A fast feed drill for machining shallow holes

Abstract

The utility model provides a kind of fast feed drill bit of processing shallow hole, including integrally-formed shank and blade part, the blade part is inverted conical in axial direction, the blade part front end is equipped with tool tip, the tool tip is the inner recess structure along radial direction, and tool tip outer edge is equipped with tool tip chamfer, the end face of tool tip is equipped with two end edges that are central symmetry, end edge outer edge is linked with blade band to blade part side surface, one side of blade band is equipped with tool groove, the blade part area of tool groove inner ring forms positive core, the rear side of end edge rotation direction is sequentially equipped with end edge one rear corner surface and end edge two rear corner surface, and the inclination angle of end edge one rear corner surface is less than the inclination angle of end edge two rear corner surface. The structural design of tool groove can fast feed processing, improve processing efficiency;The structural design of end edge makes cutting light and fast, processing stable, improves hole precision;Processing stable makes drill bit cutting workpiece part gradually wear, improves service life.

Description

Technical Field

[0001] This utility model relates to the field of cutting tool technology, and in particular to a fast-feed drill bit for machining shallow holes. It is applied in the automotive and mold industries, and can efficiently machine shallow holes for materials such as stainless steel, titanium alloys, and high-temperature alloys. Background Technology

[0002] When machining shallow holes with a large diameter, the drill bit needs to be drilled at a low speed. However, the machine tool has low power at low speeds, and insufficient machine tool power will lead to unstable drilling, resulting in large fluctuations in hole diameter, poor hole accuracy, and reduced lifespan of the drill bit.

[0003] In view of this, it is necessary to improve the existing drill bits to solve the above problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to overcome the shortcomings of the prior art, this utility model provides a fast feed drill bit for machining shallow holes, which can improve the feed speed and make the cutting light and fast when machining shallow holes, thus making the drilling stable.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a fast-feed drill bit for processing shallow holes, including an integrally formed shank and a cutting edge. The cutting edge is inverted conical in the axial direction. The cutting edge has a cutting tip at its front end. The cutting tip has a radially concave structure and a cutting tip chamfer on its outer edge. The cutting tip has two centrally symmetrical end cutting edges on its end face. The outer edge of the end cutting edges is connected to the side of the cutting edge with a cutting band. A cutting groove is provided on one side of the cutting band. The cutting groove extends from the cutting tip to the junction of the cutting edge and the shank. The cutting edge area in the inner circle of the cutting groove forms a positive core. The rear side of the end cutting edge in the direction of rotation is provided with a first rear angle face and a second rear angle face. The inclination angle β1 of the first rear angle face is smaller than the inclination angle β2 of the second rear angle face.

[0006] Furthermore, the preferred inverted cone angle α1 of the cutting edge is 0.9°-1.1°, with α1 being 1°, which is greater than that of conventional drill bits. This reduces friction with the inner wall of the hole, thereby reducing the generation of frictional heat during high-feed drilling. Drill bits with this structure are suitable for machining shallow holes.

[0007] Furthermore, the concavity angle γ of the blade tip is 1.5°-2.5°. Preferably, the concavity angle γ is 2°.

[0008] Preferably, the inclination angle β1 of the first rear corner face of the end blade is 9°, and the inclination angle β2 of the second rear corner face of the end blade is 23°.

[0009] In this embodiment, the inner concave angle of the cutting edge is 2° and the first clearance angle of the end edge is 9°, resulting in sharp cutting and ensuring smooth cutting even at high feed rates.

[0010] Furthermore, the chamfer α2 of the cutting edge is 60°, and the length L2 of the chamfer is 1.4mm-1.6mm. Preferably, the length L2 of the inner chamfer is 1.5mm, the number of cutting edges of the drill bit is 2, and the chamfer of the cutting edge is 60°. When the drill bit enters the hole, it is subjected to symmetrical force, reducing axial force, making the clamping stable and avoiding vibration.

[0011] Furthermore, the radial extension of the end cutting edge passes through the center of the drill bit, and the eccentricity H2 of the end cutting edge is 0.1mm-0.15mm.

