Bolt and connecting structure

Abstract

The utility model provides a bolt and a connecting structure. The bolt comprises a head part, a first column body and a second column body which are connected in sequence, the first column body and the second column body are coaxially arranged; the first column body is provided with a self-tapping thread, and the second column body is provided with a fastening thread; and the screwing direction of the self-tapping thread is opposite to that of the fastening thread. According to the connecting structure, the sealing performance and the anti-corrosion performance of the connecting position between the stud and the connected base body are improved, and the fastening effect and the reliability of the connecting structure are enhanced.

Description

Technical Field

[0001] The utility model belongs to the technical field of tooling accessories, in particular to a bolt and a connection structure. Background Art

[0002] In the prior art, the bearing surface projection welding bolts need to be welded to the connected substrate. The shortcomings of the above scheme are: the corrosion resistance of the connection position after welding is poor, and the sealing performance is not good; and when the connected substrate is made of materials such as aluminum alloy, the bolts often cannot be welded to the connected parts. Utility Model Content

[0003] The utility model aims to solve the technical problems in the prior art such as poor corrosion resistance of bolts welded on connected parts, and provides a bolt and a connection structure.

[0004] In view of the above technical problems, an embodiment of the present invention provides a bolt, comprising a head, a first cylinder and a second cylinder connected in sequence; the first cylinder and the second cylinder are coaxially arranged; a self-tapping thread is provided on the first cylinder, and a fastening thread is provided on the second cylinder; the self-tapping thread and the fastening thread have opposite rotation directions.

[0005] Optionally, the self-tapping thread includes a self-tapping guide surface, which is arranged on the side of the self-tapping thread away from the head; on the plane where the central axis of the first cylinder is located, the distance between the self-tapping guide surface and the central axis of the first cylinder gradually decreases from the head toward the second cylinder.

[0006] Optionally, the self-tapping thread further includes a limiting surface, and the limiting surface is arranged at a preset angle with the self-tapping guide surface, and the preset angle is 55°-65°.

[0007] Optionally, the angle between the limiting surface and the central axis of the first column is 90°.

[0008] Optionally, the head includes a screw-on portion and a limiting flange; the limiting flange is connected between the screw-on portion and the first column.

[0009] Optionally, the bolt further includes a first chip accumulation groove provided on an end surface of the limiting flange facing away from the screwing portion.

[0010] Optionally, the first chip accumulation groove is an annular groove formed in a recessed manner on the end surface of the limiting flange facing away from the screw connection portion.

[0011] Optionally, the bolt further includes a second chip accumulation groove provided on the first column; an extension direction of the second chip accumulation groove is parallel to the central axis of the first column.

[0012] Optionally, the diameter of the first cylinder is greater than the diameter of the second cylinder.

[0013] The utility model also provides a connection structure, comprising a nut and the above-mentioned bolt, wherein the nut is provided with an internal thread, and the nut is threadably connected to the bolt through the internal thread and the fastening thread.

[0014] In the utility model, the bolt includes a head, a first column and a second column connected in sequence; the first column and the second column are coaxially arranged; the first column is provided with a self-tapping thread, and the second column is provided with a fastening thread; the self-tapping thread and the fastening thread have opposite rotation directions.

[0015] In the present invention, the bolt is composed of a head, a first column and a second column connected in sequence. A self-tapping thread is provided on the first column. The first column of the bolt can be directly screwed into the light hole of the connected base using the self-tapping thread until the head abuts against the connected base. The connection between the above-mentioned first column and the connected base does not require welding, and regardless of whether the connected base is made of aluminum alloy material, a tight connection between the first column and the connected base can be achieved, thereby improving the sealing and corrosion resistance of the connection position between the stud and the connected base.

