Composite drill bit for machining taper hole

Abstract

The utility model discloses a composite drill bit for machining a taper hole. A tool bit of the composite drill bit for machining the taper hole comprises a spiral drilling part and a taper reaming part integrally connected to the spiral drilling part. The taper reaming part is provided with at least one chip breaking tooth, the first chip breaking tooth at the lower end is close to the tail end root circle of the spiral drilling part, the lower end of the upper blocking face of the chip breaking tooth and the upper end of the lower guiding face of the chip breaking tooth integrally intersect at the chip breaking end, and a chip breaking groove is formed in the space defined by the upper blocking face and the lower guiding face. A bottom hole is pre-machined through the spiral drilling part, taper reaming is conducted on the bottom hole through the taper reaming part, metal chips obliquely move inwards along the lower guide faces of the chip breaking teeth and are blocked and broken by the upper blocking faces, and efficient and integrated machining of the taper hole is achieved. The tapered hole drilling and reaming integrated machine tool has the effects of drilling and reaming integrated tapered holes, good chip breaking and discharging performance, rapidness and stability in cutting, high surface quality of drilled holes and high product yield.

Description

Technical Field

[0001] The utility model relates to the field of metal drilling, and particularly relates to a composite drill bit for machining tapered holes. Background Art

[0002] In industries such as automotive, aerospace, medical devices, shipbuilding, and machine tool manufacturing, a large number of metal parts involve drilling tapered holes. When drilling tapered holes, different drills are often used for two processes: pre-drilling the bottom hole and then reaming the tapered hole. The difficulty in chip breaking and chip evacuation in these processes is greater than that of drilling ordinary holes. The defects of traditional drills processed separately are as follows: First, the metal chips produced by cutting are long and cannot be quickly evacuated in time after cutting, resulting in unstable cutting process, large cutting deformation, and poor surface quality of the drilled hole. Second, the cutting chips cannot be removed in time, making it difficult for the cutting fluid to reach the bottom of the hole and the drill tip, and it cannot be fully cooled and lubricated, so the processing is carried out at a relatively high temperature, greatly reducing the drill bit life and the quality of the drilled hole. Third, traditional drill bits need to replace the drill tools for two drills, and the cutting speed is controlled very low, consuming a lot of time and having low cutting efficiency, which is difficult to meet the needs of large-scale production. Therefore, in order to adapt to the increasing development of the manufacturing industry and to pursue higher cutting efficiency and good processing quality, a new drill tool for drilling tapered holes is needed. Summary of the Utility Model

[0003] In order to solve one or more of the above problems, the utility model provides a composite drill bit for machining tapered holes.

[0004] According to one aspect of the utility model, the composite drill bit for machining tapered holes includes a tool body. One end of the tool body forms a tool tip and the other end forms a tool shank. Its characteristics are as follows:

[0005] The tool tip includes a spiral drilling part and a tapered reaming part integrally connected to the upper end of the spiral drilling part. The spiral drilling part is cylindrical and the tapered reaming part is an inverted cone.

[0006] At least one chip breaking tooth is provided on the circumferential wall of the tapered reaming part. The first chip breaking tooth at the lower end is close to the root circle at the end of the spiral drilling part. The chip breaking tooth includes a lower guiding surface with a diameter gradually decreasing from bottom to top and an upper blocking surface with a diameter gradually increasing from bottom to top. The lower end of the upper blocking surface and the upper end of the lower guiding surface are integrally intersected at the chip breaking end, and the space surrounded by the two forms a chip breaking groove.

[0007] The spiral drilling part pre-processes the bottom hole, and the tapered reaming part reams the bottom hole into a tapered hole. The metal chips move obliquely inward along the lower guiding surface of the chip breaking tooth and are blocked and broken by the upper blocking surface inclined outward upward, realizing efficient one-piece machining of tapered holes.

[0008] In some embodiments, the depth of the chip breaking tooth is 0.15 mm, that is, the radius of the upper end circle of the upper blocking surface is 0.15 mm larger than the radius of the lower end circle.

[0009] In some embodiments, the included angle between the lower guiding surface and the radial surface is 80°, and the included angle between the upper blocking surface and the radial surface is 40°.

