Alloy steel inlaid plate drill and efficient precision manufacturing method thereof

Abstract

According to the alloy-inlaid steel plate drill and the efficient precision manufacturing method thereof, a three-order chip division type cutting edge structure is adopted, layered cutting is achieved under the synergistic effect of an inner edge, a middle edge and an outer edge, a micro-groove array formed through laser machining on the surface of a drill body is matched, the brazing bonding strength is remarkably improved, the chip removal path is optimized, and the chip removal efficiency is improved. A high-precision micro-groove network is constructed on the surface of the drill body through a laser micromachining technology, and an anchoring foundation is provided for subsequent welding; the precise manufacturing process covers key process innovation: the angle tolerance of a cutting edge is ensured to be less than or equal to + / -0.5 degrees and the margin run-out is ensured to be less than or equal to 0.02 mm through five-axis linkage grinding, and a micro-arc cutting edge is molded by a magnetic nano passivation technology to reduce cutting vibration. According to the scheme, the technical bottlenecks of chip removal blockage, blade falling and short service life of a traditional steel plate drill are solved, and the manufactured drill bit has high cutting efficiency, excellent wear resistance and excellent process stability.

Description

Technical Field

[0001] This invention relates to the field of metal cutting technology, specifically to a drill bit for inserting alloy steel plates and its efficient and precise manufacturing method. Background Technology

[0002] Plate drills, as efficient and energy-saving cutting tools for drilling holes in metal structural components, are widely used in hole processing operations in industries such as steel structure engineering, machinery manufacturing, shipbuilding, bridge construction, and rail transportation.

[0003] Traditional hollow drills have many limitations, such as being simple to manufacture but difficult to remove chips, and only suitable for drilling thin plates or brittle materials. Existing alloy steel plate drills suffer from problems such as unclear processing parameters and non-standardized production processes, affecting product quality and performance stability.

[0004] Therefore, it is necessary to provide a drill bit for inserting alloy steel plates with a reasonable structure, standardized production process, and clear processing parameters, as well as its production process. Summary of the Invention

[0005] The purpose of this invention is to provide a drill bit for inserting alloy steel plates and a method for its efficient and precise manufacturing, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A drill bit with inlaid alloy steel plate includes a cylindrical drill body, a shank and an end cutting edge. The end cutting edge is provided in multiple sets and is evenly arranged in a circular shape at the end of the drill body. The drill body includes an inner hole of the cutting edge, a chip removal groove and a cutting edge band. The end cutting edge is configured with a three-stage chip-breaking structure, consisting of an inner cutting edge, a middle cutting edge, and an outer cutting edge arranged sequentially from the inside out. The surface of the drill body is provided with a laser-processed microgroove array, the outer circle of the inner hole of the cutting edge is provided with a chip removal groove along the end cutting edge, the wall thickness of the drill body decreases along the axial direction to form an inverted taper secondary back angle, and the cutting edge band is provided on the outside of the end cutting edge of each group.

[0007] As a further aspect of the present invention: the drill body material is 42CrMo alloy steel, and the end cutting edge is a carbide insert.

[0008] As a further aspect of the present invention: the helix angle of the chip removal groove is 35°±2°, and the groove width tolerance is ±0.05mm.

[0009] As a further aspect of the present invention: the inner cutting edge angle is 25°±1°, the outer cutting edge angle is 18°±1°, and the end cutting edge rake angle is 5°.

[0010] As a further embodiment of the present invention: the handle can be a right-angle handle, a universal handle, a four-hole handle, or a threaded handle.

[0011] As a further aspect of the present invention, a pre-set recessed mechanical interlocking structure is provided at the bottom of the end cutting edge.

[0012] A highly efficient and precise manufacturing method for inserting alloy steel plate drills includes the following steps: Step 1: Tool body preparation and pretreatment; Step 2: Machining the internal cooling channels; Step 3: Milling and shaping; Step 4: Surface microstructure enhancement; Step 5: Strengthening and toughening composite treatment; Step 6: Gradient pressure brazing; Step 7: Precision grinding; Step 8: Post-processing and verification.

