Novel pulling nail and manufacturing method thereof

Abstract

The embodiment of the invention provides a novel drawing nail and a manufacturing method thereof. The novel pulling nail comprises a core rod, a nail sleeve and a locking ring. The core rod is provided with a rod body and a tail protrusion which are connected, and a first step facing the tail protrusion is arranged on the outer side wall of the rod body. And the locking ring is sleeved outside the rod body. The rod body is sleeved with the nail sleeve, the first end of the nail sleeve abuts against the tail protrusion, a second step opposite to the tail protrusion is arranged on the inner side wall of the second end of the nail sleeve, and the first step and the second step are configured to jointly limit a lock ring groove used for containing the lock ring so as to jointly limit axial movement of the lock ring. Therefore, the lock ring is locked in the lock ring groove by the first step and the second step, and the lock ring cannot fall off from the lock ring cavity even if the pulling nail is impacted, so that the riveting failure of the pulling nail is avoided, and the rivet can adapt to the working condition of a severe vibration environment.

Description

Technical Field

[0001] This invention relates to the field of fastener technology, and in particular to a novel pull pin and its manufacturing method. Background Technology

[0002] In the aviation field, aircraft and aerospace vehicles face stringent weight control requirements. To achieve weight reduction, composite materials are extensively used in components such as the fuselage and wing skin. Furthermore, the structures of aircraft fuselages and wing skins are generally compact and enclosed. Since ordinary bolts, nuts, and rivets require double-sided installation, they cannot meet the installation needs of aircraft. Therefore, single-sided fasteners are typically chosen to better meet the single-sided connection requirements of aircraft.

[0003] However, in the use of existing pull pins, the locking ring between the pin sleeve and the core rod may fall off when subjected to vibration, causing the pull pin connection to fail. Summary of the Invention

[0004] To address the problems mentioned in the background section or other similar issues, embodiments of the present invention provide a novel snap fastener and its manufacturing method.

[0005] One embodiment of the present invention provides a novel pull pin, comprising a core rod, a pin sleeve, and a locking ring. The core rod has a connected rod body and a tail protrusion, and a first step facing the tail protrusion is provided on the outer side wall of the rod body. The locking ring is fitted onto the rod body. The pin sleeve is fitted onto the rod body, with a first end of the pin sleeve abutting against the tail protrusion, and a second step facing away from the tail protrusion is provided on the inner side wall of the second end of the pin sleeve. The first step and the second step are configured to jointly define a locking ring groove for receiving the locking ring, thereby jointly restricting the axial movement of the locking ring.

[0006] Optionally, the outer wall of the rod has a tapered outer surface, which is located on the side of the first step facing the tail, and the diameter of the tapered outer surface gradually decreases towards the first step. The inner wall of the second end of the nail sleeve has a tapered inner surface, which is located on the side of the second step facing the tail, and the diameter of the tapered inner surface gradually decreases towards the second step. When the tapered outer surface and the tapered inner surface are in contact, the first step and the second step together define the locking ring groove and retain the locking ring within the locking ring groove.

[0007] Optionally, the conical outer surface is parallel to the conical inner surface.

[0008] Optionally, the outer surface of the locking ring is a first inclined surface, which is parallel to the inner surface of the cone; and / or, the inner surface of the locking ring is a second inclined surface, which is parallel to the outer surface of the cone.

[0009] Optionally, a necking groove is provided on the outer wall of the rod, and the necking groove is located on the side of the first step opposite to the tail protrusion.

[0010] Optionally, the necking groove has an initial position relative to the rivet sleeve, at a predetermined distance from the end face of the second end of the rivet sleeve, and a fracture position flush with the end face of the second end of the rivet sleeve. When the necking groove is in the initial position, the first step and the locking ring are located on the side of the second step facing the tail protrusion. When the necking groove is in the fracture position, the first step is located on the side of the second step away from the tail protrusion, and the first step and the second step together define the locking ring groove and retain the locking ring within the locking ring groove.

[0011] Optionally, the locking ring is a C-shaped ring with an expandable diameter.

[0012] Optionally, the step surface of the first step and the step surface of the second step are both perpendicular to the axial direction of the core rod.

