A special drilling tool for drilling a conical hole and a manufacturing method thereof

Abstract

The application provides a special drilling tool for drilling a taper hole and a manufacturing method thereof, and steps are as follows: step 1, preparing a blank; step 2, processing a taper; step 3, processing a grinding groove; step 4, processing a main flank surface 2 of a chisel; step 5, grinding two main flank surfaces 1 of a drill tip; and step 6, grinding a first chip flute. The application is used for drilling a small inner hole and a large outer hole, effectively improves the drilling efficiency of the taper hole, and solves the processing problem of one-time forming of the taper hole.

Description

Technical Field

[0001] This invention belongs to the technical field of drilling tools for short conical holes in operation and transportation, specifically relating to a special drilling tool for drilling conical holes and its manufacturing method. Background Technology

[0002] In existing machining technologies, for (such as) Figure 1 The hole shown is a tapered hole with a smaller inner diameter and a larger outer diameter. Drilling this type of hole typically involves two steps: drilling and reaming. This requires two clamping operations, which can lead to poor centering and inconvenient operation. Currently, there are no dedicated drilling tools available on the market that can directly drill tapered holes. Therefore, it is necessary to design a dedicated tapered hole drilling tool to improve the efficiency of tapered hole drilling and solve similar problems encountered in practical work. The following technical solution is proposed to address this issue. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a special drilling tool for drilling tapered holes and its manufacturing method, which improves the processing efficiency of drilling tapered holes and solves the processing problem of drilling tapered holes.

[0004] The technical solution adopted in this invention is: a method for manufacturing a special drilling tool for drilling tapered holes, comprising the following steps:

[0005] Step 1: Prepare the blank: Prepare a blank material of ultra-fine or ultra-micro particle cemented carbide for a special drilling tool with a cutting edge diameter of φ3mm × shank diameter of φ6mm × taper angle of 36° × length of 50mm. Make the tool blank according to the shank diameter of φ6mm and the length of 50mm.

[0006] Step 2, machining the taper: Machining the front end to a taper G of 36°±1°, and leaving a mark on the front end face of the cutting edge. The plane.

[0007] Step 3, Machining the Grinding Groove: The groove angle is 110°±5°, and the core thickness k of the conical cutting edge of the groove is φ0.45±0.05mm; the two cutting edges of the main cutting edge are parallel and staggered by k values; the back surfaces of the main cutting edge are parallel and staggered by 0.7k values; when the grinding wheel diameter is φ150mm, the groove length is 13±1mm; when the grinding wheel diameter is φ120mm, the groove length is 11±1mm.

[0008] Step 4: Grind the second main flank face: The second main flank face is formed into a curved surface through grinding; the grinding amount of the second main flank face = 0.022 × the diameter of the tool holder.

[0009] Step 5: Grind the two main flank faces of the drill tip: Ensure that the included angle F between the two main cutting edges of the drill tip is 120°~140°±2°; the included angle between the chisel edge of the drill tip and the main cutting edge is 50°~55°; the length H of the chisel edge of the drill tip is 0.55±0.05mm; and the clearance angle of the main flank face is 25°±2°.

[0010] Step 6: Grind the first chip removal groove: Grind the length H of the chisel edge of the drill tip to shorten it to 0.20±0.05mm; accordingly, grind the first chip removal groove at both ends of the chisel edge of the drill tip; the angle β on the back of the first chip removal groove is 45°±5°; the rake angle α of the drill tip is 28°±2°.

[0011] In the above technical solution, further: the grinding amount of the second main flank blade is 0.13±0.01mm.

[0012] In the above technical solution, further: the first chip removal groove is a drill tip chip removal groove; the drill tip chip removal groove is connected to the second chip removal groove; the second chip removal groove is a straight chip removal groove; and the first chip removal groove and the second chip removal groove each have two symmetrical ones.

[0013] In the above technical solution, further: the width of the transition surface of the middle part of the drill tip cutting edge in step 6 is 0.70±0.10mm.

