Threaded blind rivet and preparation method and installation method thereof

Abstract

The invention relates to the technical field of fasteners, in particular to a threaded pulling nail and a preparation method and an installation method thereof. The thread drawing nail comprises a nail sleeve, a core rod, a forming sleeve, a lining and a mounting nut. The forming sleeve and the lining sleeve are arranged on the core rod in a sleeving manner; the nail sleeve and the mounting nut are screwed on the core rod; a threaded hole and a limiting hole are formed in the center of the nail sleeve; a nail sleeve locking shoulder is formed between the limiting hole and the threaded hole; the core rod comprises a clamping section, a first screw section, a second screw section, a limiting step section and a core rod head from top to bottom; external threads with the same shape are arranged on the peripheral surfaces of the first screw section and the second screw section, and a broken diameter groove is formed between the first screw section and the second screw section; the top surface of the head of the core rod is an inverted conical surface and forms a conical surface groove; a core rod stop shoulder is formed on the top surface of the limiting step section; the lower end of the forming sleeve abuts against the interior of the conical surface groove. After the blind rivet is riveted, the limiting step section can be inserted into the limiting hole, and the core rod locking shoulder and the rivet sleeve locking shoulder abut against each other to form limiting.

Description

Technical Field

[0001] This invention relates to the field of fastener technology, and in particular to a threaded pull pin and its preparation and installation methods. Background Technology

[0002] Threaded pull pins are special fasteners combining threaded structures and core-pulling technology, and have key applications in the aerospace industry. Existing technology, such as patent application CN120777268A, discloses a threaded pull pin and its installation device, installation method, and manufacturing method. The threaded pull pin includes a core rod, a pin body, and a pin sleeve. The core rod includes a head protrusion, a first external thread segment, a second external thread segment, and a clamping segment connected in sequence. A necking groove is provided between the first and second external thread segments, and the major diameter D1 of the first external thread segment is larger than the major diameter D2 of the second external thread segment. The pin body is sleeved on the core rod, and the pin body has a first internal thread segment and a second internal thread segment. The major diameter D3 of the first internal thread segment is larger than the major diameter D4 of the second internal thread segment. The second internal thread segment is located at the end of the pin body away from the head protrusion. The first internal thread segment matches the first external thread segment, and the second internal thread segment matches the second external thread segment. The second internal thread segment can limit the first external thread segment in the axial direction of the core rod.

[0003] The aforementioned prior art has the following problems: (1) It is necessary to process two different internal threads with different shapes in the nail body, where the major diameter of the thread is D3 > the major diameter of the thread is D4. Since the conventional thread processing method is to use a tap to tap the thread, resulting in a threaded through hole structure, the nail body structure in the existing technology is difficult to process and is not conducive to mass production.

[0004] (2) It is necessary to process two different external threads with different shapes at both ends of the thread major diameter D1 > thread major diameter D2 on the mandrel. When using a cold rolling machine to process the thread rolling, the operation of processing two external threads with different major diameters is more complicated and not conducive to mass production.

[0005] (3) Limiting interference is achieved by using the external thread section size D1 of the core rod and the major diameter size D4 of the nail body thread to abut against each other. The interference amount of a typical specification is about 0.29mm. The interference amount is small. During the limiting, there is a risk of the thread on the external thread section of the core rod breaking, which makes the limiting unreliable.

