TWI823173B - Self-drilling screw - Google Patents

Abstract

A self-drilling screw includes a head, a shank extending outwards from the head, a thread portion spirally disposed on the shank, and a drilling portion disposed on the shank and opposite to the head. The drilling portion has two symmetrical cutting grooves respectively extending from a tip of the drilling portion to the shank, a plurality of drilling bodies disposed between the cutting grooves, and a plurality of guiding grooves slantingly formed on the drilling bodies. Each drilling body has a first severing edge, a second severing edge, and a cutting edge formed between the first and second severing edges to thereby help increase the sharpness of the drilling body during cutting and improve the cutting and screwing effect. Chips caused during a cutting operation can be excluded outwards quickly through the cutting grooves and guiding grooves to thereby reduce the screwing resistance effectively.

Description

Drill tail screw

The present invention relates to a screw, in particular to a drill tail screw.

Referring to Figure 1, a conventional drill tail screw 1 includes a screw head 11, a rod body 12 extending outward from the screw head 11, a plurality of spiral rings provided on the threads 13 on the rod body 12, and a screw thread 13 on the rod body 12. There is a drill tail 14 on the body 12 opposite to one end of the screw head 11, and two cutting grooves 15 extending from the drill tail 14 to the rod body 12; wherein, the drill tail 14 has a drill tail 14 extending outward from the rod body 12. Drill body 141, a drill tip 142 provided at the end of the drill body 141, and a blade 143 formed on the drill body 141 and connected with the cutting groove 15; in addition, the two cutting grooves 15 are symmetrical and The staggered ring extends from the drill body 141 to the rod body 12; therefore, when the drill screw 1 is locked, the chips generated during the cutting of the object can be directly discharged into the cutting groove 15, and Since the cutting groove 15 extends to the rod body 12, the chips discharged can also be discharged into the thread 13 along the cutting groove 15, so that the chips can be quickly discharged out of the object.

However, after actual use, it was found that the drill tail 14 only discharges chips through the cutting groove 15 at first, and the buffering and chip holding effect it can produce is limited. Therefore, a large amount of chips generated in the initial stage of locking is still easy to block the cutting. In addition to causing locking resistance in the groove 15, the drill tail 14 only relies on the blade edge 143 to cut the object, and its cutting sharpness is limited and needs to be improved.

Therefore, the purpose of the present invention is to provide a drill tail screw that can effectively improve the drill tail sharpness and chip removal effect, and effectively reduce the overall locking resistance.

Therefore, the drill tail screw of the present invention includes a screw head, a rod body extending outward from the screw head, a spiral ring provided on the screw thread on the rod body, and a screw head provided on the rod body and opposite to the screw head. A drill tail at one end; wherein, the drill tail has two symmetrical cutting grooves extending from the drill tip to the rod body, a drill body located between the two cutting grooves, and chip guides respectively provided at an angle on the drill body. groove, and each of the aforementioned drill bodies is respectively formed with a cutting surface extending from the drill tip to the direction of the rod body, one connecting the outer edge surface of the cutting surface, and one connecting the outer edge surface to the cutting surface of the other drill body. The chip discharge surface of the surface is a chip guide surface that is concave on the outer edge surface and forms the chip guide groove, and a tapered surface located at the end of the drill body and connecting the cutting surface, the outer edge surface, and the chip discharge surface respectively. , a first blade formed at the junction of the tapered surface and the cutting surface, a second blade formed between the cutting surface and the outer edge surface, and a cutting edge formed between the first blade and the second blade ; Therefore, through the design of the first blade, the second blade and the cutting edge of the drill body, the sharpness of the drill tail can be effectively improved, the cutting capacity and cutting speed are increased, and at the same time, the cutting groove and the guide Due to the design of the chip groove, the cutting groove can provide enough chip space for the chip to be accommodated and buffered. The chips can also be quickly discharged through the cutting groove and chip guide groove, effectively reducing the locking resistance.

The aforementioned and other technical contents, features and effects of the present invention will be clearly understood in the following detailed description of the preferred embodiments with reference to the drawings.

Referring to Figures 2 and 3, the first preferred embodiment of the drill screw 3 of the present invention is shown. The drill screw 3 includes a screw head 31, and a rod 32 extending outwardly from the screw head 31 with a central axis 32a. , a spiral ring is provided on the thread 33 on the rod body 32, and a drill tail 34 is provided on the rod body 32 and opposite to one end of the screw head 31; wherein, the drill tail 34 has a drill tail 34 formed on the drill tail. The drill tip 341 at the end of 34 has two symmetrical cutting grooves 342 extending from the drill tip 341 to the rod body 32, a drill body 343 located between the two cutting grooves 342, and a drill body 343 respectively inclined and provided on the drill body 343. Chip guide 344.