[0014] In the above technical solution, further: the grinding point on the diamond grinding wheel for grinding the cutting edge of the drill tip is located at 45°±5° below its horizontal line.

[0015] In the above technical solution, further: the special drilling tool for drilling tapered holes has a tool holder; a pair of symmetrical chip removal grooves are formed between the tool holder and the drill tip; the drill tip has a pair of symmetrical drill tip cutting edges; a drill tip chisel edge is provided between the tips of the drill tip cutting edges; the tail of the drill tip cutting edge is connected to the first main cutting edge; the tail of the first main cutting edge is connected to the second main cutting edge; the second main cutting edge is a side tapered cutting edge; the first main cutting edge has a first main flank face behind it; the second main cutting edge has a second main flank face behind it.

[0016] In the above technical solution, further: the diameter of the tool holder 7 is 2mm larger than the maximum opening diameter of the conical hole to be drilled.

[0017] The present invention also claims protection for a special drilling tool for drilling tapered holes, wherein the special drilling tool for drilling tapered holes is a special drilling tool for drilling tapered holes manufactured by any method for manufacturing special drilling tools for drilling tapered holes.

[0018] Advantages of this invention compared to existing technologies:

[0019] 1. The second main cutting edge of this invention is a side-tapered cutting edge, used together with the first main cutting edge. It features sharp cutting, smooth chip removal, long service life, low axial resistance during drilling, and efficient machining capabilities. Figure 1 The shape of the conical hole shown.

[0020] 2. The cutting tool material of the present invention is selected according to the specific material being processed, and is a high-performance ultra-fine particle cemented carbide with good cost performance. The durability of this material is more than 5 times higher than that of high-speed steel, and it can be re-sharpened and reused multiple times, which helps to reduce and control processing costs.

[0021] 3. The chip removal groove of this invention is a double groove, which makes the groove shape machining and the machining of the two pairs of main back face relatively simple. The sharpening of the tool after it becomes dull is also relatively simple, effectively reducing the manufacturing cost and the overall use cost.

[0022] 4. The taper G of the cutting edge of this invention is easy to detect, making it convenient for users to recheck the included angle parameters; the included angle of the tapered cutting edge does not require complex calculation, making it convenient for users to grind.

[0023] 5. The groove angle and cutting edge core thickness of this invention ensure that the tool has good chip removal performance and rigidity, resulting in excellent performance.

[0024] 6. The main back face of the present invention is formed into a curved surface by grinding, which refers to the existing grinding technology of 60° center drilling, and effectively solves the problem of machining a large tapered surface.

[0025] 7. In this invention, the included angle F is controlled between 120° and 140°. A smaller included angle results in a longer cutting edge length, lower cutting resistance, and better drilling centering. Conversely, a larger included angle results in a shorter cutting edge length, higher cutting resistance, and poorer tool centering, making the tool prone to wobble during drilling. Therefore, good symmetry between the two cutting edges is required. When the included angle exceeds 140°, the centering of the tool tip is significantly poor during drilling, and the increased component of force in the diameter direction leads to increased tool wobble and higher cutting resistance. Therefore, this angle range is a unique technical parameter of this invention.

[0026] 8. The chisel edge H of the drill tip of the tool of the present invention is ground separately for the second time after the two main cutting edges of the drill tip are machined and a certain core thickness is retained in the grinding groove. The length of the chisel edge H is about 0.20±0.05mm. At this time, the axial resistance of drilling is small, the operation is light and fast, and the drill tip edge maintains a certain strength. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the tapered hole structure that needs to be processed in this invention;

[0028] Figure 2 This is a schematic diagram of the tapered machining process of the present invention;

[0029] Figure 3(a) is a front view of the grinding groove processing procedure of the present invention;

[0030] Figure 3(b) is a side view of the grinding groove processing procedure of the present invention;

[0031] Figure 3(c) is a magnified detail view of Figure 3(b);

[0032] Figure 4 This is a schematic diagram of the two processes of grinding the main back face of the present invention;

[0033] Figure 5(a) is a front view of the process of grinding the two main rake faces of the drill tip according to the present invention.