[0013] As a further aspect of the present invention: the gradient pressure brazing in step 6 uses a solution containing 0.5% nano-Ce Ag-Cu-Ti solder, brazing temperature 780℃ and holding for 3 minutes.

[0014] As a further aspect of the present invention: in the precision grinding process in step 7, the end cutting edge is precision ground by five-axis linkage, the tolerance of the inner / outer cutting edge angle is controlled within ±0.5°, and the cutting edge runout is ≤0.02mm.

[0015] As a further aspect of the present invention: in the post-processing and verification in step 8, the cutting edge is passivated to form an arc of R0.03mm, and the sandblasting process uses 120-mesh aluminum oxide and 150-180-mesh glass sand in steps.

[0016] Compared with the prior art, the beneficial effects of the present invention are: by using a three-stage blade structure (inner / middle / outer blade) to synergistically separate chips, cutting resistance is reduced, and the problem of chip entanglement in thick plate drilling is solved.

[0017] By increasing the brazing area by 30% through microgroove arrays and combining it with gradient pressure brazing technology, the weld shear strength reaches ≥300MPa, eliminating the risk of blade breakage. Through a combination of cryogenic treatment and pulse nitriding, the surface hardness reaches ≥1100HV, thus improving fatigue life.

[0018] The five-axis linkage precision grinding technology achieves an angular tolerance of ±0.5° and a blade runout of 0.02mm, ensuring that the bore diameter deviation is ≤IT9 grade accuracy.

[0019] By combining spiral grooves with a reverse taper secondary back angle, smooth chip removal and drilling straightness are ensured, achieving efficient chip removal. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of a drill bit embedded in an alloy steel plate.

[0021] Figure 2 This is a side view schematic diagram of a drill bit embedded in an alloy steel plate.

[0022] Figure 3 for Figure 1 A magnified structural diagram of A in the diagram.

[0023] Figure 4 This is a process flow diagram for a high-efficiency and precision manufacturing method of inserting drills into alloy steel plates.

[0024] The components include: drill body 10, shank 11, torque transmission structure 12, positioning surface 13, ejector pin hole 14, microgroove array 15, end cutting edge 16, inner hole of cutting edge 17, chip removal groove 18, and cutting edge band 19; Outer edge 160, middle edge 161, inner edge 162. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] Please see Figures 1-3A type of alloy steel plate drill is configured with a cylindrical thin-walled structure, including a drill body 10, a shank 11, and end cutting edges 16; multiple sets of end cutting edges 16 are uniformly arranged in a circular shape at the end of the drill body 10; the drill body 10 includes an inner hole 17, a chip removal groove 18, and a cutting edge 19; the inner hole 17 is opened at the center of the end of the drill body 10, the chip removal groove 18 is opened between adjacent end cutting edges 16, and the cutting edge 19 is connected and arranged on the outside of the end of each set of end cutting edges 16; The end cutting edge 16 is set as the main cutting edge, and it has three edges according to the diameter. The inner edge 162, the middle edge 161, and the outer edge 160 are respectively set from the inside to the outside along the radial inclined direction of the ejector pin hole 14, forming a multi-stage cutting structure, improving the chip removal effect, and reducing the single-edge cutting force by more than 30%. The inner hole 17 of the cutting edge has a chip removal groove 18 on the outer circle of the cutting edge 16, and the wall thickness of the drill body 10 decreases along the axial direction to form an inverted taper secondary back angle.

[0030] The shank 11 includes a torque transmission structure 12, a positioning surface 13, and a pin hole 14. The torque transmission structure 12 is connected to one end of the drill body 10 away from the end cutting edge 16. Multiple positioning surfaces 13 are provided at equal intervals in a ring on the circumferential side wall of the shank 11. A pin hole 14 is provided in the middle of the shank 11. The handle 11 has a structure with right-angle handle, universal handle, four-hole handle, threaded handle, etc., and adopts a constant handle diameter design within a certain specification range.

