A double-sided milling tool with a positive axial rake angle

Abstract

This utility model discloses a double-sided milling cutter with a positive axial rake angle, relating to the field of metal cutting technology. It includes a cutter head structure with several insert structures mounted on its surface. Each insert structure consists of a flank face, a first connecting arc, a second connecting arc, a short cutting edge, a long cutting edge, a side cutting edge rake face, a bottom cutting edge rake face, an end face, insert screw holes, and a rake face arc. The insert structure has a triangular, double-sided, asymmetrical structure. Flank faces with alternating inner and outer edges are distributed around the insert structure, connected by the first connecting arc. The two ends of the flank faces have different lengths, and the long cutting edge is set as a side cutting edge. Unlike conventional double-sided inserts, this double-sided milling cutter with a positive axial rake angle still has a flank angle even when the axial rake angle is designed to be positive, preventing interference with the workpiece. Furthermore, the radial rake angle remains negative, changing the traditional double-sided insert's limitation of only having two negative rake angles and achieving a positive and negative rake angle mode.

Description

Technical Field

[0001] This utility model relates to the field of metal cutting technology, specifically to a double-sided milling tool with a positive axial rake angle. Background Technology

[0002] Tool geometry parameters have a significant impact on machining quality and tool life. Reasonable parameter selection can improve productivity and reduce costs while ensuring machining quality and tool life.

[0003] Indexable milling cutters have various angles, including rake angle, clearance angle, principal cutting edge angle, secondary cutting edge angle, and inclination angle. To meet different machining needs, there are multiple combinations of these angles. Among these angles, the principal cutting edge angle and rake angle are the most important.

[0004] The rake angle of a milling cutter can be decomposed into the radial rake angle and the axial rake angle. The radial rake angle mainly affects the cutting power; the axial rake angle affects the formation of chips and the direction of axial force. When it is positive, the chip flies away from the machined surface.

[0005] Commonly used front corner combinations are as follows:

[0006] ① Double Negative Rake Angle: End mills with a double negative rake angle typically use square (or rectangular) inserts without a clear rake angle. These mills have multiple cutting edges (usually eight), high strength, and good impact resistance, making them suitable for roughing cast steel and cast iron. Due to the large chip shrinkage ratio, a large cutting force is required, thus demanding a machine tool with high power and rigidity. Because the axial rake angle is negative, chips cannot flow out automatically, easily leading to built-up edge and tool vibration when cutting tough materials. Whenever possible, it is recommended to prioritize double negative rake angle end mills to fully utilize and save inserts. Even when double positive rake angle end mills produce chipping (i.e., high impact load), double negative rake angle end mills should still be preferred, provided the machine tool allows it.

[0007] ②) Double positive rake angle: Double positive rake angle end mills use inserts with a small clearance angle, resulting in a sharp cutting edge. Due to the small chip shrinkage ratio, the cutting power consumption is lower, and the chips are discharged in a spiral shape, making it less prone to built-up edge formation. This type of end mill is best suited for machining soft materials and materials such as stainless steel and heat-resistant steel. For machine tools with poor rigidity (such as boring and milling machines with long spindle overhangs), low power, and when machining welded structural parts, double positive rake angle end mills should also be given priority.

[0008] ③ Positive and negative rake angles (axial positive rake angle, radial negative rake angle): This type of end mill combines the advantages of double positive and double negative rake angle end mills. The axial positive rake angle is beneficial for chip formation and removal; the radial negative rake angle can improve the cutting edge strength and enhance impact resistance. This type of end mill provides smooth cutting, efficient chip removal, and high metal removal rate, making it suitable for large-mass milling operations.

[0009] Currently, all double-sided cutting inserts have a double negative rake angle. The fundamental reason is that the flank face of cutting inserts on the market is a straight wall shape with a 0° angle. However, in actual cutting processes, the flank face needs to be deflected to allow the cutting tip to cut the workpiece. Since the flank face has a clearance angle and will not interfere with the workpiece, the deflection angle can only be negative, that is, the axial rake angle must be negative. If the axial rake angle is positive, one end of the flank face will interfere with the workpiece being cut, resulting in an incorrect cutting angle and failure to achieve cutting.

[0010] However, the disadvantages of a negative axial rake angle include: poor sharpness, resulting in high cutting resistance; chips cannot flow out automatically, leading to poor chip removal; and the tendency to develop built-up edge and tool vibration when cutting tough materials, thus reducing tool life. Therefore, to address these shortcomings, a double-sided milling tool with a positive axial rake angle is proposed. Utility Model Content

[0011] To address the shortcomings of existing technologies, this utility model provides a double-sided milling tool with a positive axial rake angle, which solves the problems mentioned in the background art.