[0006] (4) The end face of the head protrusion used to axially phase the nail sleeve is a plane. When the nail sleeve is squeezed by the head protrusion of the core rod to form the pier head, the end of the nail sleeve that contacts the head protrusion is prone to flaring deformation. Summary of the Invention

[0007] The main objective of this invention is to provide a threaded pull pin and its preparation and installation methods, in order to solve the aforementioned technical problems.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a threaded pull pin, comprising a pin sleeve, a core rod, a forming sleeve, a bushing, and a mounting nut; the forming sleeve and the bushing are both sleeved on the core rod, and the bushing is embedded in the countersunk hole of the forming sleeve; the pin sleeve and the mounting nut are both screwed onto the core rod; the pin sleeve has a threaded hole and a limiting hole at its center; a pin sleeve stop shoulder is formed between the limiting hole and the threaded hole; the core rod includes, from top to bottom, a clamping section, a first screw section, a second screw section, and a limiting platform. The stage and the core rod head; the outer peripheral surfaces of the first screw section and the second screw section are provided with external threads of the same shape, and a cut-off groove is provided between the first screw section and the second screw section; the top surface of the core rod head is set as an inverted conical surface and forms a conical groove; the top surface of the limiting stage forms a core rod stop shoulder; the lower end of the forming sleeve abuts against the conical groove; after the pin is riveted, the limiting stage can be inserted into the limiting hole, and the core rod stop shoulder and the pin sleeve stop shoulder abut against each other to form a limit.

[0009] Preferably, a paint receiving countersunk hole is provided below the central threaded hole of the mounting nut, and the diameter of the paint receiving countersunk hole is larger than the major diameter of the central threaded hole of the mounting nut; the paint receiving countersunk hole is used to accommodate dry film lubricating paint that falls off during the installation process.

[0010] Preferably, the top surface of the second screw segment is set as a plane, and the top surface of the second screw segment is connected to the bottom end of the first screw segment by an inverted cone; the outer cone surface of the inverted cone and the top surface of the second screw segment together form the cut-off groove.

[0011] Preferably, after the rivet is attached, when the core rod stop shoulder and the rivet sleeve stop shoulder abut against each other to form a limiting position, the top plane of the second screw section is not higher than the top surface of the rivet sleeve.

[0012] Preferably, after the pull pin is riveted, when the core rod stop shoulder and the nail sleeve stop shoulder abut against each other to form a limit, the distance between the top plane of the second screw section and the top surface of the nail sleeve is t, which satisfies: 0≤t≤0.5mm.

[0013] Preferably, a tool relief groove is provided between the lower end of the second screw section and the limiting stage.

[0014] In a second aspect, the present invention provides a method for preparing a threaded pull pin, comprising the following steps: manufacturing a pin sleeve, a core rod, a forming sleeve, a bushing, and an mounting nut respectively, and then assembling them to obtain the above-mentioned threaded pull pin; The manufacturing steps of the rivet sleeve include: forging a blank by a warm forging machine, followed by sandblasting, heat treatment, turning the shape and center stepped hole, tapping, and surface treatment. The manufacturing steps of the core rod include: cold heading on a multi-station cold heading machine to obtain a blank, followed by electroplating, grinding, wire rolling, heat treatment and surface treatment in sequence; The manufacturing steps of the molded sleeve include: sequentially turning, heat treatment, and surface treatment using tubing material; The bushing is machined from tubing. The manufacturing steps of the mounting nut include: turning the outer shape and stepped inner hole, tapping, milling the outer hexagon, and surface treatment.

[0015] Preferably, the material of the nail sleeve is TC4 or Ti6Al4V; the material of the core rod is GH2132 or A286; the material of the molded sleeve is 06Cr18Ni9 or 304; and the material of the bushing is polyoxymethylene.

[0016] Preferably, in the manufacturing steps of the nail sleeve, the heat treatment method is as follows: solution treatment and aging treatment are adopted, the solution temperature is 955°C, the holding time is 60 minutes, and water cooling is adopted; the aging temperature is 540°C, the holding time is 360 minutes, and furnace cooling is adopted; the surface treatment method is as follows: the surface is treated with fluorinated phosphate, and the surface is coated with hexadecyl alcohol or paraffin. In the manufacturing steps of the core rod, the heat treatment method is: aging treatment, aging temperature ℃, holding for 960 minutes, and gas cooling; the surface treatment method is: sandblasting and passivation treatment, and dry film lubrication coating on the surface. In the manufacturing steps of the molded sleeve, the heat treatment method is annealing at 1100℃ for 60 minutes, using gas cooling; the surface treatment method is sandblasting and passivation, followed by dry film lubrication. In the manufacturing process of the mounting nut, the surface treatment is nickel plating or zinc plating.

