A milling cutter for machining nodular cast iron

Abstract

The application relates to a milling cutter technical field, especially a milling cutter for machining nodular cast iron, which comprises a cutter body assembly in a cylindrical structure, the cutter body assembly comprises a blade part and a handle part connected head to tail, the blade part is subjected to thickening treatment; further comprising a cutter blade assembly, the cutter blade assembly is composed of four cutting edge bodies which are equidistantly distributed along the circumferences of the top ends of the blade part, the cutting edge bodies comprise a main cutting edge and an auxiliary cutting edge which are adjacent to and connected with the top ends of the blade part, and the main cutting edge is provided with a blade edge strengthening structure. The thickened blade part of the cutter body assembly provides rigid support, the four equidistantly distributed cutting edge bodies synchronously participate in cutting, the main cutting edge removes main materials, the auxiliary cutting edge assists in trimming the surface and shares the cutting force, the blade edge strengthening structure can enhance the cutting sharpness and wear resistance, and the comprehensive realization of efficient cutting operation is realized. The application has the characteristics of improving the machining efficiency.

Description

Technical Field

[0001] This application relates to the field of milling cutter technology, and in particular to a milling cutter for machining ductile iron. Background Technology

[0002] Ductile iron is widely used in automotive mold manufacturing due to its high strength, wear resistance, and good casting properties. However, the high hardness of ductile iron poses a significant challenge to machining tools.

[0003] In related technologies, the following two solutions are mainly used for machining ductile iron: one is to use carbide end mills, which improve surface hardness and wear resistance by adding coatings (such as TiN, TiAlN, etc.), which is low in cost and has a mature manufacturing process; the other is to use a multi-flute design (such as a three-flute end mill) to disperse the cutting force and avoid excessive concentrated stress on a single cutting edge, thereby extending the tool life.

[0004] Existing ductile iron end mills suffer from the following problems: the tool coating is prone to peeling under high-speed cutting or high feed rates, resulting in poor stability; multi-edged rotary tools struggle to eliminate radial runout of the teeth, leading to inconsistent tooth loads, uneven wear, and a risk of chipping. As the automotive industry moves towards lightweight and high-precision manufacturing, the cutting performance of current ductile iron machining tools is insufficient to meet the ever-increasing demands for machining efficiency in modern manufacturing. Utility Model Content

[0005] To improve machining efficiency, this application provides a milling cutter for machining ductile iron.

[0006] The milling cutter for machining ductile iron provided in this application adopts the following technical solution: A milling cutter for machining ductile iron includes a cylindrical cutter body assembly, the cutter body assembly including a cutting edge and a shank connected end to end, the cutting edge being thickened; it also includes a cutting edge assembly, the cutting edge assembly consisting of four cutting edge bodies equidistantly distributed circumferentially along the tip of the cutting edge, the cutting edge body including a primary cutting edge and a secondary cutting edge adjacent to and connected to the tip of the cutting edge, the primary cutting edge being provided with a cutting edge reinforcement structure.

[0007] By adopting the above technical solution, the thickened cutting edge of the tool body assembly provides rigid support, and the four circumferentially equidistant cutting edges participate in cutting simultaneously. The main cutting edge removes the main material, the secondary cutting edge assists in surface finishing and shares the cutting force, and the edge reinforcement structure can enhance cutting sharpness and wear resistance, thus comprehensively achieving efficient cutting operations and improving processing efficiency.

[0008] Preferably, the edge reinforcement structure is a narrow and flat extension surface integrally formed on the edge of the main cutting edge, the surface of the extension surface is flush with the surface of the main cutting edge, and the corners are rounded.

[0009] By adopting the above technical solutions, the one-piece molding design enhances the overall strength of the cutting edge and reduces stress concentration; the extension surface is flush with the main cutting edge to ensure a smooth transition in the cutting process and reduce chip retention and surface scratches; the rounded corners help control the chip flow direction and resist the abrasion of graphite in ductile iron, reducing the risk of chipping and cracking.

[0010] Preferably, the secondary cutting edge is disposed behind the main cutting edge along the extension direction of the main cutting edge, and forms a layered cutting structure with the main cutting edge.

[0011] By adopting the above technical solution, the layered structure forms a stepped cutting layer, which allows the cutting force to be released in stages. This can force the chips to break in layers and reduce instantaneous load fluctuations, thereby reducing the risk of long chip entanglement and improving machining stability.

[0012] Preferably, the outer diameter of the handle is larger than the outer diameter of the blade, and both its tail end and the top end connected to the blade are provided with stepped connecting sections.

[0013] By adopting the above technical solutions, the large outer diameter of the shank provides a stronger support base, and the stepped connecting section forms multiple mechanical locks at the tail and top, reducing loosening or micro-displacement during machining, ensuring efficient transmission of cutting force, and reducing stress concentration points at the shank-edge joint, thereby improving overall fatigue resistance.

