Integral composite three-blade drill
The design of the integral composite three-flute drill solves the problems of uneven cutting force and low material removal rate of traditional mechanically clamped drill bits, achieving efficient and precise drilling, reducing costs and maintenance difficulty, and improving processing quality and lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-02
- Publication Date
- 2026-04-14
AI Technical Summary
Traditional mechanically clamped drill bits suffer from uneven cutting force distribution, low material removal rate, and difficulty in ensuring machining accuracy and surface quality due to their two-flute structure, and they also encounter bottlenecks in high-efficiency and high-precision machining.
The integrated composite three-flute drill consists of a tool body, a modular three-flute center drill tip, and an indexable chuck peripheral insert. It features three symmetrically distributed main cutting edges and an internal cooling channel, combined with a spiral chip removal groove, to achieve high rigidity, convenient maintenance, and efficient cooling.
It significantly improves material removal rate, enhances processing efficiency and precision, extends tool life, reduces usage costs and maintenance difficulty, and ensures the stability and quality of the processing.
Smart Images
Figure CN121847848A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metal cutting tool technology, and in particular to an integral composite three-flute drill. Background Technology
[0002] In the field of metal cutting, drilling is a fundamental and crucial process. With the manufacturing industry's increasing demands for processing efficiency and precision, the performance of drilling tools has become a major focus. The integral composite three-flute drill, as a new type of drilling tool, integrates the advantages of multiple cutting tools.
[0003] Currently, the main drilling tools on the market include solid carbide drills, welded composite drills, and traditional indexable drills. Solid carbide drills possess excellent rigidity and precision; however, their manufacturing cost is high. Once the cutting edge wears down, they often need to be scrapped entirely or regrinded. Regrinding is not only costly but may also affect the drill's precision, resulting in high operating costs. Welded composite drills achieve functional integration by welding cutting sections made of different materials; however, stress concentration is prone to occur at the weld joints. Under intermittent cutting or high-load machining scenarios, the weld joints are highly susceptible to cracking and failure, making reliability difficult to guarantee. Traditional indexable drills use replaceable inserts, offering better economic efficiency. However, their centering ability is generally weak, and they are prone to wobble in the early stages of drilling. Moreover, most are two-flute designs, making it difficult to significantly improve material removal rates under the same machining parameters.
[0004] The two-flute structure of traditional indexable drill bits reveals significant shortcomings when facing complex machining scenarios. Because only two cutting edges participate in cutting, uneven cutting force distribution occurs when machining materials with high hardness or toughness. This not only accelerates drill wear but also affects drilling accuracy and surface quality. Furthermore, the two-flute structure limits feed rate increases; forcibly increasing the feed rate can easily induce vibration, further reducing machining quality and shortening tool life. These structural defects have created a significant bottleneck for traditional indexable drill bits in the pursuit of high-efficiency, high-precision machining. Summary of the Invention
[0005] The purpose of this invention is to provide an integral composite three-flute drill to solve the problems of uneven cutting force distribution, low material removal rate, and difficulty in ensuring machining accuracy and surface quality caused by the two-flute structure of traditional mechanically clamped drill bits.
[0006] This invention provides an integral composite three-flute drill, comprising a cutter body, a mechanically clamped peripheral insert, and a modular three-flute center drill tip. The cutter body is an integral structure with a center drill tip mounting groove at its front end. The modular three-flute center drill tip is detachably connected to the center drill tip mounting groove via connecting screws. The cutter body has insert positioning grooves, and one or more mechanically clamped peripheral inserts are pressed into these grooves by fastening screws. These mechanically clamped peripheral inserts are indexable inserts with three effective cutting edges. An internal cooling channel is provided inside the cutter body, extending directly to the cutting areas of the modular three-flute center drill tip and the mechanically clamped peripheral inserts.
[0007] Furthermore, the central drill tip mounting groove at the front end of the cutter body is a non-standard hole with a positioning ridge or a conical surface.
