Combined self-tapping screw

Abstract

The utility model discloses a combined self-tapping screw which is characterized in that a self-tapping screw body is sequentially provided with a polished rod part, a screw rod clamping ring, an incomplete thread and a complete thread downwards along the head of a bolt; the gasket is arranged on the polished rod part in a sleeving manner; the outer diameter of the screw clamping ring is larger than the diameter of an inner hole of the gasket, and meanwhile the outer diameter of the screw clamping ring is larger than the outer diameter of the incomplete thread. And the outer diameter of the screw rod clamping ring is smaller than the aperture of a prefabricated hole of a metal plate or a non-metal material plate which is correspondingly assembled with the combined self-tapping screw. The screw rod clamping ring is formed in the thread rolling process of the self-tapping screw body. When the self-tapping screw is assembled, a gasket is not clamped, and the self-tapping screw is stably and reliably attached to the gasket; and no new technology needs to be added for production of the self-tapping screw, and the production cost is low.

Description

Technical Field

[0001] The utility model belongs to the technical field of fastener manufacturing, and in particular relates to a self-tapping screw that can ensure stable fitting with a gasket during assembly. Background Art

[0002] Fasteners are a type of mechanical parts used for fastening and connection and are extremely widely used. Various fasteners can be seen on various machines, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, meters and supplies.

[0003] A self-tapping screw is a threaded fastener that drills a hole in a prefabricated hole of a metal plate or non-metallic material plate to form a self-drilled hole that matches the internal thread of the prefabricated hole. Generally, it refers to a self-tapping type external thread that plays a self-tapping role and does not need to be used with a nut. Existing self-tapping screws are mostly used to connect thin metal plates (steel plates, sawn plates, etc.).

[0004] like Figure 1 As shown in the figure, the combined self-tapping screws on the market have incomplete threads 10 and complete threads 20 formed on the screw. The incomplete threads 10 caused by the process characteristics are generated near the gasket 30, and the incomplete threads 10 of the self-tapping screws are sharp. During transportation, the incomplete threads 10 may occasionally penetrate into the gasket 30, causing the gasket to get stuck. Figure 2 As shown, the gasket 30 cannot rotate freely, and the bolt head 40 cannot fit with the gasket 30 during assembly. Utility Model Content

[0005] In order to solve the problems existing in the prior art, the utility model provides a combined self-tapping screw. The self-tapping screw does not get stuck in the gasket during assembly, and the fit with the gasket is stable and reliable; and the production of the self-tapping screw does not require the addition of new processes, and the production cost is low.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A combined self-tapping screw comprises a self-tapping screw body and a gasket; the self-tapping screw body comprises a bolt head and a self-tapping thread, and the self-tapping thread comprises an incomplete thread and a complete thread; the self-tapping screw body is provided with a smooth rod portion, a screw clamp, an incomplete thread and a complete thread in sequence downward from the bolt head; the gasket is sleeved on the smooth rod portion; the outer diameter of the screw clamp is larger than the inner hole diameter of the gasket, and at the same time, the outer diameter of the screw clamp is larger than the outer diameter of the incomplete thread; and the outer diameter of the screw clamp is smaller than the aperture of the prefabricated hole of the metal plate or non-metallic material plate assembled corresponding to the combined self-tapping screw.

[0008] In the combined self-tapping screw as described above, the distance between the center of the screw clamp ring and the bolt head is 1.70-2.00 mm.

[0009] In the combined self-tapping screw as described above, the screw clamp ring is formed during the thread rolling process of the self-tapping screw body.

[0010] The technical solution provided above has the following beneficial effects:

[0011] First, when the combined self-tapping screw of the utility model is assembled into the prefabricated hole of the metal plate or non-metallic material plate, the gasket is stably and reliably close to the bottom end face of the bolt head, providing high-strength fastening force and good sealing for the metal plate or non-metallic material plate.

