A cutting tool with double-layer indexable insert synchronous rough and finish machining

Abstract

The utility model relates to the technical field of milling cutter, concretely is a kind of cutting tool with double-layer indexable insert synchronous rough and finish machining, the utility model uses double-layer insert structure, the inner layer's triangular circular arc insert is responsible for finish machining, the outer layer's autorotation circular insert is responsible for roughing, can complete roughing and finish machining procedure simultaneously in one machining process, significantly improve processing efficiency. Under different working conditions, through the reasonable division of labour of inner and outer layer inserts, processing demand can be better satisfied, the problem of frequent replacement or multiple clamping of traditional cutter is avoided, and processing accuracy and stability are improved.

Description

Technical Field

[0001] This utility model relates to the field of milling cutter technology, specifically a cutting tool with double-layer indexable inserts for simultaneous roughing and finishing. Background Technology

[0002] In the field of modern precision machining, the machining efficiency of face milling cutters directly determines the surface accuracy and production efficiency of complex workpieces. In particular, in the machining of key components such as aerospace aluminum alloy structural parts and hardened steel planes of automotive molds, stringent requirements are placed on the adaptability of the cutting tools to working conditions, chip removal and cooling performance, and tool changing efficiency.

[0003] Traditional face milling cutters generally use a single-layer insert structure. Their single function leads to multiple technical bottlenecks in the machining process. On the one hand, single-layer inserts need to frequently switch between the large depth of cut and high load conditions of roughing and the thin-layer cutting and high precision requirements of finishing. For example, when machining complex curved surfaces of titanium alloys, roughing (depth of cut ≥ 5mm) must be completed first with a large arc cutting edge insert, and then a small tip angle insert must be used for finish milling (depth of cut ≤ 0.5mm). The step-by-step operation leads to a 40%-60% increase in the machining cycle, and the positioning error introduced by multiple tool settings can reach ±0.02mm, which is difficult to meet the requirements of high-precision machining. On the other hand, the chip removal and cooling structure design of single-layer inserts has inherent defects: the long, curled chips generated during roughing are prone to entangle the cutting edge (especially when machining sticky materials such as stainless steel), and traditional external cooling methods are difficult to effectively reduce the temperature of the cutting zone (the measured cutting edge temperature can reach more than 800°C), causing the insert to fail due to thermal wear; while during finishing, if the thin-sheet chips cannot be broken off and discharged in time, they will form scratches on the machined surface (the roughness Ra value can deteriorate to more than 1.6μm).

[0004] From a structural design perspective, the existing fixed installation method of single-layer inserts reveals significant shortcomings: the inserts are rigidly locked to the tool body with screws, and replacing a single worn insert requires disassembling the entire tool head, with an average tool change time of more than 5 minutes, and the positioning accuracy of the inserts depends on manual adjustment; at the same time, a single insert needs to take into account different cutting loads, resulting in stress concentration at the root of the cutting edge during roughing (stress value can reach 1200MPa), and a 30% increase in the incidence of micro-chipping of the cutting edge during finishing, and a reduction in the overall tool life of more than 25% compared to specialized cutting inserts.

[0005] With the increasing demand for high-efficiency machining in high-end manufacturing, enabling multiple processes to be completed in a single setup, the technical contradictions of traditional single-layer insert face milling cutters in terms of adaptability to multiple working conditions, chip removal and cooling efficiency, and ease of tool changing are becoming increasingly prominent. There is an urgent need to develop a dual-layer insert structure with functional division of labor to break through the performance limitations of single-layer inserts and achieve synergistic optimization of simultaneous roughing and finishing operations, efficient chip removal and cooling, and rapid indexing and changing. The dual-layer layout of an outer circular rotating insert and an inner triangular finishing insert proposed in this invention, through micro-textured self-driving technology, integrated internal cooling and chip breaking design, and an integrated mounting structure, is a systematic solution addressing the aforementioned industry pain points. Utility Model Content

[0006] The purpose of this invention is to provide a cutting tool with double-layer indexable inserts for simultaneous roughing and finishing, in order to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing, comprising:

[0009] The cutter head has a mounting hole and a cooling groove. The working surface of the cutter head has an inner cutter groove and an outer cutter groove, with the outer cutter groove located around the inner cutter groove.

