CN220600189U - Self-tapping self-drilling screw with small drill tail and connecting structure - Google Patents

Abstract

The application provides a little brill tail self-tapping self-drilling screw and connection structure relates to screw technical field. The small-bit self-tapping self-drilling screw is used for tapping a metal sheet and comprises a threaded portion and a drilling portion connected to the threaded portion, the drilling portion is used for drilling, the threaded portion comprises a main body section and a transition section, the transition section is connected between the main body section and the drilling portion, the outer diameter of the transition section is smaller than that of the main body section, and at least part of the transition section is larger than that of the drilling portion. The metal sheet can at least receive the extrusion effect of changeover portion like this and form the turn-ups, so increase metal sheet and the cooperation area of main part section, except that the pore wall of metal sheet, still have the turn-ups to cooperate with screw thread portion, and then improve little self-tapping self-drilling screw to the tensioning force of metal sheet, prevent little self-tapping self-drilling screw and skid.

Description

Self-tapping self-drilling screw with small drill tail and connecting structure

Technical Field

The application relates to the technical field of screws, in particular to a small-bit self-tapping self-drilling screw and a connecting structure.

Background

In daily life, the small self-tapping self-drilling screw is used everywhere for fixing objects. The small self-tapping self-drilling screw is meshed with the structure to be fixed through threads of the small self-tapping self-drilling screw to form threaded connection. In the related art, particularly, when a small-bit self-tapping self-drilling screw is used to tap into a metal sheet, an electric or pneumatic tool gun is usually required to screw the small-bit self-tapping self-drilling screw. However, during operation, the small-bit self-tapping self-drilling screw is easy to slip relative to the thin plate, so that the problem of loose fixation is caused.

Disclosure of Invention

Based on the above, it is necessary to provide a small-bit self-tapping self-drilling screw so that the small-bit self-tapping self-drilling screw is not easy to slip when a metal sheet is tapped and the tension of the small-bit self-tapping self-drilling screw is improved.

The small-bit self-tapping self-drilling screw is used for tapping into a metal sheet and comprises a threaded part and a drilling part connected with the threaded part, wherein the drilling part is used for drilling; the threaded portion comprises a main body section and a transition section, the transition section is connected between the main body section and the drilling portion, the outer diameter of the transition section is smaller than that of the main body section, and at least part of the transition section is larger than that of the drilling portion.

It will be appreciated that the drilling portion may drill holes in the sheet metal. After drilling, the threaded portion continues to attack the metal sheet, wherein the transition section is greater than the drilling portion due to at least part of the outer diameter of the transition section in the process of attacking the metal sheet, meanwhile, the outer diameter of the transition section is smaller than that of the main body section, the metal sheet can be extruded by the transition section at least to form a flanging, the matching area of the metal sheet and the main body section is increased, besides the hole wall of the metal sheet, the flanging is matched with the threaded portion, and accordingly the tension force of the small-bit self-tapping self-drilling screw on the metal sheet is improved, and slipping of the small-bit self-tapping self-drilling screw is prevented.

In one embodiment, the outer diameter of the transition section continuously decreases from the threaded portion toward the drilling portion along the axial direction of the small-bit self-tapping self-drilling screw.

It will be appreciated that the continuous decrease provides a smoother transition with a gradual continuous increase in the compressive force to form the flange at one time in the sheet metal.

In one embodiment, the outer diameter of the transition section decreases in a gradient from the threaded portion toward the drilling portion along the axial direction of the small-bit self-tapping self-drilling screw.

It can be appreciated that the gradient gradually-decreasing manner can perform sectional extrusion on the metal sheet, so as to enhance the extrusion effect on the metal sheet to form the flanging.

In one embodiment, the transition section comprises at least two stepped section bodies, the outer diameter of each stepped section body is from large to small from the main section towards the drilling part along the axial direction of the small-bit self-tapping self-drilling screw, and any two adjacent stepped section bodies are connected with each other.

It will be appreciated that the provision of stepped sections facilitates the formation of a gradient transition section.

In one embodiment, along the axial direction of the small-bit self-tapping self-drilling screw, the outer diameter of the step section body is 70% -90% of the outer diameter of the step section body.

It can be appreciated that, under the condition that the length of the transition section is fixed, the arrangement of at least two step section bodies ensures that the outer diameter of each step section body is not greatly different, thereby being beneficial to forming good transition when extruding the metal sheet.

In one embodiment, the transition section has a minimum outer diameter of 45% -65% of the outer diameter of the body section.