[0031] In this embodiment of the invention, the inner hole 17 of the cutting part and the ejector pin hole 14 are connected by an internal through hole to form an internal cooling channel. The drill body 10 is made of 42CrMo alloy steel with a hardness ≥40 HRC; The end cutting edge 16 is made of carbide insert with a hardness ≥91HRA, wherein the inner cutting edge angle is 25°±1°, the outer cutting edge angle is 18°±1°, and the end cutting edge rake angle is 5°. The end cutting edge 16 insert extends 10 mm above the drill body: end face ≤ 1.0 mm, side face ≤ 0.5 mm; Chip removal groove 18: helix angle 30°-45°, depth to width ratio 1.5:1; Ejector hole 14: diameter φ6.35 / φ8mm, used for matching ejector pins; Handle 11 structure: right angle handle (φ12-100mm), universal handle / four-hole handle (φ12-60mm).

[0032] In one embodiment of the present invention, the outer surface of the drill body 10 is machined with an annularly spaced microgroove array 15 to increase the solder penetration area by 30%; Specifically, the microgroove array 15 is 0.2 mm wide, 0.3 mm deep, and 1.5 mm apart; The bottom of the end cutting edge 16 is provided with a pre-set recess to form a mechanical interlocking structure and improve shear strength. It should be noted that the above structures are connected by a gradient heating brazing process followed by slow cooling to prevent cracks from forming in the blade.

[0033] Progressive layered cutting is achieved through a chip-splitting three-stage cutting edge structure: inner edge 162, middle edge 161, and outer edge 160 working together. The inner cutting edge 162 first cuts into the material to form a guide hole, and the middle cutting edge 161 and the outer cutting edge 160 successively expand the hole diameter and break the chips; Synergistic effect: Optimized cutting resistance distribution reduces peak cutting force by more than 30% compared to single-blade structure, solving the chip entanglement problem when drilling thick plates; Meanwhile, the laser microgroove array 15 on the surface of the drill body 10 increases the brazing filler metal wetting area and strengthens the metallurgical bond; The blade has a pre-dimpled pit at the bottom to create a mechanical anchoring effect, resisting shear deformation. With the help of gradient pressure brazing process, the shear strength of the weld is improved, eliminating the risk of blade breakage during mass production.

[0034] like Figure 4 As shown, in a preferred embodiment of the present invention, a high-efficiency and precision manufacturing method for inserting alloy steel plate drills includes the following steps: Step 1: Tool body preparation and pretreatment ① CNC cutting and blanking: Use a fully automatic CNC cutting machine to cut 42CrMo alloy steel bars according to specifications, with a hardness ≥40 HRC and a length tolerance of ±0.2mm; ② Centerless grinding of outer diameter: The M1080 centerless grinder removes 0.2mm of the surface layer, eliminates rolling defects, and achieves a surface roughness Ra≤1.6μm.

[0035] Ensuring the uniformity of material structure lays the foundation for subsequent precision machining.

[0036] Step 2: Machining of internal cooling channels ① Deep hole drilling: Machining the inner hole 17 of the cutting edge and the ejector pin hole 14 on a hexagonal lathe or a high-precision drilling machine; ② Parameter settings: Speed: 200-300 rpm, to avoid vibration; Feed rate: 0.05-0.1 mm / r, to prevent skew; Coaxiality ≤ 0.05mm, used to ensure the straightness of the internal cooling channel; This creates a coolant flow channel, reducing the temperature in the cutting zone.

[0037] Step 3: Milling and shaping (1) Spiral groove milling Clamping method: Double center positioning or guide sleeve assistance to eliminate radial runout; End mill selection: Custom carbide spiral end mill; Parameter control: Helix angle = 35° ± 2°, groove width tolerance ± 0.05 mm, eccentricity e = 3.4 ± 0.1 mm The quality requirement is that the tank wall must be free of tool marks.