[0016] In addition, the self-tapping thread on the first column and the fastening thread on the second column have opposite rotation directions. In this way, after the first column is screwed into the light hole of the connected base using the self-tapping thread, if it is necessary to tighten the nut on the fastening thread of the second column, at this time, rotating the nut will make the first column have a rotation tendency in the same direction as the rotation direction of the self-tapping thread, thereby making the connection between the first column and the connected base tighter, thereby ensuring that the first column will not loosen between the connected base. In this way, two-way fastening between the stud and the nut and the connected base is achieved, which significantly enhances the fastening effect and reliability of the connection structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic structural diagram of a bolt provided in one embodiment of the present utility model;

[0019] Figure 2 This is a schematic structural diagram of a bolt provided by another embodiment of the present invention;

[0020] Figure 3 This is a partial structural diagram of a bolt provided in one embodiment of the present utility model;

[0021] Figure 4 This is a partial cross-sectional structural diagram of a first column of a bolt provided by an embodiment of the present utility model;

[0022] Figure 5 This is a structural diagram of a bolt provided in another embodiment of the present invention.

[0023] The reference numerals in the specification are as follows:

[0024] 1-head, 11-screw connection part, 12-limiting flange, 2-first column, 21-self-tapping thread, 211-self-tapping guide surface, 212-limiting surface, 3-second column, 31-fastening thread, 4-first chip accumulation groove, 5-second chip accumulation groove. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] In the description of the present invention, it should be understood that the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0027] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0028] like Figures 1 to 2As shown, one embodiment of the present invention provides a bolt, comprising a head 1, a first cylinder 2, and a second cylinder 3 connected in sequence; the first cylinder 2 and the second cylinder 3 are coaxially arranged; the first cylinder 2 is provided with a self-tapping thread 21, and the second cylinder 3 is provided with a fastening thread 31; the self-tapping thread 21 and the fastening thread 31 have opposite rotation directions. Furthermore, the self-tapping thread 21 can be a left-handed thread, and the fastening thread 31 is a right-handed thread. In other embodiments, the self-tapping thread 21 is a right-handed thread, and the fastening thread 31 is a left-handed thread. In one embodiment, the bolt is an integrally formed structural component with a compact structure, which can enhance the overall strength and stability of the bolt.

[0029] It can be understood that the bolt is composed of a head 1, a first cylinder 2 and a second cylinder 3 connected in sequence. A self-tapping thread 21 is provided on the first cylinder 2. When the bolt is connected to the connected substrate, the bolt is screwed into the light hole of the connected substrate. The coaxially arranged first cylinder 2 and second cylinder 3 can ensure the coaxiality of the screwing and the stability of the bolt as a whole. After the bolt enters the light hole of the connected substrate, it is manually or with the help of a tool in a preset rotation direction (the preset rotation direction corresponds to the rotation direction of the self-tapping thread 21, such as the self-tapping thread 21). (If the rotation direction is right-hand, the preset rotation direction is clockwise; conversely, if the rotation direction of the self-tapping thread 21 is left-hand, the preset rotation direction is counterclockwise.) Rotate the head 1 of the bolt and continue feeding it toward the axis of the light hole. At this time, the self-tapping thread 21 on the first column 2 squeezes and cuts an internal threaded hole in the light hole. Then, the first column 2 of the bolt is screwed into the light hole until the head 1 tightly abuts against the end face of the connected substrate facing away from the first column 2, thereby completing the fixed connection between the first column 2 and the connected substrate. The connected substrate can be a sheet metal part or an aluminum alloy substrate on a vehicle.

[0030] It can be understood that after the bolt enters the light hole, the sharp thread edge on the self-tapping thread 21 of the first column 2 cuts the material around the light hole, and an internal threaded hole matching the self-tapping thread 21 is formed on the peripheral wall of the light hole, so that the bolt can be directly screwed into the internal threaded hole of the connected substrate. The connection between the above-mentioned first column and the connected substrate of the utility model does not require welding, and regardless of whether the connected substrate is made of aluminum alloy material, the first column and the connected substrate can be tightly connected, thereby enhancing the tightness and sealing of the connection between the bolt and the connected substrate, and also improving the corrosion resistance of the connection position between the bolt and the connected substrate.

