TWI854910B - Screw - Google Patents

Abstract

A screw mainly includes a plurality of ribs formed on a shank of the screw, a discharging portion formed between any two adjacent ribs, and a plurality of cutting portions formed on thread convolutions of the screw. The discharging portion has two inclined surfaces connected with the ribs respectively and an accommodation groove located between and connected with the inclined surfaces. Two thread flanks of each thread convolution converge at a thread crest. Thread roots of respective thread flanks define two different vertical distances with a baseline of the thread crest. One of the thread flanks has two flank sections extending slantingly respectively to define two different flank angles with the baseline of the thread crest. Thus, the cutting portions and the ribs assist in cutting cooperate with the asymmetric arrangement of the thread convolutions to increase the cutting efficiency, thereby reducing drilling resistance and enhancing pull-out resistance whereby the screw is not easily pulled out of a workpiece. Chips caused by cutting the workpiece are guided by the inclined surfaces into the accommodation groove, thereby removing the chips quickly.

Description

Screws

The present invention relates to a screw structure, in particular to a screw structure that improves cutting ability, achieves rapid chip removal, and achieves tight engagement, thereby reducing locking resistance, improving locking effect, and increasing pull-out resistance.

Referring to FIG. 1 and FIG. 2 , the conventional screw 1 includes a rod 11, and the rod 11 has two opposite ends forming a first end and a second end, a head 12 formed at the first end, a tail 13 formed at the second end, and a plurality of screw threads 14 spirally disposed on the rod 11, wherein each of the screw threads 14 has an upper tooth surface 141 extending outward from the rod 11 and facing the head 12, and a lower tooth surface 141 extending outward from the rod 11 and facing the head 12. The lower tooth surface 142 of the tail portion 13 and a tooth peak 143 formed at the junction of the upper and lower tooth surfaces 141 and 142 are used for locking. First, the tail portion 13 is positioned against the surface of an object 2, and then a rotational torque is applied to the head portion 12 so that the tail portion 13 is used to drill and expand the hole, and then the screw teeth 14 are cut to gradually drive the screw 1 to be screwed into the object 2, so that the locking operation of the screw 1 can be completed.

However, after actual use, it was found that the chip holding and chip removal space provided by the conventional screw 1 was insufficient, so that the chips generated during the locking process could not be discharged in time, and the screw 1 continued to squeeze the chips, which easily caused the locking resistance to increase and the locking speed to decrease. If the chips were squeezed continuously, the object 2 might even crack. In addition, the insufficient chip holding space would also cause the screw 1 to bite after locking. The force and locking properties are poor, resulting in poor pull-out resistance of the screw 1, making the screw 1 easily loose from the object 2. Furthermore, the screw threads 14 are symmetrically arranged, that is, the upper and lower tooth surfaces 141 and 142 are symmetrical tooth surfaces and have symmetrical angles, which further limits the cutting ability of the screw threads 14. It is difficult to effectively and quickly screw and lock the object 2 by only cutting the object 2 with the screw threads 14, which needs to be improved.

Therefore, the purpose of the present invention is to provide a screw that can greatly improve the cutting ability and achieve a tight bite, while having sufficient space for chip accommodation and chip removal, thereby reducing the locking resistance, increasing the locking speed, and increasing the pull-out resistance.

Therefore, the screw of the present invention comprises a rod, a head and a tail located at two ends of the rod, a plurality of threads spirally disposed on the rod, a plurality of ribs extending between the threads and protruding on the rod, and a chip removal portion formed between any two adjacent ribs, wherein each thread has a first tooth surface and a second tooth surface protruding outward from the rod and facing opposite directions, and the first and second tooth surfaces gradually converge at a tooth peak, and the tooth peak defines a reference line perpendicular to the center line of the rod, and the first and second tooth surfaces respectively form a first tooth bottom and a second tooth bottom at the junction with the rod, and the vertical distances formed between the first and second tooth bottoms and the reference line are different, and the first tooth surface has a first tooth segment connected to the first tooth bottom, and a second tooth segment connected to the first tooth segment, and the first and second tooth segments respectively form different angles with the reference line, and in addition, the tooth peaks of at least two screw teeth A plurality of rotary cutting parts are formed on the upper surface of the screw thread, and the chip removal part has a receiving groove extending between the screw threads, and two inclined surfaces respectively connecting the receiving groove and the convex ribs. Therefore, the convex ribs and the rotary cutting parts assist the rotary cutting to improve the cutting ability. In addition, the chips generated by the rotary cutting can be guided by the inclined surfaces into the receiving groove, which is more conducive to rapid chip removal, thereby reducing the generation of locking resistance, improving the locking speed, and avoiding cracking of the material. Part of the chips can also be removed. After locking, the screw threads are accommodated in the inclined surfaces, the receiving grooves and the rotary cut parts, thereby increasing the bite force and locking property after locking. In addition, each of the first and second tooth bottoms forms a different vertical distance with the reference line, and each of the first and second tooth segments forms a different angle with the reference line, so that the screw threads are asymmetrically arranged, which can also improve the cutting effect, achieve a tight bite after locking, and enhance the pull-out resistance after locking to prevent the screw from being easily pulled out.

