End mill

Abstract

The utility model provides an end mill, which belongs to the technical field of milling cutters and comprises a connecting part and a cutting part which are connected, the cutting part comprises a cylinder, side blades and a bottom blade, one end of the cylinder is coaxially connected with the connecting part, the side blades and the bottom blade are provided with wear-resistant coatings, the side blades are spirally arranged on the outer circumference of the cylinder at intervals, and first chip flutes are arranged between the side blades. The side edge comprises a first main cutting edge and a side edge front tool face and a side edge rear tool face which are located on the two sides of the first main cutting edge, the side edge rear tool face comprises a first rear tool face and a second rear tool face, the bottom edges are arranged on the end face of the other end of the cylinder at intervals, and a second chip containing groove communicated with the first chip containing groove is formed between the bottom edges. The bottom edge comprises a second main cutting edge and a bottom edge front tool face and a bottom edge rear tool face which are located on the two sides of the second main cutting edge, the bottom edge rear tool face comprises a third rear tool face and a fourth rear tool face, and an auxiliary cutting edge is formed between the third rear tool face and the fourth rear tool face. The rigidity, the wear resistance, the machining precision and the stability of the end mill can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of milling cutters, in particular to an end milling cutter. Background Art

[0002] An end mill is a milling cutter widely used on CNC machine tools. It has cutting edges on both the cylindrical surface and the end face, which can be used for cutting simultaneously or separately. It is mainly used for operations such as plane milling, groove milling, step milling and profile milling.

[0003] In the prior art, end mills often have unreasonable structural designs, resulting in insufficient hardness and strength of the tool, and the blade is prone to chipping and rapid wear, which reduces the processing accuracy and stability and shortens the service life of the tool. Utility Model Content

[0004] Based on this, the purpose of the present invention is to provide an end milling cutter, which aims to improve the hardness and strength of the end milling cutter through structural optimization, and improve the service life, processing accuracy and processing stability.

[0005] To achieve the above-mentioned purpose, the utility model provides an end mill, comprising a connected connecting portion and a cutting portion, the cutting portion having a base surface, a cutting plane, and a reference plane, the cutting portion comprising a cylinder, a plurality of side blades, and a plurality of bottom blades, the cylinder having a first end and a second end, the first end being coaxially connected to the connecting portion, a plurality of side blades being spirally arranged on the outer circumference of the cylinder at intervals, a first chip groove being provided between adjacent side blades, the side blade comprising a first main cutting edge and a side blade rake face and a side blade flank face located on both sides of the first main cutting edge, the side blade flank face comprising a first flank face and a second flank face connected to each other, the angle between the side blade rake face and the base surface is 11° to 13°, the angle between the first flank face and the cutting plane is 11° to 13°, the angle between the second flank face and the cutting plane is 24° to 26°, the side blades are provided with a wear-resistant coating, and the plurality of said The bottom blade is arranged on the end face of the second end at intervals, the positions of the bottom blade and the side blade correspond, a second chip groove is provided between adjacent bottom blades, the second chip groove is connected to the first chip groove, the bottom blade includes a second main cutting edge and a bottom blade front blade face and a bottom blade back blade face located on both sides of the second main cutting edge, the bottom blade back blade face includes a third back blade face and a fourth back blade face connected to each other, a secondary cutting edge is formed between the third back blade face and the fourth back blade face, the angle between the second main cutting edge and the reference plane is 1°~3°, the angle between the secondary cutting edge and the reference plane is 2.5°~3°, the angle between the bottom blade front blade face and the reference plane is 5°~7°, the angle between the third back blade face and the reference plane is 9°~11°, and the angle between the fourth back blade face and the reference plane is 22°~24°, wherein the reference plane is a plane perpendicular to the central axis of the cylinder, and the bottom blade is provided with a wear-resistant coating.

