Micro-diameter rotary cutting tool with rigidity enhancing structure

Abstract

The application discloses a micro-diameter rotary cutting tool with a rigidity reinforcing structure, characterized in that at least the cutter body is made of integral hard alloy material, the diameter is 0.2 mm to 6 mm, a plurality of cutting edges are arranged on the cutter body, a chip groove is arranged between adjacent cutting edges, the chip groove has a groove bottom surface, one or a plurality of groove bottom surface protrusions are arranged on the groove bottom surface, so that the cross-sectional area of the cutter body is locally increased in the area where the groove bottom surface protrusions are arranged, and the groove bottom surface protrusions are arranged so that the cross-sectional area of the chip groove at the area is reduced by less than 30%. The application aims at three technical bottlenecks of the micro-diameter milling cutter in precision machining, i.e., chip removal difficulty, insufficient rigidity and vibration sensitivity, and realizes comprehensive improvement of the performance of the micro-diameter cutter through innovative rigidity reinforcing structure design.

Description

Technical Field

[0001] This invention relates to the field of cutting technology, and more specifically, to a micro-diameter rotary cutting tool with a rigid reinforcement structure and its preparation method. Background Technology

[0002] In the field of precision manufacturing, micro-end mills are key tools for achieving sub-millimeter-level feature machining, and their performance directly determines the machining accuracy and production efficiency of micro-components. With continuous technological advancements, high-end manufacturing fields such as microelectronic packaging structures, precision medical implants (e.g., micro-threaded bone screws), aerospace micro-sensor cavities, and optical diffraction elements are placing increasingly higher demands on the machining accuracy of micro-components, posing even more stringent challenges to the performance of micro-end mills. Traditional design methods, when reducing tool size, result in a geometrical decrease in the tool's bending and torsional rigidity, leading to a high susceptibility to elastic deformation and even fracture during machining, severely impacting machining accuracy and production efficiency. Furthermore, the heat dissipation and chip removal performance of existing micro-end mills are insufficient to meet the demands of high-precision machining. Due to limited chip groove space, chips tend to remain in the cutting area when machining viscous materials, not only triggering secondary cutting and accelerating tool wear but also potentially causing a decline in the surface finish. Meanwhile, the insufficient heat dissipation channel design in the cutting edge area leads to the accumulation of cutting heat, resulting in a generally short lifespan for micro-diameter end mills when machining high-temperature alloys and brittle materials, as well as insufficient stability of the machined surface quality, which seriously restricts the further development of precision machining technology. Summary of the Invention

[0003] This invention provides a micro-diameter rotary cutting tool with a rigid reinforcement structure and its preparation method, specifically including the following embodiments:

[0004] Implementation Method 1. A micro-diameter rotary cutting tool with a rigid reinforcement structure, characterized in that it comprises:

[0005] Blade body,

[0006] Optional tool holders for direct or indirect connection to machine tools.

[0007] An optional chin for connecting the blade body and the handle.

[0008] At least the blade body is made of a single piece of cemented carbide, with a diameter ranging from 0.2 mm to 6 mm.

[0009] The tool body has multiple cutting edges arranged along its circumference, and chip removal grooves extending along the axial direction of the tool body are provided between adjacent cutting edges. The chip removal grooves have a bottom surface.

[0010] The bottom surface of the groove is provided with one or more groove bottom surface protrusions arranged at intervals, thereby increasing the cross-sectional area of ​​the cutter body locally in the area where the groove bottom surface protrusions are provided, and the groove bottom surface protrusions are provided so that the cross-sectional area of ​​the chip removal groove at that location is reduced by less than 30%.

[0011] Embodiment 2. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that the height of the protrusion on the bottom surface of the groove accounts for 20% to 80% of the depth of the chip removal groove, for example, 20% to 60%, for example, 40% to 60%.

[0012] Implementation Method 3. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Implementation Method 1 is characterized in that, in the axial direction of the tool body, the groove bottom surface protrusion has a convex arc-shaped top profile, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, and the ratio of its top width to its root width is 0.3 to 0.8:1, for example, 0.4 to 0.7:1.

[0013] Embodiment 4. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that, when multiple groove bottom surface protrusions are provided, the ratio of the distance between adjacent groove bottom surface protrusions to the depth of the chip removal groove is 0.3 to 10, for example 0.5 to 10, for example 0.6 to 10.

[0014] Implementation Method 5. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Implementation Method 1 is characterized in that the groove bottom surface protrusion is simultaneously provided at the corresponding positions of adjacent chip removal grooves, that is, the groove bottom surface protrusion is distributed along the circumferential direction of the tool body in the chip removal groove, thereby increasing the core thickness of the tool body.

[0015] Implementation Method 6. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Implementation Method 5 is characterized in that the groove bottom protrusions provided at different positions in the axial direction of the tool body have varying dimensions, so that the core thickness increase value at different positions in the axial direction of the tool body varies.

[0016] Implementation Method 7. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Implementation Method 1 is characterized in that the groove bottom surface protrusion is provided only within the range of increased core thickness of the tool body.

[0017] Implementation Method 8. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Implementation Method 1 is characterized in that the same groove bottom surface protrusion has a varying height, with its highest point located at the lowest point of the groove bottom surface.

[0018] Embodiment 9. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that, in the direction perpendicular to the axis of the tool body, the height of the protrusion on the bottom surface of the same groove changes in opposite directions to the depth of the bottom surface of the groove.

[0019] Embodiment 10. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that, in a direction perpendicular to the axis of the tool body, the bottom surface of the same groove protrudes with a convex arc-shaped top profile.

[0020] Embodiment 11. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that the bottom protrusion of the groove extends downward or horizontally in the direction of the cutting edge within the chip removal groove.

[0021] Embodiment 12. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that, in the axial direction of the tool body, the axial dimension of the protrusion on the bottom surface of the chip removal groove is less than or equal to one-half of the axial dimension of the bottom surface, for example, less than or equal to one-third of the axial dimension of the bottom surface.

[0022] Embodiment 13. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 1 is characterized in that the chip removal groove further has a surface facing the cutting rotation direction, which is a rake face, and the top of the protrusion of the groove bottom surface is connected to the rake face, that is, the protrusion of the groove bottom surface extends to the rake face.

[0023] Embodiment 14. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 13, characterized in that the rake face has a corrugated rake face protrusion and concavity, the corrugated rake face protrusion and concavity comprising one or more rake face protrusions and one or more rake face concave portions, the rake face protrusions and the rake face concave portions being arranged sequentially in the extending direction of the chip removal groove, thereby causing the rake face to intersect with the outer peripheral surface of the tool body to form the corrugated cutting edge of the cutting edge.