The above-mentioned 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 FIG. 3, FIG. 3A, FIG. 3B and FIG. 4, the first preferred embodiment of the present invention, the screw 3 includes a rod 31 having a center line L, a first end and a second end formed at opposite ends of the rod 31, a head 32 formed at the first end of the rod 31, a tail 33 formed at the second end of the rod 31, a plurality of threads 34 spirally wound around the rod 31, and a plurality of protruding protrusions protruding outward from the outer periphery of the rod 31. The ribs 35 extend between the screw threads 34 in a direction not parallel to the center line L of the rod 31, and a chip removal portion 36 is formed between any two adjacent ribs 35. In this embodiment, four ribs 35 are provided on the rod 31, and the ribs 35 are symmetrically arranged. In addition, the tail portion 33 is arranged in a pointed tail shape in this embodiment, which can be adjusted and changed according to actual use requirements, such as a pointed tail, a drilled tail, and other different forms.

As mentioned above, each of the screw threads 34 has a first tooth surface 341 extending outward from the rod body 31, a second tooth surface 342 extending outward from the rod body 31 and facing the opposite direction of the first tooth surface 341, and a tooth peak 343 formed at the junction of the first tooth surface 341 and the second tooth surface 342. The first tooth surface 341 is connected to the outer periphery of the rod body 31 at a first tooth bottom 344, and the second tooth surface 342 is connected to the outer periphery of the rod body 31 at a second tooth bottom 345. Referring to FIG. 6, FIG. 6A and FIG. 6B, the tooth peak 343 defines a reference line R perpendicular to the center line L of the rod body 31. In addition, the tooth peaks of at least two screw threads 34 are 343 is provided with a plurality of rotary cutting portions 37 arranged at intervals, and a vertical distance formed between a first tooth bottom 344 of each of the first tooth surfaces 341 and a baseline R of the tooth peak 343 is different from a vertical distance formed between a second tooth bottom 345 of each of the second tooth surfaces 342 and the baseline R, wherein each of the first tooth surfaces 341 has a first tooth segment 3411 connected to the first tooth bottom 344, and a second tooth segment 3412 connected to the first tooth segment 3411, and an angle formed between each of the first tooth segments 3411 and the baseline R of the tooth peak 343 is different from an angle formed between each of the second tooth segments 3412 and the baseline R of the tooth peak 343.

Referring to FIG. 3 and FIG. 4 , in this embodiment, the screw threads 34 are divided into a plurality of first screw threads 34A and a plurality of second screw threads 34B located between the first screw threads 34A, so that the screw 3 is arranged in a double screw thread state, wherein the first thread surface 341A of each first screw thread 34A faces the head 32, and the second thread surface 342A of each first screw thread 34A faces the tail 33. 6 and 6A, a reference line parallel to the center line L is defined between the first tooth bottom 344A of each first tooth surface 341A and the reference line R, and the length of the reference line is defined as a first vertical distance D1 in this embodiment, and another reference line parallel to the center line L is also defined between the second tooth bottom 345A of each second tooth surface 342A and the reference line R. , and the length of the reference line is defined as a second vertical distance D2 in this embodiment, preferably the first vertical distance D1 is greater than the second vertical distance D2, and the definitions of the third, fourth, fifth, and sixth vertical distances D3, D4, D5, and D6 are also derived from the length of the reference line parallel to the center line L, and will not be repeated. In addition, the first tooth surface 341A of each first screw tooth 34A has There is a first tooth segment 3411A connected to the first tooth bottom 344A, and a second tooth segment 3412A connected to the first tooth segment 3411A and the tooth peak 343A, and each of the first tooth segments 3411A forms a first angle θ1 with the reference line R, and each of the second tooth segments 3412A forms a second angle θ2 with the reference line R, and it is preferred that the first angle θ1 is greater than the second angle θ2.