[0012] Secondly, the utility model combined self-tapping screw adds a screw clamp ring, and the gasket moves freely between the screw clamp ring and the lower end of the bolt head to prevent the inner hole of the gasket from contacting the incomplete thread, thereby avoiding the gasket interference phenomenon caused by occasional incomplete threads penetrating into the gasket.

[0013] Third, the screw clamp ring of the utility model is formed together with the self-tapping thread in the thread rolling process of the self-tapping screw body, so no additional production process is added and the production cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of a self-tapping screw in the prior art;

[0016] Figure 2 It is a schematic diagram of the cross-sectional structure of a self-tapping screw in the prior art;

[0017] Figure 3 It is a three-dimensional structural schematic diagram of the combined self-tapping screw of the utility model;

[0018] Figure 4 It is a schematic diagram of the cross-sectional structure of the combined self-tapping screw of the utility model;

[0019] Figure 5 It is a schematic diagram of the three-dimensional structure of the self-tapping screw body of the utility model before thread rolling;

[0020] Figure 6 It is a three-dimensional structural schematic diagram of the thread rolling of the self-tapping screw body of the utility model. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention is further described in detail below in conjunction with 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 used to limit the present invention.

[0022] In the claims, specification and the above-mentioned drawings of the utility model, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. is to distinguish different objects rather than to describe a specific order.

[0023] In the claims, specification and the above-mentioned drawings of the utility model, unless otherwise explicitly defined, directional words, such as the terms "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the specific protection scope of the utility model.

[0024] In the claims, specification and the above drawings of the utility model, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0025] In the claims, specification and drawings of the present utility model, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0026] Now combined Figure 3 and Figure 4 As shown, the utility model composite self-tapping screw includes a self-tapping screw body 100 and a gasket 200. The self-tapping screw body 100 includes a bolt head 110, a screw collar 120 and a self-tapping thread 130, the screw collar 120 is arranged between the bolt head 110 and the self-tapping thread 130, and a polished rod portion 140 is arranged between the screw collar 120 and the bolt head 110, and the gasket 200 is sleeved on the polished rod portion 140.

[0027] The combined self-tapping screw of the utility model comprises a bolt head 110 , a washer 200 , a screw collar 120 and a self-tapping thread 130 which are arranged in sequence from top to bottom. The self-tapping thread 130 comprises an incomplete thread 131 and a complete thread 132 .

[0028] Specifically, the bolt head 110 of the utility model can be round, hexagonal, octagonal, etc. In this embodiment, the bolt head 110 is a cylinder with a diameter of 9.00-10.00 mm and a thickness of 3.00-5.00 mm. A hexalobular groove 111 is provided on the top of the bolt head 110, and the hexalobular groove 111 is a T25 hexalobular groove with a depth of 1.50-2.00 mm.

[0029] The self-tapping screw body 100 of the utility model includes a polished rod portion 140 , a screw rod collar 120 , an incomplete thread 131 and a complete thread 132 in order from the bolt head 110 downwards.

[0030] The polished rod 140 of the utility model is integrally connected to the lower end of the bolt head 110. In this embodiment, the polished rod 140 is a rod with a diameter of 3.50-3.60 mm. The gasket 200 of the utility model is sleeved on the polished rod 140. When the combined self-tapping screw of the utility model is assembled with the prefabricated hole of the metal plate or non-metallic material plate, the gasket 200 is tightly attached to the bottom end surface of the bolt head 110.

[0031] The outer diameter of the screw collar 120 of the utility model is larger than the inner diameter of the gasket 200, and at the same time, the outer diameter of the screw collar 120 is larger than the outer diameter of the incomplete thread 131; and the outer diameter of the screw collar 120 is smaller than the aperture of the prefabricated hole of the metal plate or non-metallic material plate corresponding to the combined self-tapping screw of the utility model. In this embodiment, the outer diameter of the screw collar 120 is 4.50-4.80mm; the self-tapping thread 5 is a PF5 self-tapping thread, and can also be a CT, PT thread, etc., without special limitation.

