Variable increment twist drill

Abstract

The utility model relates to a variable increment twist drill which comprises a drill handle and a drill edge connected to the front side of the drill handle, a drill tip is arranged on the front side of the drill edge, and chip removal grooves are further formed in the two sides of the drill edge. A drill core of the drill edge is divided into three sections from one side, far away from the drill handle, of the drill edge, and the three sections are a drill tip section, a main body section and an arc-shaped transition section in sequence; the total axial length of the main body section and the drill tip section is L, the axial length of the drill tip section is L1, the thickness of the drill tip section is kept unchanged and is K1, the thickness of the main body section is gradually increased in the direction from the drill tip section to the arc-shaped transition section, the thickness of the side, close to the drill tip section, of the main body section is K2, the thickness of the side, close to the arc-shaped transition section, of the main body section is K3, K2 is equal to K1, K1 is provided with a flat increment area of 5-10 mm, and (K3-K1) / 100L is equal to 3.0-5.0 / 100 mm. According to the twist drill, the thickness of the drill core of the drill edge is designed, and the values of the corresponding K1, K2 and K3 and the relationship between the values of the K1, the K2 and the K3 and the L and the L1 are controlled respectively, so that the designed twist drill is easy to cut and has enough strength and rigidity.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of drill bits, in particular to a variable increment twist drill. BACKGROUND

[0002] In the design and manufacture of ordinary twist drills, the thickness of the drill core is a very important parameter, and the thickness of the drill core affects the cutting load, rigidity, strength and durability of the drill bit, and generally, increasing the thickness of the drill core can improve the rigidity and strength of the drill bit, but the cutting force will increase, which is not conducive to cutting processing.

[0003] In order to make the drill core meet the equal strength as much as possible, the thickness of the drill core is increased towards the shank, so as to better solve the contradiction between the strength and the cutting load. Figure 1 As shown in the conventional design, (K5-K4) / 100L, commonly used 1.4---2.0 / 100mm, but the twist drill of this structure can only meet the drilling processing under general conditions, and cannot be applied to occasions with high requirements for rigidity, strength and durability, and a twist drill with two core thickness increments is also mentioned in patent CN101585093A, which has a structure similar to that shown in Figure 1 As shown in the conventional design, (K5-K4) / 100L, commonly used 1.4---2.0 / 100mm, but the twist drill of this structure can only meet the drilling processing under general conditions, and cannot be applied to occasions with high requirements for rigidity, strength and durability, and a twist drill with two core thickness increments is also mentioned in patent CN101585093A, which has a structure similar to that shown in INNOVATION CONTENT

[0004] The technical problem to be solved by the utility model is to provide a variable increment twist drill with sufficient strength and rigidity for easy cutting.

[0005] To solve the above technical problems, the technical scheme of the utility model is as follows: a variable increment twist drill, which is characterized by comprising a drill shank and a drill blade connected to the front side of the drill shank, the front side of the drill blade is a drill tip, and a chip removal groove is also opened on both sides of the drill blade.

[0006] The drill core of the drill blade is divided into three sections from the side of the drill blade away from the drill shank, in sequence, a drill tip section, a main body section and an arc transition section; the total axial length of the main body section and the drill tip section is L, the axial length of the drill tip section is L1, the thickness of the drill tip section remains unchanged, which is K1, the thickness of the main body section gradually increases from the drill tip section to the arc transition section, the thickness of the main body section near the drill tip section is K2, the thickness of the main body section near the arc transition section is K3, K2=K1, K1 has a flat increment area of 5-10mm, and (K3-K1) / 100L=3.0-5.0 / 100mm.

[0007] Further, the cross-sectional profile of the chip removal groove is in a parabolic shape.

[0008] The advantages of the present invention are as follows: the twist drill of the present invention comprehensively considers cutting load, rigidity, strength and durability, designs the drill core thickness of the drill blade, and controls the corresponding values ​​of K1, K2, K3 and their relationship with L and L1, thereby making the designed twist drill easy to cut, having sufficient strength and rigidity, and ensuring sufficient chip space.

[0009] The chip removal groove adopts a parabolic design. While meeting the strength requirements, the chip space is maximized and the chips are discharged smoothly, thereby extending the service life of the twist drill. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of a traditional twist drill.

[0011] Figure 2 It is a schematic diagram of the variable increment twist drill of the present invention.

[0012] Figure 3 It is a schematic diagram of the chip removal groove in the present invention. DETAILED DESCRIPTION

[0013] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the following is a detailed description of the specific implementation method, structure, characteristics and effects of the present invention in combination with the accompanying drawings and preferred embodiments.

[0014] like Figure 2 、 Figure 3 The variable increment twist drill shown in the figure includes a drill shank 1 and a drill blade 2 connected to the front side of the drill shank 1. The front side of the drill blade 2 forms the drill tip. Chip removal grooves 24 are formed on both sides of the drill blade 2. The cross-sectional profile of the chip removal grooves 24 is parabolic. The parabolic design of the chip removal grooves 24 maximizes chip space while meeting strength requirements, ensuring smooth chip removal and extending the service life of the twist drill.

[0015] The drill core of the drill blade 2 is divided into three sections starting from the side of the drill blade 2 away from the drill shank 1 , which are defined as a drill tip section 21 , a main body section 22 and an arc-shaped transition section 23 in sequence.

[0016] The total axial length of the main body section 22 and the drill tip section 21 is L, the axial length of the drill tip section 21 is L1, the thickness of the drill tip section 21 remains unchanged, which is K1, and the thickness of the main body section 22 gradually increases from the drill tip section 21 to the arcuate transition section 23. The thickness of the main body section 22 on the side close to the drill tip section is K2, and the thickness of the main body section 22 on the side close to the arcuate transition section is K3. K2=K1, K1 has a flat incremental area of ​​5-10 mm, and (K3-K1) / 100L=3.0-5.0 / 100 mm.

[0017] The twist drill of the utility model comprehensively considers cutting load, rigidity, strength and durability, designs the thickness of the drill core of the drill edge 2, controls the values of corresponding K1, K2 and K3 and the relationship with L and L1, so that the designed twist drill can cut easily, has sufficient strength and rigidity, guarantees sufficient chip space, and the thickness K1 of the drill tip section 21 can be designed as Figure 1 2 / 3 of the K4 thickness of the twist drill shown in the figure.

[0018] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above with a preferred embodiment, it is not intended to limit the utility model. Any person skilled in the art can make slight changes or modifications to the disclosed technical content to obtain equivalent embodiments without departing from the technical solution of the utility model. Any modification, equivalent change and modification of the above embodiment according to the technical essence of the utility model still belong to the scope of the technical solution of the utility model.

Claims

1. A variable increment twist drill, characterized by: The drill bit is connected to the front side of the drill handle, and the drill tip is on the front side of the drill bit, and the chip removal grooves are also opened on both sides of the drill bit; The drill core of the drill bit is divided into three sections from the side of the drill bit away from the drill handle, and the three sections are in turn the drill tip section, the main body section and the arc transition section; The total axial length of the main body section and the drill tip section is L, the axial length of the drill tip section is L1, the thickness of the drill tip section remains unchanged and is K1, the thickness of the main body section gradually increases from the drill tip section to the arc transition section, the thickness of the main body section near the drill tip section is K2, the thickness of the main body section near the arc transition section is K3, K2=K1, K1 has a flat increment area of 5-10 mm, and (K3-K1) / 100L=3.0-5.0 / 100 mm.

2. The variable increment twist drill according to claim 1, wherein: The cross-sectional profile of the chip removal groove is parabolic.

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