[0008] Furthermore, a spiral chip removal groove is provided on the cutter body, which extends to the rear of the blade positioning groove.
[0009] Furthermore, the modular three-flute center drill tip has three symmetrically distributed main cutting edges at its front end. The tail end of the modular three-flute center drill tip has a standardized positioning interface that mates with the center drill tip mounting slot on the tool body.
[0010] Furthermore, the internal cooling channel extends from the end of the tool holder and branches into at least two paths, one leading directly to the top of the modular three-flute center drill tip, and the other leading to the cutting area of each clipped peripheral insert.
[0011] The beneficial effects of this invention: The integral composite three-flute drill of this invention effectively solves many problems existing in traditional drilling tools through the combined design of an integral tool body, an indexable chuck peripheral insert, and a modular three-flute center drill tip. The integral tool body ensures high tool rigidity, improving drilling accuracy and stability. The detachable design of the indexable chuck peripheral insert and the modular three-flute center drill tip makes tool maintenance more convenient and reduces operating costs. The three symmetrically distributed main cutting edges and the indexable peripheral insert cutting edges significantly improve material removal rate and increase drilling efficiency. The internal cooling channel directly reaches the cutting area, effectively reducing cutting temperature, extending tool life, and ensuring smooth chip removal, further improving machining quality. Attached Figure Description
[0012] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.
[0013] Figure 1 This is a structural diagram of the integral composite three-blade of the present invention.
[0014] Figure 2This is a front view of the integral composite three-blade design of the present invention.
[0015] Figure 3 This is a side view of the integral composite three-bladed structure of the present invention.
[0016] Figure 4 This is a partially enlarged schematic diagram of the central drill tip region of the modular three-bladed integral composite three-bladed system of the present invention.
[0017] Figure 5 This is an exploded view of the central drill tip region of the modular three-bladed integral composite three-bladed structure of the present invention.
[0018] Illustration: 1-Tool body; 2-Clamped outer peripheral insert; 3-Modular three-flute center drill tip; 4-Helical chip removal groove; 5-Internal cooling channel; 6-Main cutting edge; 7-Center drill tip mounting slot; 8-Connecting screw; 9-Fasting screw; 10-Insert positioning groove. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. The technical solutions provided by various embodiments of this invention will be described in detail below with reference to the accompanying drawings.
[0020] This invention provides an integral composite three-flute drill. The core objective is to achieve rapid and individual replacement of core cutting components through modular design, significantly reducing tool life cycle costs. The three-flute design improves material removal rate by approximately 50% compared to traditional double-flute drills at the same feed rate. The integral tool body and precise modular interface ensure the tool system has near-integral drill rigidity and stability, guaranteeing machining accuracy. Simultaneously, multiple functions such as centering, drilling, and chamfering are completed in a single feed, reducing tool change time and improving machining efficiency.
[0021] Please see Figures 1 to 5This invention discloses an integral composite three-flute drill bit, comprising a cutter body 1, a mechanically clamped peripheral insert 2, and a modular three-flute center drill tip 3. The cutter body 1 is an integral structure, providing a solid base for the entire drill bit and fundamentally avoiding the rigidity deficiencies and vibration problems associated with welded or split structures. This design is particularly suitable for machining scenarios with large overhangs and high feed rates, ensuring stability and accuracy during the drilling process. The cutter body 1 has a center drill tip mounting groove 7 at its front end. The modular three-flute center drill tip 3 is detachably connected to the center drill tip mounting groove 7 via connecting screws 8. This detachable design allows the modular three-flute center drill tip 3 to be replaced individually after wear, without replacing the entire cutter body, significantly reducing operating costs. The cutter body 1 has insert positioning grooves 10. One or more mechanically clamped peripheral inserts 2 are pressed into the insert positioning grooves 10 by fastening screws 9. The mechanically clamped peripheral inserts 2 are indexable inserts with three effective cutting edges. When one cutting edge wears out, the next cutting edge can be indexed for use, resulting in excellent economic efficiency. Furthermore, the simultaneous participation of multiple cutting edges significantly improves material removal rate. The tool body 1 has an internal cooling channel 5 inside, which directly reaches the cutting area of the modular three-blade center drill tip 3 and the outer peripheral insert 2 of the machine clip. The internal cooling channel can directly deliver coolant to the cutting area, effectively reducing the cutting temperature and tool wear. At the same time, it can also play the role of chip breaking and chip removal, ensuring the smooth progress of the machining process.