It can be appreciated that by setting the minimum outer diameter of the transition section to promote the transition section to form a certain taper, a particularly good transition effect is achieved when the small-bit self-tapping self-drilling screw is used for tapping the metal sheet.

In one embodiment, the length of the transition section is not less than twice the thickness of the sheet metal along the axial direction of the small-bit self-tapping self-drilling screw.

It can be appreciated that by setting the length of the transition section to promote the transition section to form a certain taper, a particularly good transition effect is achieved when the small-bit self-tapping self-drilling screw is used for tapping the metal sheet.

In one embodiment, the thread part is provided with a plurality of thread teeth which are axially arranged along the thread part, and the tooth distance between any two adjacent thread teeth is 60% -200% of the thickness of the metal sheet.

It can be understood that the thread teeth can be meshed with the metal sheet, the number of the thread teeth meshed with the metal sheet is more due to the arrangement of the thread tooth distance, and the tensioning force of the small-bit self-tapping self-drilling screw relative to the metal sheet is improved.

In one embodiment, the whole surface of the small-bit self-tapping self-drilling screw is provided with a coating structure, and the thickness of the coating structure is more than or equal to 50 mu m.

It can be understood that the plating layer is arranged on the surface of the small-bit self-tapping self-drilling screw, so that the corrosion resistance of the small-bit self-tapping self-drilling screw can be improved.

The application also provides a connection structure, connection structure includes sheet metal and foretell little brill tail self-tapping self-drilling screw, little brill tail self-tapping self-drilling screw's material hardness is greater than sheet metal's material hardness, little brill tail self-tapping self-drilling screw wears to locate sheet metal, so that sheet metal is followed little brill tail self-tapping self-drilling screw wears to establish one side of direction and is formed with the turn-ups, little brill tail self-tapping self-drilling screw with turn-ups threaded connection.

It can be appreciated that the small-bit self-tapping self-drilling screw has higher hardness, so that the small-bit self-tapping self-drilling screw is labor-saving when being tapped into a metal sheet. Through adopting foretell little brill tail self-tapping self-drilling screw to be connected with the sheet metal, make the sheet metal can produce the turn-ups, increase area of connection, improve sheet metal and little brill tail self-tapping self-drilling screw's joint strength.

Drawings

In order to more clearly illustrate the technical solutions of embodiments or conventional techniques of the present application, the drawings that are required to be used in the description of the embodiments or conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic view of a self-drilling screw with a small bit tail according to an embodiment of the present application;

fig. 2 is a schematic structural view of another embodiment of the self-drilling self-tapping screw with a small bit tail provided in the present application.

Reference numerals: 100. self-tapping self-drilling screw with small drill tail; 10. a threaded portion; 20. a drilling section; 30. a screw cap; 11. a main body section; 12. a transition section; 31. an assembly groove; 101. a thread tooth; 121. a step section body.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When a component is considered to be "connected" to another component, it can be directly connected to the other component or intervening components may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used in the description of the present application for purposes of illustration only and do not represent the only embodiment.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

In this application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be a direct contact of the first feature with the second feature, or an indirect contact of the first feature with the second feature via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely under the second feature, or simply indicating that the first feature is less level than the second feature.

Unless defined otherwise, all technical and scientific terms used in the specification of this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. The term "and/or" as used in the specification of this application includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 and 2, the present application provides a small-bit self-tapping self-drilling screw 100 for tapping into a metal sheet, the small-bit self-tapping self-drilling screw 100 includes a threaded portion 10 and a drilling portion 20 connected to the threaded portion 10, the drilling portion 20 is used for drilling, wherein the threaded portion 10 includes a main body section 11 and a transition section 12, the transition section 12 is connected between the main body section 11 and the drilling portion 20, the outer diameter of the transition section 12 is smaller than the outer diameter of the main body section 11, and at least part of the transition section 12 is larger than the outer diameter of the drilling portion 20.

Thus, the drilling portion 20 may drill the connection hole in the metal sheet first, and then the metal sheet may be tapped by the screw portion 10. The threaded portion 10 has a transition section 12, and since the outer diameter of the transition section 12 is at least partially larger than the outer diameter of the drilling portion 20 and the outer diameter of the transition section 12 is smaller than the outer diameter of the main body section 11, at least a portion of the transition section 12 can abut against the sheet metal and generate a pressing force on the sheet metal in the radial direction of the small-bit self-tapping self-drilling screw 100. With the continuous tapping of the transition section 12, the metal sheet generates a flanging under the action of the extrusion force, the flanging extends the length of the connecting hole, compared with the metal sheet, the matching area of the main body section 11 and the metal sheet is increased, the tension force of the main body section 11 relative to the metal sheet is enhanced, the stability of the connection of the small-bit self-tapping self-drilling screw 100 and the metal sheet is improved, and the small-bit self-tapping self-drilling screw 100 is not easy to slip in the process of tapping the metal sheet.