Continuing with the above, each drill body 343 has a cutting surface 3431 extending from the drill tip 341 to the direction of the rod body 32, one connecting the outer edge surface 3432 of the cutting surface 3431, and one connecting the outer edge surface 3432 to the other side. A chip removal surface 3433 of the cutting surface 3431 of the drill body 343, a chip guide surface 3434 recessed on the outer edge surface 3432, and one located at the end of the drill body 343 and connected to the cutting surface 3431, outer edge surface 3432, respectively. The tapered surface 3435 of the chip removal surface 3433, a first blade 3436 formed at the junction of the tapered surface 3435 and the cutting surface 3431, a second blade 3437 formed at the cutting surface 3431 and the outer edge surface 3432, and a A cutting edge 3438 is formed between the first blade 3436 and the second blade 3437. The aforementioned cutting surface 3431 is designed to be flat in this embodiment, and the cutting groove 342 is formed between the cutting surface 3431 and the other drill body 343. The chip guide surface 3433 is between the chip guide surface 3433, and the chip guide surface 3434 is inclined and recessed on the drill body 343, and the chip guide groove 344 is formed by the height difference between the chip guide surface 3434 and the outer edge surface 3432. One end of the chip guide groove 344 is connected with the cutting groove 342 .

Referring to Figure 4, when this embodiment is used, the fastening is provided on an object 4. After the drill tip 341 contacts the surface of the object 4, a pressing and twisting force is exerted through the screw head 31, and through the first After the blade 3436 gradually cuts the surface of the object 4, the locking hole 41 of the peripheral wall 411 is formed on the surface of the object 4. The first blade 3436 continues to cut the object 4, so that the drill screw 3 continues to penetrate deeply. In the object 4, the cutting edge 3438 and the second blade 3437 can cut the peripheral wall 411 again. In this way, through the design of the first blade 3436, the second blade 3437 and the cutting edge 3438, it will be possible to increase The overall cutting sharpness of the drill screw 3 and the chips (arrows in the figure) generated during the cutting of the object 4 can be directly discharged into the cutting groove 342, which is formed by the cutting surface 3431. Surrounded by the chip removal surface 3433, a larger space can be provided for the chips to be discharged and accommodated. When the drill screw 3 continues to lock the chips generated, the chips in the cutting groove 342 can be directly removed smoothly. The chips are discharged along the screw thread 33 and can also be quickly discharged through the chip guide groove 344. Under such a double chip discharge effect, the chips are not easily blocked in the locking hole 41, which can effectively avoid chip blockage and cause resistance, and effectively achieve Reduce locking resistance and increase locking speed.

Referring to Figures 5 and 6, a second preferred embodiment of the present invention is shown. The drill screw 3 still includes a screw head 31, a rod body 32, a screw thread 33, a drill tail 34 and other structures, and the aforementioned components have the effect to be achieved. They are the same as the first embodiment and will not be described in detail. In particular, in this embodiment, the spiral ring on the rod body 32 is provided with two staggered slots 35, and the threads 33 where the slots 35 pass form a break. Open type, at the same time, the surrounding area of each slot 35 passes through a chip discharge surface 3433 and a chip guide surface 3434, and each slot 35 is connected to a chip guide groove 344 and a cutting groove 342 respectively; In addition, in this embodiment, the cutting edge 3438 protrudes opposite to the direction of the central axis 32a, so that the cutting edge 3438 is located at the outermost side of the drill body 343, and in this embodiment, the cutting edge 3438 can be rotated in time. Extending in the locking direction, the cutting edge 3438 and the cutting surface 3431 are not on the same plane, so that the cutting edge 3438 protrudes on the cutting surface 3431.

Referring to Figures 6 and 7, when the drill screw 3 is gradually screwed into an object 4, and the cutting edge 3438 extends in the twisting direction, so that the cutting edge 3438 and the cutting surface 3431 are not on the same plane, so that The sharpness of the cutting edge 3438 is increased. After the first blade 3436 cuts the object 4, a locking hole 41 is formed on the object 4, so that the cutting edge 3438 is located at the outermost side of the drill tail 34 and passes through the drill tail 34. After cutting the peripheral wall 411 formed by the cutting edge 3438, a gap will be generated between the second blade edge 3437 and the peripheral wall 411, so that the second blade edge 3437 will not directly contact the peripheral wall 411, which can effectively reduce the distance between the second blade edge 3437 and the peripheral wall 411. In addition to the resistance of the peripheral wall 411, the chips (arrows in the figure) generated after cutting can be quickly discharged from the cutting groove 342 and the chip guide groove 344. At the same time, the chips can also be discharged through the cutting groove 342 and the chip guide groove 344. into the slot 35, thereby achieving the effect of rapid chip removal, so that the drill tail screw 3 can achieve good effects in terms of spin lock sharpness, locking resistance and chip removal function.