[0031] The fastening thread 31 on the second column 3 is rotated in the opposite direction to the self-tapping thread 21. In this way, after the first column 2 is screwed into the light hole of the connected base using the self-tapping thread 21, the first column 2 is fixedly connected to the connected base. At this time, when the second column 3 passes through the through hole of the mounted part and extends out, if it is necessary to tighten the nut on the fastening thread 31 of the second column 3, at this time, the nut is rotated in the preset rotation direction on the end of the second column 3 away from the head 1. While the nut is moved closer to the head 1 of the bolt to fasten the connection between the mounted part and the connected base, the first column will also be tightened. 2 has a tendency to rotate in the same direction as the rotation direction of the self-tapping thread 21, thereby making the connection between the first column 2 and the connected base more secure; that is, when the nut is screwed into the second column 3 and tightened, the first column 2 will not rotate in the direction of loosening between the nut and the connected base, so the rotational force of the nut will further push the first column 2 to screw into the connected base, realizing a two-way fastening between the stud and the nut and the connected base, further enhancing the connection tightness between the bolt, the nut and the connected base, and improving the fastening effect and reliability of the connection structure.

[0032] In the above embodiment of the present invention, the bolt is composed of a head 1, a first column 2 and a second column 3 connected in sequence. A self-tapping thread 21 is provided on the first column 2. The first column 2 of the bolt can be directly screwed into the light hole of the connected base using the self-tapping thread 21 until the head 1 abuts against the connected base. The connection between the above-mentioned first column 2 and the connected base does not require welding, and regardless of whether the connected base is made of aluminum alloy material, a tight connection between the first column 2 and the connected base can be achieved, thereby improving the sealing and corrosion resistance of the connection position between the stud and the connected base. In addition, the self-tapping thread 21 on the first column 2 and the fastening thread 31 on the second column 3 have opposite rotation directions. In this way, after the first column 1 is screwed into the light hole of the connected base using the self-tapping thread 21, if it is necessary to tighten the nut on the fastening thread 31 of the second column 3, at this time, rotating the nut will make the first column 2 have a rotation tendency in the same direction as the rotation direction of the self-tapping thread 21, thereby making the connection between the first column 2 and the connected base more secure, thereby ensuring that the first column 2 will not loosen between the connected base. In this way, two-way fastening between the stud and the nut and the connected base is achieved, which significantly enhances the fastening effect and reliability of the connection structure.

[0033] In one embodiment, if Figure 3 and Figure 4As shown, the self-tapping thread 21 includes a self-tapping guide surface 211 and a limiting surface 212; the self-tapping guide surface 211 is arranged on the side of the self-tapping thread 21 away from the head 1. Furthermore, the self-tapping thread 21 also includes a limiting surface 212; the limiting surface 212 and the self-tapping guide surface 211 are arranged at a preset angle A; the preset angle A is 55°-65°. It is understandable that the preset angle A between the limiting surface 212 and the self-tapping guide surface 211 can be set according to requirements. In this embodiment, according to the connection strength requirements and anti-loosening performance requirements, the preset angle can be 55°, 60°, 65°, etc. On the plane where the central axis of the first column 2 is located, the distance between the self-tapping guide surface 211 and the central axis of the first column 2 gradually decreases from the head 1 toward the second column 3. It can be understood that the self-tapping thread 21 is composed of several circles of threads, each of which is provided with a self-tapping guide surface 211 and a limiting surface 212. The self-tapping guide surface 211 and the limiting surface 212 of each circle of threads intersect with each other, and the self-tapping guide surface 211 is the end surface of the side of the thread away from the head 1, while the limiting surface 212 is the end surface of the side of the thread away from the second cylinder 3. When the first cylinder 2 is screwed into the light hole, the self-tapping guide surface 211 first contacts the connected substrate and gradually cuts the light hole to form a thread matching the self-tapping thread 21 on the light hole. In addition, the limiting surface 212 and the self-tapping guide surface 211 are set at a preset angle A, and on the plane where the central axis of the first cylinder 2 is located, the distance between the self-tapping guide surface 211 and the central axis of the first cylinder 2 gradually decreases from the head 1 toward the second cylinder 3, that is, the angle between the self-tapping guide surface 211 and the central axis of the first cylinder 2 ( Figure 4 The angle C) shown in the figure is an acute angle; in this way, the inclination angle of the limiting surface 212 toward the head 1 is smaller than the inclination angle of the self-tapping guide surface 211 toward the head, which will cause the self-tapping thread 21 to be barbed in the cross section where the central axis of the first column 2 is located. After the barbed self-tapping thread 21 is screwed into the connected base, it can effectively resist dynamic loads such as vibration and impact, so that the first column 2 can maintain a stable connection with the connected base even when subjected to reverse torque, prevent the bolt from loosening, and improve the firmness of the connection.