[0017] Thirdly, the present invention provides a method for installing a threaded rivet, wherein the threaded rivet is inserted into the mounting hole of the component to be connected, the head of a rivet gun is fitted onto the nut to be installed, and the core of the rivet gun clamps the clamping section of the core rod; the rivet gun is started, and the nut and the rivet sleeve rotate relative to the axis of the core rod while moving downward along the axis of the core rod until they can be inserted into the limiting hole at the limiting stage, and the stopping shoulder of the core rod and the stopping shoulder of the rivet sleeve abut against each other to form a limiting resistance torque, causing the core rod to break at the broken diameter groove position.

[0018] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) In this invention, since the center of the rivet sleeve only has a threaded hole and a limiting hole, and the threaded hole has only the same thread specification, a threaded through hole can be obtained by tapping with a tap. Compared with the prior art, the rivet sleeve center only adopts the structural form of the same specification thread, which simplifies the thread processing and is conducive to mass production. In addition, the outer peripheral surfaces of the first screw section and the second screw section on the core rod are provided with external threads of the same shape, which is conducive to the use of a cold thread rolling machine for thread rolling. Compared with the prior art, the use of external threads of the same shape in the first screw section and the second screw section is conducive to simplifying the processing and mass production.

[0019] (2) In this invention, after the rivet is riveted, it can be inserted into the limiting hole by using the limiting platform stage, and the core rod stop shoulder and the rivet sleeve stop shoulder abut against each other to form a limiting. This limiting method overcomes the problem of thread breakage risk in the prior art, and the limiting method is more reliable.

[0020] (3) In this invention, by utilizing the conical groove on the top surface of the core rod head to cooperate with the lower end of the forming sleeve, when riveting, the lower end face of the forming sleeve is close to the conical groove. Under the action of the conical groove, the lower end face of the forming sleeve can be gathered, thereby preventing the lower end of the forming sleeve from flaring out.

[0021] (4) In this invention, when the riveting is about to end, the core rod stop shoulder and the nail sleeve stop shoulder come into contact with each other and generate additional resistance, causing the core rod to break immediately from the cut-off groove, thereby achieving the design objective of good flatness consistency after riveting. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the threaded pull pin provided by the present invention; Figure 2 for Figure 1 Sectional view of AA; Figure 3 This is a schematic diagram of the core rod structure in this invention; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 This is a cross-sectional view of the nail sleeve in this invention; Figure 6 This is a top view of the nail sleeve in this invention; Figure 7 This is a cross-sectional view of the molded sleeve in this invention; Figure 8 This is a schematic diagram showing the core rod stop shoulder and the nail sleeve stop shoulder abutting against each other to form a limiting position in this invention; Figure 9 This is a schematic diagram of the structure of the threaded pull pin after riveting provided by the present invention; Figure 10 This is a perspective view of the threaded pull pins after riveting provided by the present invention.

[0024] Explanation of reference numerals in the attached diagram: 100, nail sleeve; 101, limiting hole; 102, nail sleeve stop shoulder; 103, outer conical surface; 104, threaded hole; 105, outer circle of nail sleeve; 106, conical nail head; 107, upper end face; 200. Core rod; 201. Clamping section; 202. First screw section; 202a. Inverted cone; 203. Second screw section; 210. Core rod head; 212. Conical groove; 220. Limiting platform stage; 222. Core rod stop shoulder; 231. Relief groove; 233. Cut-off groove; 234. Flat surface; 300, forming sleeve; 303, countersunk hole; 400, bushing; 500. Installation nut; 502. Paint receiving countersunk hole; 503. Cylindrical section; 504. External hexagonal section. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] In a first aspect, this embodiment provides a threaded pull pin, including a pin sleeve 100, a core rod 200, a forming sleeve 300, a bushing 400, and a mounting nut 500.