[0012] Furthermore, the core height H1 is 25% of the cutting diameter D2.

[0013] Furthermore, the groove is a straight groove with a groove opening angle α3 of 108°-112°.

[0014] In this embodiment, the tool groove is a straight groove with a groove opening angle of 110°. The height of the positive core is 25% of the cutting diameter. The cutting edge passes through the center, and the eccentricity is 0.1mm. This increases the tool groove space, making chip removal smooth. At the same time, it reduces the radial force generated during drilling, reduces the possibility of hole enlargement, and improves hole accuracy.

[0015] Furthermore, in order to avoid collisions, a blade back is provided on the side wall of the blade that is connected to the first and second rear corner surfaces of the end blade.

[0016] Furthermore, the scope of application of this drill bit is as follows: the drill bit is used to process shallow holes with a diameter of 20-32mm, and the hole depth does not exceed the hole diameter.

[0017] The beneficial effects of this utility model are:

[0018] (1) When drilling shallow holes with large diameters, due to the structural design of the tool groove, it is possible to feed quickly, improve the processing efficiency, and the linear speed and feed rate are about 25% higher than those of conventional drill bits, and the time to drill a hole is reduced by about 25%;

[0019] (2) Due to the structural design of the cutting edge, the cutting is light and the machining is stable, which improves the hole accuracy. The hole enlargement is 0.02 mm, which is at least 50% lower than before;

[0020] (3) The processing is stable, which causes the part of the drill bit that cuts the workpiece to wear gradually, thus improving its service life. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is a three-dimensional structural diagram of the drill bit of this utility model.

[0023] Figure 2 This is a side view of the drill bit of this utility model.

[0024] Figure 3 This is a side view of the drill bit of this utility model.

[0025] Figure 4 yes Figure 3 A magnified structural diagram of point I in the middle.

[0026] Figure 5 yes Figure 3 A schematic diagram of the cross-sectional structure of BB.

[0027] Figure 6 This is a schematic diagram of the cutting tip structure of the drill bit of this utility model.

[0028] Figure 7 This is a schematic diagram showing the dimensions of the drill bit of this utility model.

[0029] In the diagram: 1. Handle, 2. Blade, 3. Tip, 31. Tip chamfer, 4. End edge, 5. Blade band, 6. Groove, 7. Core, 8. First rear face of the end edge, 9. Second rear face of the end edge, 10. Back of the blade. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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 this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0033] like Figures 1-7 As shown, this utility model discloses a fast-feed drill bit for machining shallow holes, comprising an integrally formed shank 1 and a cutting edge 2. The cutting edge 2 is axially tapered, and the tapered angle α1 of the cutting edge 2 is 0.9°-1.1°. Preferably, in this embodiment, the tapered angle α1 is 1°. The cutting edge 2 has a cutting tip 3 at its front end, which is a radially concave structure. The concavity angle γ of the cutting tip 3 is 1.5°-2.5°. Preferably, in this embodiment, the concavity angle γ is 2°. Furthermore, the outer edge of the cutting tip 3 has a cutting tip chamfer 31, the size α2 of which is 60°, and the length L2 of which is 1.4mm-1.6mm. Preferably, in this embodiment, the length L2 of the chamfer is 1.5mm. The tip 3 has two centrally symmetrical end cutting edges 4 on its end face, i.e., the number of cutting edges is 2. The radial extension of the end cutting edges 4 (i.e., the cutting edges) passes through the center of the drill bit, and the eccentricity H2 of the end cutting edges 4 is 0.1mm-0.15mm. In this embodiment, the eccentricity H2 is 0.1mm. A cutting band 5 is connected to the side of the cutting part 2 from the outer edge of the end cutting edge 4. A cutting groove 6 is provided on one side of the cutting band 5. The cutting groove 6 extends from the tip 3 to the junction of the cutting part 2 and the shank 1. The cutting groove 6 is a straight groove with a groove opening angle α3 of 108°-112°. Preferably, in this embodiment, the groove opening angle α3 is 110°. The cutting part 2 region of the inner circle of the cutting groove 6 forms a core 7. The height H1 of the core 7 is 25% of the cutting diameter D2. The rear side of the end blade 4 in the direction of rotation is provided with a first rear corner surface 8 and a second rear corner surface 9, and the inclination angle β1 of the first rear corner surface 8 is smaller than the inclination angle β2 of the second rear corner surface 9. In this embodiment, β1 is 9° and β2 is 23°. A blade back 10 is provided on the side wall of the blade portion 2 where the first rear corner surface 8 and the second rear corner surface 9 are connected.