It should be noted that, at least part of the outer diameter of the transition section 12 is larger than that of the drilling section, which means that the transition section 12 can generate extrusion force on the metal sheet only by the part with the outer diameter larger than that of the drilling section, so that the metal sheet is turned over, but the transition section 12 must be smaller than the main section 11, so that after the turned over edge is generated, the subsequent main section 11 is ensured to be connected and matched with the turned over edge. The transition section 12 has a first section body and a second section body connected to the first section body, the first section body is connected to the drilling portion 20, the second section body is connected to the main section 11, the outer diameter of the first section body is smaller than or equal to the outer diameter of the drilling portion 20, and the outer diameter of the second section body is larger than the drilling portion 20 and smaller than the main section 11, so that even if the first section body cannot generate flanging, the second section body can still generate extrusion force on the metal sheet, thereby generating flanging.

As shown in fig. 1 and 2, in a specific embodiment, the threaded portion 10 has a plurality of threads 101 arranged in succession along its own axial direction, and the pitch s between any two adjacent threads 101 is 60% -200% of the thickness of the metal sheet. In this way, the thread 101 can engage with the wall of the connecting hole and the inner wall of the flange of the metal sheet, so as to improve the tension of the thread 10 against the metal sheet. Further, by defining the pitch of the thread 101, the metal sheet can be engaged with more thread 101 to improve the tension of the thread 10 to the metal sheet. In some embodiments, the pitch s between any two adjacent threads 101 is 60%, 100% or 200% of the sheet metal thickness.

For convenience of explanation, the outer diameter of the threaded portion 10 in the present application may be based on the maximum outer diameter of the thread 101, that is, the major diameter of the thread, or may be based on the minor or major diameter of the thread 101 in other embodiments, depending on the actual situation.

In an alternative embodiment, as shown in fig. 1, the outer diameter of the transition section 12 decreases continuously from the main section 11 toward the drilling portion 20 along the axial direction of the small-bit self-tapping self-drilling screw 100. That is, the trend of the cross-sectional profile of the outer diameter surface of the transition section 12 is tapered, and the extrusion force of the transition section 12 on the metal sheet needs to be continuously increased along with the increase of the contact area between the transition section 12 and the metal sheet, so that the process of forming the flanging of the metal sheet is continuous, i.e. the flanging can be formed by one-step extrusion. Meanwhile, by the arrangement, the small-bit self-tapping self-drilling screw 100 forms smooth transition from drilling into the metal sheet to tapping into the metal sheet, and forms a flanging at the same time of transition, so that the operation is convenient.

In another alternative embodiment, as shown in fig. 2, the cross-sectional profile of the outer diameter surface of the transition section 12 decreases in a gradient from the threaded portion 10 toward the drilling portion 20 along the axial direction of the small-bit self-tapping self-drilling screw 100. That is, the extrusion force of the transition section 12 to the metal sheet is increased stepwise, and the extrusion force required for each layer is increased to a certain extent compared with the previous layer. By means of the arrangement, in the process of tapping the small-bit self-tapping self-drilling screw 100 into the metal sheet, the structure of the metal sheet can be observed in a layered mode, flanging is gradually formed on the basis of ensuring structural integrity of each layer of metal sheet, and a good transition effect is achieved.

Specifically, as shown in fig. 2, a gradient decrease is defined as: the transition section 12 includes at least two stepped sections 121, each stepped section 121 having an equal outer diameter, the outer diameters of the at least two stepped sections 121 being from large to small from the main section 11 toward the drilling portion 20 along the axial direction of the small-bit self-tapping self-drilling screw 100, and any adjacent two stepped sections 121 being connected to each other. That is, the outer diameter of the transition section 12 decreases stepwise from the main section 11 toward the drilling portion 20 in the axial direction of the small-bit self-tapping self-drilling screw 100. Thus, the step section 121 is arranged to facilitate the formation of the transition section 12 which gradually decreases in a gradient manner, and when tapping, the front step section 121 extrudes the metal sheet to form the flanging, the rear step section 121 is abutted against the metal sheet and continuously generates extrusion force on the metal sheet, and the contact area between the rear step section 121 and the metal sheet is larger, so that the required extrusion force is larger, and the flanging is further formed. In actual production, the single step body 121 may include one thread 101 or more than two threads 101 having the same outer diameter, so as to form the gradient transition section 12.

