阅读说明：本技术 一种密封型抽芯铆钉 (Sealed self-plugging rivet ) 是由 桂林景 张晓斌 唐伟 程艳红 王锴 刘小鹏 董敬 袁娅 于 2019-08-27 设计创作，主要内容包括：本发明提供一种密封型抽芯铆钉,在芯杆尾部套装有能够进行鼓包变形的管体,所述管体进行鼓包变形段的部分的外表面上设置有至少一个环形密封槽,所述环形密封槽内套设有第二密封圈,所述芯杆尾部设有能够对管体限位的限位台,所述管体与所述限位台之间套设有第一密封圈,所述第一密封圈外周还套设有垫片。本发明结构简单、便于安装、性能可靠且具有高度密封性能。(The invention provides a sealed self-plugging rivet, wherein a pipe body capable of bulging deformation is sleeved on the tail part of a core rod, at least one annular sealing groove is arranged on the outer surface of the part of the pipe body at the bulging deformation section, a second sealing ring is sleeved in the annular sealing groove, a limiting table capable of limiting the pipe body is arranged on the tail part of the core rod, a first sealing ring is sleeved between the pipe body and the limiting table, and a gasket is further sleeved on the periphery of the first sealing ring. The invention has simple structure, convenient installation, reliable performance and high sealing performance.)

1. The utility model provides a canned type self-plugging rivet, is equipped with body (2) that can carry out the swell deformation at core bar (1) afterbody cover, body (2) are provided with at least one ring seal groove (22) on the surface of the part of swell deformation section, ring seal groove (22) endotheca is equipped with second sealing washer (9), core bar (1) afterbody is equipped with can be to spacing platform (15) of body (2), body (2) with the cover is equipped with first sealing washer (8) between spacing platform (15), first sealing washer (8) periphery still overlaps and is equipped with gasket (7).

2. Sealed blind rivet according to claim 1, characterized in that a memory alloy expansion body (3) is provided between the portion of the tubular body (2) undergoing the bulging deformation section and the mandrel (1).

3. The sealed blind rivet according to claim 1, wherein a closing-up sealing groove (16) is formed in a section of the stem body of the core rod (1) adjacent to the limiting table (15), a section of the tube body (2) close to the limiting table (15) is matched with the closing-up sealing groove (16) to close up inwards, and the first sealing ring (8) is sleeved on a section of the closing-up sealing groove (16).

4. The blind rivet of the type defined in claim 1, wherein the end face of the tube (2) at the section deformed by bulging is an inclined face with a gradually decreasing outer radial end, on which the serrations (23) are provided.

5. Blind rivet of the sealed type according to claim 1, characterized in that said gasket (7) is of rigid material, preferably metal, and said first sealing ring (8) and second sealing ring (9) are of plastically deformable material, preferably rubber; the section of the gasket (7) and the section of the first sealing ring (8) are rhombic or rectangular, and the section of the second sealing ring (9) is circular.

6. The blind rivet of the type defined in claim 1, wherein the stem (1) is sheathed with a shank (4), a locking ring (5) and a thrust bush (6) in this order from the tubular body (2) onwards; the tail of the nail body (4) is provided with a conical surface (43) with gradually decreasing outer diameter, and the outer diameter of the end part of the conical surface (43) is slightly smaller than the inner diameter of the end part of the pipe body (2) adjacent to the conical surface.

7. The blind rivet of the type defined in claim 6, characterized in that the mandrel (1) is provided with a locking groove (13), the inner surface of the head of the shank (4) is provided with a tapered locking hole (41), and the locking hole (41) and the locking groove (13) can cooperate to form a wedge-shaped space for accommodating the locking ring (5); a blocking table (14) is arranged between the locking groove (13) and the limiting table (15) on the core rod (1), and a blocking step (42) capable of being matched with the blocking table (14) is arranged inside the nail body (4).

8. The sealed blind rivet according to claim 6, characterized in that the core rod (1) is of an elongated rod structure, the head part of the core rod is provided with a straight groove (11), and the middle part of the core rod is provided with a neck breaking groove (12) adjacent to and in front of the locking groove (13); the outer surface of the head of the nail body (4) is conical; the pushing and pressing bush (6) is fixed on the core rod (1), one end of a stepped hole with a large hole diameter is matched with the locking ring (5), and the pushing and pressing bush (6) can be sheared from the shearing part (61) and pushes the locking ring (5) to move towards the tail part of the core rod (1).