[0014] Preferably, a large-volume open chip removal groove is provided between adjacent cutting edges facing the shank, and the bottom of the chip removal groove is provided with an arc-shaped guide surface.

[0015] By adopting the above technical solution, the large-volume open structure provides ample chip space, which can quickly accommodate the curled chips generated by the roughing of the main cutting edge; the arc guide surface guides the chips to be smoothly discharged along the smooth curve to the rear of the shank, thereby reducing the risk of secondary cutting caused by chip accumulation and retention.

[0016] Preferably, the cutter body assembly is provided with a coolant channel that extends through the interior. The coolant channel includes at least four spray holes that are evenly arranged in a circumferential direction, and the outlet of the spray holes is directly opposite the cutting area of ​​the cutting edge.

[0017] By adopting the above technical solution, the jet holes are evenly distributed in a circumferential pattern to form a cooling enclosure. The coolant can directly cover the high-temperature core of the cutting zone, effectively suppressing the diffusion wear and thermal cracking of cemented carbide tools and extending their service life.

[0018] Preferably, both the blade assembly and the cutting edge assembly are made of CBN material.

[0019] By adopting the above technical solution, CBN, as a cutting tool and cutting edge material, has a hardness much higher than that of cemented carbide, which increases the cutting speed by several times compared to traditional cemented carbide tools. The machining cycle can be shortened by appropriately increasing the feed rate, thereby reducing production costs. Moreover, the material has stable hardness under high-temperature cutting environment and does not react chemically with ductile iron.

[0020] Preferably, the dimensional accuracy of the blade assembly can reach ±0.005mm, and its surface roughness ranges from Ra0.8 to Ra0.4μm.

[0021] By adopting the above technical solutions, the stringent requirements of high-end manufacturing industries such as automotive molds for the precision and surface quality of parts can be met.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. The thickened cutting edge of the tool body assembly provides rigid support, and four circumferentially equidistant cutting edges participate in cutting simultaneously. The main cutting edge removes the main material, while the secondary cutting edges assist in surface finishing and share the cutting force. The edge reinforcement structure enhances cutting sharpness and wear resistance, thus achieving efficient cutting operations and improving machining efficiency. 2. The one-piece molding design enhances the overall strength of the cutting edge and reduces stress concentration; the extension surface is flush with the main cutting edge to ensure a smooth transition in the cutting process and reduce chip retention and surface scratches; the rounded corners help control the chip flow direction and resist the abrasion of graphite in ductile iron, reducing the risk of chipping and cracking. 3. As a cutting edge material for cutting tools, CBN has a hardness much higher than that of cemented carbide, which increases the cutting speed several times compared to traditional cemented carbide tools. The machining cycle can be shortened by appropriately increasing the feed rate, thereby reducing production costs. Moreover, the hardness of this material is stable under high-temperature cutting environment and does not react chemically with ductile iron. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0024] Figure 2 This is a top view of an embodiment of the present application.

[0025] Explanation of reference numerals in the attached drawings: 1. Tool body assembly; 11. Shank; 12. Stepped connecting section; 13. Cutting edge; 2. Cutting edge assembly; 21. Cutting edge body; 211. Main cutting edge; 212. Secondary cutting edge; 22. Edge reinforcement structure; 23. Chip removal groove; 231. Circular arc guide surface. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0027] This application discloses a milling cutter for machining ductile iron. (See also...) Figure 1-2 A milling cutter for machining ductile iron includes a cylindrical cutter body assembly 1, which includes a cutting edge 13 and a shank 11 connected end to end, the cutting edge 13 being thickened; it also includes a cutting edge assembly 2, which consists of four cutting edge bodies 21 equidistantly distributed along the circumferential direction of the top edge of the cutting edge 13, the cutting edge body 21 including a main cutting edge 211 and a secondary cutting edge 212 adjacent to each other and connected to the top edge of the cutting edge 13, the main cutting edge 211 having an integrally formed edge reinforcement structure 22.

[0028] Correspondingly, when the milling cutter is working, the thickened cutting edge 13 of the cutter body assembly 1 provides rigid support, and the four circumferentially equidistant cutting edges 21 participate in cutting simultaneously, increasing the cutting stroke. Among them, the main cutting edge 211 is responsible for the main material removal, and its edge reinforcement structure 22 can enhance the cutting sharpness and wear resistance. The secondary cutting edge 212 assists in surface finishing and shares the cutting force. The multi-edge structure design achieves efficient cutting.