[0038] Blade Groove Machining Innovative clamping design: Horizontally placed vertical CNC indexing head + universal rotary milling head tilted at 17°; Pre-control of cutting edge inclination angle: Set to 8°-10° during rough milling to compensate for subsequent grinding wear; Interlocking structure machining: A 0.5mm spherical recess is pre-machined at the bottom of the blade groove of the carbide saw blade end mill.

[0039] Ensuring smooth chip removal provides a structural basis for the mechanical interlocking of the blades.

[0040] Step 4: Surface microstructure enhancement Laser micromachining: Equipment: Fiber laser marking machine Parameters: Pulse width 100ns, power 50W, scan speed 800mm / s Morphology: The drill body surface is machined with a grid of microgrooves, 0.2mm wide × 0.3mm deep × 1.5mm spacing, 15 in number; Increase the brazing area by 30% and improve the capillary penetration depth of the solder.

[0041] Step 5: Strengthening and Toughening Composite Treatment Step-by-step process: ① Pulse ion nitriding: Temperature: 520℃±10℃ Atmospheric pressure: 350 Pa Pulse ratio: ON / OFF Results: A compound layer with a thickness of ≥15μm was formed on the surface, and the hardness was ≥1100. .

[0042] ② Cryogenic treatment: Liquid nitrogen environment -196℃, keep warm for 2 hours → slow cooling to room temperature (≤5℃ / min); Operating mechanism: Transforms retained austenite into martensite, thereby improving wear resistance; Synergistic effect: Fatigue life increased by 200%, and resistance to chipping and breakage is enhanced.

[0043] Step 6: Gradient pressure brazing The process flow is as follows: The cutting tool is preheated at 300°C for 6 hours to eliminate internal stress in the cemented carbide. Then, a stepped heating process is employed, gradually heating the tool body to 600°C for preheating to avoid thermal shock cracking. Finally, it is brazed at 780°C and held for 3 minutes to melt Ag-Cu-Ti + 0.5% nano-Ce. The solder is then subjected to pressure welding, maintaining a constant pressure of 0.5 MPa. After welding, it is subjected to gradient slow cooling, that is, the temperature is gradually reduced to 300°C, and the rate of reduction is controlled at ≤10°C / s. The hard brittle phase is generated, that is, the above brazing can ensure the weld shear strength ≥300 MPa. The gradient pressure brazing process is adopted: internal stress is eliminated by preheating the blade, the temperature is controlled in stages (to avoid hot cracking), and the constant pressure of 0.5MPa is used to completely expel pores, so that the weld is free of sand holes and cracks, and the blade's resistance to falling off is improved compared with traditional high frequency welding.

[0044] Step 7: Precision grinding (1) Grinding the outer diameter of the cutting edge Equipment: High-precision cylindrical grinding machine Grinding wheel: Diamond grinding wheel (P300×127×32 WA80K5V35) Parameters: linear speed 25m / s, grinding depth 0.01-0.02mm / cycle, for preventing burns; (2) Precision grinding of inner hole Taper control: 0.17-0.62mm / 5mm length, forming a secondary rear angle; Clamping: ER spring collet, maintaining radial runout ≤0.005mm; (3) Precision grinding of the cutting edge Equipment: Five-axis CNC tool grinder Control parameters: Inner cutting edge angle: 25°±0.5°; outer cutting edge angle: 18°±0.5° Blade width 0.1mm, runout ≤0.02mm Surface roughness Ra≤0.4μm; The cutting edge is formed in one go through five-axis linkage precision grinding technology, the tolerance of the inner / outer cutting edge angle is controlled within ±0.5°, the cutting edge runout is ≤0.02mm, ensuring micron-level cutting edge consistency and guaranteeing chip separation effect.

[0045] Step 8: Post-processing and verification ① Sandblasting treatment: Coarse spraying: 120 mesh aluminum oxide particles with Ra=3.2μm to remove oxide scale; Fine blasting: 150-180 mesh glass sand to improve surface stress distribution; ② Edge dulling: Equipment: Magnetic grinding machine Medium: SiC + diamond micro powder mixed slurry Result: Edge radius R0.03mm (50% improvement in chipping resistance) ③ Cutting test: Q235 steel plate is used, and its thickness is equal to the drill body diameter × 0.6. Continuous drilling of ≥120 holes, maintaining no chipping on the cutting edge, and hole diameter deviation ≤IT9.