[0032] In this embodiment, the gasket 200 has a diameter of 15.00-18.00 mm and a thickness of 1.20-1.80 mm, and the inner hole diameter of the gasket 200 is 4.00-4.35 mm. The distance L between the center of the screw clamp 120 and the bolt head 110 is 1.70-2.00 mm.

[0033] The thread rolling process of the self-tapping screw body of the utility model is as follows Figure 5 and 6As shown, the screw clamp 120 is formed in the thread rolling process of the self-tapping screw body. Specifically, the self-tapping screw body 100 of the utility model is a bolt structure 100A before thread rolling. The bolt head 110A of the bolt structure 100A is the bolt head 110 of the self-tapping screw body 100 of the utility model, and the bolt head 110A is composed of a lower polished rod 120A and a screw rod portion 130A in sequence downward. In this embodiment, the lower polished rod 120A is a polished rod with a diameter of 3.50-3.70 mm and a length of 4.60-4.80 mm. When rolling, an integrated tooth plate 500 is used. The integrated tooth plate 500 is a structure in which the blade 510 and the tooth plate are integrated, and the tooth plate is arranged at the lower end of the blade 510. The function of the integrated thread plate 500 is to roll out threads by extruding the polished rod, which is a normal equipment in the thread rolling process. The blade 510 is stationary during thread rolling. As the bolt structure 100A rotates and is pulled downward by the thread plate during thread rolling, the blade 510 pushes the blank of the polished rod 120A under the head upward to form the screw clamp 120 of the utility model.

[0034] like Figure 6 As shown, when the bolt structure 100A is thread rolling, the blade 510 is arranged at the fixed end of the thread rolling machine. The thread rolling machine of this embodiment adopts a thread rolling machine with a specification of C253H. The blade 510 is stationary during thread rolling. As the bolt structure 100A rotates while being pulled downward by the thread plate during thread rolling, the blade 510 pushes the blank of the polished rod 120A under the head upward to form the screw clamp 120 of the utility model.

[0035] Since the combined self-tapping screw of the utility model is provided with a screw clamp 120, the outer diameter of the screw clamp 120 is larger than the inner hole diameter of the gasket 200, and the gasket 200 can only move freely between the screw clamp 120 and the lower end of the bolt head 110, so that the inner hole of the gasket 200 cannot contact the incomplete thread 131, thus avoiding the phenomenon that the incomplete thread 131 occasionally penetrates the gasket 200 and causes the gasket to get stuck.

[0036] The screw collar 120 of the utility model is produced together with the self-tapping thread 130 when the self-tapping screw body 100 is threaded and formed by using an integrated thread plate, so there is no additional production cost.

[0037] The dimensions and specifications listed in this article are all for this implementation case, and the specific product dimensions can be set according to actual conditions.

[0038] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A combined self-tapping screw, comprising a self-tapping screw body (100) and a gasket (200); wherein: The self-tapping screw body (100) comprises a bolt head (110) and a self-tapping thread (130), wherein the self-tapping thread (130) comprises an incomplete thread (131) and a complete thread (132); the self-tapping screw body (100) is provided with a smooth rod portion (140), a screw clamp (120), an incomplete thread (131) and a complete thread (132) in sequence downward along the bolt head (110); the gasket (200) is sleeved on the smooth rod portion (140); the outer diameter of the screw clamp (120) is greater than the inner hole diameter of the gasket (200), and at the same time, the outer diameter of the screw clamp (120) is greater than the outer diameter of the incomplete thread (131); and the outer diameter of the screw clamp (120) is smaller than the hole diameter of the prefabricated hole of the metal plate or non-metallic material plate corresponding to the assembled self-tapping screw.

2. A combined self-tapping screw according to claim 1, characterized in that: The distance between the center of the screw clamp (120) and the bolt head (110) is 1.70-2.00 mm.

3. A combined self-tapping screw according to claim 1 or 2, characterized in that: The screw clamp (120) is formed during the thread rolling process of the self-tapping screw body (100).

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