Combined fastener

Abstract

The utility model discloses a combined fastener which comprises a screw and a threaded sleeve, the screw comprises a screw head, a threaded rod and a connecting column connecting the screw head and the threaded rod, a plurality of grooves are evenly distributed in the circumference of the bottom face of the connecting column, and the grooves enable the bottom face of the connecting column to form a plurality of first tooth portions; a self-tapping thread is arranged on the periphery of the threaded sleeve, the threaded sleeve is provided with a threaded hole, an external thread of the threaded rod can be connected with an internal thread in the threaded hole, a plurality of second tooth parts are evenly distributed on the top face of the threaded sleeve in a circumferential mode, and the tooth direction of the second tooth parts is opposite to the tooth direction of the first tooth parts. The first tooth part can be connected with the second tooth part in an engaged mode. The combined fastener provided by the utility model is easy to assemble and low in cost, and is beneficial to prolonging the service life of a mounting piece.

Description

Technical Field

[0001] The utility model relates to a combined fastener and belongs to the technical field of fasteners. Background Art

[0002] For materials with low contact strength, such as plastic products, the commonly used fastening screws are self-tapping screws and mechanical screws. The disadvantage of the self-tapping fastening method is that it cannot be disassembled and reused repeatedly, and the plastic screw column will cause the thread to slip and fail due to repeated disassembly. The mechanical fastening method requires pre-embedded nuts in the plastic screw column in advance or hot-melt installation of nuts later before use. The disadvantage of this method is that it increases the cost of use. Utility Model Content

[0003] The utility model aims to provide a combined fastener which is easy to assemble, has low cost and can extend the service life of the mounting piece.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A combined fastener, comprising:

[0006] A screw, comprising a screw head, a threaded rod, and a connecting column connecting the screw head and the threaded rod, wherein the bottom surface of the connecting column is uniformly provided with a plurality of grooves in a circumference, and the plurality of grooves form a plurality of first teeth on the bottom surface of the connecting column; and

[0007] A screw sleeve, wherein the outer circumference of the screw sleeve is provided with a self-tapping thread, the screw sleeve has a screw hole, the external thread of the threaded rod can be connected with the internal thread in the screw hole, the top surface of the screw sleeve is circumferentially evenly distributed with a plurality of second tooth portions, the tooth direction of the second tooth portion is opposite to the tooth direction of the first tooth portion, and the first tooth portion can be engaged and connected with the second tooth portion.

[0008] As a further improved technical solution of the utility model, the first tooth portion includes a first tooth surface and a second tooth surface, the second tooth portion includes a third tooth surface and a fourth tooth surface, the first tooth surface is parallel to the axis of the screw, the third tooth surface is parallel to the axis of the sleeve, the first tooth surface abuts against the third tooth surface, the second tooth surface and the fourth tooth surface are both spiral surfaces, the second tooth surface is the bottom surface of the groove, and the second tooth surface at least partially abuts against the fourth tooth surface.

[0009] As a further improved technical solution of the utility model, the second tooth portion also includes a fifth tooth surface, the fourth tooth surface connects the third tooth surface and the fifth tooth surface, the fifth tooth surface is parallel to the third tooth surface, and when the first tooth surface and the third tooth surface complete the abutment, the fifth tooth surface, the top surface of the screw sleeve and the second tooth surface form a gap.

[0010] As a further improved technical solution of the utility model, the screw head and the connecting column are both cylinders, the outer diameter of the screw head is larger than the outer diameter of the connecting column, the outer diameter of the connecting column is larger than the outer diameter of the threaded rod, and the screw head is provided with a cross groove.

[0011] As a further improved technical solution of the utility model, the screw sleeve includes a threaded section and a light section connected to the threaded section, the self-tapping thread is arranged on the threaded section, the light section includes the top surface, and the second tooth portion protrudes out of the top surface.

[0012] As a further improved technical solution of the utility model, the outer diameter of the connecting column is equal to the outer diameter of the light segment.

