the tool end blade. The expression is as follows:

[0015] Preferably, the axial length D of the end cutting edge is smaller than the tool radius R.

[0016] Preferably, the cutting edge equation of the end cutting edge is:

[0017]

[0018] The cutting edge equation of the peripheral edge is:

[0019] Where u is the tool parameter, which is determined by the axial length D of the tool end edge and the axial length L of the peripheral edge, β is the helix angle of the peripheral cutting edge, x2, y2 and z2 are the coordinates of the points on the end edge, and x3, y3 and z3 are the coordinates of the points on the peripheral cutting edge.

[0020] Compared with the prior art, the technical effects and advantages of the present invention are as follows: the high-efficiency contour milling cutter for curved surface processing has a rotary surface structure of the end blade that is different from that of the traditional ball-end milling cutter, and has a larger effective cutting width and an effective cutting radius R e The effective cutting speed is larger and the axial length D of the end edge is smaller, which is suitable for processing small curvature flat surfaces. e The increase in the tool's instantaneous material removal rate increases tool processing efficiency and quality. The increase in effective cutting speed improves the surface quality of the workpiece. The reduction in the axial length of the end cutting edge reduces vibration during milling, reduces spindle load, increases tool life, and improves surface quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A comparison diagram of the rotary generatrix of a high-efficiency profiling milling cutter and a ball-end milling cutter for machining mold curved surfaces according to the present invention;

[0022] Figure 2 This is a numerical simulation diagram of the rotary surface of a high-efficiency contour milling cutter for mold curved surface processing according to the present invention;

[0023] Figure 3 This is a numerical simulation diagram of the cutting edge of a high-efficiency contour milling cutter for machining mold curved surfaces according to the present invention;

[0024] Figure 4 This is a front view of the overall structure of a high-efficiency contour milling cutter for machining mold curved surfaces according to the present invention;

[0025] Figure 5 This is a side view of the overall structure of a high-efficiency contour milling cutter for machining mold curved surfaces according to the present invention;

[0026] Figure 6 This is a cross-sectional view of the end edge portion AA of a high-efficiency copy milling cutter for machining mold curved surfaces according to the present invention;

[0027] Figure 7 This is a BB cross-sectional view of the peripheral blade portion of a high-efficiency profiling milling cutter for machining mold curved surfaces according to the present invention.

[0028] In the figure: 1. Tool; 2. Shank; 3. Blade; 3-1. End blade; 3-2. Circumferential blade; 3-3. First flank surface of end blade; 3-4. Second flank surface of end blade; 3-5. First flank surface of circumferential blade; 3-6. Second flank surface of circumferential blade; 3-7. Spiral groove; 4. Tool axis; 5. Rotational generatrix of the blade of a high-efficiency contour milling cutter for machining mold curved surfaces; 6. Rotational generatrix of the blade of a ball-end milling cutter; 7. Rotational surface of the end blade; 8. Rotational surface of the circumferential blade. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] See also Figure 1-7 The present invention provides a technical solution: a high-efficiency profiling milling cutter for machining mold curved surfaces. In this embodiment, the tool material selected is cemented carbide. Cemented carbide has high hardness, good bending strength, and good impact toughness, making it one of the preferred tool materials. The tool radius R is 5mm, the tool length is 75mm, and the tool shank portion 2 and the blade portion 3 are located at the end of the tool 1. The shank portion 2 is in the shape of a cylinder, and the cylinder radius R is the tool radius R. The blade portion 3 is located at the front end of the tool 1 and includes: an end blade portion 3-1 and a peripheral blade portion 3-2. The peripheral blade portion 3-2 has a cylindrical rotating surface with multiple cutting edges evenly distributed around it. The cutting edges spirally extend along the tool axis 4 to the end of the peripheral blade portion rotating surface 8. The end blade portion 3-1 has an end blade portion rotating surface 7 that is a parametric surface with the same number of equal-lead cutting edges evenly distributed around it as the peripheral blade portion 3-2.