[0013] Another embodiment of the present invention provides a novel method for manufacturing a pull pin, the method comprising the following steps: forming a core rod, forming a pin sleeve, and forming a locking ring. The step of forming the core rod includes: providing a core rod blank; processing the core rod blank using a cold heading machine or a warm heading machine to obtain a core rod semi-finished product having the tail protrusion and the rod body; removing dirt and coating from the surface of the core rod semi-finished product; and performing thread rolling on the core rod semi-finished product to machine a first step on the outer surface of the rod body. The step of forming the pin sleeve includes: providing a pin sleeve blank; processing the pin sleeve blank using a cold heading machine or a warm heading machine to obtain a pin sleeve semi-finished product; and machining a second step on the inner surface of the pin sleeve semi-finished product.

[0014] Optionally, the step of forming the core rod further includes: heat-treating the core rod semi-finished product by means of aging heat treatment; and surface-treating the core rod semi-finished product to obtain the core rod finished product.

[0015] The locking ring groove of the novel pull pin in this embodiment of the invention can firmly hold the locking ring inside it. Even if the pull pin is impacted, the locking ring will not fall out of the locking ring cavity, thereby avoiding pull pin riveting failure and adapting to harsh working conditions with vibration. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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 these drawings without creative effort. In the drawings:

[0017] Figure 1 This is a schematic diagram of the novel pull pin in its initial state according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the novel pull pin in the working state according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of the core rod structure in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the nail sleeve structure in an embodiment of the present invention;

[0021] Figure 5 This is a front view of the locking ring in an embodiment of the present invention;

[0022] Figure 6 This is a side view of the locking ring in an embodiment of the present invention. Detailed Implementation

[0023] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] An embodiment of the first aspect of the present invention provides a novel pull pin. The novel pull pin includes a core rod, a pin sleeve, and a locking ring. The core rod has a connected rod body and a tail protrusion, and a first step facing the tail protrusion is provided on the outer side wall of the rod body. The locking ring is fitted onto the rod body. The pin sleeve is fitted onto the rod body, with a first end abutting against the tail protrusion, and a second step facing away from the tail protrusion is provided on the inner side wall of the second end of the pin sleeve. The first and second steps are configured to jointly define a locking ring groove for receiving the locking ring, thereby jointly restricting the axial movement of the locking ring. Thus, the locking ring is locked within the locking ring groove by the first and second steps, and even if the pull pin is impacted, the locking ring will not dislodge from the locking ring cavity, thereby preventing pull pin riveting failure and enabling it to adapt to harsh vibration environments.

[0025] The embodiments of this application will now be described with reference to the accompanying drawings.

[0026] Figure 1This is a schematic diagram of the novel pull pin in its initial state according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the novel pull pin in working condition according to an embodiment of the present invention.

[0027] like Figure 1 and Figure 2 As shown, the new type of pull pin includes a core rod 100, a pin sleeve 200, and a locking ring 300.

[0028] like Figure 1 and Figure 3 As shown, the core rod 100 includes a rod body 101 and a tail protrusion 102 connected to each other. The rod body 101 extends from the tail protrusion 102 along the pulling direction W to the end of the rod body 110. The rod body 101 and the tail protrusion 102 can be an integral structure. The diameter of the tail protrusion 102 is larger than the diameter of the rod body 101. A stepped surface 103 is formed between the tail protrusion 102 and the rod body 101.

[0029] like Figure 1 and Figure 3 As shown, the rod body 101 includes a first rod segment 1011 and a second rod segment 1012. A boss 1017 is provided on the outer wall of the first rod segment 1011, and the boss 1017 is spaced apart from the tail protrusion 102. A necking groove 1014 is provided between the first rod segment 1011 and the second rod segment 1012. Exemplarily, the necking groove 1014 is an annular groove surrounding the centerline of the rod body 101, and the cross-sectional shape of the necking groove 1014 is triangular.

[0030] like Figure 1 and Figure 3 As shown, the outer wall of the first rod segment 1011 has a first step 1013 and a conical outer surface 1015. The first step 1013 has a step surface 1016 facing away from the neck groove 1014 (i.e., towards the tail protrusion 102). The conical outer surface 1015 is located on the side of the first step 1013 facing the tail protrusion 102. The conical outer surface 1015 extends to the step surface 1016 along the drawing direction W, and the diameter of the conical outer surface 1015 gradually decreases along the drawing direction W. The conical outer surface 1015 and the step surface 1016 together form an annular receiving groove 120 for receiving the locking ring 300.