[0034] Figure 5(b) is a side view of one process of grinding the two main back faces of the drill tip in this invention;

[0035] Figure 6 This is a front view of the first chip removal groove process of the present invention;

[0036] Figure 7 This is a perspective view of the first chip removal groove process of the present invention;

[0037] Figure 8 This is a schematic diagram of the grinding wheel dressing shape for the chip removal groove of the drill tip in this invention;

[0038] Figure 9 This is a schematic diagram of the grinding wheel grinding point of the chip removal groove of the drill tip in this invention;

[0039] In the figure: 1-Main cutting edge one, 101-Two cutting edge faces, 102-Back face, 2-Main flank face two, 3-Main flank face one, 4-Drill tip chisel edge, 5-Drill tip cutting edge, 6-Main cutting edge two, 7-Tool holder, 8-Second chip groove, 9-Diamond grinding wheel, 901-Grinding point. Detailed Implementation

[0040] The following will refer to the appendices in the embodiments of the present invention. Figure 1-9 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] A method for manufacturing a special drilling tool for drilling tapered holes, comprising the following steps:

[0042] Step 1: Prepare the blank: Prepare a blank of ultra-fine or ultra-micron micron cemented carbide material for a special drilling tool with a cutting edge diameter of φ3mm × shank diameter of φ6mm × taper angle of 36° × length of 50mm. Make the tool blank according to the shank diameter of φ6mm and the length of 50mm. To improve tool durability and reduce operating costs, select a suitable ultra-fine or ultra-micron micron cemented carbide material with good cost performance based on the specific material being machined, such as K180, TF25+, WF25, KS09, etc. This material has a durability more than 5 times higher than high-speed steel, and cemented carbide can be reused multiple times after wear and resharpening, reducing production costs.

[0043] In the above embodiments, the diameter of the tool holder 7 is 2mm larger than the maximum diameter of the conical hole to be drilled, thus meeting the requirements for the size of the conical hole opening.

[0044] (like Figure 2 (As shown) Step 2, machining the taper: Machining the front end to a taper G of 36°±1°, and leaving a mark on the front end face of the cutting edge. The plane.

[0045] (As shown in Figure 3) Step 3: Machining the grinding groove: The groove angle is 110°±5°, and the core thickness k of the conical cutting edge of the grinding groove is φ0.45±0.05mm; the two cutting edges 101 of the main cutting edge 1 are parallel and staggered by k values; the back surface 102 of the main cutting edge 1 is parallel and staggered by 0.7k values; when the grinding wheel diameter is φ150mm, the groove length is 13±1mm; when the grinding wheel diameter is φ120mm, the groove length is 11±1mm. Since the larger the grinding wheel diameter, the greater the increase in the core thickness of the grinding groove, considering that too large an increase in core thickness will affect chip removal and too small an increase will reduce the rigidity of the cutting edge, the selection of its parameters can ensure that the tool has good chip removal performance and rigidity, resulting in good performance. This is also a key point of this invention.

[0046] (like Figure 4 (As shown) Step 4: Grind the second main flank face: The second main flank face 2 is formed into a curved surface through grinding; the grinding amount of the second main flank face 2 = 0.022 × the diameter of the tool holder.

[0047] It should be noted that, due to the large width of the conical surface after the groove machining, the second main flank face 2 is formed into a curved surface through grinding. This grinding technique, referencing existing 60° center drilling grinding technology, effectively solves the machining challenge of a large conical surface. The grinding amount of the second main flank face 2 is determined based on the tool holder diameter, and the corresponding calculation formula is: Grinding amount of the second main flank face 2 = 0.022 × tool holder diameter.