[0006] The beneficial effects of the present invention include at least: by optimizing the structural parameter design of the cutting part, the structural parameters include the angle between the side edge rake face and the base plane, the angle between the first flank face and the cutting plane, the angle between the second flank face and the cutting plane, the angle between the second main cutting edge and the reference plane, the angle between the secondary cutting edge and the reference plane, the angle between the bottom edge rake face and the reference plane, the angle between the third flank face and the reference plane, and the angle between the fourth flank face and the reference plane, the tool rigidity is increased, the cutting force and cutting heat are reduced, the processing accuracy and stability are improved, and thus it is beneficial to improve the processing quality of the processed object; at the same time, a wear-resistant coating is provided on the side edge and the bottom edge of the cutting part, which reduces the diffusion and chemical reaction between the tool and the processed object, reduces the degree of blade wear, and thus improves the service life of the end mill.

[0007] In addition, the end mill according to the present invention may also have the following additional technical features:

[0008] Furthermore, a ratio of a diameter of a minimum circle between the bottoms of the first chip grooves to a maximum diameter of the side cutting edges in the reference plane is 62-66:100.

[0009] Furthermore, the angle between the tangent line of the side edge and the central axis of the cylinder is 34° to 36°.

[0010] Furthermore, the cross section of the first chip groove is arc-shaped.

[0011] Furthermore, the side blades are arranged at equal intervals.

[0012] Furthermore, the bottom blades are arranged at equal intervals.

[0013] Furthermore, at least one second main cutting edge extends to the center of the end surface of the second end.

[0014] Furthermore, the wear-resistant coating is a diamond coating.

[0015] Furthermore, the thickness of the diamond coating is 0.005 mm to 0.014 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of an end mill according to an embodiment of the present invention;

[0017] Figure 2 for Figure 1 A partial enlarged view of point A in the middle;

[0018] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0019] Figure 4 A cross-sectional view of a side blade in one embodiment of the present utility model;

[0020] Figure 5 A cross-sectional view of a bottom blade in one embodiment of the present utility model;

[0021] Figure 6 A top view of a bottom blade in one embodiment of the present invention;

[0022] Description of main component symbols:

[0023] Connecting portion 100, cutting portion 200, cylinder 210, side edge 220, first main cutting edge 221, side edge rake face 222, side edge flank face 223, first flank face 2231, second flank face 2232, bottom edge 230, second main cutting edge 231, bottom edge rake face 232, bottom edge flank face 233, third flank face 2331, fourth flank face 2332, minor cutting edge 2333, first chip flute 240, second chip flute 250;

[0024] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0027] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0028] In addition, this application provides examples of various specific processes and materials, but a person skilled in the art may recognize the application of other processes and / or the use of other materials.

[0029] Reference Figures 1 to 6The utility model provides an end mill, comprising a connecting portion 100 and a cutting portion 200 connected to each other. The connecting portion 100 and the cutting portion 200 are made of cemented carbide. The cutting portion 200 has a base surface Pr, a cutting plane Ps, and a reference plane T. The cutting portion 200 comprises a cylindrical body 210, a plurality of side blades 220, and a plurality of bottom blades 230. The plurality of side blades 220 are spirally arranged on the outer circumference of the cylindrical body 210, and a gap is provided between each side blade 220. The gap forms a first chip groove 240. The cutting chips generated when the side blade 220 cuts the workpiece are accommodated by the first chip groove 240 and discharged along the extension direction of the first chip groove 240. Figure 1 In the direction shown, the lower end of the cylinder 210 is coaxially connected to the connecting part 100 to improve the processing accuracy and cutting stability of the end mill. A plurality of bottom blades 230 are arranged at intervals on the end face of the upper end of the cylinder 210 and are connected to the side blade 220 extending to the part of the upper end of the cylinder 210. A gap is provided between each bottom blade 230, and the gap forms a second chip groove 250. The chips of the workpiece cut by the bottom blade 230 on the upper end of the cylinder 210 are discharged into the first chip groove 240 by the second chip groove 250, thereby preventing chip accumulation during cutting.

[0030] The side edge 220 includes a first main cutting edge 221, and a side edge rake surface 222 and a side edge flank surface 223 located on either side of the first main cutting edge 221. The side edge flank surface 223 includes a first flank surface 2231 and a second flank surface 2232 connected to each other, with the first flank surface 2231 being closer to the first main cutting edge 221. The bottom edge 230 includes a second main cutting edge 231, and a bottom edge rake surface 232 and a bottom edge flank surface 233 located on either side of the second main cutting edge 231. The bottom edge flank surface 233 includes a third flank surface 2331 and a fourth flank surface 2332 connected to each other, with a secondary cutting edge 2333 formed between the third flank surface 2331 and the fourth flank surface 2332.

