Multi-thread self-tapping screw

Abstract

The utility model provides a multi-thread self-tapping screw, which belongs to the technical field of screws and comprises an outer cylinder and an inner rod. A regular polygon screw head is arranged at the top of the outer cylinder, a mounting cavity is formed in the outer cylinder, and a slot is formed in the bottom; the mounting cavity is circular; the inner rod is matched in the mounting cavity, the top of the inner rod is provided with a head part, and the bottom of the inner rod is provided with a distraction section; the top surface of the head part is concave downwards to form a cross-shaped connecting groove; the opening section comprises a big-end-down conical section, and the bottom end of the opening section is of a pointed end structure. The screw comprises the inner rod and the outer cylinder, and the inner rod is in threaded fit with the interior of the outer cylinder and can ascend relative to the outer cylinder to drive the opening section at the bottom to open the bottom, divided by the groove, of the outer cylinder, so that the fixing effect of the screw is improved. Meanwhile, when the inner rod is matched in the outer cylinder, the bottom of the inner rod can extend to the bottom of the outer cylinder to serve as the tip of the self-tapping screw, so that self-tapping is facilitated, and the applicability of the screw is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to screw technical field, concretely relates to a multi thread self tapping screw. BACKGROUND

[0002] Screw is a kind of common fastener, has widely used in mechanical manufacturing, building, furniture and many other fields, and there are various kinds. There is a kind of multi thread screw in prior art, the screw includes threaded cooperation inner rod and outer cylinder, inner rod bottom has driving ball to prop open outer cylinder bottom, to improve fixed effect. But screw is hollow inside, bottom is relatively blunt, cannot self tapping, and applicability is poor. For this reason, the utility model provides a kind of multi thread self tapping screw. SUMMARY

[0003] The utility model aims at providing a kind of multi thread self tapping screw.

[0004] To solve the above technical problem, the utility model aims at being realized as follows:

[0005] A kind of multi thread self tapping screw, including: outer cylinder and inner rod;The outer cylinder top is provided with regular polygonal screw head, is internally provided with installation cavity, bottom is provided with several slots evenly distributed along its circumference;The installation cavity is circular, is arranged along the outer cylinder axis, and penetrates the outer cylinder;Regular polygonal screw head center is provided with through-hole;The through-hole penetrates the regular polygonal screw head and the installation cavity is communicated;The outer cylinder outer surface and inner surface are all provided with thread;

[0006] The inner rod is cooperated in the installation cavity, top is provided with head, bottom is provided with prop open section;The head top surface is concave and forms cross connection groove;Prop open section includes a small upper large lower conical section, bottom end is set as sharp structure;The inner rod surface is provided with thread to cooperate with the thread of the outer cylinder;

[0007] The inner surface of the bottom of the outer cylinder is provided with the inner convex of the conical section.

[0008] On the basis of the above scheme and as the preferred scheme of the above scheme, the regular polygonal screw head is hexagonal screw head;The through-hole is circular.

[0009] On the basis of the above scheme and as the preferred scheme of the above scheme, the head is circular, and is matched with the through-hole.

[0010] On the basis of the above scheme and as the preferred scheme of the above scheme, the regular polygonal screw head is provided with retaining ring at the top end port of the through-hole.

[0011] On the basis of the above scheme and as the preferred scheme of the above scheme, the head top edge is provided with the embedding groove matched with the retaining ring.

[0012] In the above scheme and as a preferred scheme of the above scheme, the bottom end of the expansion section is conical.

[0013] In the above scheme and as a preferred scheme of the above scheme, the bottom end of the outer cylinder is provided with an inclined portion; the inclined portion can be spliced with the conical structure as the tip of the self-tapping screw.

[0014] The utility model discloses the beneficial effect is: the utility model discloses inner rod and outer cylinder, inner rod is screwed together in the inside of outer cylinder, can ascend relative to outer cylinder, drives the expansion section of bottom and opens the bottom of outer cylinder splited with the slot, to improve the fixed effect of screw. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the structure schematic diagram of the utility model.

[0016] Figure 2 It is the structure schematic diagram of the outer cylinder of the utility model.

[0017] Figure 3 It is the structure schematic diagram of the inner rod of the utility model.

[0018] Figure 4 It is the sectional view of the utility model.

[0019] In the drawing: 1, outer cylinder;11, regular polygon screw head;12, installation cavity;13, slot;14, through -hole;15, inner convex;16, baffle ring;2, inner rod;21, head;22, expansion section;23, cross connection recess;24, fitting groove. DETAILED DESCRIPTION

[0020] The utility model is further explained below in connection with the drawings and specific embodiment.

[0021] As Figure 1 And Figure 4 As shown in a kind of multi-threaded self-tapping screw, comprising: outer cylinder 1 and inner rod 2.

[0022] As Figure 2 As shown, outer cylinder 1 is cylindrical structure, surface is provided with thread. Outer cylinder 1 top is provided with regular polygon screw head 11, inside is provided with installation cavity 12, bottom is provided with several slots 13 evenly distributed along its circumference.

