Expansion screw with internal and external threads

Abstract

The utility model relates to the technical field of fasteners, in particular to an expansion screw with internal and external threads, which comprises an external screw, a mounting hole is arranged on the inner wall of the external screw, a plug pin is arranged on the inner wall of the mounting hole, and a self-tapping head is integrally fixed at the bottom end of the outer wall of the external screw. According to the self-tapping screw, the plug pin is installed in the outer screw, so that the pressure bearing block and the fixing block can be extruded towards the bottom end by the plug pin during installation, the clamping teeth and the wedge-shaped clamping plate can deform and move towards the outer side, and the self-tapping screw is convenient to use and high in practicability. And the clamping teeth and the wedge-shaped clamping plate can abut against and be fixed to the inner wall of the threaded hole, so that the fixing effect of the outer screw and the threaded hole is enhanced, and the situation that the outer screw is disengaged and needs to be fixed secondarily is avoided.

Description

Technical Field

[0001] This utility model relates to the field of fastener technology, specifically to an internal and external thread expansion screw. Background Technology

[0002] Screws are known as the "rice of industry" due to their wide applicability in various fields such as construction, machinery, and chemicals. Furthermore, there are many types of screws, such as ordinary screws and self-tapping screws. These screws are prone to repeated removal and need to be re-secured during use: 1) The material of the fastener is soft, and the gripping force between the screw and the fastener is weak, making it easy for the screw to come loose entirely; 2) Multiple drilling during installation causes the fastener to loosen internally, and the screw gradually comes loose under external force after installation.

[0003] When a screw is removed from a screw hole and then re-secured, it can easily damage the threads inside the fastener, affecting the securing effect between the screw and the fastener. In severe cases, it can cause the threads to strip, preventing the screw from securing the fastener. Therefore, existing fastening screws still have certain shortcomings in use.

[0004] In conclusion, it is necessary to invent an expansion screw with internal and external threads. Utility Model Content

[0005] Therefore, this utility model provides an internal and external thread expansion screw to solve the problem that when a screw is removed from the threaded hole and then re-fixed, it is easy to damage the threads inside the fastener, which affects the fixing effect between the screw and the fastener. In severe cases, it can cause the threaded hole to strip, resulting in the screw being unable to fix the fastener.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an internal and external thread expansion screw, comprising an external screw, an installation hole provided on the inner wall of the external screw, a pin provided on the inner wall of the installation hole, a self-tapping head integrally fixed to the bottom end of the outer wall of the external screw, and a tightening component provided on the top end of the outer wall of the self-tapping head and located at the bottom end of the inner wall of the installation hole.

[0007] Preferably, a hexagonal clip is integrally fixed to the top of the outer wall of the external screw, and a groove is provided on the top of the outer wall of the hexagonal clip, with the bottom of the inner wall of the groove communicating with the top of the mounting hole.

[0008] Preferably, the upper end of the outer wall of the pin is provided with an external thread layer, and the inner wall of the mounting hole and the position corresponding to the external thread layer are provided with internal threads for connection. The pin is fixed to the inner wall of the mounting hole through the external thread layer and the internal threads.

[0009] Preferably, an inner head is integrally fixed to the top of the outer wall of the insert, the outer wall of the inner head is in contact with the inner wall of the groove, and a cross groove is formed on the top of the outer wall of the inner head.

[0010] Preferably, the clamping component includes a pressure block, which is slidably connected to the inner wall of the mounting hole and located below the pin, and a fixing block is provided on the inner wall of the mounting hole and below the pressure block.

[0011] Preferably, the top of the outer wall of the self-tapping head is integrally fixed with a locking tooth, and the multiple locking teeth are evenly arranged in a ring array. The upper end of the inner wall of each locking tooth is fixed with a reinforcing block.

[0012] Preferably, the other end of each reinforcing block passes through the inner wall of the mounting hole and is fixedly connected to the outer wall of the fixing block. The bottom of the outer wall of the external screw and the position corresponding to the reinforcing block are provided with a relief groove. The outer wall of the reinforcing block is slidably connected to the inner wall of the relief groove.

[0013] Preferably, a wedge-shaped column is fixed to the bottom of the outer wall of the pressure block, the bottom of the wedge-shaped column is fixed to the top of the outer surface of the fixed block, and a wedge-shaped card plate is slidably connected to the inner wall of the mounting hole and the outer side of the wedge-shaped column by opening an insertion hole. The end of the wedge-shaped card plate with the mounting hole is slidably connected to the outer wall of the wedge-shaped column.