[0031] like Figure 1 and Figure 3 As shown, the outer wall of the second rod segment 1012 is provided with an outer ring groove, which cooperates with the inner ring groove of the installation tool (such as an installation gun) so that the installation tool can pull the core rod 100 to move in the pulling direction W.

[0032] like Figure 1 and Figure 4As shown, the rivet sleeve 200 has a sleeve body 201 and a head protrusion 202. The sleeve body 201 extends from the head protrusion 202 in a direction opposite to the pulling direction W to the sleeve end 210. The sleeve body 201 and the head protrusion 202 can be an integral structure. The sleeve end 210 serves as the first end of the rivet sleeve 200 and is used to abut against the stepped surface 103 of the tail protrusion 102 of the core rod 100. The head protrusion 202 serves as the second end of the rivet sleeve 200 and is used to cooperate with the rod body 101 of the core rod 100 to achieve riveting and locking.

[0033] like Figure 1 and Figure 4 As shown, the outer diameter of the head protrusion 202 is larger than the outer diameter of the sleeve 201. A step surface 203 is formed at the transition connection between the head protrusion 202 and the sleeve 201. This step surface 203 is also the lower end surface of the head protrusion 202.

[0034] like Figure 1 and Figure 4 As shown, the inner wall of the head protrusion 202 has a second step 2021 and a conical inner surface 2022. The second step 2021 has a step surface 2023 facing away from the tail protrusion 102. The conical inner surface 2022 is located on the side of the second step 2021 facing the tail protrusion 102. The inner diameter of the conical inner surface 2022 gradually decreases along the drawing direction W.

[0035] Preferably, the conical inner surface 2022 is parallel to the conical outer surface 1015, so that the two can fit together and form surface contact. The conical inner surface 2022 of the rivet sleeve 200 not only guides the movement of the locking ring 300 in the pulling direction W, but also axially limits the movement of the core rod 100 in the pulling direction W.

[0036] Optionally, the conical inner surface 2022 may extend along the drawing direction W to the step surface 2023, or extend along the drawing direction W to the cylindrical inner surface 2024 of the second step 2021, which is connected to and perpendicular to the step surface 2023.

[0037] Optionally, the step surface 1016 of the first step 1013 and the step surface 2023 of the second step 2021 are both perpendicular to the axial direction of the core rod 100, thereby providing a more reliable limit for the locking ring 300.

[0038] like Figure 5 and Figure 6As shown, the locking ring 300 is a non-closed ring, that is, the locking ring 300 has an opening 303, so that the locking ring 300 is approximately C-shaped. The diameter of the C-shaped locking ring 300 can expand and contract, making it easy to fit onto the rod 101. Optionally, the outer surface 301 of the locking ring 300 is an inclined surface parallel to the conical inner surface 2022 of the nail sleeve 200, and / or, the inner surface 302 of the locking ring 300 is an inclined surface parallel to the conical outer surface 1015 of the core rod 100. Thus, the locking ring 300 can more easily slide along the conical inner surface 2022 of the nail sleeve 200 to above the second step 2021 under the push of the core rod 100.

[0039] For example, the locking ring 300 is made of a high-temperature alloy, such as a high-temperature alloy of grade GH2132 (A286).

[0040] Figure 1 This shows the initial, assembled but not riveted state of the rivet sleeve 200 and the core rod 100. Figure 1 As shown, the rivet 200 is fitted onto the rod body 101 of the core rod 100. The end 210 of the rivet 200 abuts against the stepped surface 103 of the tail protrusion 102 of the core rod 100. The locking ring 300 is fitted onto the conical outer surface 1015 of the core rod 100. The first step 1013, the neck groove 1014, and the locking ring 300 are located on the side of the second step 2021 facing the tail protrusion 102 (i.e., Figure 1 Below the second step 2021, the axial distance between the conical inner surface 2022 and the conical outer surface 1015 is a preset distance L, and the distance between the neck groove 1014 and the upper end face 2025 of the head protrusion 202 is also a preset distance L. This position of the neck groove 1014 is its initial position.

[0041] The riveting method using the tapped pins of this application is as follows:

[0042] First, Figure 1 The assembly shown is inserted into the connection hole 501 of the component to be connected 500 (e.g., Figure 2 As shown), the stepped surface 203 of the head protrusion 202 of the nail sleeve 200 sits on the upper end surface 502 of the part to be connected 500.