[0023] The mounting cavity 12 is circular, arranged along the axis of the outer cylinder 1, and penetrates the outer cylinder 1. The regular polygonal screw head 11 is a regular hexagonal screw head 11, with a circular through hole 14 in the center. The through hole 14 penetrates the regular polygonal screw head 11 and communicates with the mounting cavity 12, and the diameter of the through hole 14 is greater than the diameter of the mounting cavity 12. At the same time, the inner surface of the outer cylinder 1 is provided with threads.

[0024] As shown in the drawings, the inner rod 2 can be fitted in the mounting cavity 12, with a head 21 at the top and a spreading section 22 at the bottom. Figure 3

[0025] The head 21 is circular and placed in the through hole 14, with a cross-shaped connecting groove 23 formed in the top surface to cooperate with the tool. The spreading section 22 includes a conical section with a small top and a large bottom, and the bottom end is provided with a pointed structure. The diameter of the largest diameter of the conical section is not greater than the diameter of the inner rod 2. The inner surface of the bottom of the outer cylinder 1 is provided with an inner convex 15 matched with the conical section. When the inner rod 2 is relatively raised, the spreading section 22 spreads the bottom of the outer cylinder 1 by cooperating with the inner convex 15, to improve the fixing effect of the screw.

[0026] The surface of the inner rod 2 is provided with threads to cooperate with the threads of the outer cylinder 1, to realize the threaded connection of the two.

[0027] Preferably, the regular polygonal screw head 11 is provided with a stop ring 16 at the top of the through hole 14. The stop ring 16 can stop the head 21 to limit the movement range of the inner rod 2. At the same time, the top edge of the head 21 is provided with a matching groove 24 matched with the stop ring 16. When the inner rod 2 moves to the stop ring 16, the matching groove 24 is matched with the stop ring 16, so that the top surface of the head 21 is flush with the top surface of the regular polygonal screw head 11, to achieve the purpose of closing the through hole 14.

[0028] The bottom end of the spreading section 22 is conical. The bottom end of the outer cylinder 1 is provided with an inclined part, which can be matched with the conical structure to form the tip of the self-tapping screw. When the inner rod 2 is relatively moved to the bottom end, the end of the spreading section 22 is matched with the inclined part.

[0029] Working process: when the self-tapping screw is in the initial state, the inner rod 2 is located at the relatively bottom end, the bottom end cooperates with the inclined part of the bottom of the outer cylinder 1 as the tip of the self-tapping screw, and the tool is used to cooperate with the cross-shaped connecting groove 23 to drive the self-tapping screw to tap in. After tapping is completed, the tool is used to drive the inner rod 2 to reverse, so that it is relatively raised with the outer cylinder 1, until the end surface of the head 21 is flush with the top surface of the regular polygonal screw head 11. At this time, the spreading section 22 of the inner rod 2 spreads the bottom end of the outer cylinder 2. When reversing, to avoid the rotation of the outer cylinder 1, the tool can be used to hold the regular polygonal screw head 11.

[0030] ​The preferred embodiments of the present application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes without creative labor based on the concept of the present application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the existing technology within the concept of the present application shall be within the protection scope defined by the claims.

Claims

1. A multi-threaded self-tapping screw, characterized by, Include: The outer cylinder (1) and the inner rod (2); the outer cylinder (1) top is provided with a regular polygon screw head (11), the inside is provided with an installation cavity (12), the bottom is provided with a plurality of evenly distributed slot (13) along its circumference; the installation cavity (12) is circular, along the outer cylinder (1) axis arrangement, and through the outer cylinder (1); the regular polygon screw head (11) center is provided with a through hole (14); the through hole (14) through the regular polygon screw head (11) and the installation cavity (12) communication; the outer surface and the inner surface of the outer cylinder (1) are provided with threads; The inner rod (2) is matched in the installation cavity (12), and the top is provided with a head (21), and the bottom is provided with a opening section (22); the top surface of the head (21) is concave to form a cross connection groove (23); the opening section (22) includes a small upper and large lower conical section, and the bottom end is provided as a sharp structure; the surface of the inner rod (2) is provided with threads to be matched with the threads of the outer cylinder (1); The inner surface of the bottom of the outer cylinder (1) is provided with an inner convex (15) matched with the conical section.

2. A multi-threaded self-tapping screw as defined in claim 1, wherein, The regular polygon screw head (11) is a regular hexagonal screw head; the through hole (14) is circular.

3. A multi-threaded self-tapping screw as defined in claim 2, wherein, The head (21) is circular, matched with the through hole (14).

4. A multi-threaded self-tapping screw as defined in claim 2, wherein, The regular polygon screw head (11) is provided with a stop ring (16) at the top end of the through hole (14).

5. A multi-threaded self-tapping screw as defined in claim 4, wherein, The top edge of the head (21) is provided with an embedded groove (24) matched with the stop ring (16).

6. A multi-threaded self-tapping screw as defined in claim 1, wherein, The bottom end of the opening section (22) is conical structure.

7. A multi-threaded self-tapping screw as defined in claim 6, wherein, The bottom end of the outer cylinder (1) is provided with an inclined part; the inclined part can be combined with the conical structure as a self-tapping screw tip.

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