[0010] In some embodiments, the distance between the chip-breaking end of the chip-breaking teeth at the lower end and the root circle of the end of the spiral drilling part is 3 mm.

[0011] In some embodiments, there are two chip-breaking teeth, and the distance between the two chip-breaking teeth is 4 mm.

[0012] In some embodiments, the chip-breaking end is a circumferential line or a cylindrical surface with a small height.

[0013] In some embodiments, the spiral drilling part is a twist drill structure, and its end face is provided with at least two cutting edges and its circumferential surface is provided with at least two spiral first tool backs, and spiral first chip evacuation grooves are formed between adjacent first tool backs.

[0014] In some embodiments, the circumferential surface of the taper reaming part is provided with at least two spiral second tool backs, and spiral second chip evacuation grooves that are connected to the first chip evacuation grooves are formed between adjacent second tool backs.

[0015] In some embodiments, the lower end of the cylindrical upper chip evacuation section is integrally formed on the upper end of the taper reaming part, and the upper chip evacuation section is provided with a spiral upper chip evacuation groove, and the upper chip evacuation groove is connected to the second chip evacuation groove below.

[0016] In some embodiments, the tool shank is a cylindrical straight shank or a conical taper shank;

[0017] Or the spiral internal cooling hole of the tool body extends from the upper end face of the tool tip to the lower end face of the tool shank.

[0018] The spiral drilling part of the composite drill bit for processing tapered holes plays the role of drilling the bottom hole, and the tapered reaming part plays the role of tapered reaming of the bottom hole, thereby realizing integrated drilling and reaming of the tapered hole, and no longer requiring a bottom hole. In addition, the tapered reaming part is provided with chip breaking teeth to break the slender metal chips generated in the reaming, so that the metal chips are more finely broken during cutting, thereby ensuring good chip breaking and chip removal. The beneficial effects are: first, the composite drill bit has good chip breaking and chip removal, which realizes that the metal chips are finely broken and can be discharged quickly during drilling, the cutting process is smooth, the cutting deformation is small, and the surface quality of the drilled hole is high, and the product is The product yield rate is high; secondly, metal chips are quickly and effectively removed, the cutting fluid can easily reach the bottom of the hole and the drill tip, and can give full play to the cooling and lubrication effects, so that the processing is carried out at an appropriate temperature, greatly improving the life and durability of the drill bit, while ensuring the drilling quality; thirdly, the composite drill bit completes the drilling and expansion of tapered holes in one go, and the cutting speed can be controlled at a higher speed, saving processing time, effectively improving processing efficiency, and meeting the needs of large-scale production; fourthly, the chip breaker teeth have a simple structure and a good chip breaking effect, ensuring that the chips are fine in size and can be effectively removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic front view of a composite drill bit for machining a tapered hole according to one embodiment of the present invention;

[0020] Figure 2 for Figure 1 An enlarged schematic diagram of point A of a composite drill bit for machining a tapered hole is shown;

[0021] Blade 01,

[0022] Cutting head 1, spiral drilling portion 10, cutting edge 100, first blade back 101, first chip groove 102, tapered hole expansion portion 11, chip breaker tooth 110, lower guide surface 111, upper blocking surface 112, chip breaking end 113, chip breaker groove 114, second chip groove 115, upper chip section 12, upper chip groove 121;

[0023] Handle 2;

[0024] Internal cooling holes 3. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below with reference to the accompanying drawings. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inward" and "outward" refer to directions toward or away from the geometric center of a particular component, respectively.

[0026] Figures 1 to 2A composite drill bit for machining tapered holes according to an embodiment of the present invention is schematically shown. As shown in the figure, the composite drill bit for machining tapered holes comprises a cutter body 01, with a cutter head 1 formed at one end and a shank 2 formed at the other end, and is characterized by:

[0027] The cutter head 1 includes a spiral drilling portion 10 and a tapered reaming portion 11 integrally connected to the upper end of the spiral drilling portion 10. The spiral drilling portion 10 is cylindrical and has an inverted cone shape. The spiral drilling portion 10 is preferably a twist drill structure, with at least two cutting edges 100 on its end surface and at least two spiral first blade backs 101 on its circumference, with spiral first chip grooves 102 formed between adjacent first blade backs 101. The tapered reaming portion 11 is preferably configured such that at least two spiral second blade backs 115 are formed on its circumference, with spiral second chip grooves 115 formed between adjacent second blade backs 115, and the second chip grooves 115 are connected to the first chip grooves 102.