[0010] The cutting tool includes a triangular arc insert disposed in the inner tool groove and a rotating circular insert disposed in the outer tool groove. The protrusion height of the triangular arc insert relative to the working surface is greater than that of the rotating circular insert relative to the working surface. The rotating circular insert is used for roughing and can rotate during cutting, while the triangular arc insert is used for finishing.

[0011] Preferably, the cutter head has a cooling channel, the inlet of the cooling channel is located at the cooling groove, and the outlet of the cooling channel is located at the inner cutter groove and opposite to the triangular arc blade. After the coolant enters from the inlet of the cooling channel, it is sprayed out from the outlet of the cooling channel to cool the triangular arc blade and the rotating circular blade.

[0012] Preferably, the rotating circular blade is mounted on the side wall of the outer blade groove by means of a bearing, and the rotating circular blade is provided with a circular blade boss and a spiral micro-texture, the spiral micro-texture being arranged in a circle along the rotating circular blade.

[0013] Preferably, the rotating circular blade is arranged at an angle of 5-12° on the sidewall of the outer blade groove, and one is arranged every 60° along the circumference of the blade disc.

[0014] Preferably, the triangular arc blade is provided with a triangular blade boss, and a chip breaking groove is provided below the cutting edge of the triangular arc blade.

[0015] Preferably, the triangular arc blade is arranged on the side wall of the inner blade groove at an angle of 5-12°, and one is arranged every 45° along the circumference of the blade disc.

[0016] Preferably, the size of the inlet of the cooling channel is larger than the size of the outlet of the cooling channel.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This utility model adopts a double-layer blade structure. The inner triangular arc blade is responsible for finishing, while the outer rotating circular blade is responsible for roughing. Roughing and finishing processes can be completed simultaneously in one machining process, which significantly improves machining efficiency. Under different working conditions, the reasonable division of labor between the inner and outer blades can better meet the machining requirements, avoid the problem of frequent tool changes or multiple clamping in traditional tools, and improve machining accuracy and stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the working surface (from below) of this utility model;

[0020] Figure 2 This is a top view of the structure of this utility model;

[0021] Figure 3 This is a side view of the structure of this utility model;

[0022] Figure 4 This is a cross-sectional structural diagram of the present invention;

[0023] Figure 5 This is a schematic diagram of the triangular arc blade of this utility model;

[0024] Figure 6 This is a schematic diagram of the structure of the self-rotating circular blade of this utility model.

[0025] In the diagram: 1. Cutter head; 2. Mounting hole; 3. Cooling groove; 4. Inner cutter groove; 5. Outer cutter groove; 6. Triangular circular cutter insert; 7. Rotating circular cutter insert; 8. Inlet; 9. Outlet; 10. Bearing; 11. Circular cutter boss; 12. Spiral microtexture; 13. Triangular cutter boss; 14. Chip breaker groove. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Please see Figures 1 to 6 This utility model provides a technical solution:

[0028] A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing, comprising:

[0029] The cutter head 1 is circular in shape and has a double-layer blade structure. The cutter head 1 has a mounting hole 2 for mounting the cutter head 1. A cooling groove 3 is provided at the mounting hole 2. The working surface of the cutter head 1 has an inner groove 4 and an outer groove 5, with the outer groove 5 located around the inner groove 4.

[0030] The cutting tool includes a triangular arc insert 6 housed in the inner tool groove 4 and a rotating circular insert 7 housed in the outer tool groove 5. The tool employs a hexagonal screw positioning structure. The rotating circular insert 7 has a built-in bearing 10, whose outer ring is fixed to the outer tool groove 5 by hexagonal screws. The rotating circular insert 7 can rotate around the inner ring of the bearing 10, and has multiple circumferentially distributed cutting edges. Changing the cutting edge simply requires loosening the screws and rotating the insert. The triangular arc insert 6 is locked in place by hexagonal screws, and its bottom positioning point ensures installation accuracy. The triangular arc insert 6 has multiple indexable cutting edges, simplifying the cutting edge changing operation. This structure enables rapid insert changing, ensuring machining accuracy and efficiency in various working conditions.

[0031] The radius of the arc of the triangular circular arc insert 6 is equal to the side length of the inner equilateral triangle. Based on the equal width characteristic of the Reilly triangle, its constant width can ensure that the cutting height remains unchanged, eliminate the fluctuation of the cutting depth, and ensure the workpiece size and shape accuracy.