6 and 6B, the first tooth surface 341B of each second screw tooth 34B faces the tail portion 33, and the second tooth surface 342B of each second screw tooth 34B faces the head portion 32. In this embodiment, a third vertical distance D3 is formed between the first tooth bottom 344B of each first tooth surface 341B and the reference line R, and a fourth vertical distance D4 is formed between the second tooth bottom 345B of each second tooth surface 342B and the reference line R. The straight distance D3 may be greater than the fourth vertical distance D4. In addition, the first tooth surface 341B of each second screw tooth 34B has a first tooth segment 3411B connected to the first tooth bottom 344B, and a second tooth segment 3412B connected to the first tooth segment 3411B and the tooth peak 343B, and a third angle θ3 is formed between each first tooth segment 3411B and the reference line R, and a fourth angle θ4 is formed between each second tooth segment 3412B and the reference line R, and the third angle θ3 may be greater than the fourth angle θ4.

According to the above, by utilizing the difference in the vertical distances D1, D2, D3, and D4, the first screw threads 34A and the second screw threads 34B can produce asymmetric tooth surfaces. At the same time, the difference in the angles θ1, θ2, θ3, and θ4 also makes the first tooth surfaces 341A and 341B of the first screw threads 34A and the second screw threads 34B form a multi-segment structure, that is, to produce asymmetric tooth segments. Therefore, the above conditions are more conducive to improving the cutting ability of the screw threads 34 (i.e., the first screw threads 34A and the second screw threads 34B) to achieve a tight bite, and increase the pull-out resistance of the screw 3 after locking, so as to prevent the screw 3 from being easily pulled out of an object 4 (Figure 7).

3, 3A and 4, each of the chip removal portions 36 has a receiving groove 361 extending between the screw teeth 34, and two inclined surfaces 362 respectively located on both sides of the receiving groove 361, so that the inclined surfaces 362 are respectively connected to the receiving groove 361, and the other sides of the inclined surfaces 362 are respectively connected to the two adjacent ribs 35, so that when the ribs 35 are rotary cut to generate chips, the inclined surfaces 362 can guide the aforementioned chips into the receiving groove 361, and then quickly discharge the chips outward. In this embodiment, Each of the rotary cutting portions 37 has at least one groove 371 and a plurality of cutting grooves 372 formed on both sides of each of the grooves 371, and each of the grooves 371 is formed by the tooth peak 343 being recessed inwardly so that two cutting teeth 373 are formed on both sides of each of the grooves 371. The grooves 371 are preferably arranged in an arc shape. In this embodiment, the cutting grooves 372 are arranged in pairs, and each of the grooves 371 is located between any two groups of cutting grooves 372 and is connected to the cutting grooves 372 to form the cutting teeth 373.

Referring to FIGS. 3 to 7 , when the screw 3 is locked, the tail portion 33 is first positioned against the surface of an object 4, and then a rotational torque is applied to the head portion 32 to drive the tail portion 33 to drill downwardly into the object 4, and then the object 4 is cut by the screw teeth 34 (i.e., the first and second screw teeth 34A, 34B). At this time, the grooves 371, the cutting grooves 372, and the cutting edges 373 of the cutting portions 37, and the ribs 35 formed on the rod body 31, are used to assist in cutting and enhance the cutting ability. When the ribs 35 cut the object 4 and generate chips, the chips generated can be affected by the inclined surfaces 371 located on both sides of the ribs 35. 62 guides and enters the receiving groove 361, and then is quickly discharged outward. In addition, the chips generated by the rotary cutting can also quickly move outward through the receiving groove 361, the cutting grooves 372 and the grooves 371. Therefore, the configuration of the inclined surfaces 362, the receiving groove 361, the cutting grooves 372 and the grooves 371 can effectively increase the chip removal and chip accommodation space, and is more conducive to quickly discharging the chips outward, which not only greatly improves the The generation of locking resistance is reduced, and the screw 3 will not be hindered by the chips during the locking process and can be quickly screwed into the object 4, which further increases the locking speed. At the same time, it can also avoid the accumulation of the chips and the squeezing, which may cause the object 4 to crack. In addition, the asymmetric tooth surface, asymmetric tooth segment and asymmetric angle formed by the aforementioned screw teeth 34 can effectively increase the cutting ability during locking, and at the same time achieve the screw 3 and the object 4. The objects 4 are tightly engaged with each other to enhance the pull-out resistance of the screw 3 after being locked. Furthermore, after the screw 3 is screwed into the object 4, part of the chips can be accommodated in the inclined surfaces 362, the receiving grooves 361, the cutting grooves 372 and the grooves 371, which can further increase the fastening force between the screw 3 and the object 4, thereby enhancing the engagement force and locking property after locking, and effectively preventing the screw 3 from being loosened from the object 4.