[0013] As a further improved technical solution of the present utility model, the number of the first tooth portions is three, and the number of the second tooth portions is equal to the number of the first tooth portions.

[0014] As a further improved technical solution of the utility model, the threaded sleeve is configured to be screwed into the mounting piece, and the screw is screwed into the threaded sleeve to fix the mating piece to the mounting piece, and a notch is provided on the self-tapping thread, and the notch is configured to fill a portion of the mounting piece.

[0015] As a further improved technical solution of the utility model, the screw sleeve includes a first wall surface, a transition surface and a second wall surface, the notch includes a space enclosed by the first wall surface, the transition surface and the second wall surface, the transition surface connects the first wall surface and the second wall surface, the axis of the screw sleeve is located in the plane where the first wall surface is located, and the second wall surface extends obliquely from the transition surface in a direction opposite to the rotation direction of the self-tapping thread.

[0016] As a further improved technical solution of the utility model, each circle of the self-tapping thread is provided with four notches, and the four notches of each circle of the self-tapping thread are respectively arranged longitudinally along the outer circumference of the screw sleeve.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] The combined fastener provided by the utility model comprises a screw and a threaded sleeve, the screw is threadedly connected with the threaded sleeve, the screw is provided with a first tooth portion, and the threaded sleeve is provided with a second tooth portion, the first tooth portion can be engaged and connected with the second tooth portion, when the combined fastener is used for the first time, force is applied to the screw, the first tooth portion drives the second tooth portion, so that the threaded sleeve and the screw are synchronously screwed into the mounting piece, which is easy to assemble and low in cost; when disassembly is required, the screw only needs to be screwed out of the threaded sleeve, and the threaded sleeve is retained in the mounting piece, and the thread of the threaded sleeve replaces the mounting piece to bear wear, thereby extending the service life of the mounting piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of a combined fastener;

[0020] Figure 2 yes Figure 1 Schematic diagram of the decomposition of

[0021] Figure 3 yes Figure 1 The main view;

[0022] Figure 4 yes Figure 3 A magnified schematic diagram of the middle A area;

[0023] Figure 5 yes Figure 4 Schematic diagram of the decomposition of

[0024] Figure 6 yes Figure 2 A three-dimensional diagram of the middle screw from another angle;

[0025] Figure 7 yes Figure 6 Bottom view of

[0026] Figure 8 yes Figure 2 A three-dimensional schematic diagram of the middle screw sleeve from another angle;

[0027] Fig. 9 yes Figure 8 Bottom view of

[0028] Fig.10 It is a diagram of the usage status of the combined fastener. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. If there are several embodiments, the features of these embodiments can be combined with each other without conflict. When the description refers to the drawings, unless otherwise specified, the same numbers in different drawings represent the same or similar elements. The contents described in the following exemplary embodiments do not represent all embodiments consistent with the present invention; on the contrary, they are merely examples of devices, products and / or methods that are consistent with some aspects of the present invention and are recorded in the claims of the present invention.

[0030] The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the scope of protection of the present invention. The singular forms "a", "said" or "the" used in the specification and claims of the present invention are also intended to include plural forms, unless the context clearly indicates other meanings.

[0031] It should be understood that the words used in the specification and claims of the present invention, such as "first", "second" and similar words, do not indicate any order, quantity or importance, but are only used to distinguish the names of features. Similarly, words such as "one" or "an" do not indicate a quantitative limitation, but indicate the existence of at least one. Unless otherwise specified, words such as "front", "rear", "upper", "lower" and similar words appearing in the present invention are only for the convenience of description and are not limited to a specific position or a spatial orientation. Words such as "include" or "comprise" are an open-ended expression, meaning that the elements appearing before "include" or "comprise" include the elements appearing after "include" or "comprise" and their equivalents, which does not exclude that the elements appearing before "include" or "comprise" may also include other elements. If "several" appears in the present invention, it means two or more.