[0048] (like Figure 4 As shown in the above embodiment, preferably, the grinding amount of the main flank face 2 is 0.13±0.01mm.

[0049] (As shown in Figure 5) Step 5: Grind the two main flank faces of the drill tip: Ensure that the included angle F between the two main cutting edges of the drill tip is 120°~140°±2°. A smaller included angle results in a longer cutting edge length, lower cutting resistance, and better drilling centering; a larger included angle results in a shorter cutting edge length, higher cutting resistance, and poorer tool centering, making the tool prone to wobble during drilling. Therefore, good symmetry between the two cutting edges is required. When the included angle is greater than 140°, the centering of the drill tip is significantly poor during drilling, and the increased component of force in the diameter direction will cause the tool to wobble more and the cutting resistance to increase. Therefore, the included angle F of 120°~140°±2° is also a unique technical parameter of this invention. In addition, the included angle between the drill tip chisel edge 4 and the main cutting edge 1 is 50° to 55°; the length H of the drill tip chisel edge 4 is 0.55 ± 0.05 mm; and the clearance angle of the main flank face 3 is 25° ± 2°.

[0050] (like Figure 6 (As shown) Step 6: Grind the first chip removal groove: This is the chip removal groove that the drill tip initially contacts when the chips flow out. All surfaces of this groove must be flat, and there should be no protrusions that affect chip flow during machining. Furthermore, to reduce drilling resistance, the length H of the drill tip chisel edge 4 is ground to 0.20±0.05mm; correspondingly, the two ends of the drill tip chisel edge 4 are ground into the first chip removal groove; the angle β on the back of the first chip removal groove is 45°±5°; the drill tip rake angle α is 28°±2°.

[0051] It should be noted that the length H of the drill tip chisel edge 4 is ground separately for the second time after the core thickness is retained in the grinding groove and the two main cutting edges of the drill tip are machined. At this time, the axial resistance of drilling is small, the operation is smooth, and the drill tip edge maintains a certain strength.

[0052] (like Figure 6 , Figure 7 As shown in the above embodiment, the first chip removal groove is a drill tip chip removal groove; the drill tip chip removal groove is connected to the second chip removal groove 8; the second chip removal groove 8 is a chip removal straight groove; and the first chip removal groove and the second chip removal groove 8 are respectively symmetrical.

[0053] It should be noted that this invention uses a two-groove tool, which is relatively simple to machine, as are the two pairs of main flank faces, and is also easy to regrind after the tool becomes dull. The two pairs of main cutting edges can ensure the centering and balance of cutting forces when drilling tapered holes. Other multi-groove tools, such as three-groove or four-groove tools, have complex machining processes and are inconvenient to regrind, so they are not used. Due to the simple machining and regrinding processes, the tool of this invention has relatively low manufacturing and overall operating costs.

[0054] Furthermore, the present invention uses a straight groove, which makes the groove machining, grinding of the main back face, and detection of the cone angle G of the main cutting edge more convenient, and users can also re-check the angle parameters; while the machining of the spiral groove and the process of grinding the back of the cone surface are more complicated, and obtaining a certain cone surface cutting edge angle requires complicated calculations, which makes it more inconvenient for users to perform grinding, so it is not used.

[0055] In the above embodiment, further: the width of the transition surface of the middle part of the drill tip cutting edge 5 in step 6 is 0.70±0.10mm.

[0056] (like Figure 9 As shown in the above embodiment, further: the grinding point 901 on the diamond grinding wheel 9 that grinds the drill tip cutting edge 5 is located at 45°±5° below its horizontal line.

[0057] (like Figure 6 , Figure 7 As shown in the above embodiment, further: the special drilling tool for drilling tapered holes has a tool holder 7; a pair of symmetrical chip removal grooves are formed between the tool holder 7 and the drill tip; the drill tip has a pair of symmetrical drill tip cutting edges 5; a drill tip chisel edge 4 is provided between the tips of the drill tip cutting edges 5; the tail of the drill tip cutting edge 5 is connected to the main cutting edge 1; the tail of the main cutting edge 1 is connected to the main cutting edge 2 6; the main cutting edge 2 6 is a side tapered cutting edge; the main cutting edge 1 has a main flank face 3 behind it; the main cutting edge 2 6 has a main flank face 2 behind it.