[0014] The beneficial effects of this utility model are:

[0015] In this invention, by installing a pin inside the external screw, the pin can press the bearing block and the fixing block towards the bottom during installation. This allows the clamping teeth and the wedge-shaped plate to deform and move outward, enabling them to abut against the inner wall of the threaded hole. This enhances the fixing effect between the external screw and the threaded hole, preventing the external screw from coming loose and requiring secondary fixing, thus making it more convenient for users. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of the present invention viewed from the front.

[0017] Figure 2 This is a partial cross-sectional view of the present invention from the front view.

[0018] Figure 3 This utility model Figure 2 Enlarged structural diagram at point A;

[0019] Figure 4 In this utility model Figure 1 A partial structural schematic diagram viewed from above;

[0020] Figure 5This is a three-dimensional structural diagram of the self-tapping head in this utility model from an upward viewing direction.

[0021] In the diagram: 100, external screw; 200, hexagonal collet; 300, self-tapping head; 310, reinforcing block; 400, insert pin; 410, external thread layer; 420, internal top head; 430, bearing block; 431, wedge-shaped post; 440, fixing block; 450, wedge-shaped clamping plate. Detailed Implementation

[0022] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0023] See attached document Figures 1-5 This utility model provides an expansion screw with internal and external threads, including an external screw 100. The inner wall of the external screw 100 has a mounting hole for installing a pin 400 inside. A hexagonal collet 200 is integrally fixed to the top of the outer wall of the external screw 100. The top of the outer wall of the hexagonal collet 200 has a groove, the bottom of which communicates with the top of the mounting hole. The hexagonal collet 200 is designed to facilitate tightening of the external screw 100 by means of a wrench or other tools. The inner wall of the mounting hole has the pin 400, and the upper end of the outer wall of the pin 400 has an external thread layer 41. 0. The inner wall of the mounting hole and the position corresponding to the external thread layer 410 are provided with internal threads for connection. The pin 400 is fixed to the inner wall of the mounting hole through the external thread layer 410 and the internal threads. The top of the outer wall of the pin 400 is integrally fixed with an inner head 420. The outer wall of the inner head 420 contacts the inner wall of the groove. The top of the outer wall of the inner head 420 is provided with a cross groove. The pin 400 is provided to cooperate with the self-tapping head 300 to strengthen the fixing effect between the external screw 100 and the threaded hole on the fastener. The inner head 420 and the cross groove are provided to facilitate the personnel to fix the pin 400 in the mounting hole.

[0024] A self-tapping head 300 is integrally fixed to the bottom of the outer wall of the external screw 100. A tightening component is provided at the top of the outer wall of the self-tapping head 300 and at the bottom of the inner wall of the mounting hole. The tightening component includes a bearing block 430, which is slidably connected to the inner wall of the mounting hole and located below the pin 400. The bearing block 430 can support the bottom of the outer wall of the pin 400. A fixing block 440 is provided below the bearing block 430 and on the inner wall of the mounting hole. A locking tooth is integrally fixed to the top of the outer wall of the self-tapping head 300. Multiple locking teeth are evenly arranged in a ring array. The strength of the locking teeth needs to be greater than the strength of the fastener. The locking teeth are arranged in a way that is narrower at the top and wider at the bottom. This is mainly to ensure that when the bearing block 430 moves downward, the reinforcing block 310 can lock it in place. The outer edge of the teeth expands outward to improve the fixing effect between the outer screw 100 and the inner wall of the mounting hole. The upper end of the inner wall of the locking teeth is fixed with a reinforcing block 310. The other end of the reinforcing block 310 passes through the inner wall of the mounting hole and is fixedly connected to the outer wall of the fixing block 440. The bottom end of the outer wall of the outer screw 100 and the position corresponding to the reinforcing block 310 are provided with a relief groove. The outer wall of the reinforcing block 310 is slidably connected to the inner wall of the relief groove. The reinforcing block 310 is designed to press down on the connecting end of the locking teeth when the pressure block 430 drives the fixing block 440 to move downward, so that it can bend outward and abut against the inner wall of the mounting hole. The locking teeth are normally smaller than the diameter of the thread end of the outer screw 100.

[0025] A wedge-shaped post 431 is fixed to the bottom of the outer wall of the pressure block 430. The bottom end of the wedge-shaped post 431 is fixed to the top of the outer surface of the fixing block 440. The pressure block 430 is designed to be wider at the top and narrower at the bottom. A wedge-shaped clamping plate 450 is slidably connected to the inner wall of the mounting hole and the outer side of the wedge-shaped post 431 through an insertion hole. One end of the wedge-shaped clamping plate 450 with the mounting hole is slidably connected to the outer wall of the wedge-shaped post 431, and the insertion end of the wedge-shaped clamping plate 450 is connected to the wedge-shaped post 431. The outer wall side abuts against the wedge. When the wedge post 431 moves downward, the wedge plate 450 can extend outward, so that the outer wall of the wedge plate 450 abuts against the inner wall of the threaded hole. During normal use, the wedge plate 450 can be fixed to the inner wall of the insertion hole through the thermoplastic point. When the insertion pin 400 is not installed, the wedge plate 450 can be retracted into the insertion hole and is smaller than the diameter of the threaded end, so as to avoid the wedge plate 450 affecting the rotation of the outer screw 100 by the personnel.