[0032] Reference Figures 1 to 10 As shown, the utility model discloses a combined fastener for fixing a mounting member and a mating member, the combined fastener comprises a screw 1 and a screw sleeve 2, the outer periphery of the screw sleeve 2 is provided with a self-tapping thread 211, the mounting member has a screw column, the screw column has a mounting hole 100, before the screw sleeve 2 is installed, there is no thread in the mounting hole 100, because the mounting member is made of a plastic material with low contact strength, during the process of the screw sleeve 2 being screwed into the mounting hole 100, the self-tapping thread 211 forms a mating thread in the mounting hole, so that the screw sleeve 2 is screwed into the mounting member. The screw 1 is provided with an external thread, the screw sleeve 2 has a screw hole 20, and the screw hole 20 has an internal thread, and the screw 1 is screwed into the screw hole 20 of the screw sleeve 2 to fix the mating member to the mounting member. When disassembly is required, the screw 1 only needs to be screwed out of the screw sleeve 2, and the screw sleeve 2 is retained in the mounting member, and the thread of the screw sleeve 2 replaces the mounting member to bear the wear, thereby extending the service life of the mounting member.

[0033] See also Figure 2 The screw 1 includes a screw head 11, a threaded rod 12, and a connecting column 13 connecting the screw head 11 and the threaded rod 12. The threaded rod 12 has an external thread that can be connected to the internal thread in the screw hole 20. For details, see Figure 6 The connecting column 13 includes a bottom surface 13a, and the threaded rod 12 extends outward from the bottom surface 13a.

[0034] See also Figure 5 and Figure 6 The bottom surface 13a of the connecting column 13 is evenly distributed with a plurality of grooves 130 in a circumferential manner, and the plurality of grooves 130 form a plurality of first teeth 131 on the bottom surface 13a of the connecting column 13. Figure 2The top surface 22a of the screw sleeve 2 is evenly distributed with a plurality of second teeth 23 in a circumferential manner. The tooth direction of the second teeth 23 is opposite to that of the first teeth 131, and the first teeth 131 can be engaged with the second teeth 23. When the combined fastener is used for the first time, the screw 1 and the screw sleeve 2 are installed in place, and the first teeth 131 is just engaged with the second teeth 23. Then, force is applied to the screw 1, and the screw 1 applies force to the second teeth 23 through the first teeth 131 to screw the screw sleeve 2 into the mounting part, completing the assembly of the mounting part and the mating part; during subsequent disassembly, the first teeth 131 and the second teeth 23 do not affect the withdrawal of the screw 1.

[0035] See also Figure 5 and Figure 6 The first tooth portion 131 includes a first tooth surface 1311, and the second tooth portion 23 includes a third tooth surface 231. The first tooth surface 1311 is parallel to the axis of the screw 1, and the third tooth surface 231 is parallel to the axis of the screw sleeve 2. The first tooth surface 1311 and the third tooth surface 231 are in contact with each other. When the screw 1 and the screw sleeve 2 are screwed into the mounting member together, the first tooth surface 1311 is a force-applying surface, and the third tooth surface 231 is a force-bearing surface. The first tooth surface 1311 and the third tooth surface 231 are in contact with each other, so that the screw sleeve 2 and the screw 1 can rotate synchronously. Specifically, the axis of the screw 1 is located in the plane where the first tooth surface 1311 is located, and the axis of the screw sleeve 2 is located in the plane where the third tooth surface 231 is located. The first tooth surface 1311 and the third tooth surface 231 are both vertical surfaces. Compared with the inclined cooperation of the first tooth surface 1311 and the third tooth surface 231, the utility model is more conducive to the screw 1 applying force to the screw sleeve 2.

[0036] See also Figure 5 and Figure 8 The first tooth portion 131 includes a second tooth surface 1312, and the second tooth portion 23 includes a fourth tooth surface 232. Both the second tooth surface 1312 and the fourth tooth surface 232 are helical surfaces. The second tooth surface 1312 is the bottom surface of the groove 130, and the second tooth surface 1312 at least partially abuts against the fourth tooth surface 232. A helical surface refers to a surface that extends helically relative to the screw 1 or the screw sleeve 2. When the screw 1 is screwed out of the screw sleeve 2, the helical surface of the first tooth portion 131 can provide a reverse force to the helical surface of the second tooth portion 23, which can accelerate the separation of the screw 1 from the screw sleeve 2.