To sum up the foregoing, the drill tail screw of the present invention is that the drill tail has two symmetrical cutting grooves extending from the drill tip to the rod body, a drill body provided between the two cutting grooves, and guides respectively inclined on the drill body. Chip flutes; therefore, through the design of the first blade, the second blade and the cutting edge of the drill body, the sharpness of the drill body during cutting can be improved, and the cutting flutes and chip guides provide sufficient In addition to the chip-containing space for containing and buffering the chips, the chips can also be quickly discharged through the cutting groove and chip guide groove.

However, the above descriptions are only for illustrating the preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, that is, simple equivalent changes and modifications may be made based on the patent scope of the present invention and the contents of the description of the invention. , should still fall within the scope covered by the patent of this invention.

[customary knowledge] 1: Drill tail screw 11:Screw head 12: Rod body 13: screw thread 14: drill tail 15: Cutting groove 141:Drill body 142:Drill tip 143:Blade [Creation] 3: Drill tail screw 31:Screw head 32: Rod body 32 a:Central axis 33: screw thread 34: drill tail 35: Grooving 341:Drill tip 342:Cutting groove 343:Drill body 344: Chip guide 3431:Cutting surface 3432:Outer edge surface 3433: Chip removal surface 3434: Chip guide surface 3435:Conical surface 3436:The First Blade 3437:Second Blade 3438:Cutting edge 4:Object 41: Locking hole 411: Surrounding wall

Figure 1 is a schematic diagram of a conventional drill tail screw. Figure 2 is a schematic three-dimensional view of the first preferred embodiment of this embodiment. Figure 3 is a schematic plan view of the first preferred embodiment of this embodiment. Figure 4 is a schematic diagram of the locking state of the first preferred embodiment of this embodiment. Figure 5 is a schematic three-dimensional view of the second preferred embodiment of this embodiment. Figure 6 is a schematic plan view of the second preferred embodiment of this embodiment. Figure 7 is a schematic diagram of the locking state of the second preferred embodiment of this embodiment.

3: Drill tail screw

31:Screw head

32: Rod body

32a:Central axis

33: screw thread

34: drill tail

341:Drill tip

342:Cutting groove

343:Drill body

344: Chip guide

3431:Cutting surface

3432:Outer edge surface

3433: Chip removal surface

3434: Chip guide surface

3435:Conical surface

3436:The First Blade

3437:Second Blade

3438:Cutting edge

Claims (3)

A drill tail screw, which includes a screw head, a rod body extending outward from the screw head and forming a central axis, a spiral ring provided on the thread of the rod body, and a thread provided on the rod body and On the contrary, there is a drill tail at one end of the screw head; in addition, a drill tip is formed at the end of the drill tail, which is characterized in that: the drill tail has two symmetrical cutting grooves extending from the drill tip to the rod body, and are respectively provided in the two cutting grooves. The drill body between them, and chip guides respectively inclined on the drill body; wherein each drill body has a cutting surface extending from the drill tip to the direction of the rod body, and a cutting surface connected to the outer edge of the cutting surface surface, a chip removal surface connecting the outer edge surface to the cutting surface of another drill body, a chip guide surface recessed on the outer edge surface and forming the chip guide groove, and a chip guide surface located at the end of the drill body and respectively The tapered surface connecting the cutting surface, the outer edge surface and the chip discharge surface, a first blade formed at the junction of the tapered surface and the cutting surface, a second blade formed at the cutting surface and the outer edge surface, and A cutting edge formed between the first blade and the second blade; in addition, the cutting groove is formed between the cutting surface and the chip discharge surface of another drill body, and the cutting groove is connected with the chip guide groove; furthermore, the cutting groove is formed between the cutting surface and the chip discharge surface of another drill body, and the cutting groove is connected with the chip guide groove; , the spiral ring on the rod body is provided with two staggered slots, and the threads where the slots pass through form a broken pattern, and the place where each slot ring is located passes through at least one of the chip removal surfaces and a The chip guide surface and each groove are respectively connected with a chip guide groove and a cutting groove. The drill tail screw according to claim 1, wherein the cutting edge is opposite to the The direction of the central axis protrudes. The drill tail screw according to claim 1 or claim 2, wherein each cutting edge extends in the twist-locking direction.

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