[0024] The top of the raised section of the groove bottom surface is connected to the recessed portion of the front cutting face, that is, the raised section of the groove bottom surface extends into the recessed portion of the front cutting face.

[0025] Embodiment 15. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to Embodiment 13, characterized in that the wavelength of the corrugated cutting edge is 0.2 mm to 1.5 mm and the amplitude is 5 micrometers to 0.5 mm.

[0026] Embodiment 16. Preparation of a micro-diameter rotary cutting tool with a rigid reinforcement structure as described in any one of Embodiments 1 to 15, characterized in that the groove bottom surface protrusion is prepared by a machining method that does not produce thermal damage.

[0027] Implementation Method 17. The method according to Implementation Method 16, wherein the protrusion on the bottom surface of the groove is prepared by a femtosecond pulsed laser processing method.

[0028] Embodiment 18. A method for preparing a micro-diameter rotary cutting tool according to any one of Embodiments 1 to 15, characterized in that it comprises the following steps:

[0029] Chip removal grooves are ground into the blank of a rotary cutting tool to form the bottom surface of the grooves.

[0030] A femtosecond pulsed laser processing method is used to process a groove bottom protrusion on the groove bottom surface.

[0031] This application addresses three major technical bottlenecks faced by micro-diameter end mills (diameter ≤ 6mm) in precision machining: chip removal difficulties, insufficient rigidity, and vibration sensitivity. Through an innovative rigidity-enhancing structural design, it achieves a comprehensive improvement in the performance of micro-diameter tools. Its beneficial technical effects mainly include:

[0032] 1. This application increases the cross-sectional area of ​​the tool body by setting a raised bottom surface of the groove to form a rigidity-enhancing structure. This significantly improves the bending / torsional rigidity of the tool, reduces the risk of tool deflection, chipping, and breakage, and significantly improves machining stability, thereby increasing tool life and supporting higher speeds and feed rates. At the same time, the raised bottom surface of the groove reduces the cross-sectional area of ​​the chip removal groove by less than 30%, thus preserving sufficient chip removal space. This breaks through the traditional mutual exclusion of "rigidity-chip removal" in micro-tools, ensuring smooth chip removal while increasing tool rigidity.

[0033] 2. The raised bottom surface of the groove in this application enables the chips to leave the machining area quickly, avoids secondary cutting problems caused by chip accumulation, reduces unnecessary friction between the tool and the chips, and significantly improves chip removal efficiency by "lifting" the chips through the raised surface. This avoids tool damage or surface vibration caused by poor chip removal, thereby improving the surface finish and dimensional accuracy of the machined surface.

[0034] 3. The raised bottom surface of the tank enhances the flow of cutting fluid, improves heat dissipation efficiency, and reduces thermal damage.

[0035] The cutting tools employing the rigid reinforcement structure of this application possess both high stability and long lifespan, enabling them to adapt to deep cavity milling and thin-walled microstructure machining of challenging materials such as titanium alloys and high-temperature alloys, achieving simultaneous improvement in surface roughness and precision. They have broad application prospects in the microelectronics, medical device, aerospace, and mold manufacturing industries. For example, in PCB milling, chip packaging structure milling, precision forming of endoscope components, micro-sensor cavity machining, and detailed engraving of optical lens cores and microfluidic chip molds, these cutting tools demonstrate their superior performance, becoming indispensable core tools in the field of micro-manufacturing. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0037] Figure 1 This is a schematic diagram of the micro-diameter end mill with a rigid reinforcement structure used in Example 1;

[0038] Figure 2 This is a schematic diagram of the blade body.

[0039] Figure 3 This is a cross-sectional view of the cutter body at the protrusion on the bottom surface of the groove;

[0040] Figure 4 This is a cross-sectional view of the cutter body along the axis of the cutter body at the protrusion on the bottom surface of the groove;

[0041] Figure 5 This is a schematic diagram of the micro-diameter end mill body with a rigid reinforcement structure used in Example 6;

[0042] Figure 6 This is a cross-sectional view of the cutter body at the protrusion on the bottom surface of the groove;

[0043] Figure 7 This is a schematic diagram of the micro-diameter end mill body with a rigid reinforcement structure used in Example 7;

[0044] Figure 8 This is a schematic diagram of the micro-diameter end mill body with a rigid reinforcement structure in Example 8;

[0045] Figure 9 This is a schematic diagram of the blade body;

[0046] Figure 10 This is a schematic diagram showing the changes in the cross-section of the rigidity-reinforced structure.

[0047] Reference numerals: 100-tool body, 200-tool shank, 300-tool neck, 110-cutting edge, 120-chip groove, 10-rake face, 11-rake face protrusion, 12-rake face depression, 20-groove bottom, 30-corrugated cutting edge, 40-groove bottom protrusion. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0049] This application discloses a micro-diameter rotary cutting tool with a rigid reinforcement structure. The micro-diameter rotary cutting tool comprises: a tool body; an optional tool holder for direct or indirect connection to a machine tool; and an optional tool neck for connecting the tool body and the tool holder. At least the tool body is made of a single piece of cemented carbide with a diameter of 0.2 mm to 6 mm. The tool body has multiple cutting edges, and chip removal grooves are provided between adjacent cutting edges. Each chip removal groove has a bottom surface, and one or more groove bottom surface protrusions are provided on the bottom surface, thereby locally increasing the cross-sectional area of ​​the tool body in the area where the groove bottom surface protrusions are provided. Furthermore, the groove bottom surface protrusions reduce the cross-sectional area of ​​the chip removal groove at that location by less than 30%.

[0050] In this application, "micro-diameter rotary cutting tool" refers to a rotary cutting tool with a tool body diameter greater than or equal to 0.2 mm and less than or equal to 6 mm. "Cross-section" refers to a cross-section perpendicular to the axis of the tool body. The cross-sectional area of ​​the tool body refers to the area of ​​the tool body material portion within the cross-section of the tool body. The cross-sectional area of ​​the chip removal groove refers to the area of ​​the chip removal groove portion within the cross-section of the tool body. The cross-sectional area of ​​the tool body and the cross-sectional area of ​​the chip removal groove together constitute the area of ​​the tool body cutting the outer circle of the rotary cutting.

[0051] In some embodiments, the diameter of the blade body is 0.5 mm to 6 mm, for example 0.6 mm to 5 mm, for example 0.8 mm to 4 mm, for example 1 mm to 3 mm, for example 0.8 mm to 3 mm.