Technical Field

The invention relates to the technical field of fasteners, in particular to a sealed blind rivet.

background

In the design process of high-end equipment for aerospace, navigation and the like, the equipment is designed to be compact in structural design by considering the factors of volume and weight, the connection and installation space of structural members with compact design is narrow, and common bolt and nut fasteners cannot meet the installation requirements of occasions due to the fact that the common bolt and nut fasteners need to be installed on two sides. Therefore, riveting is generally adopted in the occasions where the installation space is narrow and double-sided operation is inconvenient. The riveting mode used at the structural joint is generally a self-plugging rivet, and the self-plugging rivet has the characteristics of light weight, more reliable connection, high strength, convenience and quickness in installation and the like, and is widely applied to various aerospace vehicles.

The currently used blind rivets can be mostly only used in atmospheric environment, and cannot be used or can only be used for structural connection of oil storage spaces in a short time due to the fact that the blind rivets do not have a sealing and corrosion-resistant function or have low sealing and corrosion-resistant grade, for example, the joints of certain oil tank structural members with narrow spaces cannot be basically used for structural single-side connection of the outer surface of a navigation or seabed deep submersible vehicle or an oil storage area.

Some self-plugging rivet connecting pieces are sealed in a mode of fully covering rubber at a riveting part, but because all rubber materials are exposed outside and are in direct contact with storage liquid such as oil and the like in a structural part, the rubber is easily and quickly corroded, and the sealing reliability is low; in addition, the rubber is enabled to continuously bear the axial pretightening force of the riveting structure after the riveting is finished due to the full-wrapping structure of the rubber, so that the rubber is continuously subjected to stress corrosion to further accelerate the breakage.

Disclosure of Invention

The invention aims to provide a sealing type self-plugging rivet which is simple in structure, convenient to install, reliable in performance and high in sealing performance.

According to the sealed self-plugging rivet, the tail of the core rod is sleeved with the pipe body capable of bulging deformation, the outer surface of the part of the pipe body at the bulging deformation section is provided with at least one annular sealing groove, the annular sealing groove is internally sleeved with a second sealing ring, the tail of the core rod is provided with a limiting table capable of limiting the pipe body, a first sealing ring is sleeved between the pipe body and the limiting table, and the periphery of the first sealing ring is further sleeved with a gasket. Through the structural design, the pipe body can successfully pass through the seal of the second sealing ring and the seal of the first sealing ring after the bulge deforms, the two sealing rings are not exposed to the outside while forming the seal, less pre-tightening force is borne, and the corrosion damage of the sealing rings under stress is avoided.

A memory alloy expansion body is arranged between the part of the tube body at the bulging deformation section and the core rod; a section of the rod body, adjacent to the limiting table, on the core rod is provided with a closing-in sealing groove, a section of the rod body, close to the limiting table, is matched with the closing-in sealing groove to close in, and the first sealing ring is sleeved on a section of the closing-in sealing groove; the end face of the pipe body bulging deformation section is an inclined plane with the outer radial end gradually decreasing, and insections are arranged on the inclined plane. Above-mentioned design has effectively improved seal structure's stability and reliability, makes sealed structure form more easily in the riveting installation on the one hand, avoids turning up, defect such as blind end footing structure is bad, and on the other hand can provide long-term continuous stable internal force, avoids because of the sealed inefficacy that reasons such as structure lax lead to.

The gasket is made of a rigid material, preferably metal, and the first sealing ring and the second sealing ring are made of plastic-easy materials, preferably rubber; the gasket and the first sealing ring are rhombic or rectangular in cross section, and the second sealing ring is circular in cross section.

The core rod is sleeved with a nail body, a locking ring and a pushing and pressing bushing in sequence from the pipe body to the front; the tail of the nail body is provided with a conical surface with gradually decreasing outer diameter, and the outer diameter of the end part of the conical surface is slightly smaller than the inner diameter of the end part of the pipe body adjacent to the conical surface.

Furthermore, a locking groove is formed in the core rod, a tapered locking hole is formed in the inner surface of the head of the nail body, and the locking hole and the locking groove can be matched to form a wedge-shaped space capable of accommodating a locking ring; the nail body is provided with a locking groove, a limiting table and a nail body, wherein the locking groove is arranged on the core rod, the limiting table is arranged between the locking groove and the nail body, and a blocking step which can be matched with the blocking table is arranged in the nail body.