[0058] The present invention also claims protection for a special drilling tool for drilling tapered holes, wherein the special drilling tool for drilling tapered holes is a special drilling tool for drilling tapered holes manufactured by any of the methods for manufacturing special drilling tools for drilling tapered holes.

[0059] The working principle of this invention is as follows: the cutting edge of the tool includes a drill tip cutting edge and a main cutting edge one, as well as a main cutting edge two, namely a side tapered cutting edge. The cutting edge has sharp cutting, smooth chip removal, long service life, and low axial resistance of the drilling tool. The problem of one-time forming drilling of a tapered hole with a large upper part and a small lower part is solved by the proprietary design of the transverse cutting edge.

[0060] From the above description, it can be seen that the second main cutting edge of this invention is a side-tapered cutting edge, used together with the first main cutting edge. It features sharp cutting, smooth chip removal, long service life, low axial resistance during drilling, and efficient machining capabilities. Figure 1 The shape of the conical hole shown.

[0061] The cutting tool material of this invention is selected according to the specific material being processed, and is a high-performance ultra-fine particle or ultra-micro particle cemented carbide with good cost performance. This material is more than 5 times more durable than high-speed steel and can be re-sharpened and reused multiple times, which helps to reduce and control processing costs.

[0062] The chip removal groove of this invention is a double groove, which is relatively simple to machine and to machine the two pairs of main flank faces. It is also relatively easy to sharpen the tool after it becomes dull, thus effectively reducing the manufacturing cost and the overall cost of use.

[0063] The present invention makes it easy to detect the taper G of the cutting edge, which is convenient for users to re-check the included angle parameters; the included angle of the tapered cutting edge does not require complicated calculation, which is convenient for users to grind.

[0064] The groove angle and cutting edge core thickness of this invention ensure that the tool has good chip removal performance and rigidity, resulting in excellent performance.

[0065] The main back face of this invention is formed into a curved surface by grinding, which is based on the existing grinding technology of 60° center drilling, and effectively solves the problem of machining a large tapered surface.

[0066] In this invention, the included angle F is controlled between 120° and 140°. A smaller included angle results in a longer cutting edge length, lower cutting resistance, and better drilling centering. Conversely, a larger included angle results in a shorter cutting edge length, higher cutting resistance, and poorer tool centering, making the tool prone to wobble during drilling. Therefore, good symmetry between the two cutting edges is required. When the included angle exceeds 140°, the centering of the tool tip is significantly compromised during drilling, and the increased force in the diameter direction exacerbates tool wobble and increases cutting resistance. Thus, this angle range is a unique technical parameter of this invention.

[0067] The chisel edge H of the drill tip of the tool of the present invention is ground separately for the second time after the two main cutting edges of the drill tip are machined and a certain core thickness is retained in the grinding groove. The length of the chisel edge H is about 0.20±0.05mm. At this time, the axial resistance of drilling is small, the operation is light and fast, and the drill tip edge maintains a certain strength.

[0068] In summary, this invention is used for drilling non-concave tapered holes with a smaller inner diameter and a larger outer diameter. It effectively improves the drilling efficiency of tapered holes while solving the problem of drilling tapered holes in one step. The material durability is more than 5 times higher than that of high-speed steel, and it can be reground and reused multiple times, which helps to reduce and control processing costs. It does not require complicated calculations, making it convenient for users to reground. It has good chip removal performance and rigidity, resulting in excellent performance. It solves the problem of machining large tapered surfaces. It has low cutting resistance, good centering, is not prone to wobble, is easy to use, has high strength, and a long service life.

