TWI756988B - External tooth type expansion screw and its manufacturing method - Google Patents

Abstract

The present invention provides the structure technology of the external screw type expansion screw and the manufacturing method of the external rod. The external screw type expansion screw includes the external rod, the pressing part and the rotating part. It is made by processes such as tooth forming and drilling, which is different from the casing made of sheet metal for general expansion screws, which can provide better fixing and shearing effects of the external screw type expansion screw, so that the external screw type expansion screw of the present invention can be obtained. It is durable and reusable.

Description

External tooth type expansion screw and its manufacturing method

The present invention provides a structural technology and a manufacturing method for an expansion screw, especially an expansion screw made of metal materials.

Expansion screw, also known as gecko, is a common workpiece that is placed in a hole and uses the tightening effect to achieve a fixed effect. The conventional expansion screw mainly includes a sleeve and an expansion part used to expand and deform the sleeve, so that the expansion screw It can produce a strong positioning effect relative to the hole through the principle of expansion and expansion.

Expansion screws used to fix heavy objects are usually made of metal materials, and most of the sleeves of such expansion screws are made of metal tubes. A number of cracks or expansion grooves are arranged on the outer wall of the tube, so that the expansion component can push or press the section of the expansion groove at the end of the casing to deform and press into the hole.

Because the sleeve will be deformed when the hole is tightened, most of the expansion screws can usually only be used once; secondly, when the expansion part is operated, the expansion part is often idling relative to the sleeve and the sleeve cannot be expanded. situation. In addition, during the construction process, the casing may not enter the wall or get stuck in the hole. When the casing is to be pulled out during the construction process, or the casing is to be removed in the future, it may happen that the casing cannot be taken out or the wall is damaged, which affects the appearance. In addition, when the casing is pulled out through the forceps, the casing is deformed and cannot be reused.

The main purpose of the present invention is to design a reusable external thread type expansion screw that is strong in structure and easy to operate. An outer rod, which is made of metal wire, the front end of the outer rod is cold-forged into a screw head, the outer rod has an external thread, the center of the outer rod is provided with a through hole, and the end of the outer rod is provided with at least The two expansion grooves make the end of the outer rod stretched to show the effect of expansion when the end of the outer rod is pushed from the inside to the outside.

When implemented, the external tooth type expansion screw further comprises: a pressing piece, which is made of metal material and has a tapered portion located at the end of the outer rod; the small diameter end of the tapered portion faces the through hole and has an outer diameter smaller than the The outer diameter of the large-diameter end of the part is larger than that of the through hole, and the outer peripheral surface of the tapered part is provided with a radially convex convex part, and the convex part is inserted into one of the two expansion grooves so that the pressing member cannot rotate relative to the outer rod ; And a rotating piece, which is made of metal material and has a rotating part exposed outside the front end of the outer rod, and is screwed with the pressing piece.

During implementation, the rotating member is in the shape of a nut, the pressing member is generally in the shape of a bolt and includes an inner rod connected to the conical portion, the inner rod is threaded through the through hole, and the inner rod is screwed to the rotating member.

When implemented, the rotating member takes the shape of a bolt and includes an inner rod connected to the rotating portion, the inner rod is fastened through the through hole, and the inner rod is screwed to the pressing member.

In practice, the convex portion is formed by extruding the surface of the pressing member.

When implemented, the outer peripheral surface of the screw head is in the form of a hexagonal column.

During implementation, a protruding piece is provided between the screw head and the external thread.

During implementation, the outer rod surface has a toothless area, and the toothless area is located between the lug portion and the external thread.

During implementation, the difference between the diameter of the through hole and the bottom diameter of the external thread should be at least 1.2mm.

In practice, the ratio of the bottom diameter of the through hole to the pitch of the external thread is greater than or equal to 1.8 and less than or equal to 2.

During implementation, an anti-slip portion is provided on the outer peripheral surface of the tapered portion.

During implementation, the anti-slip portion protrudes from the outer peripheral surface.

During implementation, the anti-slip portion is recessed on the outer peripheral surface.

Another object of the present invention is to provide a method for manufacturing the outer rod of an external thread type expansion screw, so that the outer rod has an integrated structure, which at least includes the following steps: a wire drawing step, which uses a metal wire to draw a wire to form a rod shape Modeling body; a punching step, stamping the front end of the rod-shaped modeling body to form a cold forged screw head; a tooth forming step, performing tooth forming processing on the surface of the rod-shaped modeling body within a preset range to form an external screw teeth; a drilling step of performing axial drilling in the center of the rod-shaped shaped body to form a through hole; and a groove cutting step of cutting grooves at the end of the rod-shaped shaped body to form at least two expansion grooves.