In a further embodiment, the outer diameter of the latter step 121 is 70% -90% of the outer diameter of the former step 121, along the axial direction of the small-bit self-tapping self-drilling screw 100, from the main body 11 towards the drilling portion 20. In this way, the outer diameter difference between the adjacent step sections 121 can be ensured to be smaller, which is beneficial to forming gradually increased abutting area and extrusion force corresponding to the abutting area on the metal sheet, so that good transition is realized, and the metal sheet is turned and the metal sheet structure is protected. In some specific embodiments, the outer diameter of the latter step 121 is 70%, 80% or 90% of the outer diameter of the former step 121, along the axial direction of the small-bit self-tapping self-drilling screw 100, from the main body section 11 toward the drilling portion 20.

In a specific embodiment, the transition section 12 has a minimum outer diameter of 45% -65% of the outer diameter of the body section 11. Thus, the minimum outer diameter of the transition section 12 and the outer diameter of the main body section 11 have a certain gap, which is beneficial to the transition section 12 to extrude the metal sheet to form a flanging with enough length to be matched with the main body section 11. In some embodiments, the minimum outer diameter of the transition section 12 is 45%, 50% or 65% of the outer diameter of the body section 11.

In a further embodiment, the length of the transition section 12 is no less than twice the thickness of the sheet metal along the axial direction of the small-bit self-tapping self-drilling screw 100. In this way, it is ensured that the transition section 12 has a sufficient length to have a certain taper for transition in the case of a determined minimum outer diameter, so that the extrusion force to the metal sheet is in a gradually increasing state, avoiding having a larger fault to the extrusion force of the metal sheet, so as to protect the metal sheet structure. Of course, the length of the transition section 12 is naturally not as good as it is, should be at a level that ensures that the pressing force is sufficient to turn the sheet metal into a turn-up.

In an alternative embodiment, the drilling portion 20 is configured with a continuous drill edge that is sharp in configuration to facilitate forming a sharp drilling portion 20 so that the drilling portion 20 may be in point contact with the sheet metal during drilling to form a stress riser to facilitate drilling into the sheet metal. In the manufacturing process, the drilling portion 20 may be manufactured with reference to the conventional process, and only the drilling into the metal sheet is required, and the drilling portion 20 is not particularly limited.

In an alternative embodiment, the hardness of the material of the small-bit self-tapping self-drilling screw 100 is greater than that of the metal sheet, so that the small-bit self-tapping self-drilling screw 100 can be driven to tap into the metal sheet with smaller force, thereby saving the force and ensuring that the small-bit self-tapping self-drilling screw 100 is not easy to slip when drilling. In a specific embodiment, the metal sheet is made of stainless steel. Thus, the small-bit self-tapping self-drilling screw 100 made of carbon steel or stainless steel is difficult to tap, so that the small-bit self-tapping self-drilling screw 100 made of alloy steel is manufactured in the embodiment, the hardness of the small-bit self-tapping self-drilling screw 100 is larger than that of a stainless steel metal sheet, the small-bit self-tapping self-drilling screw 100 is enabled to tap the metal sheet with smaller force, the effect of saving force can be achieved, and the small-bit self-tapping self-drilling screw 100 is not easy to slip when drilling. Of course, as other embodiments, the small-bit self-tapping self-drilling screw 100 made of different materials can be selected according to the material characteristics of the metal sheet for connection, so long as the material hardness of the small-bit self-tapping self-drilling screw 100 is ensured to be greater than that of the metal sheet.

In an alternative embodiment, the full surface of the self-drilling self-tapping screw 100 has a coating structure with a thickness of 50 μm or more. Thus, the corrosion resistance of all surfaces of the small-bit self-tapping self-drilling screw 100 is improved, and places with higher corrosion resistance are satisfied. Meanwhile, the enough coating thickness ensures the stability of the corrosion resistance, and of course, the coating thickness also needs to meet the normal effect of the self-tapping self-drilling screw 100 with small drill bit. For example, the surface of the self-drilling screw 100 may be plated with nickel, chrome or hot rust for corrosion protection, and the thickness of the coating structure may be 50 μm, 60 μm or 70 μm.