[0012] To achieve the above objectives, this utility model provides the following technical solution: A double-sided milling cutter with a positive axial rake angle, comprising a cutter head structure. A plurality of insert structures are mounted on the surface of the cutter head structure. Each insert structure consists of a flank face, a first connecting arc, a second connecting arc, a short cutting edge, a long cutting edge, a side cutting edge rake face, a bottom cutting edge rake face, an end face, insert screw holes, and a rake face arc. The insert structure has a triangular, double-sided, asymmetrical structure. Flank faces with alternating inner and outer edges are distributed around the insert structure. The flank faces are connected by the first connecting arc. The two ends of the flank faces have different lengths. The long cutting edge is... The blade is set as a side blade, and the short blade is set as a bottom blade. The outer periphery of the blade structure is connected by three sets of staggered back blades through a second connecting arc. The upper and lower end faces of the blade structure are asymmetrical. The inclined surface of the blade structure surface connected to the short blade is the bottom blade rake face, and the inclined surface of the blade structure connected to the long blade is the side blade rake face. Both the bottom blade rake face and the side blade rake face are inclined towards the end face, and the concave part of the bottom blade rake face and the side blade rake face is connected to the end face. The side blade rake face and the bottom blade rake face are connected by a rake face arc. The end face is triangular, and a blade screw hole is provided at the geometric center of the end face.

[0013] Preferably, the surface of the cutter head structure is provided with a plurality of positioning surfaces, all of which are in contact with the back face of the outer periphery of the blade structure, and a plurality of blade seats are fixedly connected to the surface of the cutter head structure, with the end faces of the blade structure all in contact with the blade seats.

[0014] Preferably, the surface of the blade holder is provided with a blade screw hole, and the blade structure is mounted on the surface of the blade structure by screws. One end of each screw passes through the blade screw hole and the blade screw hole to mount the blade structure on the surface of the blade structure.

[0015] Preferably, the positioning surface has an interlaced wedge-shaped structure.

[0016] Preferably, the surface of the cutter head structure has a plurality of chip grooves.

[0017] Preferably, the surface of the blade holder is provided with a clearance groove.

[0018] This utility model provides a double-sided milling tool with a positive axial rake angle, which has the following beneficial effects:

[0019] 1. This positive axial rake angle double-sided milling tool differs from conventional double-sided inserts in that it still has a back angle even when the axial rake angle is designed to be positive, so it will not interfere with the workpiece being cut, and the radial rake angle is still negative. This changes the traditional double-sided insert mode that can only be negative, and realizes a positive and negative rake angle mode.

[0020] 2. This double-sided milling tool with a positive axial rake angle cleverly achieves a positive axial rake angle while still maintaining a clearance angle through an alternating inner and outer positioning method, preventing interference with the workpiece. Furthermore, the radial rake angle remains negative, changing the traditional double-sided insert's limitation of only having two negative rake angles. This allows for a positive and negative rake angle configuration, resulting in low cutting resistance, improved impact resistance, and extended tool life. Additionally, chip removal performance is enhanced, reducing chip sticking and achieving stable, long-life machining. It also boasts a high metal removal rate, making it suitable for large-mass milling operations, thus improving machining efficiency compared to traditional double-negative rake angle tools. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the blade installation of this utility model;

[0022] Figure 2 This is a schematic diagram of the cutter head structure of this utility model;

[0023] Figure 3 This is a schematic diagram of the blade structure of this utility model;

[0024] Figure 4 This is a side view of the blade structure of this utility model;

[0025] Figure 5 This is a top view of the blade structure of this utility model;

[0026] Figure 6 This is a schematic diagram of the axial structure of the cutter head structure and the blade structure of this utility model.

[0027] Figure 7 This is a schematic diagram of the radial structure of the cutter head structure and the blade structure of this utility model.

[0028] Figure 8 This is a schematic diagram of the overall front view of this utility model;

[0029] Figure 9 This is a bottom view of the overall design of this utility model.

[0030] In the diagram: 1. Back face; 2. First connecting arc; 3. Second connecting arc; 4. Short edge; 5. Long edge; 6. Side edge front face; 7. Bottom edge front face; 8. End face; 9. Insert screw hole; 10. Front face arc; 11. Positioning surface; 12. Cutter head screw hole; 13. Insert holder; 14. Clearance groove; 15. Screw; 16. Chip groove; 17. Cutter head structure; 18. Insert structure. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0032] Please see Figures 1 to 9 This utility model provides a technical solution: a double-sided milling cutter with a positive axial rake angle, including a cutter head structure 17. A plurality of insert structures 18 are mounted on the surface of the cutter head structure 17. Each insert structure 18 consists of a flank face 1, a first connecting arc 2, a second connecting arc 3, a short cutting edge 4, a long cutting edge 5, a side cutting edge 6, a bottom cutting edge 7, an end face 8, insert screw holes 9, and a rake face arc 10. The insert structure 18 has a triangular double-sided asymmetrical structure. Flank faces 1 are arranged in an alternating pattern around the insert structure 18, connected by the first connecting arc 2. The two ends of the flank faces 1 have different lengths. The long cutting edge 5 is set as a side cutting edge, and the short cutting edge 4 is set as a bottom cutting edge. The outer periphery of the insert structure 18 is composed of three sets of alternating patterns. The back face 1 is connected by the second connecting arc 3. The upper and lower end faces 8 of the insert structure 18 are asymmetrical. The inclined surface of the insert structure 18 connected to the short cutting edge 4 is the bottom cutting edge rake face 7. The inclined surface of the insert structure 18 connected to the long cutting edge 5 is the side cutting edge rake face 6. Both the bottom cutting edge rake face 7 and the side cutting edge rake face 6 are inclined towards the end face 8. The concave parts of the bottom cutting edge rake face 7 and the side cutting edge rake face 6 are connected to the end face 8. The side cutting edge rake face 6 and the bottom cutting edge rake face 7 are connected by the rake face arc 10. The end face 8 is triangular. The insert screw hole 9 is provided at the geometric center of the end face 8. The long cutting edge 5 is mainly used for side wall machining, such as the side wall of the stepped surface and the side wall of the groove. The short cutting edge 4 is mainly used for plane machining, and is used for plane machining during plunge milling.