[0022] The central drill tip mounting groove 7 at the front end of the cutter body 1 is a non-standard hole with a positioning edge (such as an internal hexagon or internal triangle) or a conical surface. This non-standard hole design ensures that the modular three-flute central drill tip 3 can be installed without gaps and reliably transmit torque, guaranteeing the stability and cutting accuracy of the drill tip. A spiral chip removal groove 4 is provided on the cutter body 1, extending behind the insert positioning groove 10. The spiral chip removal groove guides the chips out smoothly, preventing chip accumulation in the cutting area and preventing chips from scratching the machined surface, thus improving machining quality. The front end of the modular three-flute central drill tip 3 has three symmetrically distributed main cutting edges 6. These three symmetrically distributed main cutting edges make the drill tip more evenly stressed during cutting, providing strong self-centering ability and smooth cutting, effectively improving drilling accuracy. Moreover, at the same spindle speed and feed per edge, the total feed rate is about 50% higher than that of a double-flute drill tip, significantly improving machining efficiency. The modular three-flute center drill tip 3 has a standardized positioning interface at its tail. This standardized positioning interface mates with the center drill tip mounting slot 7 of the tool body 1. This standardized interface design ensures high-precision and high-repeatability positioning between the modular three-flute center drill tip 3 and the tool body 1, maintaining consistent machining accuracy even after drill tip replacement. The internal cooling channel 5 extends from the end of the tool holder and branches into at least two paths. One path leads directly to the top of the modular three-flute center drill tip 3, while the other path leads to the cutting areas of the various machine-clamped outer peripheral inserts 2. This branched internal cooling channel design ensures that coolant reaches the cutting areas of both the center drill tip and the outer peripheral inserts simultaneously, comprehensively cooling the cutting parts and further improving the cooling effect.
[0023] During operation, the assembled integral composite three-flute drill bit is loaded into the machining center spindle, appropriate cutting parameters are set, and the internal cooling system is activated. The modular three-flute center drill tip 3 first contacts the workpiece, and its three main cutting edges 6 begin cutting, achieving precise centering and drilling a guide hole. Due to the symmetrical distribution of the three main cutting edges, the cutting process is smooth, effectively avoiding initial swaying during drilling. As the drill bit feeds, the cutting edges of the indexable outer peripheral insert 2 gradually participate in the cutting, enlarging the hole diameter to the required size. Multiple cutting edges work simultaneously, greatly improving the material removal rate; and the chamfering of the hole opening can be completed synchronously through a specific cutting edge shape. During the cutting process, the internal cooling channel 5 continuously delivers coolant to reduce the cutting temperature and tool wear, while the spiral chip removal groove 4 smoothly discharges chips, ensuring a smooth machining process. After machining, if the modular three-flute center drill tip 3 is worn, simply loosen the connecting screw 8 to remove the old drill tip and replace it with a new modular three-flute center drill tip 3 without disassembling the outer peripheral insert or the entire tool holder; if the machine clamp outer peripheral insert 2 is worn, simply loosen the fastening screw 9, rotate it or replace it with a new insert. The entire maintenance process is quick and easy with short downtime.