[0052] This application incorporates a raised groove bottom surface to locally increase the cross-sectional area of ​​the tool body, thereby increasing the amount of material used in the tool and enhancing its strength and rigidity. Those skilled in the art can rationally select the raised surface based on the tool body diameter, core thickness, and length-to-diameter ratio. Typically, the raised groove bottom surface increases the cross-sectional area of ​​the tool body by more than 5%, 8%, 10%, or 15% compared to when the raised surface is not present. This application does not limit the specific shape of the raised groove bottom surface; the increase in cross-sectional area refers to the maximum range of increase after the raised surface is incorporated, not a requirement that every location with the raised surface must reach this value. The number of raised groove bottom surfaces is closely related to the length-to-diameter ratio of the tool body; the larger the length-to-diameter ratio, the more raised surfaces should be. When the length-to-diameter ratio of the tool is less than 2, a single raised surface can achieve good results.

[0053] This application limits the reduction in the cross-sectional area of ​​the chip removal groove caused by setting the bottom surface protrusion to be less than 30%, for example, less than 25%, less than 20%, or less than 15%. This application limits the reduction ratio of the cross-sectional area of ​​the chip removal groove to the maximum range of reduction in the cross-sectional area of ​​the chip removal groove after setting the bottom surface protrusion. An excessively large protrusion size will block the chip removal channel, thereby adversely affecting chip removal.

[0054] The chip removal groove in this application can be a straight groove extending parallel to the axial direction of the tool body, an inclined groove extending obliquely along the axial direction of the tool body, or a spiral groove extending spirally along the axial direction of the tool body. The protrusions on the bottom surface of the groove can be provided simultaneously in all chip removal grooves, or only in some chip removal grooves. They can be provided simultaneously in the same position in different chip removal grooves, or in different positions in different chip removal grooves, so that the different protrusions are staggered.

[0055] Existing micro-diameter end mills face a "rigidity-chip removal" mutual constraint. Only by increasing the size of the chip flute and providing sufficient chip removal space can chip retention be avoided. However, increasing the chip flute size inevitably means a decrease in tool strength, and the tool cannot obtain the required rigidity. For tools with a diameter of 6mm or more, the tool body can retain sufficient core thickness to obtain the required strength while also providing sufficient chip removal space, thus avoiding this mutual constraint. This mutual constraint is an important reason restricting the application of micro-diameter end mills in the field of precision manufacturing. However, the inventors unexpectedly discovered that although the convex design of the bottom surface of the flute locally reduces the cross-sectional area of ​​the chip removal groove, when the local cross-sectional area of ​​the chip removal groove is not significantly reduced, such as when the reduction value is less than 30% as specified in this application, it can not only enhance the rigidity of the tool, allowing the tool to be set with a larger length-to-diameter ratio, but also accelerate chip removal, significantly improve chip removal efficiency, thereby extending tool life and improving machining accuracy.

[0056] Unrestricted by theory, the mechanism by which the rigidity-enhanced structure of this application improves chip removal efficiency may lie in the following: When chips enter the chip removal groove, the raised bottom surface forms micro-fulcrums that partially "lift" the chips away from the groove bottom surface. This transforms the originally attached and sliding chips into a jumping motion pattern of alternating contact with the micro-fulcrums. Under centrifugal force, the chips continuously shift outward. With the high-speed rotation of the tool, the lifting action of the raised bottom surface acts as a guide, rapidly directing the chips to the outer periphery of the tool, reducing contact between the chips and the machined surface. The raised bottom surface, under the high-speed rotation of the tool, forms a "screw conveyor"-like propulsion structure, which helps the chips exit along a predetermined path, reducing the risk of chip blockage and maintaining the continuity of the machining process. Furthermore, the raised bottom surface forms a constantly changing curved surface, continuously disturbing and altering the flow path of the chips and coolant during tool rotation, breaking the flow balance and forming a pulsed propulsion that significantly improves chip removal efficiency. In addition, the rigidity-enhanced structure reconstructs the characteristics of the chip removal flow field. The bulge at the bottom of the groove accelerates the fluid through the contraction of the flow channel, and a low-pressure adsorption zone is generated behind the bulge. This causes a qualitative change in the material transport efficiency in the micro-scale chip removal channel, which not only eliminates the machining vibration caused by chip retention in traditional micro-diameter tools, but also achieves a breakthrough improvement in tool life by reducing frictional heat accumulation.

[0057] This application's unique rigidity-enhanced structure breaks through the traditional mutually exclusive limitation of "rigidity-chip removal" in micro-tools. While significantly improving chip removal efficiency, it optimizes stress transmission paths by locally increasing the cross-sectional area of ​​the tool body through raised groove bottoms, thereby enhancing the overall rigidity of the tool. This not only strengthens the micro-diameter end mill's resistance to bending and torsion, reduces elastic deformation during machining, ensures dimensional accuracy, guarantees smooth chip removal, and reduces tool breakage rates, but its high rigidity also reduces the risk of chipping due to chatter, allowing for higher length-to-diameter ratios, exhibiting superior performance, especially in side milling and deep cavity machining. It enables the tool to operate at higher spindle speeds and feed rates, thus improving machining efficiency without sacrificing tool life.

[0058] In some embodiments, the aspect ratio of the micro-diameter rotary cutting tool is 5 or higher, or 6 or higher. Prior art micro-diameter end mills typically have an aspect ratio of less than 4; the rigidity-enhancing structure provided in this application allows the tool to have a higher aspect ratio.

[0059] In some embodiments, the height of the protrusion on the bottom surface of the chip removal groove accounts for 20% to 80% of the depth of the chip removal groove, for example, 20% to 60%, 40% to 60%, or 20% to 40%. In this application, the percentage of the height of the protrusion on the bottom surface of the chip removal groove to the depth of the groove refers to the percentage of the maximum height of the protrusion on the bottom surface of the groove to the depth of the chip removal groove. The maximum height of the protrusion on the bottom surface of the groove determines the maximum distance that the chips are partially lifted away from the bottom surface of the groove after entering the chip removal groove. It can be set within a wide range, as long as it is ensured that the protrusion is not too high, causing friction between the chips and the machined surface.

[0060] In some embodiments, the groove bottom surface protrusion has a convex arc-shaped top profile along the tool body axis, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, with the ratio of the top width to the root width being 0.3 to 0.8:1, for example, 0.4 to 0.7:1. That is, along the tool body axis, the bottom of the groove bottom surface protrusion is wider at the bottom and narrower at the top. This structural design makes the groove bottom surface protrusion stronger, better serving as a reinforcing rib, while providing a chip removal guiding surface, forming a better chip propulsion structure under high-speed tool rotation. Here, "top width" refers to the maximum axial width measured within the top range above two-thirds of the groove bottom surface protrusion height, and "root width" refers to any axial width measured within the range below one-third of the groove bottom surface protrusion height, as long as the ratio between the two axial widths meets the above range.