Further, the core rod is of a slender rod structure, the head part of the core rod is provided with a straight groove, and the middle part of the core rod is provided with a neck breaking groove adjacent to the front part of the locking groove; the outer surface of the head of the nail body is conical; the pushing and pressing bushing is fixed on the core rod, one end of the stepped hole with the larger hole diameter is matched with the locking ring, and the pushing and pressing bushing can be sheared by the shearing part and pushes the locking ring to move towards the tail part of the core rod.

The sealed self-plugging rivet provided by the invention has the advantages of simple structure, convenience in installation, good sealing effect and sealing reliability, higher forming yield of a sealing structure and long-term stable sealing stability.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

Fig. 1 is a schematic view of the overall structure of an example of the present invention.

FIG. 2 is a schematic structural view of a core rod of the present invention.

Fig. 3 is a partially enlarged view of a portion a in fig. 2.

Fig. 4 is a structural schematic diagram of the nail body of the invention.

FIG. 5 is a schematic structural diagram of the memory alloy expansion body of the present invention.

Fig. 6 is a schematic structural view of the tube of the present invention.

Fig. 7 is a partially enlarged view of a portion B in fig. 6.

Fig. 8 is a schematic view of the structure of the gasket of the present invention.

Fig. 9 is a schematic structural view of the first seal ring of the present invention.

Fig. 10 is a schematic view of the structure of a second seal ring of the present invention.

Fig. 11 is a schematic view of the construction of the push bushing of the present invention.

Figure 12 is a schematic view of the structure of the locking ring of the present invention.

Fig. 13 is a schematic view of the structure of the present invention after completion of the rivet installation.

Fig. 14 is a partially enlarged view of a portion C in fig. 13.

Detailed Description

For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

An exemplary structure of the sealed blind rivet of the present invention is shown in fig. 1, and includes a mandrel 1, a tube 2, a memory alloy expansion body 3, a nail body 4, a locking ring 5, a pushing bush 6, a gasket 7, a first sealing ring 8 and a second sealing ring 9.

The core rod 1 (shown in figures 2-3) is of a slender rod structure, the head part of the core rod is provided with a straight groove 11, the middle part of the core rod is sequentially provided with a neck breaking groove 12, a locking groove 13 and a blocking platform 14 in an adjoining manner, the tail part of the core rod is provided with a limiting platform 15, and a section of the core rod adjacent to the limiting platform 15 is provided with a closing-up sealing groove 16. The straight thread groove 11 can increase the friction force between the core rod 1 and the riveter chuck, when the riveter works, the riveter chuck clamps the straight thread groove 11 under the action of high-pressure gas and pulls the core rod 1 backwards, and the straight thread enables the riveter chuck not to slip when clamping the core rod 1. The blocking table 14 can be matched with the blocking step 42 in the nail body 4, so that the axial displacement of the core rod 1 is limited, and the core rod 1 cannot be pulled continuously after being pulled to a target position. The locking groove 13 can be matched with the locking hole 41 of the nail body 4 to form a wedge-shaped space, and the locking ring 5 can be extruded into the wedge-shaped space during locking, so that the locking purpose is achieved. The neck breaking groove 12 is broken at the neck breaking groove 12 after the tensile force borne by the core rod 1 exceeds the strength of the core rod 1, after the axial displacement of the core rod is limited by the mutually matched blocking platform 14 and the blocking step 42, the rivet gun chuck clamps the core rod 1 and cannot move backwards and forwards continuously, the tensile force value exceeds the limit value borne by the neck breaking groove 12, and the neck breaking groove 12 is broken. Spacing platform 15 is used for spacing body 2 and gasket 7, borders on with spacing platform 15 and sets up binding off seal groove 16, and the body 2 binding off of being convenient for on the one hand does not take place the body and turns up at the riveting in-process through body 2 of binding off, and on the other hand is convenient for set up first sealing washer 8 and gasket 7.

The nail body 4 (figure 4) is sleeved on the core rod 1 adjacent to the pipe body 2, is a hollow rotary part, and is internally provided with a blocking step 42 used for being matched with the blocking table 14. The internal surface of the head of the nail body 4 is provided with a tapered locking hole 41 which is used for being matched with the locking groove 13 to form a wedge-shaped space, and the external surface of the head of the nail body 4 is also provided with a tapered locking hole which can be matched with a riveting hole of a to-be-riveted piece to form a countersunk head. The tail of the nail body 4 is provided with a conical surface 43 with gradually decreasing outer diameter, the outer diameter of the end part of the conical surface 43 is slightly smaller than the inner diameter of the end part of the pipe body 2 adjacent to the conical surface, and the pipe body 2 is driven to form bulge deformation in the installation process conveniently.