Referring to FIG. 8, FIG. 9, FIG. 9A and FIG. 10, the second preferred embodiment of the present invention still includes the components described in the first embodiment, and its purpose and function are the same as those of the first embodiment, which will not be described in detail here. The special features of this embodiment are: the tail portion 33 has a drill body 331 connected to the second end of the rod body 31, and two guide grooves 332 recessed on the drill body 331 and arranged opposite to each other, and the guide grooves 332 are respectively connected to the receiving portion of each chip removal portion 36. The groove 361 is connected, and the present embodiment is based on the configuration of the screw 3 in a single-thread state. The first tooth surface 341 of each of the screw teeth 34 faces the head 32, and the second tooth surface 342 of each of the screw teeth 34 faces the tail 33. In addition, the fifth vertical distance D5 formed by the first tooth bottom 344 of each of the first tooth surfaces 341 and the reference line R is different from the sixth vertical distance D5 formed by the second tooth bottom 345 of each of the second tooth surfaces 342 and the reference line R. The fifth angle θ5 formed by the first tooth segment 3411 of each first tooth surface 341 and the reference line R is also different from the sixth angle θ6 formed by the second tooth segment 3412 of each first tooth surface 341 and the reference line R. The tail 33 is provided in a drill tail shape in the present embodiment, and it can be adjusted and changed according to actual use requirements, such as a pointed tail, a drill tail, etc. Therefore, when the tail 33 is used to drill the object 4 at the initial stage of locking, the tail The chips generated by the drilling of the screw 33 can enter the receiving groove 361 along the guide grooves 332, so that the tail 33 can quickly guide the hole and drill into the object 4, and the chips can be quickly discharged outward through the guide grooves 332 and the receiving groove 361, which can not only effectively and quickly discharge the chips, but also improve the locking speed. In addition, the guide grooves 332 can also accommodate a proper amount of chips, and further improve the bite force and locking property after locking, so that the screw 3 is not easy to loosen after locking.

In summary, the screw of the present invention has the ribs on the rod, and the chip removal portion is provided between any two adjacent ribs. The chip removal portion has two inclined surfaces connected to the ribs, and a receiving groove provided between the inclined surfaces and connected to the inclined surfaces. At the same time, the screw threads are provided with the rotary cutting portions. In addition to the rotary cutting portions and the ribs assisting the screw threads in cutting to improve the cutting ability, the inclined surfaces can also guide the generated chips into the receiving groove to facilitate the rapid discharge of the chips to the outside, which is more conducive to reducing the locking. In addition, the first and second tooth bottoms of the screw teeth and the base line of the tooth peak form different vertical distances respectively, and the first and second tooth segments of each first tooth surface extend at different angles, so that the screw teeth are asymmetrically arranged, which can increase the cutting ability, achieve the effect of close engagement with the object, and improve the tensile strength after locking. In addition, the inclined surfaces, the receiving grooves and the rotary cutting parts can also accommodate a proper amount of chips, thereby increasing the engagement force and locking property after locking, so that the screw is not easy to loosen.

However, the above is only to illustrate the preferred embodiment of the present invention, and should not be used to limit the scope of implementation of the present invention. In other words, all simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the invention specification should still fall within the scope of the patent of the present invention.

(Knowledge) 1: Screw 11: Rod 12: Head 13: Tail 14: Screw thread 141: Upper tooth surface 142: Lower tooth surface 143: Tooth peak 2: Object (Present invention) 3: Screw 31: Rod 32: Head 33: Tail 34: Screw thread 34A: First screw thread 34B: Second screw thread 35: Rib 36: Chip removal section 37: Peeling section 331: Drill body 332: Guide groove 341, 341A, 341B: First tooth surface 342, 342A, 342B: Second tooth surface 343, 343A, 343B: Tooth peak 344, 344A, 344B: first tooth bottom 345, 345A, 345B: second tooth bottom 361: receiving groove 362: inclined surface 371: groove 372: cutting groove 373: cutting edge 3411, 3411A, 3411B: first tooth segment 3412, 3412A, 3412B: second tooth segment θ1: first angle θ2: second angle θ3: third angle θ4: fourth angle θ5: fifth angle θ6: sixth angle D1: first vertical distance D2: second vertical distance D3: third vertical distance D4: fourth vertical distance D5: fifth vertical distance D6: sixth vertical distance L: center line R: reference line 4: object