[0034] Furthermore, the first cylinder 2 may be heat treated to enhance the wear resistance and fatigue resistance of the self-tapping thread 21 .

[0035] In one embodiment, if Figure 3 and Figure 4 As shown, the angle between the limiting surface 212 and the central axis of the first column 2 ( Figure 4The angle B) shown in the figure is 90°. In this way, when the bolt is screwed into the connected base, the limiting surface 212 can closely fit the surface of the connected base to prevent the first column 2 from deflecting or shaking, and the angle between the limiting surface 212 and the central axis of the first column 2 is 90°, which can also provide good support for the self-tapping thread 21. In addition, the stability and verticality of the stud can be maintained during the process of the first stud and the first column 2 being screwed into the connected base, ensuring that the bolt can be screwed in accurately along the central axis to prevent deflection or distortion.

[0036] In one embodiment, if Figure 1 and Figure 5 As shown, the head 1 includes a screwing portion 11 and a limiting flange 12; the limiting flange 12 is connected between the screwing portion 11 and the first column 2. It is understandable that the screwing portion 11 and the screwing portion 11 can be an integrated structure, which is compact and has no gaps, and can enhance the overall strength and stability of the bolt. The bolt can be rotated by holding the screwing portion 11; and the limiting flange 12 can increase the contact area between the head 1 and the connected base, thereby improving the structural strength of the bolt. Moreover, when the limiting flange 12 abuts against the connected base, it can be determined that the connection between the first column 2 and the connected base is in place, which facilitates assembly and prevents the bolt from being over-screwed into the connected base.

[0037] In one embodiment, if Figure 1 and Figure 5 As shown, the bolt also includes a first chip groove 4 provided on the end face of the limiting flange 12 away from the screwing portion 11. It is understandable that the shape and size of the above-mentioned first chip groove 4 can be set according to needs, for example, it can be set as an annular groove, or a plurality of grooves spaced circumferentially along the central axis of the first column 2 on the end face of the limiting flange 12. When the self-tapping thread 21 of the first column 2 is self-tapped in the connected base, the first chip groove 4 can collect the cut chips to prevent the chips from entering the thread gap. Furthermore, when the self-tapping thread 21 is threadedly connected to the connected base, the resistance between the first column 2 and the connected base during the tightening process can be reduced to prevent the first column 2 from breaking, and it can also prevent the limiting flange 12 and the surface of the connected base from being unable to fit due to chips.

[0038] In one embodiment, if Figure 1 and Figure 5 As shown, the first chip accumulation groove 4 is an annular groove formed indented on the end surface of the limiting flange 12 away from the screw connection portion 11. It can be understood that the first chip accumulation groove 4 is an annular groove formed indented on the end surface of the limiting flange 12 away from the screw connection portion 11. The annular groove can fully utilize the circumferential space of the limiting flange 12. In this way, the annular grooves are evenly distributed around the first column 2, which can evenly collect debris and prevent debris accumulation.

[0039] In one embodiment, if Figure 1 and Figure 5 As shown, the bolt also includes a second chip groove 5 provided on the first column 2; the extension direction of the second chip groove 5 is parallel to the central axis of the first column 2. It is understandable that the second chip groove 5 is provided on the first column 2, and the shape and size of the second chip groove 5 can be set according to demand. For example, the second chip groove 5 can be provided as a strip groove with an extension direction parallel to the central axis of the first column 2, or the second chip groove 5 includes a plurality of strip grooves with an extension direction parallel to the central axis of the first column 2 and spaced apart on the circumferential surface of the first column 2. The second chip groove 5 and the first chip groove 4 can exist independently or be provided on the bolt at the same time. The second chip groove 5 can directly collect the chips generated by cutting during self-tapping. Since the extension direction of the second chip groove 5 is parallel to the central axis of the first column 2, it is conducive to the smooth discharge of chips along the groove, avoiding accumulation inside the bolt.