[0031] The end blade rotation surface 7 is formed by rotating the end blade rotation generatrix 5 around the tool axis 4. The end blade rotation generatrix 5, the end blade rotation surface 7 and the end blade 3-1 cutting edge equation are all constructed in the tool coordinate system. The equation of the end blade rotation generatrix 5 is as follows:

[0032]

[0033] The end blade rotation generatrix 5 rotates around the tool axis 4 to form an end blade rotation surface 7. The equation of the end blade rotation surface 7 in the tool coordinate system is: The tool end edge rotation surface 7 changes with the tool parameters a and b. The tool parameter a is determined by the tool radius R, and the tool parameter b is determined by the axial length D of the tool end edge. The expression is as follows:

[0034] The end cutting edge rotating surface 7 has an axial length D of less than the tool radius R. The cutting edge equation of the end cutting edge 3-1 is:

[0035]

[0036] The cutting edge equation of the peripheral edge portion 3-2 is:

[0037]

[0038] The helix angle β ranges from 30° to 60°. In this embodiment, β is 45°. A larger helix angle of the tool is beneficial to chip discharge.

[0039] Combine Figure 1 This embodiment is explained. In this embodiment, the axial length D of the end blade is 4mm. Under the premise of ensuring the maximum processing depth of the tool, the effective cutting linear speed of the tool is increased and the wear near the tool tip is reduced. Substituting the axial length D of the end blade and the tool radius R = 5mm into the expression of tool parameters a and b, the tool parameters a = 7.27mm and b = 10.08mm are obtained. The numerical simulation of the rotating surface and cutting edge of the blade portion 3 is carried out. The simulation results are as follows: Figure 2 and Figure 3 shown.

[0040] like Figure 1 It can be seen that when this embodiment is adopted, the effective cutting radius R of the profile milling cutter of the present invention is e >Effective cutting radius R b , axial length of the end blade D <R。

[0041] Combine Figure 2 and Figure 3 To illustrate this embodiment, the revolving surface of the end blade portion 3-1 is tangentially connected to the revolving surface of the peripheral blade portion 3-2, and the cutting edge of the end blade portion 3-1 is smoothly tangentially connected to the cutting edge of the peripheral blade portion 3-2, extending helically along the tool axis 4 to the vertex of the end blade portion revolving surface 7. The smooth tangential connection between the revolving surface of the blade portion 3 and the cutting edge ensures a smooth cutting process and ensures machining quality.

[0042] Combine Figure 4-7 The geometric parameters of the tool structure are explained. The cutting performance of the high-efficiency contour milling cutter for mold curved surface processing is also closely related to the tool geometric structure. The geometric parameters of the tool end blade 3-1 include: end blade rake angle γ, tool chip groove 3-7, end blade first clearance angle α1 and end blade second clearance angle α2. The end blade first clearance angle α1 corresponds to the end blade first clearance surface 3-3, and the end blade second clearance angle α2 corresponds to the end blade second clearance surface 3-4.

[0043] The range of the end edge rake angle γ is 5° to 30°. In this embodiment, the end edge rake angle γ is 15°. Selecting a larger rake angle can reduce the deformation and friction of the chips. The range of the first clearance angle α1 of the end edge and the second clearance angle α2 of the end edge are 0° to 30°. In this embodiment, the first clearance angle α1 of the end edge and the second clearance angle α2 of the end edge are 15° and 25° respectively. Selecting a larger clearance angle can reduce the wear of the flank and increase the sharpness of the cutting edge. The number of chip grooves is usually 2 to 6. In this embodiment, the tool 1 has 2 chip grooves. Fewer chip grooves are conducive to the discharge of chips.

[0044] The geometric parameters of the peripheral blade portion 3-2 include: peripheral blade rake angle u, peripheral blade first clearance angle v1, peripheral blade second clearance angle v2, and the corresponding peripheral blade first clearance surface 3-5 and peripheral blade second clearance surface 3-6. The peripheral blade rake angle u ranges from 5° to 30°. In this embodiment, the peripheral blade rake angle u is 15°. Selecting a larger rake angle can reduce chip deformation and friction. The peripheral blade first clearance angle v1 and the peripheral blade second clearance angle v2 range from 0° to 30°. In this embodiment, the peripheral blade first clearance angle v1 and the peripheral blade second clearance angle v2 are 15° and 25°, respectively. Selecting a larger clearance angle can reduce flank wear and increase cutting edge sharpness.