[0046] Meanwhile, the above manufacturing method utilizes microgroove laser processing to precisely construct a grid array with a width of 0.2mm and a depth of 0.3mm, thereby increasing the solder penetration depth and reducing the probability of poor soldering.

[0047] The residual austenite was transformed into wear-resistant martensite by cryogenic treatment (-196℃); By generating a 15μm ultra-hard nitrided layer (1100HV) through pulsed ion nitriding, the product achieves "hard surface and tough interior", and its fatigue life exceeds the industry average.

[0048] All components in this application are made of metal or plastic materials with suitable strength in their respective fields to ensure that their structural rigidity meets actual requirements.

[0049] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A drill bit for inserting alloy steel plates, characterized in that, The drill body (10) includes a cylindrical structure, a shank (11) and an end cutting edge (16). The end cutting edge (16) is provided in multiple sets and is evenly arranged in a circular shape at the end of the drill body (10). The drill body (10) includes an inner hole (17) of the cutting edge, a chip removal groove (18) and a cutting edge (19). The end cutting edge (16) is configured as a three-stage chip-breaking structure, with the inner edge (162), middle edge (161), and outer edge (160) arranged sequentially from the inside to the outside. The surface of the drill body (10) is provided with a laser-processed microgroove array (15), the outer circle of the inner hole (17) of the cutting edge is provided with a chip removal groove (18) along the end cutting edge (16), the wall thickness of the drill body (10) decreases along the axial direction to form an inverted taper secondary back angle, and the cutting edge band (19) is connected and set outside the end of each set of end cutting edges (16).

2. The alloy steel plate drill bit according to claim 1, characterized in that, The drill body (10) is made of 42CrMo alloy steel, and the end cutting edge (16) is a carbide insert.

3. The alloy steel plate drill bit according to claim 1, characterized in that, The chip removal groove (18) has a helix angle of 35°±2° and a groove width tolerance of ±0.05mm.

4. The alloy steel plate drill bit according to claim 1, characterized in that, The inner blade (162) has an angle of 25°±1°, the outer blade (160) has an angle of 18°±1°, and the end blade rake angle is 5°.

5. The alloy steel plate drill bit according to claim 1, characterized in that, The handle (11) may be a right-angle handle, a universal handle, a four-hole handle, or a threaded handle.

6. The alloy steel plate drill bit according to claim 1, characterized in that, The end cutting edge (16) has a pre-set recessed mechanical interlocking structure at its bottom.

7. A highly efficient and precise manufacturing method for inserting alloy steel plate drills, characterized in that, Including the following steps: Step 1: Tool body preparation and pretreatment; Step 2: Machining the internal cooling channels; Step 3: Milling and shaping; Step 4: Surface microstructure enhancement; Step 5: Strengthening and toughening composite treatment; Step 6: Gradient pressure brazing; Step 7: Precision grinding; Step 8: Post-processing and verification.

8. The efficient and precision manufacturing method for the alloy steel plate drill according to claim 7, characterized in that: The gradient pressure brazing in step 6 uses Ag-Cu-Ti solder containing 0.5% nano CeO2, with a brazing temperature of 780℃ and a holding time of 3 minutes.

9. The efficient and precision manufacturing method for the alloy steel plate drill according to claim 7, characterized in that, In the precision grinding process in step 7, the end cutting edge (16) is precision ground by five-axis linkage, the tolerance of the inner / outer cutting edge angle is controlled within ±0.5°, and the runout of the cutting edge (19) is ≤0.02mm.

10. The efficient and precision manufacturing method for the alloy steel plate drill according to claim 7, characterized in that, In the post-processing and verification of step 8, the cutting edge is passivated to form an arc of R0.03mm, and the sandblasting process uses 120-mesh aluminum oxide and 150-180-mesh glass sand in steps.

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