[0032] The triangular arc insert 6 is provided with a triangular cutting head 13 and an inverted trapezoidal chip breaker groove 14 below the cutting edge. The triangular arc insert 6 is installed at an angle of 5-12° in the inner cutting groove 4 opened in the central area of ​​the cutter head 1, and is densely arranged at 45° around the circumference of the cutter head 1, focusing on finishing of thin layer cutting of 0.1-0.5mm to ensure the accuracy of the machined surface.

[0033] The self-rotating circular insert 7 is mounted on the side wall of the outer groove 5 of the cutter head 1 at an angle of 5-12° and is evenly distributed along the circumference of the cutter head 1 at 60°. It is mainly responsible for roughing, and its circular cutting edge can adapt to large depth of cut conditions, efficiently removing the blank material. The self-rotating circular insert 7 is provided with a circular cutter boss 11, and a spiral micro-texture 12 is evenly arranged on the rake face. The insert has an internal bearing 10, which enables it to rotate autonomously during cutting.

[0034] The cutting blade is installed at a 5-12° angle. This special installation angle optimizes the distribution of cutting force, reduces vibration and noise during the cutting process, and improves machining stability and surface quality. At the same time, the angled installation also makes it easier for chips to be discharged, further improving the chip removal effect.

[0035] The circular cutter boss 11 on the rotating circular insert 7 cooperates with the helical microtexture 12. During the cutting process, the chip impact force and airflow act on the circular cutter boss 11 and the helical microtexture 12, driving the rotating circular insert 7 to rotate. The bearing 10 inside the rotating circular insert 7 reduces rotational resistance, allowing the rotational speed of the rotating circular insert 7 to be adaptively adjusted according to the cutting load, evenly distributing the wear area of ​​the rotating circular insert 7, and extending the service life of the rotating circular insert 7.

[0036] The triangular circular arc insert 6 forms a height difference of about 1mm in the axial direction. The triangular circular arc insert 6 is in a higher position, while the rotating circular insert 7 is in a lower position. This arrangement allows roughing and finishing to be carried out simultaneously.

[0037] The cutter head 1 employs a double-layer insert structure. The inner triangular arc insert 6 is responsible for finishing, while the outer rotating circular insert 7 is responsible for roughing. The inner inserts are densely arranged, allowing the cutting force to be more evenly distributed across multiple inserts. Each insert bears a relatively smaller cutting load, thus reducing wear on individual inserts and extending the overall tool life. Simultaneously, the densely arranged inserts improve the quality of the machined surface and reduce surface roughness. The inner and outer inserts on the cutter head 1 are arranged at different angles: the outer inserts are evenly arranged at 60 degrees, while the inner inserts are evenly arranged at 45 degrees. The number of inner and outer inserts is not fixed, but the number of inner inserts used for finishing is greater than that of outer inserts, significantly improving tool durability, enabling more efficient surface finishing, and drastically reducing surface roughness, providing reliable assurance for precision machining.

[0038] The combination of triangular and circular inserts fully leverages the advantages of both. Circular inserts offer a larger cutting area and stronger roughing capability, quickly removing large amounts of material. The circular insert designed in this invention can rotate, and the built-in bearing 10 reduces friction during rotation. The alternating operation of the cutting edges ensures even wear, improving machining performance. The triangular insert employs a Reilly triangle structure. The unique equal-width geometry of the Reilly triangle maintains a constant cutting height. A stable cutting height reduces cutting force fluctuations, decreases machining vibration and noise, improves surface finish, and allows for a lower principal cutting edge angle and reduced cutting thickness, thereby reducing cutting force. It also boasts high cutting edge strength and excellent finishing performance, meeting the requirements of high-precision machining. The combination of these two design elements ensures the end mill performs exceptionally well at different machining stages.

[0039] The cutter head 1 has a cooling channel. The inlet 8 of the cooling channel is located at the cooling tank 3, and the outlet 9 of the cooling channel is located at the inner cutter groove 4 and is opposite to the triangular arc cutter 6. After the coolant enters from the inlet 8 of the cooling channel, it is sprayed out from the outlet 9 of the cooling channel to cool the triangular arc cutter 6 and the rotating circular cutter 7. The cooling channel is connected to the external coolant supply system. The outlet 9 of the cooling channel is on the same plane as the cutting part of the cutter, which can directly flush the cutting part and provide cooling and chip removal power for the cutting process.