[0043] Then, the installation tool is fitted onto the second rod segment 1012 of the core rod 100, so that the inner ring groove of the installation tool matches the outer ring groove of the second rod segment 1012, and the end face of the installation tool abuts against the upper end face 2025 of the nail sleeve 200.

[0044] Then, the installation tool is activated, pulling the core rod 100 so that it moves relative to the rivet sleeve 200 in the pulling direction W. During this process, the tail protrusion 102 of the core rod 100 drives the tail of the rivet sleeve 200 to move synchronously, causing the tail of the rivet sleeve 200 to bulge at the lower end face 503 of the part to be connected, forming a riveting protrusion 220. At the same time, the locking ring 300 moves upward along the conical inner surface 2022 of the rivet sleeve 200 under the push of the core rod 100 (during this process, the locking ring 300 is in a contracted state and squeezed in the receiving groove 120 formed by the conical outer surface 1015 and the stepped surface 1016). When the conical outer surface 1015 and the conical inner surface 2022 are in contact... During the bonding process, the core rod 100 moves a preset distance L along the pulling direction W and can no longer move. At this time, the locking ring 300, the neck break groove 1014, and the first step 1013 move to the top of the second step 2021, and the neck break groove 1014 is also flush with the upper end face 2025 of the head protrusion 202 (this is the breakage position of the neck break groove 1014). At this time, the locking ring groove 400 between the first step 1013 and the second step 2021 is also formed simultaneously. The locking ring 300 is locked in the locking ring groove 400 by the first step 1013 and the second step 2021. Then the core rod 100 breaks at the neck break groove 1014, and the riveting process ends.

[0045] Figure 2 The riveting state (i.e., working state) of the new type of pull pin is shown. For example... Figure 2 As shown, in the riveting state, the part to be connected 500 is fixed between the head protrusion 202 and the riveting protrusion 220 of the rivet sleeve 200. The upper end face of the locking ring 300 abuts against the step surface 1016 of the first step 1013, and the lower end face of the locking ring 300 abuts against the step surface 2023 of the second step 2021. Thus, the locking ring 300 is held in the locking ring groove 400 by the first step 1013 and the second step 2021. Even if the rivet is vibrated, the locking ring 300 will not fall off, thereby avoiding riveting failure and improving riveting reliability.

[0046] A second aspect of the present invention provides a method for manufacturing a novel pull pin, the method comprising the following steps:

[0047] Step S100: Forming the core rod 100;

[0048] Step S200: Molding nail sleeve 200;

[0049] Step S300: Forming the locking ring 300.

[0050] In some embodiments, step S100 includes:

[0051] Step S110: Provide mandrel blank; for example, select GH2132 high-temperature alloy or TB9 titanium alloy wire with appropriate specifications and lubrication coating as mandrel blank;

[0052] Step S120: The mandrel blank is processed using a cold heading machine or a warm heading machine to obtain a semi-finished mandrel with a tail protrusion 102 and a rod body 101 (i.e., the upsetting forming step); for example, the selected wire is upset in a four-die cold heading machine to obtain a semi-finished mandrel.

[0053] Step S130: Remove contaminants and coatings from the surface of the core rod semi-finished product (i.e., coating removal step), for example, by placing the core rod semi-finished product into a vibratory mill and pickling line for processing to remove surface contaminants and raw material copper plating generated during forging; and

[0054] Step S140: The core rod semi-finished product is threaded to process the first step 1013 and the neck groove 1014 on the outer surface of the rod body 101 (i.e., the thread rolling step).

[0055] Optionally, step S100 further includes:

[0056] Step S150: Heat treatment of the mandrel semi-finished product by means of aging heat treatment (i.e. heat treatment step); for example, for GH2132 high temperature alloy wire, the cleaned mandrel semi-finished product can be placed in a vacuum aging furnace, heated with the furnace, and subjected to aging heat treatment at 600℃~700℃ for 8h~16h, and then cooled with the furnace.

[0057] Step S160: Perform surface treatment on the core rod semi-finished product to obtain the core rod finished product (i.e., surface treatment step); for example, passivate or coat the core rod semi-finished product with molybdenum disulfide on an automatic coating machine, and the thickness of the coated molybdenum disulfide coating can be 3μm to 12μm.