[0024] This invention successfully integrates the rigidity of a solid drill bit with the economy of a mechanically indexable drill bit through a combination design of an integral cutter body 1, a detachable modular three-flute center drill tip 3, and an indexable external peripheral insert 2. The integral cutter body ensures drilling accuracy and stability, while the detachable and indexable design reduces operating costs and maintenance difficulty. The design of three main cutting edges and multiple external cutting edges significantly improves machining efficiency, and the design of internal cooling channels and spiral chip removal grooves ensures smooth machining and extends tool life.
[0025] The present invention will be described in detail below with reference to a preferred embodiment of a Φ39mm integral composite three-flute drill for machining through holes of gear ring bolts. The tool body is 120mm in total length, made of 1.2344 alloy steel, and heat-treated to HRC50-52 to ensure rigidity and sufficient toughness. The shank is a BT50 tapered shank. The modular three-flute center drill tip has a diameter of 18mm, is made of ultra-fine particle cemented carbide, and has a TiAlN coating. The tail is a cylindrical interface with two symmetrical drive planes, which transitions to the corresponding hole on the tool body with a clearance of <0.005mm, and is secured from the rear of the tool body by an axial screw. The indexable peripheral insert is a standard square WCMT series insert (specially profiled and ground), with three indexable cutting edges, and is fastened to the tool body by a countersunk screw.
[0026] During machining, the assembled drill bit is loaded into the machining center spindle. Cutting parameters are set to a spindle speed of S = 900 rpm and a feed rate of F = 200 mm / min (0.22 mm per blade due to its three-flute configuration). The internal cooling system is activated at 2 MPa, and a drilling cycle is then executed. The center drill tip first contacts the workpiece, achieving precise centering and drilling a guide hole. Then, the cutting edges of the two outer peripheral inserts simultaneously participate in the cutting, enlarging the hole diameter to Φ20 mm and completing a C0.5 chamfer on the hole opening. After machining, the hole dimensions are stable, and the surface finish is high. Regarding maintenance and replacement, after machining a certain number of times, if the center drill tip wears out, simply loosen the rear axial screw to remove the old drill tip and replace it with a new one; there is no need to disassemble the outer peripheral inserts or the entire tool holder. If the outer peripheral inserts wear out, simply loosen the fastening screws with a cross wrench, rotate the insert, or replace it with a new one. The entire maintenance process is quick and simple, with minimal downtime.
[0027] The embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention.
Claims
1. An integral composite three-flute drill, characterized in that, include: The tool body (1), the mechanically clamped peripheral insert (2), and the modular three-flute center drill tip (3) are all integral structures. The tool body (1) has a center drill tip mounting groove (7) at the front end. The modular three-flute center drill tip (3) is detachably connected to the center drill tip mounting groove (7) by connecting screws (8). The tool body (1) has a blade positioning groove (10). One or more mechanically clamped peripheral inserts (2) are pressed into the blade positioning groove (10) by fastening screws (9). The mechanically clamped peripheral inserts (2) are indexable inserts with three effective cutting edges. The tool body (1) has an internal cooling channel (5) that reaches the cutting area of the modular three-flute center drill tip (3) and the mechanically clamped peripheral inserts (2).
2. The integral composite three-flute drill according to claim 1, characterized in that, The central drill tip mounting groove (7) at the front end of the cutter body (1) is a special-shaped hole with a positioning edge or a conical surface.
3. The integral composite three-flute drill according to claim 1, characterized in that, The blade body (1) is provided with a spiral chip removal groove (4), which extends to the rear of the blade positioning groove (10).
4. The integral composite three-flute drill according to claim 1, characterized in that, The modular three-bladed center drill tip (3) has three symmetrically distributed main cutting edges (6) at its front end; the modular three-bladed center drill tip (3) has a standardized positioning interface at its rear end, which cooperates with the center drill tip mounting groove (7) of the tool body (1).
5. The integral composite three-flute drill according to claim 1, characterized in that, The internal cooling channel (5) extends from the end of the tool holder and branches into at least two paths, one leading directly to the top of the modular three-blade center drill tip (3) and the other leading to the cutting area of each of the machine-clamped peripheral inserts (2).