[0045] Specifically, when in use, the high-efficiency copy milling cutter for mold curved surface processing of the present invention is installed in a three-axis linkage CNC milling machine or a five-axis linkage CNC milling machine.

[0046] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-efficiency contour milling cutter for curved surface machining, comprising a shank portion (2) and a blade portion (3), characterized in that: The shank portion (2) is located at the end of the tool (1), and the blade portion (3) is located at the front end of the tool (1). The shank portion (2) is in the shape of a cylinder, and the radius of the cylinder is the radius R of the tool (1). The blade portion (3) includes two parts, a peripheral blade portion (3-2) and an end blade portion (3-1). The rotating surface of the peripheral blade portion (3-2) is a cylindrical surface. The blade portion (3) includes an end blade portion rotating surface (7) and a peripheral blade portion rotating surface (8). A plurality of cutting edges are evenly distributed around the peripheral blade portion rotating surface (8). The cutting edge of the peripheral blade portion (3-2) extends spirally along the tool axis (4) in a constant lead manner to the end of the peripheral blade portion rotating surface (8); the rotating surface of the end blade portion (3-1) is a parametric surface, and the same number of constant lead cutting edges as the peripheral blade portion (3-2) are distributed around the parametric surface. The end blade rotation surface (7) includes an end blade rotation generatrix (5) formed by rotating around the tool axis (4). The end blade rotation generatrix (5), the end blade rotation surface (7) and the end blade (3-1) cutting edge equation are all constructed under the tool coordinate system O-XYZ. The tool coordinate system O-XYZ construction process is as follows: the vertex of the end blade rotation surface (7) is used as the tool coordinate system origin O, the tool axis (4) is used as the coordinate system Z axis, the direction of the end blade (3-1) vertex pointing to the tool handle (2) is used as the Z axis positive direction, the starting direction of the end blade (3-1) cutting edge at the vertex is used as the X axis direction, and the Y axis direction conforms to the right-hand rule. The end blade rotation generatrix (5) equation is constructed in the XOZ plane as follows: Where x and z are the coordinates of the point on the XOZ surface end blade rotation generatrix (5), the tool parameter θ is the angle parameter of the end blade rotation generatrix (5), and the tool parameters a and b are the width parameter and height parameter of the end blade rotation generatrix (5), respectively. The end blade portion rotation generatrix (5) rotates around the tool axis (4) to form an end blade portion rotation surface (7). The equation of the end blade portion rotation surface (7) in the tool coordinate system is: Where x1, y1 and z1 are the coordinates of the point on the end blade rotation surface (7), is the angle between the radial line of a point on the end blade rotation surface (7) and the XOZ plane; The tool end blade rotation surface (7) changes with the changes in tool parameters a and b. The tool parameter a is determined by the tool radius R, and the tool parameter b is determined by the axial length D of the tool end blade. The expression is as follows:

2. The high-efficiency copy milling cutter for curved surface machining according to claim 1, characterized in that: The end blade portion revolving surface (7) is tangentially connected to the peripheral blade portion revolving surface (8), and the cutting edge of the end blade portion (3-1) and the cutting edge of the peripheral blade portion (3-2) on the revolving surface are smoothly tangentially connected and spirally extend along the axis (4) to the vertex of the end blade portion revolving surface (7).

3. The high-efficiency copy milling cutter for curved surface machining according to claim 1, characterized in that: The axial length D of the end cutting edge (3-1) is smaller than the tool radius R.

4. The high-efficiency copy milling cutter for curved surface machining according to claim 1, characterized in that: The cutting edge equation of the end edge portion (3-1) is: The cutting edge equation of the peripheral edge (3-2) is: Where u is the tool parameter, which is determined by the axial length D of the tool end edge and the axial length L of the peripheral edge, β is the helix angle of the cutting edge of the peripheral edge (3-2), x2, y2 and z2 are the coordinates of the point on the cutting edge of the end edge (3-1), and x3, y3 and z3 are the coordinates of the point on the cutting edge of the peripheral edge (3-2).

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