Hard alloy three-blade drill

Abstract

The utility model belongs to the technical field of machining cutters, and particularly relates to a hard alloy three-blade drill which comprises a cutter handle and a blade which are integrally formed, the blade comprises three spiral blades and a drill core, spiral grooves are arranged among the three spiral blades in a surrounding mode, the blade diameter ratio of the drill core to the spiral blades is 30%, the blade part back cone ratio of the spiral blades is 1000: 4, and the blade diameter ratio of the drill core to the spiral blades is 30%. The spiral edge comprises a chisel edge and a cutter edge, and the edge width of the cutter edge is 6% * Dia of the outer diameter value of the spiral edge. The thickness of the drill core of the three-edge drill bit is particularly stable in the center, the drill core enters the chip groove in a transition mode almost without steps, and therefore friction between cuttings and the drill bit is reduced. Compared with a common three-edge drill, the positive rake angle is combined with the sharp main cutting edge, so that the cutting resistance is effectively reduced. Meanwhile, due to the special geometric shape of the drill tip, the residual core diameter is high in centering and positioning precision, good in balance and anti-shaking, the straightness, roundness and cylindricity of a machined hole are higher than those of a two-edge hole, and the machining precision is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical processing cutter technical field especially relates to a hard alloy three blade drill. BACKGROUND

[0002] Three blade drill is the cutter that often will apply in mechanical processing. Generally speaking, three blade drill is used to carry out small chip, small cutting resistance processing, for example, cast iron processing, nodular cast iron processing and aluminum alloy processing, sometimes also can be considered to be suitable for processing steel, for example, stainless steel, alloy steel and carbon steel.

[0003] But three blade drill chip removal groove is smaller than two blade drill, and the cutting resistance in processing is also bigger than two blade drill, three blade drill bit often will because of high resistance and bad chip removal in processing cause broken blade, thereby influence three blade drill's service life. UTILITY MODEL CONTENT

[0004] The utility model discloses a kind of hard alloy three blade drills to solve the problem that three blade drill bit will be broken because of high resistance and bad chip removal in processing in the background technology described above, and is presented.

[0005] To achieve the above object, the utility model adopts the following technical scheme:

[0006] A kind of hard alloy three blade drill, including integrally-formed handle and blade, the blade includes three spiral blades and drill core, spiral groove is arranged around between three spiral blades, the blade diameter ratio of drill core and spiral blade is 30%, the blade part back taper of spiral blade is 1000:4, the spiral blade includes horizontal blade and blade edge, the edge width of blade edge is 6% *Dia of spiral blade outer diameter value, the end face of spiral blade is 140 °, three spiral blades are all designed through double plane, end face plane first relief angle 8 ° second relief angle 20 °, end face backlash three blades are all circular arc feed design, backlash feed angle 28 °, backlash feed circular arc 15% *Dia;The horizontal blade core thickness is 0% *Dia, backlash rake angle is 0 °, backlash feed circular arc 35% *Dia.

[0007] Preferably, the spiral groove adopts three-blade spiral inner cooling design, and the spiral angle is 30 °.

[0008] Preferably, the inside of the blade is provided with a plurality of inner cooling holes.

[0009] Preferably, the surface of the spiral groove is precisely ground and polished with W diamond micro powder attached to a wool wheel.

[0010] Compared with the prior art, the utility model has the following beneficial effects:

[0011] 1. The drill core thickness of the three-blade drill bit in the utility model is particularly stable at the center, and almost no step is transitioned into the chip groove, thereby reducing the friction between the chip and the drill bit. Compared with the ordinary three-blade drill, the positive rake angle and the sharp main cutting edge are combined together, effectively reducing the cutting resistance. At the same time, the special drill tip geometry has high residual core diameter centering positioning accuracy, good balance, anti-shaking, and the straightness, roundness and cylindricity of the processed hole are higher than those of the two-blade drill, improving the machining precision.

[0012] 2. The drill bit in the utility model is drilled on the solid material, and a large amount of chips need to be discharged. The three-blade drill has three groove chip removal, and the chip is small and easy to discharge. Compared with the chip removal groove of the two-blade drill bit, the chip removal groove of the three-blade drill has small volume, shallow groove and thick core, and is matched with coating, which is more conducive to chip removal. Therefore, the rigidity of the tool is high, the machining precision is high, the hole precision can reach IT10-IT9 level, and for the three-blade drill, the feed distribution originally borne by the two-blade is distributed to the three-blade, the load of each blade is reduced, higher feed amount can be realized, the service life can be improved on the basis of the original feed amount.

[0013] 3. The unique R-shaped crescent groove gap design in the utility model makes the cutting edge longer while the cutting force is uneven, can stably segment the chip into small pieces, and cooperates with the single edge and negative chamfer design to realize the purpose of reducing the cutting resistance, and solves the machining problem of the conventional three-blade drill.

[0014] 4. The negative chamfer treatment of the blade edge in the utility model disperses the cutting resistance, thereby enhancing the rigidity of the blade edge and prolonging the service life of the tool. In addition, a proper tooth gap arc and blunt circle treatment are designed and manufactured, the blade edge is wear-resistant, the drilling is stable, and a coating with high wear resistance and oxidation resistance is provided. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A structure diagram of a hard alloy three-blade drill is provided for the utility model;

[0016] Figure 2 An internal structure diagram of a hard alloy three-blade drill is provided for the utility model;

[0017] Figure 3 A side view structure diagram of the blade edge of a hard alloy three-blade drill is provided for the utility model;

[0018] Figure 4 An internal structure diagram of the blade edge of a hard alloy three-blade drill is provided for the utility model.