[0028] The circumferential wall of the tapered reaming portion 11 is provided with at least one chip breaker tooth 110. The first chip breaker tooth 110 at the lower end is close to the terminal root circle 106 of the spiral drilling portion 10. The chip breaker tooth 110 includes a lower guide surface 111 with a diameter gradually decreasing from bottom to top and an upper blocking surface 112 with a diameter gradually increasing from bottom to top. The lower end of the upper blocking surface 112 and the upper end of the lower guide surface 111 integrally intersect at a chip breaking end 113, and the space enclosed by the two forms a chip breaking groove 114.

[0029] The spiral drilling part 10 pre-processes the bottom hole, and the tapered reaming part 11 performs tapered reaming on the bottom hole. The metal chips move obliquely inward along the lower guide surface 111 of the chip breaker tooth 110, and are blocked and broken by the upper blocking surface 112 inclined outward, thereby realizing efficient integrated processing of the tapered hole.

[0030] The spiral drilling part 10 of the composite drill bit for processing tapered holes plays the role of drilling the bottom hole, and the tapered reaming part 11 plays the role of tapered reaming of the bottom hole, realizing the integrated drilling and reaming of the tapered hole, and no longer needs the bottom hole, and the tapered reaming part 11 is provided with chip breaking teeth 110 to break the slender metal chips generated in the reaming, so that the metal chips are more finely broken during cutting, ensuring good chip breaking and chip removal; its beneficial effects are: first, the composite drill bit has good chip breaking and chip removal, realizes that the metal chips are finely broken and can be discharged quickly during drilling, the cutting process is smooth, the cutting deformation is small, and the surface quality of the drilled hole is improved High, high product yield; secondly, metal chips are quickly and effectively removed, the cutting fluid can easily reach the bottom of the hole and the drill tip, and can give full play to the cooling and lubrication effects, so that the processing is carried out at an appropriate temperature, greatly improving the life and durability of the drill bit, while ensuring the quality of drilling; thirdly, the composite drill bit completes the drilling and expansion of the tapered hole in one go, and the cutting speed can be controlled at a higher speed, saving processing time, effectively improving processing efficiency, and meeting the needs of large-scale production; fourthly, the chip breaker teeth 110 have a simple structure and have a good chip breaking effect, ensuring that the chips are fine in size and can be effectively removed.

[0031] Furthermore, the chip breaker teeth 110 have a depth of 0.15 mm, meaning the upper radius of the upper blocking surface 112 is 0.15 mm greater than the lower radius. Preferably, the angle between the lower guide surface 111 and the radial surface is 80°, while the angle between the upper blocking surface 112 and the radial surface is 40°. This advantageously achieves excellent chip breaking performance, ensuring fine shavings for quick and effective removal.

[0032] Preferably, the distance between the chip breaking end 113 of the lower chip breaker tooth 110 and the end root circle 106 of the spiral drilling portion 10 is 3 mm. The beneficial effect is that this arrangement ensures that the cutting chips are broken in time.

[0033] Preferably, there are two chip breaking teeth 110, and the distance between the two chip breaking teeth 110 is 4 mm. The beneficial effect is that this arrangement ensures that the cutting chips are broken efficiently and reliably.

[0034] Preferably, the chip breaking end 113 is a circumferential line or a cylindrical surface with a relatively small height.

[0035] Furthermore, the machine tool further comprises a cylindrical upper chip removal section 12, the lower end of which is integrally formed with the upper end of the tapered reamer 11. The upper chip removal section 12 is provided with a spiral upper chip removal groove 121, which is connected to the lower second chip removal groove 115. This arrangement further improves the speed and efficiency of chip removal.