[0028] Combination Figure 5As shown, the center hole of the nail sleeve 100 is a stepped hole, which includes a threaded hole 104 and a limiting hole 101 from top to bottom; the diameter of the limiting hole 101 is larger than the major diameter of the threaded hole 104; a nail sleeve stop shoulder 102 is formed between the limiting hole 101 and the threaded hole 104. The upper end of the nail sleeve 100 is integrally formed with a tapered nail head 106, and the lower end is provided with an outer tapered surface 103 that is larger at the top and smaller at the bottom.

[0029] Combination Figure 3 and Figure 4 As shown, the mandrel 200 includes, from top to bottom, a clamping section 201, a first screw section 202, a second screw section 203, a limiting platform stage 220, and a mandrel head 210. The outer circumferential surfaces of the first screw section 202 and the second screw section 203 are provided with external threads of the same shape, and a cut-off groove 233 is provided between the first screw section 202 and the second screw section 203. The diameter of the mandrel head 210 is larger than the diameter of the limiting platform stage 220; the top surface of the mandrel head 210 is set as an inverted conical surface and forms a conical groove 212; the diameter of the limiting platform stage 220 is larger than the major diameter of the thread of the second screw section 203, and the top surface of the limiting platform stage 220 forms a mandrel stop shoulder 222. A pair of parallel flat surfaces 234 are provided on the outer circumferential surface of the clamping section 201 for connecting the rivet gun core and transmitting installation torque.

[0030] Combination Figure 2 As shown, the forming sleeve 300 and the bushing 400 are both sleeved on the core rod 200, and the bushing 400 is embedded in the countersunk hole 303 above the center hole of the forming sleeve 300; the lower end of the forming sleeve 300 abuts against the conical groove 212; the nail sleeve 100 and the mounting nut 500 are both screwed onto the core rod 200, and the lower end of the mounting nut 500 abuts against the top surface of the nail sleeve 100; after the nail is pulled and riveted, the limiting platform stage 220 can be inserted into the limiting hole 101, and the core rod stop shoulder 222 and the nail sleeve stop shoulder 102 abut against each other to form a limiting.

[0031] Combination Figure 7 As shown, the molding sleeve 300 is a thin-walled structure with a central through hole. A countersunk hole 303 is provided above the central through hole. The countersunk hole 303 is mainly used to cooperate with the bushing 400. During the riveting process, it is used to wrap the deformation of the bushing 400 and support the smooth deformation of the bulge.

[0032] The bushing 400 is made of POM (polyoxymethylene) and has a thin-walled tubular structure. The molded sleeve 300 serves a filling function during molding, allowing the bulge to deform smoothly. It also provides lubrication during riveting and waterproofing during service.

[0033] The mounting nut 500 includes an outer hexagonal section 504 and a cylindrical section 503 integrally formed on the bottom surface of the outer hexagonal section 504. A paint receiving countersunk hole 502 is provided below the central threaded hole of the mounting nut 500, and the diameter of the paint receiving countersunk hole 502 is larger than the major diameter of the central threaded hole of the mounting nut 500; the paint receiving countersunk hole 502 is used to accommodate dry film lubricating paint that falls during the installation process, so as to avoid paint residue on the end face of the rivet sleeve 100 after riveting.

[0034] Combination Figure 4 As shown, the top surface of the second screw segment 203 is set as a plane, and the top surface of the second screw segment 203 is connected to the bottom end of the first screw segment 202 by an inverted cone 202a; the outer cone surface of the inverted cone 202a and the top surface of the second screw segment 203 together form the cut-off groove 233. Further, after the pin is riveted, when the core rod stop shoulder 222 and the pin sleeve stop shoulder 102 abut against each other to form a limiting position, the top plane of the second screw segment 203 is not higher than the top surface of the pin sleeve 100.