[0033] The surface of the cutter head structure 17 is provided with several positioning surfaces 11, all of which are in contact with the back face 1 of the outer periphery of the blade structure 18. Several blade holders 13 are fixedly connected to the surface of the cutter head structure 17, and the end face 8 of the blade structure 18 is in contact with the blade holder 13.

[0034] The surface of the blade holder 13 is provided with blade screw holes 12. The blade structure 18 is mounted on the surface of the blade structure 17 by screws 15. One end of each screw 15 passes through the blade screw hole 12 and the blade screw hole 9 to mount the blade structure 18 on the surface of the blade structure 17.

[0035] The positioning surface 11 has an interlaced wedge-shaped structure, which can effectively suppress the movement caused by cutting resistance and achieve stable long-life machining.

[0036] The surface of the cutter head structure 17 is provided with several chip grooves 16 for the smooth discharge of iron chips during the cutting process.

[0037] The surface of the blade holder 13 is provided with clearance grooves 14 to avoid the cutting edge of the blade mounted on the cutter head.

[0038] In summary, this positive-axis, rake-angle double-sided milling cutter, during use, has its flank face 1 on the outer periphery of the insert structure 18 respectively aligned with the positioning surface 11 in the cutter head, and its end face 8 aligned with the insert holder 13. Screws 15 are then used to assemble the insert structure 18 firmly onto the cutter head structure 17 by passing through the insert screw hole 9 and the cutter head screw hole 12. The cutter head positioning surface 11 has an interlaced wedge-shaped structure, which effectively suppresses movement caused by cutting resistance, achieving stable, long-life machining. Chip grooves 16 are provided on the cutter head structure 17 for smooth chip removal during cutting. Clearance grooves 14 are used to avoid the cutting edges of the inserts mounted on the cutter head.

[0039] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double-sided milling tool with a positive axial rake angle, characterized in that: The device includes a cutter head structure (17), on which several blade structures (18) are mounted. Each blade structure (18) consists of a flank face (1), a first connecting arc (2), a second connecting arc (3), a short blade (4), a long blade (5), a side cutting edge front face (6), a bottom cutting edge front face (7), an end face (8), a blade screw hole (9), and a front face arc (10). The blade structure (18) has a triangular double-sided asymmetrical structure. Flank faces (1) with alternating inner and outer edges are distributed around the blade structure (18). The flank faces (1) are connected by the first connecting arc (2). The long blade (5) is set as a side blade. The outer periphery of the blade structure (18) is connected by three sets of staggered back blades (1) through a second connecting arc (3). The inclined surface of the blade structure (18) connected to the short blade (4) is the bottom blade front blade (7). The inclined surface of the blade structure (18) connected to the long blade (5) is the side blade front blade (6). The bottom blade front blade (7) and the side blade front blade (6) are both inclined toward the end face (8). The side blade front blade (6) and the bottom blade front blade (7) are connected by a front blade arc (10). A blade screw hole (9) is provided at the geometric center of the end face (8).

2. A double-sided milling tool with a positive axial rake angle according to claim 1, characterized in that: The surface of the cutter head structure (17) is provided with a number of positioning surfaces (11), and the positioning surfaces (11) are all in contact with the back cutting surface (1) of the outer periphery of the blade structure (18). A number of blade seats (13) are fixedly connected to the surface of the cutter head structure (17), and the end face (8) of the blade structure (18) is in contact with the blade seat (13).

3. A double-sided milling tool with a positive axial rake angle according to claim 2, characterized in that: The blade holder (13) has a blade screw hole (12) on its surface. The blade structure (18) is mounted on the surface of the blade structure (17) by screws (15). One end of each screw (15) passes through the blade screw hole (12) and the blade screw hole (9) to mount the blade structure (18) on the surface of the blade structure (17).

4. A double-sided milling tool with a positive axial rake angle according to claim 2, characterized in that: The positioning surface (11) has an interlaced wedge-shaped structure.

5. A double-sided milling tool with a positive axial rake angle according to claim 1, characterized in that: The surface of the cutter head structure (17) is provided with a number of chip grooves (16).

6. A double-sided milling tool with a positive axial rake angle according to claim 2, characterized in that: The surface of the blade holder (13) is provided with a clearance groove (14).

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