The wire drawing step can apply a pulling force to the metal wire to make it pass through a specific mold, so as to achieve the purpose of accurately reducing the size and forming a specific cross-sectional shape, and maintaining the toughness and shear strength of the metal wire. The punching step can directly form a screw head with precise dimensions, sufficient structural strength and toughness at the front end of the outer rod. The tooth forming process is preferably the processing method of rolling and pressing, which can speed up the production speed and provide accurate tooth size, and maintain good structural strength, which is suitable for mass production.

During implementation, a protruding piece is arranged between the screw head and the external thread.

When implemented, the outer rod surface has a toothless area, and the toothless area is located between the lug portion and the external thread.

During implementation, the difference between the diameter of the through hole and the bottom diameter of the outer thread of the casing should be at least 1.2mm.

During implementation, the ratio of the bottom diameter of the through hole to the pitch of the external thread is greater than or equal to 1.8 and less than or equal to 2.

Compared with the general expansion screw, the external thread type expansion screw of the present invention can use the screw head to rotate the external rod, so that the external screw thread taps into the preset cement hole on the wall surface, before the rotating member is not operated to displace the pressing member. Preliminary positioning effect can be produced in advance for the cement holes on the outer rod and the wall. Conversely, the outer rod can be quickly screwed out of the cement hole on the wall by rotating the screw head, so that the outer rod can be reused. And the outer rod is a structure made of metal wire, such as wire drawing, stamping, tooth forming and drilling, which is not easy to deform and has good shearing effect. The external tooth expansion screw of the present invention has the characteristics of strong structure, easy operation and reusability.

100: External thread expansion screw

10: Outer rod

11: Screw head

12: External thread

13: Through hole

14: Expansion groove

15: Tab part

16: Teethless area

20: Pressing pieces

21: Taper

211: Anti-slip part

30: Rotary pieces

31: Rotary part

40: Inner rod

200: to be fixed

300: Wall

301: Cement holes

W1: Bottom diameter

W2: Aperture

P: pitch

S1: Wire drawing step

S2: Stamping step

S3: Tooth formation steps

S4: Drilling step

S5: Groove cutting step

The first figure is a three-dimensional appearance view of the first embodiment of the present invention.

The second figure is an exploded perspective view of the first embodiment of the present invention.

Figure 3 is a cross-sectional view of the first embodiment of the present invention.

The fourth figure is a schematic diagram of the first embodiment of the present invention when it is not expanded.

The fifth figure is a schematic diagram of the expanded state of the first embodiment of the present invention.

The sixth figure is a partial enlarged schematic diagram of the outer rod end of the first embodiment of the present invention.

Fig. 7 is a schematic diagram (1) of the shape of the anti-slip portion according to the first embodiment of the present invention.

Figure 8 is a schematic diagram (2) of the shape of the anti-slip portion according to the first embodiment of the present invention.

The ninth figure is a schematic diagram (3) of the shape of the anti-slip portion according to the first embodiment of the present invention.

Figure 10 is a schematic diagram (4) of the shape of the anti-slip portion according to the first embodiment of the present invention.

FIG. 11 is an exploded perspective view of the second embodiment of the present invention.

Figure 12 is a cross-sectional view of the second embodiment of the present invention.

The thirteenth figure is a schematic diagram of the manufacturing method of the outer rod according to each embodiment of the present invention.

Please refer to the first to third figures. The external thread expansion screw 100 shown in this embodiment includes an external rod 10 , a rotating member 30 and a pressing member 20 .

The outer rod 10 is made of metal wire drawing wire. The front end of the outer rod 10 is cold forged to form a screw head 11. The outer peripheral surface of the screw head 11 is in the form of a hexagonal column. An external thread 12, the center of the outer rod 10 is provided with a through hole 13 formed by drilling axially, and the end of the outer rod 10 is provided with two symmetrically arranged expansion grooves 14, between the aforementioned screw head 11 and the external thread 12 A protruding piece 15 is provided, and a toothless area 16 is provided between the protruding piece 15 and the external thread 12 .

The pressing member 20 is made of metal material. The pressing member 20 is generally in the shape of a bolt. It includes a tapered portion 21 at the end of the outer rod 10 and an inner rod 40 connected to the tapered portion 21. The tapered portion 21 It is integrally formed with the inner rod 40.