[0061] In some embodiments, when multiple groove bottom protrusions are provided, the ratio of the distance between adjacent groove bottom protrusions to the depth of the chip removal groove is 0.3 to 10, for example 0.5 to 10, for example 0.6 to 10, for example 0.3 to 8, for example 0.5 to 8, for example 0.6 to 8, for example 0.3 to 6, for example 0.5 to 6, for example 0.6 to 6, for example 0.3 to 5, for example 0.5 to 5, for example 0.6 to 5, for example 1 to 5, for example 1 to 10, for example 0.6 to 3. The larger the chip removal groove size, the larger the chip-holding space. An excessively large chip-holding space will reduce the speed and efficiency of chip flow out of the cutting area. A smaller chip removal groove size means a smaller chip removal distance, resulting in a higher speed and efficiency of chip flow out of the cutting area. However, an excessively small chip-holding space can easily lead to chip retention and blockage. In this application, the raised areas on the bottom of the chip groove "lift" the chips, preventing them from entering the bottom of the groove and thus reducing the chip removal distance. Areas without raised areas provide a larger chip-holding space, preventing chip retention and blockage. The distance between adjacent raised areas, including the area without raised areas, directly affects chip removal efficiency. If the ratio is too small, the raised areas are too dense, significantly reducing the chip-holding space and causing chip retention. If the ratio is too large, the raised areas are too dispersed, also reducing chip removal efficiency and negatively impacting tool rigidity. The raised chip groove design in this application allows the tool to combine the advantages of large and small chip grooves, simultaneously improving both chip removal efficiency and tool rigidity. Those skilled in the art can select an appropriate range for the ratio of adjacent raised areas to the chip groove depth based on factors such as the tool's diameter and length-to-diameter ratio.

[0062] In this application, the "spacing between adjacent groove bottom surface protrusions" can be measured axially along the tool body, taking into account the specific shape of the groove bottom surface protrusions. For example, it can measure the axial distance between the roots of adjacent groove bottom surface protrusions, or the axial distance between the tops of adjacent groove bottom surface protrusions, or the axial distance between the top of one groove bottom surface protrusion and the root of an adjacent groove bottom surface protrusion. The "chip removal groove depth" is measured radially along the tool body, referring to the distance between the lowest point of the groove bottom surface and the outer circle of the tool body during cutting rotation.

[0063] In some embodiments, the groove bottom protrusions are simultaneously provided at corresponding positions in adjacent chip removal grooves, that is, the groove bottom protrusions are distributed along the circumference of the cutter body within the chip removal grooves, thereby increasing the core thickness of the cutter body. Locally increasing the core thickness of the cutter body in the area where the groove bottom protrusions are provided can achieve greater rigidity.

[0064] In some embodiments, the groove bottom protrusions at different positions along the axial direction of the cutter body have varying dimensions, causing the increase in core thickness at different positions along the axial direction of the cutter body to vary. For example, the groove bottom protrusions are designed to cause the local core thickness of the cutter body to gradually increase away from the shank, or the groove bottom protrusions are designed to cause the local core thickness of the cutter body to gradually increase towards the shank. This design allows the cutter body to have a higher length-to-diameter ratio and also provides a larger chip handling and removal space.

[0065] In some embodiments, the groove bottom surface protrusions are only provided within the range of increased core thickness of the cutter body. That is, within the cross-section of the cutter body, the groove bottom surface protrusions are all located within the range of the outer circle formed by the highest point of the groove bottom surface protrusion. This arrangement enhances the rigidity of the cutter body while retaining sufficient chip removal space. In a preferred embodiment, the tops of the groove bottom surface protrusions have the same circumscribed circle within the same cross-section of the cutter body. In a more preferred embodiment, the groove bottom surface protrusions are simultaneously provided at corresponding positions in adjacent chip removal grooves. That is, the groove bottom surface protrusions are distributed along the circumferential direction of the cutter body within the chip removal grooves, and the tops of the groove bottom surface protrusions have the same circumscribed circle within the same cross-section of the cutter body. With this arrangement, the highest points of the groove bottom surface protrusions at corresponding positions within the chip removal grooves collectively determine the increase in core thickness of the cutter body.

[0066] In some embodiments, the same bottom surface protrusion has a varying height, with its highest point located at the lowest point of the chip removal groove. The height of the bottom surface protrusion is measured with the bottom surface of the groove as the base. The varying height of the bottom surface protrusion can provide a better chip removal surface, and setting the bottom surface protrusion to have its maximum height at the lowest point of the concave arc surface of the chip removal groove can maximize the rigidity of the tool.

[0067] In some embodiments, the height of the raised bottom surface of the groove and the depth of the groove bottom surface change in opposite directions in a direction perpendicular to the tool body axis. The raised bottom surface extends from one side of the rake face away from the rake face within the chip evacuation groove. In this extension direction, the concave arc surface of the chip evacuation groove causes a change in the depth of the groove bottom surface, i.e., a change in the distance between the groove bottom surface and the outer circle of the tool body's cutting rotation. The height of the raised bottom surface and the depth of the groove bottom surface change in opposite directions, allowing the raised bottom surface to maximize tool rigidity while maintaining sufficient chip evacuation channels, and also achieving a shorter chip evacuation path, i.e., a better "lifting" effect on the chips, thus providing a superior chip evacuation surface.

[0068] In some embodiments, the same groove bottom surface protrusion has a convex arc-shaped top profile in a direction perpendicular to the tool body axis. That is, within a cross-section of the tool body, the groove bottom surface protrusion has a convex arc-shaped top profile, which can better improve tool rigidity while achieving a better "lifting" effect on chips and providing a superior chip removal surface.

[0069] In some embodiments, the groove bottom protrusion extends downward or horizontally within the chip removal groove towards the cutting edge. That is, the groove bottom protrusion extends from the side away from the rake face towards the rake face and the cutting edge. "Extending downward" and "extending horizontally" describe the direction of extension of the groove bottom protrusion when the tool body is vertically positioned downwards. By extending downward or horizontally towards the cutting edge, the flow of chips and coolant can be enhanced. When extending downward, the cutting fluid can be guided to the cutting edge area, and the chips can be guided upward to flow out of the cutting area.

[0070] In some embodiments, the axial dimension of the protrusion on the bottom surface of the chip removal groove is less than or equal to half of the axial dimension of the bottom surface, for example, less than or equal to half but greater than or equal to one-fifth of the axial dimension of the bottom surface, or for example, less than or equal to one-third but greater than or equal to one-fifth of the axial dimension of the bottom surface. Here, both the axial dimension of the protrusion and the axial dimension of the bottom surface are measured in the axial direction of the tool body. That is, the proportion of the axial dimension of the protrusion on the bottom surface does not exceed one-half or one-third of the axial dimension of the bottom surface, and is not less than one-fifth of the axial dimension of the bottom surface. This arrangement ensures enhanced tool body rigidity while improving chip removal efficiency without significantly reducing the chip capacity of the chip removal groove, thus guaranteeing smooth chip removal.