[0040] In one embodiment, if Figure 2 As shown, the diameter of the first column 2 is larger than the diameter of the second column 3. It is understandable that when the diameter of the first column 2 is larger than the diameter of the second column 3, the first column 2 has a larger contact area and stronger bearing capacity than the second column 3, thereby enhancing the connection stability and bearing capacity between the first column 2 and the connected substrate, and reducing the risk of connection failure due to stress concentration.

[0041] The present invention also provides a connection structure comprising a nut and the aforementioned bolt, wherein the nut is provided with an internal thread, and the nut is threadedly connected to the bolt via the internal thread and the fastening thread 31. The bolt comprises a head 1, a first column 2, and a second column 3 connected in sequence; the first column 2 and the second column 3 are coaxially arranged; the first column 2 is provided with a self-tapping thread 21, and the second column 3 is provided with a fastening thread 31; the self-tapping thread 21 and the fastening thread 31 have opposite rotation directions.

[0042] In the connection structure of the above embodiment of the present invention, the bolt is composed of a head 1, a first column 2 and a second column 3 connected in sequence. A self-tapping thread 21 is provided on the first column 2. The first column 2 of the bolt can be directly screwed into the light hole of the connected base using the self-tapping thread 32 until the head 1 abuts against the connected base. The connection between the above-mentioned first column 2 and the connected base does not require welding, and regardless of whether the connected base is made of aluminum alloy material, a tight connection between the first column 2 and the connected base can be achieved, thereby improving the sealing and corrosion resistance of the connection position between the stud and the connected base. In addition, the self-tapping thread 21 on the first column 2 and the fastening thread 31 on the second column 3 have opposite rotation directions. In this way, after the first column 1 is screwed into the light hole of the connected base using the self-tapping thread 21, if it is necessary to tighten the nut on the fastening thread 31 of the second column 3, at this time, rotating the nut will make the first column 2 have a rotation tendency in the same direction as the rotation direction of the self-tapping thread 21, thereby making the connection between the first column 2 and the connected base more secure, thereby ensuring that the first column 2 will not loosen between the connected base. In this way, two-way fastening between the stud and the nut and the connected base is achieved, which significantly enhances the fastening effect and reliability of the connection structure.

[0043] The above are merely embodiments of the bolt and connection structure of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A bolt, characterized in that: It includes a head, a first column and a second column connected in sequence; the first column and the second column are coaxially arranged; the first column is provided with a self-tapping thread, and the second column is provided with a fastening thread; the self-tapping thread and the fastening thread have opposite rotation directions.

2. The bolt according to claim 1, characterized in that The self-tapping thread includes a self-tapping guide surface, which is arranged on the side of the self-tapping thread away from the head; on the plane where the central axis of the first cylinder is located, the distance between the self-tapping guide surface and the central axis of the first cylinder gradually decreases from the head toward the second cylinder.

3. The bolt according to claim 2, characterized in that The self-tapping thread further includes a limiting surface, which is arranged at a preset angle with the self-tapping guide surface, and the preset angle is 55°-65°.

4. The bolt according to claim 3, characterized in that The angle between the limiting surface and the central axis of the first column is 90°.

5. The bolt according to any one of claims 1 to 4, characterized in that The head includes a screw-on portion and a limiting flange; the limiting flange is connected between the screw-on portion and the first column.

6. The bolt according to claim 5, characterized in that The bolt further includes a first chip accumulation groove provided on an end surface of the limiting flange facing away from the screwing portion.

7. The bolt according to claim 6, characterized in that The first chip accumulation groove is an annular groove formed on the end surface of the limiting flange facing away from the screw connection portion.

8. The bolt according to any one of claims 1 to 4, characterized in that The bolt further includes a second chip accumulation groove provided on the first column; an extension direction of the second chip accumulation groove is parallel to a central axis of the first column.

9. The bolt according to claim 1, wherein The diameter of the first column is greater than the diameter of the second column.

10. A connection structure, characterized in that: It comprises a nut and a bolt according to any one of claims 1 to 9, wherein the nut is provided with an internal thread, and the nut is threadably connected to the bolt through the internal thread and the fastening thread.

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