[0031] It should be noted that the aforementioned base plane Pr is a plane passing through any point on the side edge 220 and perpendicular to the cutting speed direction of the side edge 220, the cutting plane Ps is a plane passing through any point on the side edge 220 and perpendicular to the base plane Pr, and the reference plane T is a plane perpendicular to the central axis of the cylinder 210.

[0032] Generally, since the angle between the side edge rake surface 222 and the base surface Pr and the angle between the bottom edge rake surface 232 and the reference plane T affect the deformation, friction and cutting force during the cutting process, and also affect the strength and heat dissipation volume of the blade, a larger angle can reduce cutting deformation and friction, reduce cutting force and cutting heat, and improve the quality of the machined surface. However, if the angle is too large, the strength of the blade may be reduced, especially when cutting hard materials. For this reason, Figure 4As shown, the included angle α1 between the side cutting edge rake face 222 and the base surface Pr is set to 11° to 13°, as shown in FIG. Figure 5 As shown, the included angle α2 between the bottom edge rake surface 232 and the reference plane T is set to 5° to 7°.

[0033] Generally, the angle between the bottom edge flank 233 and the reference plane T, as well as the angle between the side edge flank 223 and the cutting plane Ps, have a significant impact on the cutting performance and life of the tool. Specifically, a larger angle can reduce the friction between the tool and the workpiece, thereby improving the tool's durability, but at the same time it will reduce the tool's strength and impact resistance. On the contrary, a smaller angle can enhance the tool's strength, but will increase friction and wear. For this reason, Figure 4 As shown, the angle α3 between the first flank face 2231 and the cutting plane Ps is set to 11° to 13°, and the angle α4 between the second flank face 2232 and the cutting plane Ps is set to 24° to 26°. Figure 5 As shown, the included angle α5 between the third flank surface 2331 and the reference plane T is set to 9° to 11°, and the included angle α6 between the fourth flank surface 2332 and the reference plane T is set to 22° to 24°.

[0034] Generally speaking, the angle between the cutting edge and the reference plane T affects the distribution of cutting force, the flow of chips, and the strength and rigidity of the tool. A smaller angle can increase the strength of the cutting edge, reduce the cutting force, and improve the discharge conditions of the chips, thereby improving the stability of the tool and the processing efficiency. On the contrary, a larger angle will reduce the strength of the cutting edge, increase the cutting force, but is not conducive to the smooth discharge of chips. For this reason, Figure 1 As shown, the included angle α7 between the second main cutting edge 231 and the reference plane T is set to 1° to 3°, and the included angle α8 (not shown in the drawings) between the secondary cutting edge 2333 and the reference plane T is set to 2.5° to 3°.

[0035] Furthermore, to reduce diffusion and chemical reactions between the tool and the workpiece, minimize blade wear, and increase the lifespan of the end mill, a wear-resistant coating is provided on both the side cutting edge 220 and the bottom cutting edge 230. The wear-resistant coating can be deposited by vapor deposition, forming a thin layer of a refractory metal or non-metallic compound with good wear resistance. Preferably, the wear-resistant coating is a diamond coating with a thickness of 0.005 mm to 0.014 mm.

[0036] For example, in order to effectively enhance the strength of the side edge 220 and make the side edge 220 fully engage the edge, thereby making the end mill cutter more light and stable when cutting the workpiece, the width a of the side edge flank surface 223 is 0.48 mm, the width b of the first flank surface 2231 is 0.16 mm, α1 is 11°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 0.65 mm, the width b of the first flank surface 2231 is 0.25 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 0.96 mm, the width b of the first flank surface 2231 is 0.30 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 0.96 mm, the width b of the first flank surface 2231 is 0.30 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width b of the side edge flank surface 223 is 0.48 mm, the width b of the first flank surface 2231 is 0.16 mm, α1 is 11°, α3 is 12°, and α4 is The width a of the blade 223 is 1.2 mm, the width b of the first flank surface 2231 is 0.42 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 1.45 mm, the width b of the first flank surface 2231 is 0.5 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 1.9 mm, the width b of the first flank surface 2231 is 0.75 mm, α1 is 12°, α3 is 12°, and α4 is 25°, or the width a of the side edge flank surface 223 is 0.65 mm, the width b of the first flank surface 2231 is 0.25 mm, α1 is 12°, α3 is 12°, and α4 is 25°.