In a specific embodiment, as shown in fig. 1 and 2, the small-bit self-tapping self-drilling screw 100 is configured with a nut 30, the nut 30 is connected to an end of the threaded portion 10 remote from the drilling portion 20, and the nut 30 may be provided as a pan head or a hexagonal flange head, for example. Wherein, the nut 30 is concavely provided with an assembly groove 31 so that an external tool is matched with the assembly groove 31 to drive the small-bit self-tapping self-drilling screw 100 to be screwed through the nut 30. Illustratively, the fitting groove 31 may be provided as a straight groove or a cross groove.

The application also provides a connection structure, connection structure include sheet metal and foretell little brill tail self-tapping self-drilling screw 100, and little brill tail self-tapping self-drilling screw 100's material hardness is greater than sheet metal's material hardness, and little brill tail self-tapping self-drilling screw 100 wears to locate sheet metal to be formed with the turn-ups in sheet metal along one side of little brill tail self-tapping self-drilling screw 100 wearing direction, little brill tail self-tapping self-drilling screw 100 and turn-ups threaded connection. So, through using above-mentioned little brill tail self-tapping self-drilling screw 100, it has higher hardness to attack sheet metal, is difficult for skidding, forms turn-ups and little brill tail self-tapping self-drilling screw 100 further cooperation simultaneously at the in-process of attacking sheet metal, reinforcing little brill tail self-tapping self-drilling screw 100 and the joint strength and the connection tightness of turn-ups, this kind of connection structure has the utility of connecting more stably, reliably.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of the present application is to be determined by the following claims.

Claims (8)

1. A small-bit self-tapping self-drilling screw for tapping a metal sheet, characterized in that the small-bit self-tapping self-drilling screw (100) comprises a threaded portion (10) and a drilling portion (20) connected to the threaded portion (10), the drilling portion (20) being used for drilling;

wherein the threaded portion (10) comprises a main body section (11) and a transition section (12), the transition section (12) being connected between the main body section (11) and the drilling portion (20), the transition section (12) having an outer diameter smaller than the outer diameter of the main body section (11) and at least partially larger than the outer diameter of the drilling portion (20);

along the axial direction of the small-bit self-tapping self-drilling screw (100), the outer diameter of the transition section (12) continuously decreases or decreases in a gradient manner from the threaded portion (10) towards the drilling portion (20).

2. The small-bit self-tapping self-drilling screw according to claim 1, characterized in that the transition section (12) comprises at least two stepped section bodies (121), the outer diameters of at least two stepped section bodies (121) are from the main section (11) to the drilling section (20) from large to small along the axial direction of the small-bit self-tapping self-drilling screw (100), and any adjacent two stepped section bodies (121) are connected to each other.

3. The small-bore self-tapping self-drilling screw according to claim 2, characterized in that the outer diameter of the latter step section (121) is 70-90% of the outer diameter of the former step section (121) from the main body section (11) towards the drilling section (20) in the axial direction of the small-bore self-tapping self-drilling screw (100).

4. The small-bit self-tapping self-drilling screw according to claim 1, characterized in that the minimum outer diameter of the transition section (12) is 45% -65% of the outer diameter of the main body section (11).

5. The small-bore self-tapping self-drilling screw according to any one of claims 1-4, characterized in that the length of the transition section (12) is not less than twice the thickness of the sheet metal along the axial direction of the small-bore self-tapping self-drilling screw (100).

6. The small-bit self-tapping self-drilling screw according to any one of claims 1-4, wherein said threaded portion (10) has a plurality of threads (101) arranged in the axial direction thereof, and the pitch between any two adjacent threads (101) is 60% -200% of the thickness of said metal sheet.

7. The small-bit self-tapping self-drilling screw according to claim 1, wherein the whole surface of the small-bit self-tapping self-drilling screw (100) has a coating structure, and the thickness of the coating structure is equal to or more than 50 μm.

8. A connection structure, characterized by comprising:

a metal thin plate;

the small-bit self-tapping self-drilling screw (100) according to any one of claims 1 to 7, wherein the material hardness of the small-bit self-tapping self-drilling screw (100) is greater than that of the metal sheet, the small-bit self-tapping self-drilling screw (100) is penetrated into the metal sheet so as to form a flanging at one side of the metal sheet along the penetrating direction of the small-bit self-tapping self-drilling screw (100), and the small-bit self-tapping self-drilling screw (100) is in threaded connection with the flanging.