The small diameter end of the conical portion 21 faces the through hole 13 and has an outer diameter smaller than the through hole 13 , the outer diameter of the large diameter end of the conical portion 21 is larger than the through hole 13 , and the inner rod 40 is inserted through the through hole 13 . 40 is screwed to the rotating member 30 .

The rotating member 30 is made of metal material and is screwed to the rotating member 30 , and has a rotating portion 31 exposed outside the front end of the outer rod 10 . The rotating member 30 is in the shape of a nut, and its outer peripheral surface constitutes the rotating portion 31 And it presents the shape of a hexagonal column.

Please refer to the fourth figure, the external thread expansion screw 100 first penetrates the object to be fixed 200 through the toothless area 16 , and then uses the tab portion 15 to fasten the outside of the object to be fixed 200 , and the end of the outer rod 10 is fastened. penetrate into the cement hole 301 of the wall surface 300 . When the cement hole 301 is slightly smaller than the external thread 12, the The screw head 11 makes the outer rod 10 screw into the cement hole 301 , and vice versa, the outer rod 10 can be screwed out of the cement hole 301 by reversely rotating the screw head 11 .

Please refer to FIG. 5 , the corner positions of the expansion groove 14 in contact with the tapered portion 21 can provide a frictional force that inhibits or reduces the rotation of the tapered portion 21 , and can even be engaged with the surface of the tapered portion 21 . The pressing member 20 can be axially displaced relative to the outer rod 10 by controlling the rotation of the rotating member 30 . When the pressing member 20 is displaced into the through hole 13 , the end of the outer rod 10 is blocked by the tapered portion 21 . Pushing and expanding outward to provide radial compression force to the cement hole 301 , the external thread expansion screw 100 can be stably positioned on the wall surface 300 , and the object to be fixed 200 can be fixed.

Please refer to the sixth figure, the ratio of the bottom diameter W1 of the external thread 12 to the pitch P of the external thread 12 is preferably greater than or equal to 1.8 and less than or equal to 2, so that the external thread 12 has a considerable degree of Tapping effect, so that the external thread 12 can be screwed into or out of the cement hole 301 preset on the wall surface 300 (refer to the fourth or fifth figure). The difference between the diameter W2 of the through hole 13 and the bottom diameter W1 of the outer rod 10 is at least 1.2 mm, so that the outer rod 10 can have better structural strength and shear resistance.

Please refer to Figures 7 and 8, in order to restrain or reduce the idling of the tapered portion 21, a slip prevention portion 211 may be further provided on the outer peripheral surface of the tapered portion 21, and the anti-slip portion 211 may be recessed in the tapered portion 21 on the outer periphery. Among them, the anti-slip portion 211 shown in the seventh figure is provided on the outer peripheral surface of the tapered portion 21 in the shape of a groove, and the anti-slip portion 211 shown in the eighth figure is provided in the shape of an embossed shape. the outer peripheral surface of the portion 21 .

Please refer to the ninth and tenth figures, the anti-slip portion 211 may also protrude from the outer peripheral surface of the tapered portion 21 . Among them, the anti-slip portion 211 shown in the ninth figure is arranged on the outer peripheral surface of the tapered portion 21 in the shape of a convex rib, and the anti-slip portion 211 shown in the tenth figure is arranged in the shape of a convex piece on the conical shape the outer peripheral surface of the portion 21 .

Please refer to the eleventh and twelfth figures. The main difference between the male-type expansion screw 100 shown in this embodiment and the first embodiment is that the rotating member 30 is generally in the shape of a bolt, and the pressing member 20 is generally in the shape of a bolt. cone The shape of the nut; the rotating part 30 includes a rotating part 31 and an inner rod 40, the inner rod 40 is inserted in the through hole 13, and the rotating part 31 and the inner rod 40 are integrally formed; the pressing part 20 is a conical screw The shape of the cap for the inner rod 40 to be screwed on.

Please refer to the second figure and the thirteenth figure, the outer rod 10 shown in the foregoing embodiments can be manufactured through the following steps, so that the outer rod 10 presents an integral forged structure with better toughness and Shear strength, so that it can be penetrated into the hole in the wall to produce a good bite effect, and it can also be rotated out of the hole in the wall for repeated use: a wire drawing step S1, a rod-shaped body is formed by drawing a wire with a metal wire; a In the stamping step S2, the front end of the rod-shaped shaped body is punched to form the cold-forged screw head 11, and the tabs 15 can also be formed simultaneously; a tooth forming step S3, a predetermined range of the surface of the rod-shaped shaped body is formed. Thread forming process is performed inside to form external screw threads 12, and the toothless area 16 is located outside the range of the section; a drilling step S4, axial drilling is performed in the center of the rod-shaped body to form a through hole 13; and all grooves are Step S5 , cutting grooves at the end of the rod-shaped molding to form at least two expansion grooves 14 to obtain a finished product of the outer rod 10 .