[0026] The usage process of this utility model is as follows: Those skilled in the art can assemble the device according to the above description. Then, the personnel can use tools such as wrenches to rotate the outer screw 100 and the self-tapping head 300 into the through hole opened in the fastener. When the self-tapping head 300 is rotated, it can open the internal thread on the inner wall of the through hole, so that the outer wall of the outer screw 100 can be threadedly connected with the threaded hole.

[0027] After the external screw 100 is initially fixed to the threaded hole, the operator can remove the insert pin 400 and insert it into the mounting hole inside the external screw 100. The insert pin 400 is then rotated using a screwdriver and an inner head 420, causing the external thread layer 410 to be threadedly connected to the inner wall of the mounting hole. The insert pin 400 moves downward in the mounting hole and presses against the bearing block 430 from the top, causing it to press the wedge-shaped column 431 and the fixing block 440 downward. When the fixing block 440 moves downward, the reinforcing abutment 310 presses against the upper end of the clamping tooth, causing it to bend and extend outward. This allows the outer wall of the clamping tooth to abut against the inner wall of the threaded hole. The operator must ensure that the structural strength of the reinforcing abutment 310 is greater than the structural strength of the clamping tooth.

[0028] At the same time, when the wedge post 431 moves, it will press outward against the wedge plate 450, causing the thermoplastic point of the fixed wedge plate 450 to break, and pressing the wedge plate 450 against the inner wall of the threaded hole, thereby strengthening the fixing effect of the external screw 100 and the threaded hole.

[0029] The above description is merely a preferred embodiment of this utility model. Any person skilled in the art may modify this utility model or modify it into an equivalent technical solution using the technical solutions described above. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of this utility model are within the scope of protection claimed by this utility model.

Claims

1. An internal and external thread expansion screw, characterized by: The outer screw (100) is provided with a mounting hole in the inner wall, and the inner wall of the mounting hole is provided with a plug nail (400), the outer wall bottom end of the outer screw (100) is integrally fixed with a self-tapping head (300), and the outer wall top end of the self-tapping head (300) and the inner wall bottom end of the mounting hole are provided with a clamping part.

2. A dual thread expansion screw according to claim 1 wherein: The outer wall top end of the outer screw (100) is integrally fixed with a hexagonal chuck (200), the outer wall top end of the hexagonal chuck (200) is provided with a slot, and the inner wall bottom end of the slot is communicated with the top end of the mounting hole.

3. The dual thread expansion screw of claim 1 wherein: The outer wall top end of the plug nail (400) is integrally fixed with an inner top head (420), the outer wall of the inner top head (420) is in contact with the inner wall of the slot, and the outer wall top end of the inner top head (420) is provided with a cross slot.

4. A dual thread expansion screw according to claim 3 wherein: The clamping part comprises a pressure block (430) which is slidingly connected to the inner wall of the mounting hole and located below the plug nail (400), and the inner wall of the mounting hole and located below the pressure block (430) is provided with a fixed block (440).

5. The dual thread expansion screw of claim 1 wherein: The outer wall top end of the self-tapping head (300) is integrally fixed with a clamping tooth, and a plurality of clamping teeth are uniformly arranged in the form of an annular array, and the inner wall top end of the clamping tooth is fixed with a reinforcing block (310).

6. A box tap according to claim 5, wherein: The other end of the reinforcing block (310) penetrates the inner wall of the mounting hole and is fixedly connected with the outer wall of the fixed block (440), the outer wall bottom end of the outer screw (100) and the corresponding position of the reinforcing block (310) are provided with a avoiding slot, and the outer wall of the reinforcing block (310) is slidingly connected with the inner wall of the avoiding slot.

7. A box tap according to claim 6, wherein: The outer wall bottom end of the pressure block (430) is fixed with a wedge-shaped column (431), the bottom end of the wedge-shaped column (431) is fixed with the outer wall top end of the fixed block (440), the inner wall of the mounting hole and located outside the wedge-shaped column (431) is slidingly connected with a wedge-shaped clamping plate (450) by opening a plug hole, and one end of the wedge-shaped clamping plate (450) and the outer wall of the wedge-shaped column (431) are slidingly connected.

8. A box tap according to claim 7, wherein: ​

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