[0071] In some embodiments, the chip removal groove also has a face facing the cutting rotation direction, which is a rake face. The bottom surface of the groove is connected to the rake face, and the top of the raised portion of the bottom surface is connected to the rake face, meaning the raised portion of the bottom surface extends onto the rake face. This arrangement guides the coolant to the cutting edge area, reducing heat buildup in the cutting edge area and delaying the thermal softening of the tool material.

[0072] In some embodiments, the top of the raised bottom surface of the groove is connected to the recessed portion of the rake face. The rake face has a corrugated rake face protrusion and concavity, which includes one or more rake face protrusions and one or more rake face concavities. The rake face protrusions and the rake face concavities are arranged sequentially in the extending direction of the chip removal groove, so that the rake face intersects with the outer peripheral surface of the tool body to form the corrugated cutting edge of the cutting edge, that is, the raised bottom surface of the groove extends into the recessed portion of the rake face.

[0073] This application also uses the periodic undulation structure of the corrugated rake face to disperse the concentrated cutting force to multiple contact areas. Combined with the dynamic cutting characteristics of the corrugated cutting edge, it effectively suppresses high-frequency vibration and resonance, improves machining stability and surface finish, and is especially suitable for precision machining scenarios with thin walls and micro-structures.

[0074] The corrugated rake face also expands the heat dissipation surface area, and combined with the convex bottom of the groove to guide the cutting fluid, it forms a highly efficient heat conduction and convection cooling mechanism. This design effectively reduces heat accumulation in the cutting edge area and delays the thermal softening of the tool material, making it suitable for continuous machining of high-heat-load materials such as titanium alloys and high-temperature alloys.

[0075] The shape of the chip removal groove is determined by the shapes of the rake face and the bottom surface of the groove. The composite groove structure formed by the corrugated rake face and the raised bottom surface can synergistically control the chip shape and optimize the chip removal path, thereby improving chip removal efficiency. Specifically, the corrugated cutting edge generates curved chips, and the corrugated rake face intensifies the periodic curling of the chips, providing deformation space for the curling process. Under the high-speed rotation of the tool, the chips naturally shrink into smaller curled structures. This curling mechanism not only reduces the contact area between the chips and the tool, but also creates favorable conditions for subsequent removal through geometric changes. Under the high-speed rotation of the tool, the corrugated rake face diverts the cutting fluid into high-speed micro-vortices, enveloping the curled chips to form a swirling motion, providing a closely matched changing surface for the flow of chips and coolant. The raised bottom surface of the groove extending to the rake face can better intercept the cutting fluid, guide the cutting fluid to the cutting area, and better cooperate with the corrugated rake face.

[0076] The “composite groove type” described in this application includes the “rigid reinforcement structure” described in this application.

[0077] The collaborative design of the corrugated rake face and the raised bottom surface of the groove in this application gives the tool excellent chip removal performance, high rigidity, vibration resistance and thermal stability. It can meet the high dynamic load machining requirements such as deep cavity milling (high length-to-diameter ratio) and high feed side milling. It is especially suitable for fields with strict requirements for form and position accuracy and surface integrity, such as microelectronic packaging and medical implant threads.

[0078] In some embodiments, the wavelength of the corrugated cutting edge is 0.2 mm to 1.5 mm, and the amplitude is 5 μm to 0.5 mm. By precisely controlling the wavelength range between 0.2 mm and 1.5 mm (e.g., 0.2 mm to 1 mm) and the amplitude range between 5 μm and 0.5 mm (e.g., 5 μm to 0.1 mm, 5 μm to 0.15 mm, 5 μm to 0.18 mm), a periodic corrugated cutting edge structure is formed. This not only effectively modulates the cutting force, significantly reducing the fluctuation amplitude of the cutting force, but also significantly enhances the heat dissipation performance of the micro-area and significantly reduces the cutting temperature.

[0079] This application also discloses a micro-diameter rotary cutting tool employing the aforementioned groove shape, such as a micro-diameter end mill.

[0080] This application also discloses a method for preparing the aforementioned micro-diameter rotary cutting tool, wherein the groove bottom protrusion is prepared by a machining method that does not produce thermal damage.

[0081] In some embodiments, the protrusions on the bottom of the groove are prepared using a femtosecond pulsed laser processing method.

[0082] This application also discloses the aforementioned micro-diameter rotary cutting tool method, characterized in that it includes the following steps:

[0083] Chip removal grooves are ground into the rotary cutting tool blank to form the rake face and the bottom surface of the groove.

[0084] The groove shape is formed by machining a groove bottom protrusion on the groove bottom surface using a femtosecond pulsed laser processing method, and optionally machining a corrugated rake face concave-convex part on the rake face.

[0085] The scope described above can be used alone or in combination. The following examples will make this application easier to understand.

[0086] Example

[0087] Example 1

[0088] This embodiment provides a micro-diameter end mill with a rigid reinforcement structure, such as Figures 1 to 4 As shown, the micro-diameter milling cutter includes:

[0089] Blade body 100,

[0090] Tool holder 200 for connection with machine tools

[0091] The cervical neck 300 is used to connect the blade body and the handle.

[0092] The blade body is made of a single piece of cemented carbide, with a diameter of 2mm and a length of 4mm.

[0093] The tool body 100 has four cutting edges 110 arranged along its circumference, and chip removal grooves 120 extending obliquely along the axial direction of the tool body are provided between adjacent cutting edges. The depth of the chip removal grooves is 0.3 mm.

[0094] The chip removal groove 120 has a surface facing the cutting rotation direction, which is the rake face 10.

[0095] The chip removal groove 120 also has a concave arc surface that is connected to the rake face 10 and extends along the axial direction of the tool body, which is the bottom surface 20 of the groove.

[0096] The composite groove shape of the chip removal groove is determined by the shapes of the rake face 10 and the groove bottom surface 20, wherein,

[0097] Each of the four rake faces has a corrugated rake face protrusion and concavity, which includes three rake face protrusions 11 and two rake face concavities 12. The rake face protrusions and the rake face concavities are arranged sequentially in the extending direction of the chip removal groove, so that the rake face intersects with the outer peripheral surface of the tool body to form the corrugated cutting edge 30 of the cutting edge.

[0098] Each of the four groove bottom surfaces 20 is provided with two spaced groove bottom surface protrusions 40, thereby increasing the cross-sectional area of ​​the cutter body locally in the area where the groove bottom surface protrusions are provided, and the groove bottom surface protrusions are provided so that the cross-sectional area of ​​each chip removal groove at that location is reduced by less than 30%.