[0035] Combination Figure 8 As shown, after the pull pin is riveted, when the core rod stop shoulder 222 and the nail sleeve stop shoulder 102 abut against each other to form a limit, the distance between the top plane of the second screw section 203 and the top surface of the nail sleeve 100 is t, which satisfies: 0≤t≤0.5mm.

[0036] Combination Figure 3 As shown, a tool relief groove 231 is provided between the lower end of the second screw section 203 and the limiting stage section 220.

[0037] In this embodiment, the diameter of the limiting hole 101 is φD2, and the minor diameter of the threaded hole 104 is φD1. The typical specification interference design satisfies: φD2-φD1=0.55mm. The above interference is larger than that of the existing patent, and the structure is stable, and the limiting is more accurate.

[0038] The assembly state before riveting is as follows: Figure 2 As shown: After the bushing 400 is installed in the countersunk hole 303 of the molded sleeve 300 to form an assembly via an transition fit, it is then assembled onto the core rod 200. The molded sleeve 300 is positioned close to the head 210 of the core rod, and its lower end abuts against the tapered groove 212 of the head 210. The inner hole of the molded sleeve 300 has a clearance fit with the external thread of the second screw section 203. The pin sleeve 100 is screwed onto the first screw section 202 through its threaded hole 104. During assembly, the outer tapered surface 103 at the lower end of the pin sleeve 100 extends into the inner hole of the molded sleeve 300, and the lower end face of the pin sleeve 100 contacts the upper end face of the bushing 400, exerting a certain pressure to prevent the molded sleeve 300 from moving on the core rod 200 and affecting the installation quality. The mounting nut 500 is screwed onto the first screw section 202 through its internal threaded hole. At the same time, the lower end face of the mounting nut 500 contacts the top surface of the nail sleeve 100 and applies a certain pressure to prevent the mounting nut 500 from loosening during product transportation.

[0039] Secondly, this embodiment provides a method for preparing a threaded pull pin, including the following steps: manufacturing a pin sleeve 100, a core rod 200, a forming sleeve 300, a bushing 400, and an installation nut 500 respectively, and then assembling them to obtain the above-mentioned threaded pull pin; S1. The manufacturing steps of the nail sleeve 100 include: Raw material selection: The nail sleeve 100 uses raw materials with grade TC4 or Ti6Al4V, and the raw materials are in the annealed state.

[0040] Blank manufacturing: The blank is obtained by upsetting and forging using a warm upsetting machine.

[0041] Sandblasting: Removes the lubricating coating and debris from the blank.

[0042] Heat treatment: Solution treatment + aging treatment is adopted. Solution temperature is 955℃, holding time is 60 minutes, and water cooling is used; aging temperature is 540℃, holding time is 360 minutes, and furnace cooling is used.

[0043] Turning: Machining the outer shape and inner hole of the nail sleeve 100, specifically including the limiting hole 101 and the nail sleeve stop shoulder 102, turning the bottom hole of the threaded hole 104, turning the outer conical surface 103, the outer circle of the nail sleeve 105, the conical nail head 106 and the upper end face 107.

[0044] Threading: Machining threaded holes 104.

[0045] Surface treatment: Fluorophosphate treatment, and the surface can be coated with cetyl alcohol or paraffin as needed to provide sufficient lubrication for product riveting.

[0046] S2. The manufacturing steps of the core rod 200 include: Raw material selection: Grade GH2132 or A286, raw material state is cold drawn state.

[0047] Blank manufacturing: Cold heading is performed on a multi-station cold heading machine. The processing structure includes the outer circle of the core rod head 210, the conical groove 212, the limiting stage 220, and the flat surface 234 to obtain the blank.

[0048] Electroplating: Removing the lubricating copper layer from the blank.

[0049] Grinding: Grinding the diameter of the thread rolling blank to stabilize the thread rolling dimensions.