The finished product of the outer rod 10 is made through the processes of metal wire drawing, stamping, tooth forming and drilling to form an integrated cold forging structure, which can provide the outer tooth with strong structure, easy operation and reusability. Type expansion screw 100.

The above is only to illustrate the preferred embodiments of the present invention, not to limit the scope of implementation. All simple substitutions and equivalent changes made according to the scope of the patent application of the present invention and the content of the patent specification belong to the patent of the present invention. application category.

100: External thread expansion screw

10: Outer rod

11: Screw head

12: External thread

14: Expansion groove

15: Tab part

16: Teethless area

20: Pressing pieces

21: Taper

30: Rotary pieces

31: Rotary part

40: Inner rod

Claims (15)

An external screw type expansion screw, comprising: an external rod, which is formed by drawing a metal wire, the front end of the external rod is cold-forged into a screw head, the external rod has an external screw thread, and the screw head is connected with the screw head. A protruding piece is arranged between the outer threads, a through hole is arranged in the center of the outer rod, and at least two expansion grooves are arranged at the end of the outer rod, so that when the end of the outer rod is pushed from the inside to the outside, the The end of the outer rod is stretched to show the effect of expansion. The external thread expansion screw according to claim 1, further comprising: a pressing member made of metal material and having a tapered portion located at the end of the outer rod; the small diameter end of the tapered portion faces the through hole and is outside The diameter is smaller than the through hole, the outer diameter of the large diameter end of the conical part is larger than the through hole; Tighten fittings. The external thread expansion screw according to claim 2, wherein an anti-slip portion is provided on the outer peripheral surface of the tapered portion. The external thread expansion screw according to claim 3, wherein the anti-slip portion protrudes from the outer peripheral surface. The external thread expansion screw according to claim 3, wherein the anti-slip portion is recessed on the outer peripheral surface. The external thread expansion screw of claim 2, wherein the rotating member is in the shape of a nut, the pressing member is in the shape of a bolt and includes an inner rod connected to the tapered portion, the inner rod is threaded through In the through hole, the inner rod is screwed with the rotating member. The external thread expansion screw according to claim 2, wherein the rotating member is in the shape of a bolt and includes an inner rod connecting the rotating part, the inner rod is fastened through the through hole, and the inner rod is screwed into the through hole. The pressing piece. The external thread expansion screw according to claim 1, wherein the outer peripheral surface of the screw head is in the form of a hexagonal column. The external thread expansion screw of claim 1, wherein the outer rod has a toothless area on the outside, and the toothless area is located between the tab portion and the external thread. The external thread expansion screw according to claim 1, wherein the difference between the diameter of the through hole and the bottom diameter of the external thread is at least 1.2mm. The external thread expansion screw of claim 1, wherein the ratio of the bottom diameter of the through hole to the pitch of the external thread is greater than or equal to 1.8 and less than or equal to 2. A method for manufacturing an outer rod of an external tooth type expansion screw, comprising at least the following steps: a wire drawing step, drawing a wire with a metal wire to form a rod-shaped shaped body; a stamping step, stamping the front end of the rod-shaped shaped body to form cold forging a screw head; a tooth forming step, performing tooth forming processing within a preset range of the surface of the rod-shaped body to form external threads; a drilling step, performing axial drilling in the center of the rod-shaped body holes to form through holes; and in the step of cutting grooves, cutting grooves at the end of the rod-shaped shaped body to form at least two expansion grooves. The method for manufacturing the outer rod of an externally-threaded expansion screw according to claim 12, wherein the externally screwed teeth are formed by rolling teeth. The method for manufacturing an external rod of an external thread expansion screw as claimed in claim 12, wherein the difference between the diameter of the through hole and the bottom diameter of the external thread is at least 1.2 mm. The method for manufacturing an external rod of an external thread expansion screw as claimed in claim 12, wherein the ratio of the bottom diameter of the through hole to the pitch of the external thread is greater than or equal to 1.8 and less than or equal to 2.

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