[0029] Therefore, the four-edge equidistant layout improves the material removal rate, the thickened tool body can suppress vibration and ensure the machining stability of ductile iron under high hardness; the edge reinforcement structure 22 can cope with intermittent cutting and reduce cutting force fluctuations and the risk of edge breakage by resisting the abrasion of graphite in ductile iron, thereby reducing the occurrence of workpiece deformation and balancing machining efficiency and product quality.

[0030] Specifically, the edge reinforcement structure 22 is a narrow and flat extension surface integrally formed on the edge of the main cutting edge 211. The surface of the extension surface is flush with the surface of the main cutting edge 211, and the corners are rounded.

[0031] Correspondingly, the integrated design with the extension surface flush with the surface of the main cutting edge 211 reduces the interface weakening problem of traditional welding or coating structures, resulting in higher overall structural strength; the narrow and flat structural design can effectively disperse cutting stress, reduce the microscopic peeling wear of graphite particles on the cutting edge in ductile iron, and extend tool life.

[0032] Furthermore, the rounded corners at the corners can smoothly transition the cutting force, reduce stress concentration, and lower the risk of chipping due to sudden changes in material during the cutting process, making it suitable for intermittent cutting conditions of ductile iron. The rounded corners can also help control the chip flow direction, reducing chip retention and surface scratches.

[0033] Specifically, the secondary cutting edge 212 is positioned behind the main cutting edge 211 along its extension direction, forming a layered cutting structure with the main cutting edge 211. The main cutting edge 211 undertakes roughing to remove the main allowance, while the secondary cutting edge 212 subsequently finishes the transition surface. The layered structure allows the cutting force to be released in stages, reducing instantaneous load fluctuations, effectively suppressing vibrations caused by intermittent cutting of ductile iron, and improving system rigidity and machining stability.

[0034] Furthermore, this stepped cutting layer can force the chips to break in layers, reducing the risk of long chip entanglement; at the same time, the secondary cutting edge 212 precisely trims the residual material left by the main cutting edge 211 to control the cutting thickness, reducing the micro-unevenness of the machined surface, thereby improving machining accuracy and workpiece surface quality.

[0035] On the other hand, the outer diameter of the handle 11 of the blade assembly 1 is larger than the outer diameter of the blade 13, and a stepped connecting section 12 is provided at its tail end and the top end connected to the blade 13.

[0036] Therefore, the large outer diameter of the shank 11 provides a stronger support base, effectively suppressing vibration and bending deformation during the high-hardness machining of ductile iron and improving cutting stability. The stepped connecting section 12 forms multiple mechanical locks at the tail end (for the machine tool spindle interface) and the top end (connected to the cutting edge 13), ensuring efficient transmission of cutting force through a stable connection, maintaining the geometric accuracy consistency of the cutting edge 21, reducing machining errors, and helping to achieve a more stable surface roughness; at the same time, the stepped design smoothly transitions the stress distribution, reducing stress concentration points at the shank-cutting edge connection, and combined with the thickened cutting edge 13, improving the overall fatigue resistance.

[0037] In addition, a large-volume open chip removal groove 23 is provided between adjacent cutting edge bodies 21 facing the shank 11, and an arc-shaped guide surface 231 is provided at the bottom of the chip removal groove 23.

[0038] Correspondingly, the large-volume open structure provides ample chip space to quickly accommodate the curled chips generated by the main cutting edge 211 during roughing, reducing the pressure of chips on the machined surface and thus reducing scratches and micro-pits caused by chip retention. The arc-shaped guide surface 231 guides the chips to be smoothly discharged behind the shank 11 along the smooth curve, reducing the risk of secondary cutting caused by chip retention, while reducing cutting vibration to ensure the trajectory stability of the cutting edge 21 and reduce the waviness of the workpiece surface.

[0039] Furthermore, the large-capacity chip flute 23 supports high-feed cutting without frequent machine stops for chip removal; the rapid removal of chips from the cutting zone also reduces the tool-chip contact time, thereby reducing the cutting edge temperature and minimizing the negative impact of thermal shock on tool durability.

[0040] Specifically, in this embodiment, the cutter body assembly 1 has a coolant channel that extends through the interior. The coolant channel includes four spray holes that are evenly arranged in a circumferential direction, and the outlet of the spray holes is directly facing the cutting area of ​​the cutting edge 21.

[0041] Therefore, the uniform circumferential layout of the spray holes forms a cooling enclosure, allowing the coolant to directly cover the high-temperature core of the cutting zone. The directional spray rapidly reduces the temperature drop in the cutting zone, effectively suppressing the diffusion wear and thermal cracking of the tool and extending its service life. The coolant precisely impacts the root of the chip, reducing the risk of cutting edge adhesion and minimizing microscopic tearing of the workpiece surface material.

[0042] Furthermore, the coolant can be uniformly sprayed in a circumferential direction to guide chip flow, thereby forcing chip breaking. When the coolant penetrates to the tool tip-workpiece contact interface, the coefficient of friction decreases, narrowing the range of cutting force fluctuations.