The tube body 2 (figure 6) is a hollow tubular part, a stepped hole 21 with a large aperture and capable of accommodating the memory alloy expansion body 3 is formed in the tube body, one end with a small aperture of the tube body 2 is matched with the closing-up sealing groove 16 of the core rod 1, and closing-up processing is performed in the assembling process. The outer surface of the step hole 21 is provided with at least one annular sealing groove 22 for being matched with a second sealing ring 9 to be placed, the section of the second sealing ring 9 is preferably circular, the end face of one end (the end adjacent to the nail body 4) where the step hole 21 is located is an inclined face with the outer radial end gradually decreasing, insections 23 (shown in figure 7) are arranged on the inclined face, and the insections are used for guiding the smooth generation of feet of the pipe body 2 after contacting with a mounting plate surface in the riveting process, so that the end face of the pipe body can not turn outwards after contacting with the mounting plate surface. In the riveting process, the pipe body 2 is under the squeezing action of the nail body 4 and the core rod 1, the larger end (the end of the step hole 21) of the aperture can begin to bulge along the conical surface 43 of the nail body to deform, and finally a footing can be formed on the deformed end plate surface, so that the purpose of compressing the connecting piece is achieved, and the second sealing ring 9 is compressed on the deformed end plate surface along with the deformation of the pipe body 2 to play a sealing role.

The memory alloy expansion body 3 (figure 5) is made of memory alloy materials, is made into a hollow thin-wall part at room temperature, deforms along with the bulging deformation of the pipe body 2, and has the trend function of recovering to the shape before deformation at room temperature or low temperature. The memory alloy expansion body 3 plays a role in filling the blind end footing of the pipe body 2, and after riveting is completed, due to elasticity and deformation restoring force of the memory alloy expansion body, the blind end footing can provide continuous and stable pressing force for the connected piece and the second sealing ring 9, sealing failure can be effectively prevented, and the second sealing ring 9 can be prevented from being exposed to the outside and being in direct contact with stored media (oil and the like).

Gasket 7 (fig. 8), first sealing washer 8 (fig. 9) and second sealing washer 9 (fig. 10) are the annular, and gasket 7 is the rigidity material (like the metal, can be the same with other metal parts such as body or the nail body of fastener material), and first sealing washer 8 and second sealing washer 9 are the changeability material of plasticity (like rubber). The gasket 7 and the first sealing ring 8 are diamond-shaped or rectangular in cross section. When the self-plugging rivet assembly is assembled, a first sealing ring 8 is firstly assembled at a position of a core rod closing-in sealing groove 16 at a certain temperature, a gasket 7 is then assembled on a core rod 1 and is arranged at the periphery of the first sealing ring 8, then the tube body 2, the memory alloy expansion body 3, the nail body 4 and other residual parts are installed, then the tube body 2 and the gasket 7 on the assembly are closed on a closing-in machine, the end part of the tube body 2 after closing-in is inwards sunken to be conical and is tightly wrapped at the position of the core rod closing-in sealing groove 16, the outer diameter and the inner diameter of the gasket 7 are reduced to a certain extent under the action of external force, so that the first sealing ring 8 is tightly pressed at the position of the closing-in sealing groove 16 of the core rod 1, and finally a second sealing ring 9 is installed at a position. Because the fastener riveting installation is accomplished the back, riveting piece inside has continuous axial pretightning force, the setting of gasket 7 can avoid making the pretightning force directly all apply to first sealing washer 8, consequently, gasket 7 has born most pretightning force and can effectively prevent that first sealing washer 8 from being damaged fast because of continuously bearing stress in the use, on the other hand makes first sealing washer 8 closely compress tightly and continuously play sealed effect, the third aspect makes first sealing washer 8 can not exposed in the outside and stored medium (fluid etc.) direct contact, avoid the external chemical corrosion to first sealing washer 8.