[0034] The specific application range of this drill bit is as follows: the drill bit is used to process shallow holes with a diameter of 20-32mm, and the hole depth does not exceed the hole diameter.

[0035] In this embodiment, the total drill length L is 140mm, the kerf 6 length L1 is 60mm, the shank diameter D1 is 20mm, and the cutting diameter D2 is 22mm. Therefore, the height of the core 7 is H1 = 25%D2 = 5.5mm.

[0036] The main features and effects of the drill bit in this embodiment are as follows:

[0037] (1) The tool groove 6 is a straight groove with a groove opening angle of 110°. The height of the core 7 is 25% of the cutting diameter. The cutting edge passes through the center, and the eccentricity is 0.1mm. This increases the space of the tool groove 6, making chip removal smooth. At the same time, it reduces the radial force generated during drilling, reduces the possibility of hole enlargement, and improves hole accuracy.

[0038] (2) The inner concave angle of the cutting edge is 2° and the first clearance angle of the end edge is 9°, which makes the cutting sharp and ensures smooth cutting when machining at high feed rates;

[0039] (3) With 2 cutting edges and a 31-degree chamfer at the tip of the drill bit, the drill bit is subjected to symmetrical force when it enters the hole, which reduces the axial force, makes the clamping stable, and avoids vibration.

[0040] (4) The inverted cone angle is 1°, which is greater than that of conventional drill bits. This reduces friction with the inner wall of the hole, thereby reducing the generation of frictional heat during high-feed drilling. This structure of drill bit is suitable for machining shallow holes.

[0041] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A fast-feed drill bit for machining shallow holes, characterized in that: The device includes an integrally formed handle and a cutting edge. The cutting edge is inverted conical in the axial direction and has a tip at its front end. The tip has a radially concave structure and a chamfer on its outer edge. The tip has two centrally symmetrical end edges. The outer edge of the end edges is connected to a cutting band on the side of the cutting edge. A groove is provided on one side of the cutting band. The cutting edge area in the inner circle of the groove forms a core. A first rear angle face and a second rear angle face are provided sequentially on the rear side of the end edge in the direction of rotation. The inclination angle β1 of the first rear angle face is smaller than the inclination angle β2 of the second rear angle face.

2. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The inverted cone angle α1 of the cutting edge is 0.9°-1.1°.

3. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The concave angle γ of the blade tip is 1.5°-2.5°.

4. The rapid feed drill bit for machining shallow holes as described in claim 1, characterized in that: The inclination angle β1 of the first rear corner face of the end blade is 9°, and the inclination angle β2 of the second rear corner face of the end blade is 23°.

5. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The size α2 of the chamfer on the blade tip is 60°, and the length L2 of the chamfer on the blade tip is 1.4mm-1.6mm.

6. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The radial extension of the end cutting edge passes through the center of the drill bit, and the eccentricity H2 of the end cutting edge is 0.1-0.15mm.

7. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The core height H1 is 25% of the cutting diameter D2.

8. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: The cutting groove is a straight groove with a groove opening angle α3 of 108°-112°.

9. The fast-feed drill bit for machining shallow holes as described in claim 1, characterized in that: A blade back is provided on the side wall of the blade that is connected to the first and second rear facets of the end blade.

10. The rapid feed drill bit for machining shallow holes as described in claim 1, characterized in that: The drill bit is used to machine shallow holes with a diameter of 20-32 mm, and the hole depth does not exceed the hole diameter.

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