[0036] Preferably, the tool handle 2 is a cylindrical straight handle or a conical tapered handle. The beneficial effect is that the tool handle 2 of this shape is easy to clamp and is suitable for various working conditions.

[0037] Furthermore, the cutter body 01 is provided with a spiral inner cooling hole 3, which extends from the upper end surface of the cutter head 1 to the lower end surface of the shank 2. The beneficial effect is that the inner cooling hole 3 provided with this arrangement easily obtains good cooling quality, ensuring processing speed and cutting quality.

[0038] The above descriptions are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A composite drill bit for machining tapered holes, comprising a tool body (01), one end of the tool body (01) forms a tool tip (1) and the other end forms a tool shank (2), and it is characterized in that: The tool tip (1) includes a spiral drilling part (10) and a tapered hole expanding part (11) integrally connected to the upper end of the spiral drilling part (10). The spiral drilling part (10) is cylindrical and the tapered hole expanding part (11) is an inverted cone; At least one chip breaking tooth (110) is provided on the circumferential wall of the tapered hole expanding part (11). The first chip breaking tooth (110) at the lower end is close to the end root circle (106) of the spiral drilling part (10). The chip breaking tooth (110) includes a lower guiding surface (111) with a gradually decreasing diameter from bottom to top and an upper blocking surface (112) with a gradually increasing diameter from bottom to top. The lower end of the upper blocking surface (112) and the upper end of the lower guiding surface (111) integrally intersect at a chip breaking end (113), and the space surrounded by the two forms a chip breaking groove (114); The spiral drilling part (10) pre-machines a bottom hole, and the tapered hole expanding part (11) expands the bottom hole into a taper. Metal chips move obliquely inwards along the lower guiding surface (111) of the chip breaking tooth (110) and are blocked and broken by the upper blocking surface (112) that is obliquely outwards in the upper direction, realizing efficient one-piece machining of tapered holes.

2. The composite drill bit for machining a tapered hole according to claim 1, characterized in that The depth of the chip breaking tooth (110) is 0.15 mm, that is, the upper end circle radius of the upper blocking surface (112) is 0.15 mm larger than the lower end circle radius.

3. The composite drill bit for machining a tapered hole according to claim 2, wherein, The included angle between the lower guiding surface (111) and the radial plane is 80°, and the included angle between the upper blocking surface (112) and the radial plane is 40°.

4. A composite drill bit for machining tapered holes according to claim 1, characterized in that, The distance between the chip breaking end (113) of the chip breaking tooth (110) at the lower end and the end root circle (106) of the spiral drilling part (10) is 3 mm.

5. The composite drill bit for machining a tapered hole according to claim 4, wherein, There are two chip breaking teeth (110), and the distance between the two chip breaking teeth (110) is 4 mm.

6. The composite drill bit for machining a tapered hole according to claim 5, wherein, The chip breaking end (113) is a circumferential line or a cylindrical surface.

7. A composite drill bit for machining a tapered hole according to claim 1, characterized in that, The spiral drilling part (10) is a twist drill structure, and at least two cutting edges (100) are provided on its end face and at least two spiral first tool backs (101) are provided on its circumferential surface. A spiral first chip evacuation groove (102) is formed between adjacent first tool backs (101).

8. A composite drill bit for machining a tapered hole according to claim 7, characterized in that, At least two spiral second tool backs are provided on the circumferential surface of the tapered hole expanding part (11), and a spiral second chip evacuation groove (115) that is connected to the first chip evacuation groove (102) is formed between adjacent second tool backs.

9. A composite drill bit for machining tapered holes according to claim 8, characterized in that, The lower end of the cylindrical upper chip evacuation section (12) is integrally formed on the upper end of the tapered hole expanding part (11). The upper chip evacuation section (12) is provided with a spiral upper chip evacuation groove (121), and the upper chip evacuation groove (121) is connected to the second chip evacuation groove (115) below.

10. A composite drill bit for machining a tapered hole according to any one of claims 1 to 9, characterized in that, The tool shank (2) is a cylindrical straight shank or a conical taper shank; Or the spiral internal cooling hole (3) of the tool body (01) extends from the upper end face of the tool tip (1) to the lower end face of the tool shank (2).

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