The locking ring 5 (fig. 12) is an annular ferrule, the push bush 6 (fig. 11) is a rotary part having a stepped hole therein, the push bush 6 is fixed to the mandrel 1, and one end of the stepped hole having a large diameter and the locking ring 5 are fitted to each other to accommodate the locking ring 5. During riveting, the pushing and pressing bush 6 can be subjected to the extrusion effect of the head of the riveter and the end face of the nail body 4, and when the extrusion force exceeds a certain limit value, the pushing and pressing bush 6 can be broken at the position of the step hole, so that the locking ring can be pushed into the wedge-shaped locking space. The locking ring 5 and the pushing bush 6 are effective means for realizing locking of the other side of the riveting hole in the existing design, but are not limited to the means, the main innovation point of the invention is locking seal on one side of bulge deformation, and various technical means for realizing locking in the prior art can be adopted on the other side, besides the forms of the locking ring 5 and the pushing bush 6 in the present case, the forms of the locking ring and the locking ring groove which are designed in advance in the nail body (such as CN201811239847.X and 201710466613.8), the forms of pushing the locking ring by knocking and other modes (such as 201610829426.7), the forms of locking by pushing the mandrel (such as 10825176.X), the forms of self-locking by the mandrel (such as 201610093542.7) and the like can be included.

The riveting process of the self-plugging rivet comprises the following steps:

Firstly, dip-coating the front half section of the assembled self-plugging rivet with sealant, and then inserting the self-plugging rivet into a riveting hole of a part to be riveted to enable the head of the rivet body 4 to tightly abut against an orifice of the riveting hole of the part to be riveted. Then the tail end of the core rod 1 is inserted into a gun head of a riveter, a push bush 6 of the self-plugging rivet is abutted by the end face of the gun head of the riveter, then a trigger of the riveter is pressed, the riveter clamps a straight groove 11 of the core rod 1 of the self-plugging rivet through a chuck in the gun head, the chuck clamps the core rod 1 to retreat under the action of air pressure, a supporting surface of a core rod limiting table 15 extrudes a gasket 7 in the retreating process of the core rod 1 and extrudes the end part of the tube body 2, so that the tube body 2 drives a memory alloy expansion body 3 to retreat, in the retreating process, one end of the tube body 2 and the memory alloy expansion body 3 close to the nail body 4 generate flaring (bulging) deformation along a tail conical surface 43 of the nail body 4, in the retreating process of the tube body 2, a flaring end can touch the surface of an element to be riveted, then the supporting surface of the limiting table 15 retreats to extrude the tube body 2, and the flaring end, and form the blind end footing 10 on the surface of the connecting piece step by step, the bearing surface of body 2 and gasket 7 and spacing platform 15 can be gradually pressed and stuck completely in this process, the first seal ring 8 can be compressed to the limited area and thus finish the self-sealing performance of the fastener head, because of the separation function of gasket 7, the pressure can not be all acted on the rubber seal ring, most of the pressure is transmitted to body 2 and core bar 1 through gasket 7, only a small part of pressure is transmitted to first seal ring 8, can compress first seal ring 8 to its own elastic range, thus while guaranteeing that the mechanical performance of the product after riveting does not drop, first seal ring 8 can not be destroyed under the pressure, thus guarantee the higher sealing grade and reliability of this product. In the process that the core rod is continuously retreated, the memory alloy expansion body 3 can fill the inner gap of the blind end foot 10 which is being formed through deformation, finally a large foot bulge can be formed at the blind end of the plate surface, the foot bulge is tightly pressed by the connecting piece, at the moment, the second sealing ring 9 is completely compressed to a limited area formed by the annular sealing groove 22 and the plate surface, so that the whole sealing effect of the fastening piece is completed, due to the partition effect of the annular sealing groove 22 on the pipe body, the pressure can not be completely and directly acted on the second sealing ring 9, most of the pressure is directly transmitted to the blind end foot and the connected piece, only a small part of the pressure is transmitted to the second sealing ring 9, the second sealing ring 9 can be compressed to the elastic range of the second sealing ring 9, and the second sealing ring 9 can not be damaged under the pressure effect while the mechanical property of a product after riveting is ensured not to be reduced, thereby ensuring higher sealing grade and reliability of the product.

When the core bar 1 retreats to the final position, that is, the blocking table 14 of the core bar 1 coincides with the blocking step 42 of the inner hole of the nail body 4, the core bar 1 cannot retreat continuously, at this time, the locking groove 13 of the core bar 1 and the locking hole 41 of the nail body 4 form a wedge-shaped space, the pushing and pressing bush 6 is cut off from the cutting part 61 by the riveter continuously pulling, the cut pushing and pressing bush 6 pushes the locking ring 5 to move to the wedge-shaped space, and finally the pushing and pressing deformation completely enters the wedge-shaped space, and in the process that the pulling force on the core bar 1 continuously increases, when the force value which can be borne by the core bar neck breaking groove 12 is exceeded, the core bar is broken from the neck breaking groove 12, thereby completing the riveting and locking.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.