[0037] For example, in order to effectively enhance the strength of the bottom edge 230 and make the bottom edge 230 fully engage the edge, thereby making the end mill cutter more light and stable when cutting the workpiece, the width c of the bottom edge flank 233 is 0.48 mm, α2 is 6°, α5 is 10°, α6 is 23°, α7 is 2°, and α8 is 2.5° to 3°, or the width c of the bottom edge flank 233 is 0.7 mm, α2 is 6°, α5 is 10°, α6 is 23°, α7 is 2°, and α8 is 2.5° to 3°, or the bottom edge The width c of the back cutting edge 233 is 0.95 mm, α2 is 6°, α5 is 10°, α6 is 23°, α7 is 2°, and α8 is 2.5° to 3°, or the width c of the bottom edge back cutting edge 233 is 1.18 mm, α2 is 6°, α5 is 10°, α6 is 23°, α7 is 2°, and α8 is 2.5° to 3°, or the width c of the bottom edge back cutting edge 233 is 1.4 mm, α2 is 6°, α5 is 10°, α6 is 23°, α7 is 2°, and α8 is 2.5° to 3°.

[0038] It should also be noted that the side edge 220 can also be set to a certain taper to process tapered deep grooves, tapered holes, inclined surfaces, etc. For example, Figure 1As shown, the side blade 220 forms an inverted cone from its front end to the tail end (within the length L1 range), and the taper is 0.03~0.04mm / 100mm, that is, over a length of 100mm, the difference between the front end of the side blade 220 and the tail end of the side blade 220 is 0.03~0.04mm.

[0039] When the number of side cutting edges 220 is determined, when the diameter of the smallest circle between the bottoms of the first chip grooves 240 in the reference plane T is larger, the overall cross-sectional area of the side cutting edges 220 is larger, thereby improving the rigidity of the cutting edge, but reducing the space of the first chip grooves 240 and deteriorating the chip removal performance; conversely, when the diameter of the smallest circle between the bottoms of the first chip grooves 240 in the reference plane T is smaller, the chip removal performance of the first chip grooves 240 is enhanced, but the rigidity of the cutting edge is deteriorated. For this reason, in some optional embodiments, such as Figure 6 As shown, the ratio of the diameter of the minimum circle D0 between the bottoms of the first chip flutes 240 and the maximum diameter D1 of the side cutting edges 220 in the reference plane T is set to 62-66:100. For example, D0 is 5.12 mm, D1 is 8 mm, and the ratio is 64:100.

[0040] Since the larger the angle between the tangent line of the side edge 220 and the central axis of the cylinder 210, the longer the contact line between the workpiece and the side edge 220, the smaller the load applied to the side edge 220 per unit length will be, which is conducive to extending the tool life. However, as the angle between the tangent line of the side edge 220 and the central axis of the cylinder 210 increases, the axial component of the cutting resistance also increases, requiring the connection part 100 to have good rigidity. To this end, in some optional embodiments, such as Figure 1 As shown, the included angle β1 between the tangent line of the side blade 220 and the central axis of the cylinder 210 is set to 34° to 36°. Preferably, the included angle β1 between the tangent line of the side blade 220 and the central axis of the cylinder 210 is set to 35°.

[0041] In order to allow the chips generated when cutting the workpiece to be discharged smoothly in the first chip groove 240, in some optional embodiments, the cross-section of the first chip groove 240 is arc-shaped. The arc-shaped groove design helps the chips to curl when leaving the cutting area, reducing the possibility of the chips re-adhering to the tool or the workpiece, and also reducing the risk of chips clogging the first chip groove 240.