[0037] The screw head 11 and the connecting column 13 are both cylindrical, and the outer circumference of the connecting column 13 is smooth, that is, the outer circumference of the connecting column 13 is not provided with a thread structure. The outer diameter of the screw head 11 is larger than the outer diameter of the connecting column 13, and the outer diameter of the connecting column 13 is larger than the outer diameter of the threaded rod 12. Figure 2 The screw head 11 is provided with a cross slot 110. The operating slot of this structure has two force arms. The minimum rotation unit of the operation is 90°. It has high compatibility with operating tools and is easy to use.

[0038] See also Figure 4The second tooth portion 23 also includes a fifth tooth surface 233, and the fourth tooth surface 232 connects the third tooth surface 231 and the fifth tooth surface 233. The fifth tooth surface 233 is parallel to the third tooth surface 231. When the first tooth surface 1311 and the third tooth surface 231 complete the abutment, the fifth tooth surface 233, the top surface 22a of the screw sleeve 2 and the second tooth surface 1312 form a gap 24. By forming the gap 24, the risk of the screw 1 and the screw sleeve 2 being stuck is reduced.

[0039] See also Figure 5 The screw sleeve 2 includes a threaded section 21 and a light section 22 connected to the threaded section 21. The light section 22 refers to a light surface on the outer periphery thereof, that is, no thread structure is arranged on the outer periphery of the light section 22. The self-tapping thread 211 is arranged on the threaded section 21. The light section 22 includes a top surface 22a, and the second tooth portion 23 protrudes out of the top surface 22a. The light section 22 is also a cylinder, and the outer diameter of the connecting column 13 is equal to the outer diameter of the light section 22.

[0040] See also Figure 5 A notch 2110 is provided on the self-tapping thread 211, and the notch 2110 is configured to fill a portion of the mounting member 100. Since the mounting member is soft in texture, the squeezed mounting member will fill the entire notch 2110, and the self-tapping thread 211 is not easy to loosen when the screw 1 is withdrawn.

[0041] See also Figure 8 The screw sleeve 2 includes a first wall 251, a transition surface 252 and a second wall 253. The notch 2110 includes a space surrounded by the first wall 251, the transition surface 252 and the second wall 253. The transition surface 252 connects the first wall 251 and the second wall 253. The axis of the screw sleeve 2 is located in the plane where the first wall 251 is located. The second wall 253 extends obliquely from the transition surface 252 in a direction opposite to the rotation direction of the self-tapping thread 211, so that the notch 2110 forms an undercut space to prevent the screw sleeve 2 from loosening.

[0042] Each circle of self-tapping threads 211 is provided with four notches 2110 , and the four notches 2110 of each circle of self-tapping threads 211 are respectively arranged longitudinally along the outer circumference of the screw sleeve 2 , thereby forming four rows of notches 2110 . Such an arrangement improves the pull-out resistance of the screw sleeve 2 .

[0043] The number of the first tooth portions 131 is three, and the number of the second tooth portions 23 is equal to the number of the first tooth portions 131. In this embodiment, the number of the first tooth portions 131 and the number of the second tooth portions 23 are both three.