[0043] In the process described above, both the tool body assembly 1 and the cutting edge assembly 2 are made of CBN material. CBN (cubic boron nitride) is used as the cutting edge material of the tool. Its hardness is much higher than that of cemented carbide, and its hardness is stable under high-temperature cutting environment. It does not react chemically with ductile iron. The overall CBN structure eliminates the risk of interface peeling of composite tools, improves the resistance to chipping, reduces the frequency of tool replacement, and lowers operating costs. Its high hardness and wear resistance can support high-speed cutting and large feed rate, effectively shortening the production cycle and improving production efficiency.

[0044] Specifically, the dimensional accuracy of the cutting edge assembly 2 can reach ±0.005mm, and its surface roughness ranges from Ra0.8 to Ra0.4μm. The dimensional tolerance of ±0.005mm reaches the level of precision grinding, which can ensure the consistency of the cutting edge geometry parameters and reduce dimensional drift during machining; high-precision tool tip position control can suppress tool deflection caused by cutting force fluctuations and ensure workpiece dimensional accuracy.

[0045] Meanwhile, the Ra0.4μm roughness is close to the mirror effect, which can eliminate most micro-tears and burrs; the low roughness also reduces stress concentration on the contact surface of the friction pair, reduces the wear rate of the product, and meets the high surface finish requirements of automotive parts such as hydraulic sealing surfaces and bearing mating surfaces.

[0046] The implementation principle of a milling cutter for machining ductile iron according to an embodiment of this application is as follows: the thickened cutting edge 13 of the cutter body assembly 1 provides rigid support, and four circumferentially equidistant cutting edges 21 participate in cutting simultaneously, increasing the cutting stroke. The main cutting edge 211 is responsible for the main material removal, and its edge reinforcement structure 22 enhances cutting sharpness and wear resistance. The secondary cutting edge 212 assists in surface finishing and shares the cutting force. High-efficiency cutting is achieved through the multi-edge structure design. Therefore, this milling cutter improves the material removal rate through its four-edge equidistant layout, the thickened cutter body suppresses vibration, and ensures the machining stability of ductile iron under high hardness. The edge reinforcement structure 22 can handle intermittent cutting and reduces cutting force fluctuations and the risk of chipping by resisting the abrasion of graphite in ductile iron, thereby reducing workpiece deformation and balancing machining efficiency and product quality.

[0047] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A milling cutter for machining ductile iron, characterized in that, The tool includes a cylindrical blade assembly (1), which includes a blade portion (13) and a shank portion (11) connected end to end, and the blade portion (13) is thickened; it also includes a cutting edge assembly (2), which consists of four cutting edge bodies (21) equidistantly distributed along the top of the blade portion (13) in the circumferential direction, and the cutting edge body (21) includes a main cutting edge (211) and a secondary cutting edge (212) that are adjacent to each other and connected to the top of the blade portion (13), and the main cutting edge (211) is provided with a cutting edge reinforcement structure (22).

2. The milling cutter for machining ductile iron according to claim 1, characterized in that, The edge reinforcement structure (22) is a narrow and flat extension surface integrally formed on the edge of the main cutting edge (211). The surface of the extension surface is flush with the surface of the main cutting edge (211), and the corners are rounded.

3. A milling cutter for machining ductile iron according to claim 1, characterized in that, The secondary cutting edge (212) is positioned behind the main cutting edge (211) along its extension direction, and forms a layered cutting structure with the main cutting edge (211).

4. A milling cutter for machining ductile iron according to claim 1, characterized in that, The outer diameter of the handle (11) is larger than the outer diameter of the blade (13), and a stepped connecting section (12) is provided at its tail end and at the top end connected to the blade (13).

5. A milling cutter for machining ductile iron according to claim 1, characterized in that, A large-volume open chip removal groove (23) is provided between adjacent cutting edge bodies (21) facing the shank (11), and an arc-shaped guide surface (231) is provided at the bottom of the chip removal groove (23).

6. A milling cutter for machining ductile iron according to claim 1, characterized in that, The cutter body assembly (1) is provided with a coolant channel that extends through the interior. The coolant channel includes at least four spray holes that are evenly arranged in a circumferential direction. The outlet of the spray holes is directly opposite the cutting area of ​​the cutting edge body (21).

7. A milling cutter for machining ductile iron according to claim 1, characterized in that, Both the blade assembly (1) and the blade assembly (2) are made of CBN material.

8. A milling cutter for machining ductile iron according to claim 1, characterized in that, The dimensional accuracy of the blade assembly (2) can reach ±0.005mm, and its surface roughness ranges from Ra0.8 to Ra0.4μm.

Images