[0042] In order to ensure the balance and processing accuracy of the tool, in some optional embodiments, the side cutting edges 220 are arranged at equal intervals on the outer circumference of the cylinder 210.

[0043] In order to ensure the balance and processing accuracy of the tool, in some optional embodiments, the bottom blades 230 are arranged at equal intervals on the end surface of the cylinder 210.

[0044] For example, the side blades 220 and the bottom blades 230 are each provided with four, such as Figure 6 As shown, when viewed from the side of the bottom edge 230, the angle between two adjacent bottom edges 230 is 90°.

[0045] In order to reduce cutting force and improve machining quality, in some optional embodiments, as Figure 6 As shown, at least one second main cutting edge 231 extends to the center of the end face of the second end. This allows the milling cutter bottom edge 230 to cut the surface of the workpiece, because the cutting force is perpendicular to the surface, no upward thrust is generated. Consequently, the cutting force is reduced, and the machined surface quality is more stable. Furthermore, the over-centering of the bottom edge 230 improves milling stability and cutting efficiency. Specifically, when the tool cuts, frictional heat is generated at the tool tip, causing the tool to deform. However, over-centering the bottom edge 230 reduces deformation of the tool tip, thereby improving cutting efficiency and machining accuracy.

[0046] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0049] In the description of the present utility model, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0050] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0051] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0052] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. An end mill, characterized in that: The end mill comprises: Connecting part; The cutting portion, the connecting portion is connected to the cutting portion, the cutting portion has a base surface, a cutting plane, and a reference plane, and the cutting portion includes: A cylinder having a first end and a second end, wherein the first end is coaxially connected to the connecting portion; a plurality of side blades, wherein the plurality of side blades are spirally arranged at intervals on the outer circumference of the cylinder, a first chip groove is provided between adjacent side blades, the side blades include a first main cutting edge and a side blade rake face and a side blade flank face located on both sides of the first main cutting edge, the side blade flank face includes a first flank face and a second flank face connected to each other, the angle between the side blade rake face and the base plane is 11° to 13°, the angle between the first flank face and the cutting plane is 11° to 13°, the angle between the second flank face and the cutting plane is 24° to 26°, and the side blades are provided with a wear-resistant coating; A plurality of bottom blades, wherein the plurality of bottom blades are arranged at intervals on the end face of the second end, the positions of the bottom blades and the side blades correspond to each other, a second chip groove is provided between adjacent bottom blades, the second chip groove is connected to the first chip groove, the bottom blade includes a second main cutting edge and a bottom blade front blade face and a bottom blade back blade face located on both sides of the second main cutting edge, the bottom blade back blade face includes a third back blade face and a fourth back blade face connected to each other, a secondary cutting edge is formed between the third back blade face and the fourth back blade face, the angle between the second main cutting edge and the reference plane is 1°~3°, the angle between the secondary cutting edge and the reference plane is 2.5°~3°, the angle between the bottom blade front blade face and the reference plane is 5°~7°, the angle between the third back blade face and the reference plane is 9°~11°, and the angle between the fourth back blade face and the reference plane is 22°~24°, wherein the reference plane is a plane perpendicular to the central axis of the cylinder, and the wear-resistant coating is provided on the bottom blade.

2. The end mill according to claim 1, characterized in that A ratio of a diameter of a minimum circle between the bottoms of the first chip grooves in the reference plane to a maximum diameter of the side cutting edge is 62-66:

100.

3. The end mill according to claim 1, characterized in that The included angle between the tangent line of the side edge and the central axis of the cylinder is 34° to 36°.

4. The end mill according to any one of claims 1 to 3, characterized in that: The cross section of the first chip groove is arc-shaped.

5. The end mill according to any one of claims 1 to 3, characterized in that: The side blades are arranged at equal intervals.

6. The end mill according to any one of claims 1 to 3, characterized in that The bottom blades are arranged at equal intervals.

7. The end mill according to any one of claims 1 to 3, characterized in that: At least one of the second main cutting edges extends to the center of the end surface of the second end.

8. The end mill according to claim 1, wherein: The wear-resistant coating is a diamond coating.

9. The end mill according to claim 8, characterized in that The thickness of the diamond coating is 0.005 mm to 0.014 mm.

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