[0044] The above implementation modes are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of the present invention should be based on the technical personnel in the relevant technical field. Although the present invention has been described in detail in this specification with reference to the above implementation modes, ordinary technical personnel in the field should understand that the technical personnel in the relevant technical field can still modify or make equivalent substitutions to the present invention, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A combined fastener, characterized in that: include: A screw (1), the screw (1) comprising a screw head (11), a threaded rod (12), and a connecting column connecting the screw head (11) and the threaded rod (12), the bottom surface (13a) of the connecting column being uniformly distributed with a plurality of grooves (130) in a circumferential manner, the plurality of grooves (130) forming a plurality of first tooth portions on the bottom surface (13a) of the connecting column; and A screw sleeve (2), wherein the outer circumference of the screw sleeve (2) is provided with a self-tapping thread (211), the screw sleeve (2) has a screw hole (20), the external thread of the threaded rod (12) can be connected with the internal thread in the screw hole (20), the top surface (22a) of the screw sleeve (2) is circumferentially evenly distributed with a plurality of second tooth portions (23), the tooth direction of the second tooth portion (23) is opposite to the tooth direction of the first tooth portion, and the first tooth portion can be engaged with the second tooth portion (23).

2. The combined fastener according to claim 1, characterized in that: The first tooth portion comprises a first tooth surface (1311) and a second tooth surface (1312); the second tooth portion (23) comprises a third tooth surface (231) and a fourth tooth surface (232); the first tooth surface (1311) is parallel to the axis of the screw (1); the third tooth surface (231) is parallel to the axis of the screw sleeve (2); the first tooth surface (1311) abuts against the third tooth surface (231); the second tooth surface (1312) and the fourth tooth surface (232) are both helical surfaces; the second tooth surface (1312) is the groove bottom surface of the groove (130); and the second tooth surface (1312) at least partially abuts against the fourth tooth surface (232).

3. The combined fastener according to claim 2, characterized in that: The second tooth portion (23) further comprises a fifth tooth surface (233), the fourth tooth surface (232) connecting the third tooth surface (231) and the fifth tooth surface (233), the fifth tooth surface (233) being parallel to the third tooth surface (231), and when the first tooth surface (1311) and the third tooth surface (231) are in contact with each other, the fifth tooth surface (233), the top surface (22a) of the screw sleeve (2) and the second tooth surface (1312) enclose a gap (24).

4. The combined fastener according to claim 1, characterized in that: The screw head (11) and the connecting column are both cylindrical, the outer diameter of the screw head (11) is greater than the outer diameter of the connecting column, the outer diameter of the connecting column is greater than the outer diameter of the threaded rod (12), and the screw head (11) is provided with a cross groove (110).

5. The combined fastener according to claim 4, characterized in that: The screw sleeve (2) comprises a threaded section (21) and a light section (22) connected to the threaded section (21); the self-tapping thread (211) is provided on the threaded section (21); the light section (22) comprises the top surface (22a); and the second tooth portion (23) protrudes out of the top surface (22a).

6. The combined fastener according to claim 5, characterized in that: The outer diameter of the connecting column is equal to the outer diameter of the light segment (22).

7. The combined fastener according to claim 1, characterized in that: The number of the first tooth portions is three, and the number of the second tooth portions (23) is equal to the number of the first tooth portions.

8. The combined fastener according to claim 1, characterized in that: The screw sleeve (2) is configured to be screwed into the mounting member, and the screw (1) is screwed into the screw sleeve (2) to fix the mating member to the mounting member. A notch (2110) is provided on the self-tapping thread (211), and the notch (2110) is configured to fill a portion of the mounting member.

9. The combined fastener according to claim 8, characterized in that: The screw sleeve (2) comprises a first wall surface (251), a transition surface (252) and a second wall surface (253); the notch (2110) comprises a space enclosed by the first wall surface (251), the transition surface (252) and the second wall surface (253); the transition surface (252) connects the first wall surface (251) and the second wall surface (253); the axis of the screw sleeve (2) is located in the plane where the first wall surface (251) is located; and the second wall surface (253) extends obliquely from the transition surface (252) in a direction opposite to the rotation direction of the self-tapping thread (211).

10. The combined fastener according to claim 8, characterized in that: Each circle of the self-tapping thread (211) is provided with four notches (2110), and the four notches (2110) of each circle of the self-tapping thread (211) are respectively and correspondingly arranged longitudinally along the outer circumference of the screw sleeve (2).

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