[0099] The groove bottom protrusions are simultaneously provided at corresponding positions in adjacent chip removal grooves, that is, the groove bottom protrusions are distributed along the circumference of the cutter body in the chip removal groove, thereby increasing the core thickness of the cutter body.

[0100] Figure 3 The diagram shows a cross-sectional view perpendicular to the tool body axis, taken at the highest point of the protrusion on the bottom surface of the groove at the end. The dashed circle represents the outer circle of the tool body during cutting. Figure 3 In the cross-section shown, the raised bottom surface of the groove increases the area of ​​the blade material by more than 5% compared to when the raised bottom surface of the groove is not provided, and the raised bottom surface of the groove reduces the area of ​​the blank part inside the dashed circle by about 25%.

[0101] exist Figure 3 In the cross-section shown, the bottom surface of the groove protrudes with a convex arc-shaped top profile. The maximum height of the bottom surface protrusion accounts for 40% of the depth of the chip removal groove, and its highest point is located at the lowest point of the concave arc surface.

[0102] Figure 4 A cross-sectional view along the axis of the cutter body is shown at the highest point of the protrusion on the bottom surface of the groove at the end. Figure 4 As shown, the groove bottom surface protrusion has a convex arc-shaped top profile, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, with the ratio of the top width to the root width ranging from 0.6 to 0.8:1.

[0103] exist Figure 4 In the cross-section shown, the ratio of the distance between the two bottom protrusions of the groove to the depth of the chip removal groove is 5.

[0104] The same groove bottom surface protrusion has a varying height, such as Figure 2As shown, the top of the protrusion on the bottom surface of the groove is connected to the recessed portion of the front cutting face, that is, the protrusion on the bottom surface of the groove extends into the recessed portion of the front cutting face.

[0105] When the cutter body is vertically positioned downwards, the protrusion on the bottom surface of the groove extends downwards at an angle toward the cutting edge within the chip removal groove. That is, the protrusion on the bottom surface of the groove extends upwards at an angle away from the rake face within the chip removal groove.

[0106] The wave pattern of the cutting edge has a wavelength of 1 mm and an amplitude of 0.18 mm.

[0107] Example 2

[0108] The overall structure of the rigid reinforced micro-diameter end mill in this embodiment is basically the same as that in Embodiment 1. The difference is that the diameter of the cutter body is 1 mm. By setting the bottom surface protrusion of the groove, the cross-sectional area of ​​the cutter body at the highest point of the bottom surface protrusion is locally increased by more than 8%, and the cross-sectional area of ​​each chip removal groove at that point is reduced by about 30%. The depth of the chip removal groove is 0.15 mm. The maximum height of the bottom surface protrusion of the groove accounts for 30% of the depth of the chip removal groove. In the axial direction of the cutter body, the ratio of the distance between adjacent bottom surface protrusions to the depth of the chip removal groove is 3.

[0109] Example 3

[0110] The overall structure of the rigid reinforced micro-diameter end mill in this embodiment is basically the same as that in Embodiment 1. The difference is that the diameter of the cutter body is 4mm. By setting the bottom surface of the groove to protrude, the cross-sectional area of ​​the cutter body at the highest point of the bottom surface of the groove is locally increased by more than 5%, and the cross-sectional area of ​​each chip removal groove at that point is reduced by about 20%. The depth of the chip removal groove is 0.6mm. The maximum height of the bottom surface of the groove is 30% of the depth of the chip removal groove. In the axial direction of the cutter body, the ratio of the distance between adjacent bottom surface protrusions to the depth of the chip removal groove is 1.

[0111] Example 4

[0112] The overall structure of the rigid reinforced micro-diameter end mill in this embodiment is basically the same as that in Embodiment 1. The difference is that the diameter of the cutter body is 6mm. By setting the bottom surface protrusion of the groove, the cross-sectional area of ​​the cutter body at the highest point of the bottom surface protrusion is locally increased by more than 5%, and the cross-sectional area of ​​each chip removal groove at that point is reduced by about 25%. The depth of the chip removal groove is 1.5mm. The maximum height of the bottom surface protrusion accounts for 20% of the depth of the chip removal groove. In the axial direction of the cutter body, the ratio of the distance between adjacent bottom surface protrusions to the depth of the chip removal groove is 0.5.

[0113] Example 5

[0114] The overall structure of the rigid reinforced micro-diameter end mill in this embodiment is basically the same as that in Embodiment 1. The difference is that the diameter of the cutter body is 6mm. By setting the bottom surface protrusion of the groove, the cross-sectional area of ​​the cutter body at the highest point of the bottom surface protrusion is locally increased by more than 5%, and the cross-sectional area of ​​each chip removal groove at that point is reduced by about 25%. The depth of the chip removal groove is 1.5mm. The maximum height of the bottom surface protrusion accounts for 20% of the depth of the chip removal groove. In the axial direction of the cutter body, the ratio of the distance between adjacent bottom surface protrusions to the depth of the chip removal groove is 0.3.

[0115] Cutting Experiment 1

[0116] Thin-walled electronic product parts made of titanium alloy TC4 were machined using the cutting tools described in Examples 1 to 5 of this application. The machine tool used was a Beijing Jingdiao vertical machining center, and the machining method was keyway milling. The machining life (based on the number of workpieces machined) and surface finish were measured. A traditional micro-diameter end mill, which is the same as the examples but without the composite groove type, was used as a control. The machining test results are shown in Table 1 below:

[0117] Table 1

[0118]

[0119] The cutting tool using the technical solution of this application has smoother chip removal during the cutting process. Compared with the comparative machining process, the machining vibration caused by chip retention is significantly reduced. As can be seen from the above cutting test data, the tool life and product surface finish of the embodiment of this application are improved to varying degrees.

[0120] Example 6

[0121] This embodiment provides a micro-diameter end mill with a rigid reinforcement structure, such as Figures 5 to 6 As shown, the micro-diameter rotary cutting tool includes:

[0122] Blade body,

[0123] Tool holders for connection to machine tools

[0124] The blade neck is used to connect the blade body and the handle.

[0125] The blade body 100 is made of a single piece of cemented carbide, with a diameter of 0.8 mm and a length of 3 mm.

[0126] The tool body 100 has four cutting edges 110 arranged along its circumference, and chip removal grooves 120 extending along the axial direction of the tool body are arranged between adjacent cutting edges. The chip removal grooves are straight grooves.

[0127] The chip removal groove 120 has a surface facing the cutting rotation direction, which is the rake face 10.

[0128] The chip removal groove 120 also has a concave arc surface that is connected to the rake face 10 and extends along the axial direction of the tool body, which is the bottom surface 20 of the groove.