[0069] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for manufacturing a special drilling tool for drilling tapered holes, comprising a special drilling tool for drilling tapered holes; characterized in that, Includes the following steps: Step 1: Prepare the blank: Prepare a blank of ultra-fine or ultra-micro particle cemented carbide material for a special drilling tool with a cutting edge diameter of φ3mm × shank diameter of φ6mm × taper angle of 36° × length of 50mm. Make the tool blank according to the shank diameter of φ6mm and the length of 50mm. Step 2, Machining the Taper: Machin the front end with a taper G of 36°±1°, and leave a φ3 on the front end face of the cutting edge. +0 0 .20 A plane of mm; Step 3, Machining the Grinding Groove: The groove angle of the grinding groove is 110°±5°, and the core thickness k of the conical cutting edge of the grinding groove is φ0.45±0.05mm; the two cutting edges (101) of the main cutting edge (1) are parallel and staggered by k value; the back surface (102) of the main cutting edge (1) is parallel and staggered by 0.7k value; when the diameter of the grinding wheel is φ150mm, the groove length is 13±1mm; when the diameter of the grinding wheel is φ120mm, the groove length is 11±1mm. Step 4, Grinding the second main flank face: The second main flank face (2) is formed into a curved surface through grinding; the grinding amount of the second main flank face (2) = 0.022 × the diameter of the tool holder; Step 5: Grind the two main flank faces of the drill tip: Ensure that the included angle F between the two main cutting edges (1) of the drill tip is 120°~140°±2°; the included angle between the chisel edge (4) of the drill tip and the main cutting edge (1) is 50°~55°; the length H of the chisel edge (4) of the drill tip is 0.55±0.05mm; the clearance angle of the main flank face (3) is 25°±2°; Step 6: Grind the first chip removal groove: Grind the length H of the drill tip chisel edge (4) to shorten it to 0.20±0.05mm; correspondingly, grind the first chip removal groove at both ends of the drill tip chisel edge (4); the angle β on the back of the first chip removal groove is 45°±5°; the drill tip rake angle α is 28°±2°.

2. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 1, characterized in that: The grinding amount of the main back face (2) is 0.13±0.01mm.

3. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 1, characterized in that: The first chip removal groove is a drill tip chip removal groove; the drill tip chip removal groove is connected to the second chip removal groove (8); the second chip removal groove (8) is a chip removal straight groove; and the first chip removal groove and the second chip removal groove (8) are symmetrical.

4. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 1, characterized in that: In step 6, the width of the transition surface in the middle part of the drill tip cutting edge (5) is 0.70±0.10mm.

5. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 4, characterized in that: The grinding point (901) on the diamond wheel (9) that grinds the cutting edge (5) of the drill tip is located at 45° ± 5° below its horizontal line.

6. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 1, characterized in that: The special drilling tool for the taper hole has a tool holder (7); a pair of symmetrical chip removal grooves are formed between the tool holder (7) and the drill tip; a pair of symmetrical drill tip cutting edges (5) are formed on the drill tip; a drill tip chisel edge (4) is provided between the tips of the drill tip cutting edges (5); the tail of the drill tip cutting edge (5) is connected to the first main cutting edge (1); the tail of the first main cutting edge (1) is connected to the second main cutting edge (6); the second main cutting edge (6) is a side taper cutting edge; the first main cutting edge (1) has a first main flank face (3) behind it; the second main cutting edge (6) has a second main flank face (2) behind it.

7. The method for manufacturing a special drilling tool for drilling tapered holes according to claim 6, characterized in that: The diameter of the tool holder (7) is 2 mm larger than the maximum diameter of the cone hole to be drilled.

8. A special drilling tool for drilling tapered holes, characterized in that: The special drilling tool for the drilled taper hole is the special drilling tool for the drilled taper hole manufactured by the manufacturing method of any one of the special drilling tools for the drilled taper hole according to claims 1-5.

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