[0040] The cooling channel inside the cutter head 1 has a structure with a coarse inlet 8 and a narrow outlet 9, which can create a pressure difference, causing the coolant to flow in from the cooling channel inlet 8, accelerate through the channel, and then be sprayed at high speed from the cooling channel outlet 9 to the cutting area of ​​the cutting tool. This, together with the chip breaker groove 14, achieves efficient chip removal and cooling.

[0041] The cooling channels inside the cutter head 1 feature a coarse inlet (8mm) and a fine outlet (9mm), creating a pressure difference that allows the coolant to precisely flush the cutting edge with strong pressure. Simultaneously, the chip-breaking grooves 14 on the surface of the triangular arc-shaped inserts 6 work efficiently with the cooling channels: the chip-breaking grooves 14 forcibly break continuous chips into short fragments by changing the chip flow direction; and the coolant sprayed from the cooling channels quickly washes these fragments away from the cutting area, preventing chip accumulation and entanglement. These two elements complement each other, meeting chip removal requirements, ensuring smooth machining, effectively reducing cutting temperature, significantly improving tool cutting performance, and greatly enhancing machining efficiency and quality.

[0042] The inverted trapezoidal inner chip-breaking groove 14 of the triangular arc insert 6, with its gradually narrowing structure (wider at the front and narrower at the back), applies fracture stress to the chips. The chips mix with the coolant sprayed from the cooling channel and are discharged from the side of the insert body, preventing chip entanglement from affecting machining accuracy.

[0043] Working principle: The self-rotation drive is achieved through the synergy of cutting force and coolant power: the teardrop-shaped spiral micro-weave on the rake face of the self-rotating circular insert 7 generates an initial thrust during cutting due to friction caused by the high-pressure coolant. The axial and longitudinal forces of the workpiece reaction form an eccentric torque, which automatically increases the speed of the drive insert as the cutting load increases. The built-in low-friction bearing 10 provides stable support for the rotation of the self-rotating circular insert 7, reduces resistance and suppresses vibration, and ensures that the self-rotating circular insert 7 can continue to rotate under different working conditions through the composite drive force, so that the cutting edge alternates to balance wear and improve the overall machining performance. The cutter head 1 has a cooling channel inside, with a coarse inlet 8 and a fine outlet 9. The height difference between the triangular arc insert 6 and the self-rotating circular insert 7 is about 1mm. The triangular arc insert 6 is installed at a slightly higher height than the self-rotating circular insert 7. The triangular arc insert 6 is responsible for finishing, and the self-rotating circular insert 7 is responsible for roughing.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing, characterized in that, include: The cutter head has a mounting hole and a cooling groove. The working surface of the cutter head has an inner cutter groove and an outer cutter groove, with the outer cutter groove located around the inner cutter groove. The cutting tool includes a triangular arc insert disposed in the inner tool groove and a rotating circular insert disposed in the outer tool groove. The protrusion height of the triangular arc insert relative to the working surface is greater than that of the rotating circular insert relative to the working surface. The rotating circular insert is used for roughing and can rotate during cutting, while the triangular arc insert is used for finishing.

2. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 1, characterized in that: The cutter head has a cooling channel. The inlet of the cooling channel is located at the cooling groove, and the outlet of the cooling channel is located at the inner cutter groove and opposite to the triangular arc blade. After the coolant enters from the inlet of the cooling channel, it is sprayed out from the outlet of the cooling channel to cool the triangular arc blade and the rotating circular blade.

3. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 1, characterized in that: The rotating circular blade is mounted on the side wall of the outer blade groove by means of a bearing. The rotating circular blade is provided with a circular blade boss and a spiral micro-texture, and the spiral micro-texture is arranged in a circle along the rotating circular blade.

4. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 3, characterized in that: The rotating circular blade is set at an angle of 5-12° on the sidewall of the outer blade groove, and one is set every 60° along the circumference of the blade disc.

5. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 3, characterized in that: The triangular arc blade is provided with a triangular blade boss, and a chip breaking groove is provided below the cutting edge of the triangular arc blade.

6. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 5, characterized in that: The triangular arc blades are arranged on the side wall of the inner blade groove at an angle of 5-12°, and one is arranged every 45° along the circumference of the blade disc.

7. A cutting tool with double-layer indexable inserts for simultaneous roughing and finishing according to claim 2, characterized in that: The size of the inlet of the cooling channel is larger than the size of the outlet of the cooling channel.

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