[0058] In some embodiments, step S200 includes:

[0059] Step S210: Provide the rivet blank; for example, select coated high-temperature alloy GH2132 or industrial pure titanium TA1G coiled wire;

[0060] Step S220: Process the nail sleeve blank using a cold heading machine or a warm heading machine to obtain a semi-finished nail sleeve (i.e., the upsetting forming step). For example, the selected wire material is formed in one step in a six-die cold heading machine using a forming die to shape the sleeve body 201 and the head protrusion 202; and

[0061] Step S230: Machining a second step 2021 (i.e. turning step) on the inner surface of the nail sleeve semi-finished product.

[0062] In some embodiments, step S300 includes:

[0063] Step S310: Material preparation;

[0064] Step S320: Coil;

[0065] Step S330: Passivation treatment.

[0066] The above description is merely an embodiment of this specification and is not intended to limit this specification. Various modifications and variations can be made to this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of the claims of this specification.

Claims

1. A novel type of pull pin, characterized in that, include: A core rod having a connected rod body and a tail protrusion, wherein the outer side wall of the rod body is provided with a first step toward the tail protrusion; A locking ring, which is fitted onto the outside of the rod; A rivet sleeve is fitted over the rod body. The first end of the rivet sleeve abuts against the tail protrusion. The inner sidewall of the second end of the rivet sleeve is provided with a second step facing away from the tail protrusion. The first step and the second step are configured to jointly define a locking ring groove for accommodating the locking ring, so as to jointly restrict the axial movement of the locking ring.

2. The novel pull pin according to claim 1, characterized in that, The outer wall of the rod has a tapered outer surface, which is located on the side of the first step facing the tail, and the diameter of the tapered outer surface gradually decreases toward the first step; The inner wall of the second end of the nail sleeve has a tapered inner surface, which is located on the side of the second step facing the tail protrusion, and the diameter of the tapered inner surface gradually decreases towards the second step; With the outer conical surface abutting against the inner conical surface, the first step and the second step together define the locking ring groove and retain the locking ring within the locking ring groove.

3. The novel pull pin according to claim 2, characterized in that, The outer conical surface is parallel to the inner conical surface.

4. The novel pull pin according to claim 2, characterized in that, The outer surface of the locking ring is a first inclined surface, which is parallel to the inner surface of the conical shape; and / or The inner surface of the locking ring is a second inclined surface, which is parallel to the outer surface of the cone.

5. The novel pull pin according to any one of claims 1 to 4, characterized in that, The outer wall of the rod is provided with a neck break groove, which is located on the side of the first step opposite to the tail protrusion.

6. The novel pull pin according to claim 5, characterized in that, The neck groove has an initial position relative to the nail sleeve that is at a preset distance from the end face of the second end of the nail sleeve, and a fracture position that is flush with the end face of the second end of the nail sleeve. With the neck break groove in the initial position, the first step and the locking ring are located on the side of the second step facing the tail protrusion; When the neck groove is located at the fracture position, the first step is located on the side of the second step opposite to the tail protrusion, and the first step and the second step together define the locking ring groove and retain the locking ring in the locking ring groove.

7. The novel pull pin according to any one of claims 1 to 4, characterized in that, The locking ring is a C-shaped ring with an expandable diameter.

8. The novel pull pin according to any one of claims 1 to 4, characterized in that, The step surface of the first step and the step surface of the second step are both perpendicular to the axial direction of the core rod.

9. A method for manufacturing a novel pull pin according to any one of claims 1 to 8, characterized in that, The manufacturing method includes the following steps: Forming the core rod includes: Provide core rod blanks; The core rod blank is processed using a cold heading machine or a warm heading machine to obtain a core rod semi-finished product having the tail protrusion and the rod body; Remove dirt and coating from the surface of the semi-finished core rod; and The core rod semi-finished product is threaded to form a first step on the outer surface of the rod body; Forming the nail sleeve includes: Provide nail sleeve blanks; The nail sleeve blank is processed using a cold heading machine or a warm heading machine to obtain a semi-finished nail sleeve; and A second step is machined on the inner surface of the nail sleeve semi-finished product; and The locking ring is formed.

10. The method for manufacturing the novel pull pin according to claim 9, characterized in that, The molding of the core rod further includes: The core rod semi-finished product is heat-treated by aging heat treatment. The core rod semi-finished product is subjected to surface treatment to obtain the core rod finished product.

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