[0050] Thread rolling: The thread rolling process is performed using a cold thread rolling machine. The processing structure includes the relief groove 231 and the external threads on the first screw section 202 and the second screw section 203.

[0051] Heat treatment: Aging treatment is performed at an aging temperature of 660-704℃ for 960 minutes, using gas cooling; Surface treatment: Sandblasting removes the oxide layer, passivation improves corrosion resistance, and dry film lubrication is applied to the surface. Depending on the situation, cetyl alcohol or paraffin can be applied to improve the lubrication effect during the riveting process.

[0052] S3. The manufacturing steps of the molded sleeve 300 include: Raw material selection: Grade 06Cr18Ni9 or 304, raw material condition is cold drawn; Turning: The turning structure includes the center hole of the forming sleeve, the countersunk hole 303 and the outer circle, and the two end faces.

[0053] Heat treatment: Annealing is performed at 1100℃ for 60 minutes, using gas cooling.

[0054] Surface treatment: Sandblasting removes the oxide layer, passivation improves its corrosion resistance, and a dry film is applied to the surface for lubrication.

[0055] S4. The bushing 400 is machined from POM (polyoxymethylene) tubing, including machining the inner hole, outer circle, and two end faces.

[0056] S5. The manufacturing steps of the mounting nut 500 include: Raw material selection: Low carbon steel of medium grade, raw material condition is cold drawn.

[0057] Turning: Turn the outer diameter of the hexagonal section 504, the outer diameter of the cylindrical section 503, the paint-containing countersunk hole 502, and the center threaded bottom hole; Tapping: Performing tapping operations on the center threaded hole.

[0058] Milling: Milling the hexagonal structure of the outer hexagonal segment of 504.

[0059] Surface treatment: nickel or zinc plating for rust prevention.

[0060] S6. The assembly process of the threaded pull pin is as follows: Material requisition: five components are requisitioned: 100 nail sleeves, 200 core rods, 300 forming sleeves, 400 bushings, and 500 mounting nuts; Turning: Turning the cut-off groove 233 on the mandrel 200; Assembly: Assemble the nail sleeve 100, forming sleeve 300, bushing 400 and mounting nut 500 onto the core rod 200; Closure: Clamp and close the forming sleeve 300 and nail sleeve 100; Performance: Perform performance testing on the component products as required.

[0061] Thirdly, this embodiment provides a method for installing threaded pull pins, in which the threaded pull pins are inserted into the mounting holes of the components to be connected, and the head of a rivet gun is placed on the nut 500 to be installed, and the core of the rivet gun clamps the clamping section 201 of the core rod 200. When the rivet gun is started, the nut 500 and the rivet sleeve 100 rotate relative to the axis of the core rod 200 and move downward along the axis of the core rod 200 until the limiting stage 220 can be inserted into the limiting hole 101. The core rod stop shoulder 222 and the rivet sleeve stop shoulder 102 abut against each other to form a limiting torque, causing the core rod 200 to break at the position of the cut-off groove 233.

[0062] Specifically, the riveting process is as follows: The rivet gun's core clamps onto the flat surface 234 of the core rod 200, and the gun head is mounted on the outer hexagonal section 504 of the mounting nut 500. When the rivet gun is started, the core rod 200 rotates clockwise. At this time, the rivet gun and the mounting nut 500 are relatively stationary. Under the action of the threaded engagement, the core rod 200 rotates relative to the mounting nut 500 while moving upwards. Simultaneously, the upward movement of the core rod 200 forces the forming sleeve 300 upwards. The bushing 400 within the forming sleeve 300 preferentially contacts and deforms with the rivet sleeve 100. The deformed bushing 400 then presses against the countersunk hole 303 of the forming sleeve 300, causing the forming sleeve 300 to deform radially outwards, creating a micro-bulge, laying the foundation for subsequent bulge formation.