[0019] In the figure: 1 handle, 2 blade, 201 spiral blade, 202 drill core, 203 spiral groove, 204 horizontal blade, 205 blade edge. DETAILED DESCRIPTION

[0020] Clearly and completely describe the technical scheme in the embodiments of the utility model with reference to the drawings in the embodiments of the utility model, obviously, the described embodiments are only a part of the embodiments of the utility model, and not all the embodiments.

[0021] Referring to Figures 1-4 A cemented carbide three-blade drill comprises an integrally formed shank 1 and blade 2, a plurality of inner cooling holes are arranged around the inside of the blade 2, the blade 2 comprises three spiral blades 201 and a drill core 202, a spiral groove 203 is arranged around the three spiral blades 201, the spiral groove 203 adopts a three-blade spiral inner cooling design, the spiral angle is 30°, the surface of the spiral groove 203 is precisely ground, and wool wheel attached W1 diamond micro powder is used for flexible polishing.

[0022] In the embodiment, the ratio of the blade diameter of the drill core 202 to the spiral blade 201 is 30%, the blade back taper of the spiral blade 201 is 1000:4, the spiral blade 201 comprises a horizontal blade 204 and a blade edge 205, and the edge width of the blade edge 205 is 6%*Dia of the outer diameter value of the spiral blade 201.

[0023] In the embodiment, the end face of the spiral blade 201 is 140°, the three spiral blades 201 are all designed through double planes, the end face plane first clearance angle is 8° and the second clearance angle is 20°, the end face tooth gap three-blade is all designed through circular arc feed, the tooth gap feed angle is 28°, and the tooth gap feed circular arc is 15%*Dia.

[0024] In the embodiment, the core thickness of the horizontal blade 204 is 0%*Dia, and the tooth gap rake angle is 0°.

[0025] In the embodiment, the thickness of the drill core 202 of the three-blade drill bit is particularly stable at the center, almost steplessly transitions into the chip flute, thereby reducing the friction between the cutting chip and the drill bit. Compared with the common three-blade drill, the positive rake angle and the sharp main cutting edge are combined together, effectively reducing the cutting resistance. Meanwhile, the special drill tip geometry has high residual core diameter centering positioning accuracy, good balance, anti-shaking, and the straightness, roundness and cylindricity of the processed hole are higher than those of the two-blade, improving the machining precision.

[0026] In the embodiment, the drill bit drills holes in solid materials, and a large amount of cutting chips need to be discharged. The three-blade drill has three groove chip removals, the cutting chip is small and easy to discharge. Compared with the chip flute of the two-blade drill bit, the chip flute of the three-blade drill has small volume, shallow groove and large core thickness, and is matched with a coating, which is more conducive to chip removal. Therefore, the rigidity of the tool is high, the machining precision is high, the hole precision can reach IT10-IT9 level, for the three-blade drill, the feed distribution originally borne by the two blades is distributed to the three blades, the load of each blade is reduced, a higher feed amount can be realized, the service life is improved on the basis of the original feed amount.

[0027] In the embodiment, the unique R-shaped crescent slot gap design makes the cutting edge longer while the cutting force is not uniform, can stably segment the cutting chip into small pieces, and cooperates with the single edge and negative chamfer design to realize the purpose of reducing the cutting resistance, and solves the machining problem of the conventional three-blade drill.

[0028] In the embodiment, the negative chamfer treatment is performed on the blade edge to disperse the cutting resistance, thereby enhancing the rigidity of the blade edge and prolonging the service life of the cutter. In addition, a proper gap arc and blunt circle treatment are designed and manufactured, the blade edge is wear-resistant, the drilling is stable, and a coating with high wear resistance and oxidation resistance is provided.

[0029] The above is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art in the technical range disclosed by the present application, according to the technical scheme and the utility model concept of the present application, is equivalent to replace or change, should be covered in the protection scope of the present application.

Claims

1. A carbide three-edged drill, comprising an integrally formed handle (1) and a blade (2), characterized in that: The blade (2) comprises three spiral blades (201) and a drill core (202); a spiral groove (203) is arranged around the three spiral blades (201); the blade diameter ratio of the drill core (202) to the spiral blade (201) is 30%; the back cone of the blade portion of the spiral blade (201) is 1000:4; the spiral blade (201) comprises a chisel blade (204) and a blade edge (205); the edge width of the blade edge (205) is The outer diameter of the spiral blade (201) is 6%*Dia, the end face of the spiral blade 201 is 140°, the three spiral blades (201) are all designed with a double plane, the first clearance angle of the end face plane is 8° and the second clearance angle is 20°, the three end face tooth gaps are all designed with arc feed, the tooth gap feed angle is 28°, and the tooth gap feed arc is 15%*Dia; the core thickness of the transverse blade (204) is 0%*Dia, the tooth gap front angle is 0°, and the tooth gap cut arc is 35%*Dia.

2. The cemented carbide three-edge drill according to claim 1, characterized in that: The spiral groove (203) adopts a three-edged spiral internal cooling design, and the spiral angle is 30°.

3. The cemented carbide three-edge drill according to claim 1, characterized in that: A plurality of internal cooling holes are arranged around the interior of the blade (2).

4. The cemented carbide three-edge drill according to claim 1, characterized in that: The surface of the spiral groove (203) is precisely ground, and a wool wheel with W1 diamond powder is added for flexible polishing.

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