Figure 1 is a schematic diagram of a known screw. Figure 2 is a schematic diagram of a known screw in use. Figure 3 is a three-dimensional diagram of the first preferred embodiment of the present invention. Figure 3A is an enlarged view of A in Figure 3. Figure 3B is an enlarged view of B in Figure 3. Figure 4 is a schematic diagram of a partial component of the first preferred embodiment. Figure 5 is a cross-sectional view of a partial component of the first preferred embodiment. Figure 6 is a schematic diagram of the first preferred embodiment. Figure 6A is an enlarged view of C in Figure 6. Figure 6B is an enlarged view of D in Figure 6. Figure 7 is a schematic diagram of the first preferred embodiment in use. Figure 8 is a three-dimensional diagram of the second preferred embodiment of the present invention. Figure 9 is a schematic diagram of the second preferred embodiment. FIG. 9A is an enlarged view of E in FIG. 9 . FIG. 10 is a schematic diagram of the second preferred embodiment in use.

3: Screws

31: Rod

32: Head

33: Tail

34: Screw thread

34A: First thread

34B: Second thread

35: ribs

36: Chip removal section

37: Peeling Department

341A, 341B: First tooth surface

342A, 342B: Second tooth surface

343A, 343B: Tooth peak

344A, 344B: First tooth bottom

345A, 345B: Second tooth bottom

3411A, 3411B: First tooth segment

3412A, 3412B: Second tooth segment

L: Centerline

Claims (7)

A screw comprises a rod, a first end and a second end formed at opposite ends of the rod, a head connected to the first end, a tail connected to the second end, and a plurality of threads spirally arranged on the rod, wherein the rod defines a center line, each of the threads has a first tooth surface and a second tooth surface extending outward from the rod and facing opposite directions, and a tooth crest formed at the junction of the first tooth surface and the second tooth surface, and The tooth crest defines a reference line perpendicular to the center line, the first tooth surface and the outer periphery of the rod body are connected to form a first tooth bottom, and the second tooth surface and the outer periphery of the rod body are connected to form a second tooth bottom; its characteristics are: the vertical distance formed between the first tooth bottom of each screw tooth and the reference line is different from the vertical distance formed between the second tooth bottom of each screw tooth and the reference line, and the first tooth surface of each screw tooth has a connection with the rod body. The invention relates to a first tooth segment connected to the screw thread, and a second tooth segment connected to the first tooth segment, the angle formed between the first tooth segment and the reference line is different from the angle formed between the second tooth segment and the reference line, and a plurality of rotary cutting parts are provided on the tooth peaks of at least two screw threads, each of the rotary cutting parts has at least one groove, and a plurality of cutting grooves provided on both sides of each groove, and each groove is formed by being recessed inward from the tooth peak so that each groove is formed with two cutting teeth, and the plurality of rotary cutting parts are provided on the tooth peaks of the screw threads. There are multiple ribs between the teeth. The ribs are convexly arranged on the outer periphery of the rod body and extend in a direction not parallel to the center line. At the same time, there is a chip removal portion between any two adjacent ribs. The chip removal portion has a receiving groove extending between the screw teeth and two inclined surfaces arranged on both sides of the receiving groove. The inclined surfaces are respectively connected to the two ribs, so that the chips generated by the rotary cutting of the ribs can be guided into the receiving groove by the inclined surfaces, and then the chips can be discharged. According to the screw described in claim 1, the first tooth surface of each thread is facing the head direction. According to the screw described in claim 1, the threads are further divided into a plurality of first threads and a plurality of second threads disposed between the first threads, and the first thread surface of each first thread faces the head direction, while the first thread surface of each second thread faces the tail direction. A screw according to any one of claims 1 to 3, wherein the vertical distance between the first root of each thread and the reference line is greater than the vertical distance between the second root of each thread and the reference line. A screw according to any one of claims 1 to 3, wherein the angle formed between the first tooth segment and the baseline is greater than the angle formed between the second tooth segment and the baseline. According to any one of claims 1 to 3, the screw, wherein the tail portion has a drill body connected to the second end of the rod body, and two guide grooves recessed on the drill body and arranged opposite to each other, and the two guide grooves are respectively connected to the receiving groove of the chip removal portion, so that the chips generated by the drilling of the tail portion enter the receiving groove through the guide grooves. According to the screw described in claim 1, the rotary cutting portions are arranged at intervals, and at least one groove of each rotary cutting portion is in an arc shape.

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