[0063] As the molding sleeve 300 moves relative to the outer conical surface 103 of the nail sleeve 100, the nail sleeve 100, under the resultant force of the upward force of the molding sleeve 300, tends to move upward. However, the lower end face of the mounting nut 500 contacts the top surface of the nail sleeve 100 and generates friction. As the friction increases, the relative positions of the mounting nut 500 and the nail sleeve 100 remain unchanged, meaning that the mounting nut 500 and the nail sleeve 100 can be considered as a whole.

[0064] During the stage of the limiting platform 220, it is gradually inserted into the limiting hole 101. As the threaded pin is about to be riveted, the pin sleeve stop shoulder 102 on the pin sleeve 100 and the core rod stop shoulder 222 on the core rod 200 are about to contact. The riveting continues. After the pin sleeve stop shoulder 102 on the pin sleeve 100 contacts the core rod stop shoulder 222 on the core rod 200, a resistance torque is immediately generated. The greater the rotation angle of the core rod 200, the greater the resistance torque. The groove diameter 233 on the core rod 200 cannot provide a large torque, resulting in breakage. The structure after installation is shown in [reference needed]. Figure 9 and Figure 10 As shown.

[0065] In this embodiment, the core rod 200 is designed with a relief groove 231, which is mainly used to ensure that the nail sleeve stop shoulder 102 on the nail sleeve 100 can smoothly pass through the thread end of the second screw section 203 and contact the core rod stop shoulder 222 on the core rod 200.

[0066] In this embodiment, the upper end face 107 of the nail sleeve 100 is grooveless, which reduces the radar reflection area compared to a slotted nail sleeve, providing a better fastener for advanced stealth aircraft.

[0067] A limiting hole 101 and a nail sleeve stop shoulder 102 are designed on the nail sleeve 100, and a limiting platform stage 220 and a core rod stop shoulder 222 are designed on the core rod 200. When the product is installed and formed, the nail sleeve stop shoulder 102 immediately generates an interference torque with the core rod stop shoulder 222, and the core rod 200 immediately breaks from the cut-off groove 233, improving the consistency of the pull-nail riveting. In addition, in order to improve the stealth performance of the product during service, the upper end face 107 of the nail sleeve 100 is designed as a planar structure to reduce the echo intensity and reduce positive reflection.

[0068] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A threaded blind rivet, comprising a sleeve (100), a mandrel (200), a profiled sleeve (300), a bushing (400) and a mounting nut (500); the profiled sleeve (300) and the bushing (400) are sleeved on the mandrel (200), and the bushing (400) is embedded in the counterbore (303) of the profiled sleeve (300); the sleeve (100) and the mounting nut (500) are screwed on the mandrel (200); characterized in that: a threaded hole (104) and a limiting hole (101) are arranged in the center of the sleeve (100); the limiting hole (101) and the threaded hole (104) form a sleeve stop shoulder (102); the mandrel (200) comprises a clamping section (201), a first screw section (202), a second screw section (203), a limiting stage (220) and a mandrel head (210) from top to bottom; a diameter breaking groove (233) is arranged between the first screw section (202) and the second screw section (203); the top surface of the mandrel head (210) is arranged as an inverted conical surface and forms a conical groove (212); the top surface of the limiting stage (220) forms a mandrel stop shoulder (222); the lower end of the profiled sleeve (300) abuts against the conical groove (212); after riveting, the limiting stage (220) can be inserted into the limiting hole (101), and the mandrel stop shoulder (222) and the sleeve stop shoulder (102) abut against each other to form limiting. A paint accommodating counterbore (502) is arranged at the lower part of the central threaded hole of the mounting nut (500), and the diameter of the paint accommodating counterbore (502) is greater than the large diameter of the central threaded hole of the mounting nut (500); the paint accommodating counterbore (502) is used to accommodate dry film lubricant paint falling during installation. The top surface of the second screw section (203) is arranged as a plane, and the top surface of the second screw section (203) and the bottom end of the first screw section (202) are connected through an inverted cone (202a); the outer conical surface of the inverted cone (202a) and the top surface of the second screw section (203) jointly form the diameter breaking groove (233). After riveting, when the mandrel stop shoulder (222) and the sleeve stop shoulder (102) abut against each other to form limiting, the top plane of the second screw section (203) is not higher than the top surface of the sleeve (100).