[0129] The composite groove shape of the chip removal groove is determined by the shapes of the rake face 10 and the groove bottom surface 20, wherein,

[0130] Each of the four rake faces has a corrugated rake face protrusion and concavity, which includes three rake face protrusions 11 and two rake face concavities 12. The rake face protrusions and the rake face concavities are arranged sequentially in the extending direction of the chip removal groove, so that the rake face intersects with the outer peripheral surface of the tool body to form the corrugated cutting edge 30 of the cutting edge.

[0131] Three spaced groove bottom protrusions 40 are provided at the same position on each of the four groove bottom surfaces 20, thereby increasing the cross-sectional area of ​​the cutter body locally in the area where the groove bottom protrusions are provided, and the groove bottom protrusions are provided so that the cross-sectional area of ​​each chip removal groove at that location is reduced by less than 30%.

[0132] The groove bottom protrusions are simultaneously provided at the same position in adjacent chip removal grooves, that is, the groove bottom protrusions are distributed along the circumference of the cutter body within the chip removal grooves, thereby increasing the core thickness of the cutter body. Furthermore, the groove bottom protrusions are only provided within the range of increased core thickness, and the three groove bottom protrusions have varying dimensions, causing the core thickness increase value to vary at different positions along the axial direction of the cutter body. Figure 6 The diagram shows a cross-sectional view perpendicular to the tool body axis, taken at the highest point of the protrusion on the bottom surface of the groove located in the middle. The outer large dashed circle represents the outer circle of the tool body's cutting rotation, and the inner small dashed circle represents the core thickness without the protrusion. Figure 6 In the cross-section shown, the raised bottom surface of the groove increases the area of ​​the tool body material by more than 10% compared to when the groove bottom surface is not raised, and reduces the area of ​​the blank portion within the dashed circle by approximately 25%. The raised bottom surface near the blade neck increases the area of ​​the tool body material by more than 8% compared to when the groove bottom surface is not raised, and reduces the cross-sectional area of ​​the chip removal groove at that location by approximately 20%. The raised bottom surface at the end increases the area of ​​the tool body material by more than 5% compared to when the groove bottom surface is not raised, and reduces the cross-sectional area of ​​the chip removal groove at that location by approximately 15%.

[0133] exist Figure 6 Within the cross-section shown, the convex bottom surface of the groove has a convex arc-shaped top profile. The maximum height of the convex bottom surface is 40% of the depth of the chip removal groove. The top of the convex bottom surface has the same circumcircle within the same cross-section of the tool body. Figure 6The central dashed circle and the highest point of the groove bottom surface together determine the increase in the core thickness of the cutter body, that is, from the smallest range of the inner dashed circle to the range of the central dashed circle.

[0134] Along the axial direction of the cutter body, the groove bottom surface protrusion has a convex arc-shaped top profile, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, with the ratio of its top width to its root width ranging from 0.3 to 0.8:1.

[0135] In the section along the axis of the tool body at the highest point of the convex bottom surface of the middle groove, the ratio of the distance between the two convex bottom surfaces to the depth of the chip removal groove is 3.

[0136] like Figure 5 As shown, the top of the groove bottom protrusion is connected to the front cutting face, that is, the groove bottom protrusion extends to the front cutting face.

[0137] When the cutter body is vertically positioned downwards, the bottom surface of the groove protrudes horizontally within the chip removal groove towards the cutting edge, that is, the bottom surface of the groove protrudes from one side of the rake face in the chip removal groove in a direction away from the rake face.

[0138] Along the axial direction of the cutter body, the axial dimension of the protrusion on the bottom surface of the chip removal groove is less than half of the axial dimension of the bottom surface of the groove.

[0139] The wave pattern of the cutting edge has a wavelength of 2 mm and an amplitude of 0.18 mm.

[0140] Example 7

[0141] This embodiment provides another micro-diameter end mill with a rigid reinforcement structure, such as Figure 7 As shown, the difference between its structure and that of Embodiment 6 is that the diameter of the blade body 100 is 0.8 mm and the length is 1.6 mm. The chip removal groove 120 is an inclined groove, and each chip removal groove has a groove bottom surface protrusion 40 on the groove bottom surface 20 at its central position. The groove bottom surface protrusion increases the area of ​​the blade body material portion by more than 8% compared to when the groove bottom surface protrusion is not provided, and the groove bottom surface protrusion reduces the cross-sectional area of ​​the chip removal groove at that location by about 20%. In the axial direction of the blade body, the axial dimension of the groove bottom surface protrusion on the groove bottom surface of the chip removal groove is less than one-fifth of the axial dimension of the groove bottom surface. The wavelength of the corrugated cutting edge is 0.8 mm and the amplitude is 0.1 mm.

[0142] Cutting Experiment 2

[0143] Thin-walled titanium alloy TC4 parts were machined using the cutting tools described in Examples 6 and 7 of this application. The machine tool was a Beijing Jingdiao vertical machining center. The machining method was keyway milling. The machining life (based on the number of workpieces machined) and surface finish were measured. A micro-diameter end mill with the same rake face and cutting edge as Example 6 but without a raised bottom surface was used as Comparative Example 6. A conventional micro-diameter end mill with the same rake face and cutting edge as Example 6 but without a composite groove type was used as Comparative Example 7. The machining test results are shown in Table 2 below.

[0144] Table 2

[0145] detection indicators Processing life (pieces) Surface finish Ra (μm) Example 6 21 0.8 Example 7 16 0.8 Comparative Example 6 12 1.6 Comparative Example 7 6 2.2

[0146] The cutting tool using the technical solution of this application has smoother chip removal during the cutting process. Compared with the comparative machining process, the machining vibration caused by chip retention is significantly reduced. As can be seen from the above cutting test data, compared with traditional milling cutters and micro-diameter milling cutters with only corrugated rake faces, the cutting tool of this application has a raised bottom surface of the groove, which locally reduces the cross-sectional area of ​​the chip removal groove, but improves the machining life and product surface finish to varying degrees. The cutting tool has both high stability and long life.

[0147] Example 8

[0148] like Figures 8 to 10 As shown, this embodiment provides a milling cutter with a rigidity-reinforced structure, characterized in that it includes: a cutter body 100, a cutter shank 200, and a cutter neck 300. The cutter body is made of a single piece of cemented carbide, with a diameter of 0.5 mm, a length of 2.5 mm, and an aspect ratio of 5.

[0149] The tool body is provided with four cutting edges 110, and chip removal grooves 120 are provided between adjacent cutting edges. Figure 9 This is a partial schematic diagram of the end of the cutter body 100. The chip removal groove has a bottom surface 20 and a rake face 10 connected to the bottom surface and facing the cutting rotation direction.