2. Threaded pull according to claim 1, characterized in that After riveting, when the mandrel stop shoulder (222) and the sleeve stop shoulder (102) abut against each other to form limiting, the spacing between the top plane of the second screw section (203) and the top surface of the sleeve (100) is t, which satisfies: 0≤t≤0.5mm.

3. The threaded puller of claim 1, wherein, A tool withdrawal groove (231) is arranged between the lower end of the second screw section (203) and the limiting stage (220).

4. The threaded puller of claim 3, wherein, The method comprises the following steps: manufacturing the sleeve (100), the mandrel (200), the profiled sleeve (300), the bushing (400) and the mounting nut (500) respectively, and then assembling to obtain the threaded blind rivet according to any one of claims 1 to 6.

5. The threaded puller of claim 4, wherein, ​ 6. The threaded puller of claim 1, wherein, ​ 7. A method of manufacturing a threaded pull pin, characterized by ​ The manufacturing steps of the nail sleeve (100) include: blank by warm upsetting machine, then sand blasting, heat treatment, turning the shape and center step hole, tapping, surface treatment; The manufacturing steps of the core rod (200) include: blank by multi-station cold upsetting machine, then electroplating, grinding, wire drawing, heat treatment and surface treatment; The manufacturing steps of the forming sleeve (300) include: turning, heat treatment and surface treatment by using pipe material; The bushing (400) is turned by using pipe material; The manufacturing steps of the mounting nut (500) include: turning the shape and step inner hole, tapping, milling outer hexagon, surface treatment.

8. The production method according to claim 7, wherein The material of the nail sleeve (100) is TC4 or Ti6Al4V; the material of the core rod (200) is GH2132 or A286; the material of the forming sleeve (300) is 06Cr18Ni9 or 304; the material of the bushing (400) is polyformaldehyde.

9. The preparation method of claim 7, wherein, In the manufacturing steps of the nail sleeve (100), the heat treatment method is: solid solution and aging treatment, solid solution temperature 955℃, holding for 60 minutes, water cooling; aging temperature 540℃, holding for 360 minutes, furnace cooling; the surface treatment method is: surface fluorinated phosphate treatment, and coating with cetyl alcohol or paraffin on the surface; In the manufacturing steps of the core rod (200), the heat treatment method is: aging treatment, aging temperature (660-704)℃, holding for 960 minutes, gas cooling; the surface treatment method is: sand blasting and passivation treatment, surface coating with dry film lubricant; In the manufacturing steps of the forming sleeve (300), the heat treatment method is: annealing, annealing temperature 1100℃, holding for 60 minutes, gas cooling; the surface treatment method is: sand blasting and passivation treatment, surface coating with dry film lubricant; In the manufacturing steps of the mounting nut (500), the surface treatment is nickel plating or zinc plating.

10. A method of installing a threaded pull pin, characterized by, The method comprises: Inserting the threaded pull-out nail into the mounting hole of the component to be connected, using the gun head of the rivet gun to cover the mounting nut (500), and clamping the clamping section (201) of the core rod (200) by the gun core of the rivet gun; Starting the rivet gun, rotating the mounting nut (500) and the nail sleeve (100) relative to the axis of the core rod (200) while moving downward along the axial direction of the core rod (200) until the limiting step hole (220) can be inserted into the limiting hole (101), and the core rod stop shoulder (222) and the nail sleeve stop shoulder (102) abut against each other to form a limiting resistance moment, so that the core rod (200) is broken at the position of the diameter breaking groove (233).

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