[0150] The chip removal groove is a spiral groove, and multiple groove bottom surface protrusions 40 are arranged at intervals on the bottom surface of the groove, thereby locally increasing the cross-sectional area of ​​the cutter body in the area where the groove bottom surface protrusions are provided. In the cross-section at the highest point of the protrusions, the groove bottom surface protrusions reduce the cross-sectional area of ​​the chip removal groove by less than 30% at that point, and increase the cross-sectional area of ​​the cutter body by more than 5% compared to when the groove bottom surface protrusions are not provided.

[0151] The height of the bulge at the bottom of the groove accounts for 40% of the depth of the chip removal groove.

[0152] Along the axial direction of the cutter body, the groove bottom surface protrusion has a convex arc-shaped top profile, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, with the ratio of the top width to the root width being 0.4 to 0.7:1.

[0153] The ratio of the distance between the protrusions on the bottom of adjacent slots to the depth of the chip removal slot is 2.

[0154] The groove bottom protrusions are simultaneously provided at corresponding positions in adjacent chip removal grooves, meaning that the groove bottom protrusions are distributed along the circumference of the tool body within the chip removal grooves, thereby increasing the core thickness of the tool body. The groove bottom protrusions extend obliquely from one side of the rake face towards the direction away from the rake face within the chip removal grooves. The top of the groove bottom protrusion connects to the rake face, meaning that the groove bottom protrusion extends onto the rake face. The same groove bottom protrusion has a varying height, with its highest point located at the lowest point of the groove bottom surface.

[0155] Figure 10 The diagram shows cross-sectional views from left to right along a protrusion near the rake face 10, at the highest point of the protrusion, and away from the rake face. In the extension direction of the protrusion on the bottom surface of the groove, the concave arc surface of the chip removal groove causes the depth of the bottom surface of the groove to change, that is, the distance between the bottom surface of the groove and the outer circle of the cutting rotation of the tool body changes. The height of the protrusion on the bottom surface of the groove changes in the opposite direction to the depth of the bottom surface of the groove. This allows the setting of the protrusion on the bottom surface of the groove to maximize the rigidity of the tool while retaining sufficient chip removal channels, and also to obtain a shorter chip removal path, that is, to obtain a better "lifting" effect of the chips, thereby providing a better chip removal surface. Figure 10 The small dashed circle in the image indicates the core thickness of the cutter body when no protrusion is provided. Figure 10 The large dashed circle at the highest point of the protrusion in the middle also shows the increased core thickness of the tool body after the protrusion was added. This structure not only improves the overall rigidity of the tool, enhances the bending and torsional resistance of the micro-diameter end mill, reduces elastic deformation during machining, and ensures dimensional accuracy, but also significantly improves chip removal efficiency, ensures smooth chip removal, and reduces the rate of tool breakage during machining.

[0156] Cutting Experiment 3

[0157] Thin-walled electronic product parts made of titanium alloy TC4 were machined using the cutting tool described in Example 8 of this application. The machine tool was a Beijing Jingdiao vertical machining center. The machining method was keyway milling, with a keyway width of 0.8 mm and a material thickness of 2 mm. The machining life (based on the number of workpieces machined) and surface finish were measured. A conventional micro-diameter end mill without a rigid reinforcement structure was used as a comparative example (Example 8). The machining test results are shown in Table 3 below.

[0158] Table 3

[0159]

[0160] The cutting tool using the technical solution of this application has smoother chip removal during the cutting process. Compared with the comparative machining process, the machining chatter caused by chip retention is significantly reduced. As can be seen from the above cutting test data, under the comparison of a higher length-to-diameter ratio, the tool life and surface finish of this application are significantly improved.

[0161] The above description is merely an exemplary embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure, which is determined by the appended claims.

Claims

1. A micro-diameter rotary cutting tool with a rigid reinforcement structure, characterized in that, include: Blade body, Optional tool holders for direct or indirect connection to machine tools. An optional chin for connecting the blade body and the handle. At least the blade body is made of a single piece of cemented carbide, with a diameter ranging from 0.2 mm to 6 mm. The tool body is provided with multiple cutting edges, and chip removal grooves are provided between adjacent cutting edges. The chip removal grooves have a bottom surface. The bottom surface of the groove is provided with one or more groove bottom surface protrusions arranged at intervals, thereby increasing the cross-sectional area of ​​the cutter body locally in the area where the groove bottom surface protrusions are provided, and the groove bottom surface protrusions are provided so that the cross-sectional area of ​​the chip removal groove at that location is reduced by less than 30%.

2. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, Along the axial direction of the cutter body, the groove bottom surface protrusion has a convex arc-shaped top profile, and the axial width of the groove bottom surface protrusion gradually increases from the top to the root, with the ratio of the top width to the root width being 0.3 to 0.8:1, for example, 0.4 to 0.7:

1.

3. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, The groove bottom protrusions are simultaneously provided at corresponding positions in adjacent chip removal grooves, that is, the groove bottom protrusions are distributed along the circumference of the cutter body in the chip removal groove, thereby increasing the core thickness of the cutter body.

4. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, The groove bottom surface protrusion is only set within the range of increased core thickness of the cutter body.

5. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, The same bulge on the bottom surface of the groove has a varying height, with its highest point located at the lowest point of the bottom surface of the groove.

6. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, In the direction perpendicular to the axis of the blade body, the height of the bulge on the bottom surface of the groove changes in opposite directions to the depth of the bottom surface of the groove.

7. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, In a direction perpendicular to the axis of the blade body, the bottom surface of the same groove protrudes with a convex arc-shaped top profile.

8. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, The protrusion on the bottom of the groove extends downward or horizontally towards the cutting edge within the chip removal groove.

9. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, Along the axial direction of the cutter body, the axial dimension of the protrusion on the bottom surface of the chip removal groove is less than or equal to one-half of the axial dimension of the bottom surface, for example, less than or equal to one-third of the axial dimension of the bottom surface.

10. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 1, characterized in that, The chip removal groove also has a surface facing the cutting rotation direction, which is the rake face. The top of the protrusion on the bottom surface of the groove is connected to the rake face, that is, the protrusion on the bottom surface of the groove extends to the rake face.

11. The micro-diameter rotary cutting tool with a rigid reinforcement structure according to claim 10, characterized in that, The rake face has a corrugated rake face protrusion and concavity, which includes one or more rake face protrusions and one or more rake face concave portions. The rake face protrusions and the rake face concave portions are arranged sequentially in the extending direction of the chip removal groove, so that the rake face intersects with the outer peripheral surface of the tool body to form the corrugated cutting edge of the cutting edge. The top of the raised section of the groove bottom surface is connected to the recessed portion of the front cutting face, that is, the raised section of the groove bottom surface extends into the recessed portion of the front cutting face.

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