High-temperature-resistant sealing type self-plugging rivet

Abstract

The invention provides a high-temperature-resistant sealing type self-plugging rivet. The high-temperature-resistant sealing type self-plugging rivet comprises a core rod, a locking sealing nut, a rivet sleeve, a locking ring and a pushing and pressing lining. One end of the core rod is mounted in the riveter chuck, and the other end of the core rod is provided with a blocking step; the core rod is sleeved with the nail sleeve, a local annealing belt is arranged in the middle of the nail sleeve, a cone and a ring which are matched with each other are arranged between the nail sleeve and the core rod, the end of the ring abuts against the blocking step, the nail sleeve and the core rod are assembled in a rolling forming mode, and the locking sealing nut is arranged on the nail sleeve; a locking taper hole is formed in the other end of the nail sleeve, the locking taper hole and a locking groove formed in the core rod are matched to form a wedge-shaped space, the core rod is sleeved with the locking ring and the pushing and pressing bush, the locking ring is arranged in the pushing and pressing bush, and the pushing and pressing bush is broken so that the locking ring can be extruded and deformed to enter the wedge-shaped space. The high-temperature-resistant rivet has the advantages of being resistant to high temperature, high in sealing performance, wider in applicable interlayer range and larger in clamping force, and the defects of an existing rivet in high sealing requirement, high-temperature environment and high-strength application are effectively overcome.

Description

Technical Field

[0001] The present application belongs to the technical field of fasteners, and in particular relates to a high temperature resistant sealed blind rivet. Background Art

[0002] In the design process of high-end equipment such as aerospace, the structural design is generally compact in consideration of volume and weight. The connection and installation space of these compact structural parts is relatively small. Ordinary bolt and nut fasteners cannot meet the installation requirements of these occasions because they need to be installed on both sides. Therefore, riveting is generally used in these occasions where the installation space is relatively small and it is not convenient to operate on both sides. The riveting method used in the structural connection is generally blind rivets. Blind rivets have the characteristics of light weight, more reliable connection, high strength, and convenient and quick installation. They have been widely used in various types of aerospace vehicles.

[0003] At present, most of the blind rivets in use are pull-type and thread-type blind rivets. Such existing blind rivets are generally composed of a rivet sleeve, a core rod and other additional parts. The blind end bulge is completely formed by the single bulge of the rivet sleeve. It has the disadvantages of small preload force and poor sealing, and can only be used under normal temperature conditions. For general mechanical connection occasions, the existing blind rivets have basically met the assembly requirements of the product. However, in some special occasions, such as occasions with stricter requirements on preload force, single-sided connection occasions with higher requirements on air tightness, and high-temperature working areas such as the outer surface skin of hypersonic aircraft and the tail nozzle of the engine, it is difficult for the existing blind rivets to meet the strength requirements and use requirements. Summary of the invention

[0004] In view of this, the present application aims to provide a high temperature resistant sealed blind rivet to solve at least one of the above problems.

[0005] To achieve the above purpose, the technical solution of this application is implemented as follows: The present application provides a high temperature resistant sealed blind rivet, comprising a core rod, a locking sealing nut, a nail sleeve, a locking ring and a pushing bushing; One end of the core rod is installed in the chuck of the riveting gun, and the other end of the core rod is provided with a blocking step; The nail sleeve is sleeved on the core rod, a local annealing zone is provided in the middle of the nail sleeve, a matching cone and an annulus are installed between the nail sleeve and the core rod, the end of the annulus abuts against the blocking step, the nail sleeve and the core rod are assembled by roll forming, the locking sealing nut is provided on the nail sleeve, and is used to lock the core rod and the nail sleeve, and under the extrusion of the blocking step and the locking sealing nut, the annulus expands and deforms along the conical surface of the cone to squeeze the local annealing zone to produce a bulging deformation; The other end of the nail sleeve is provided with a locking cone hole, and the locking cone hole cooperates with the locking groove provided on the core rod to form a wedge-shaped space. The locking ring and the pushing bushing are sleeved on the core rod, and the locking ring is installed in the pushing bushing. In response to squeezing the pushing bushing, the pushing bushing breaks, so that the locking ring is squeezed and deformed to enter the wedge-shaped space; The core rod is controlled to break from the breaking neck groove arranged thereon to complete the riveting and locking.

[0006] Furthermore, the locking sealing nut is a blind hole nut, the hole entrance of which is a straight arm section, and a sealing groove is provided at the bottom of the inner hole, and a sealing gasket is installed in the sealing groove.

[0007] Furthermore, the core rod has a thread on its head, the nail sleeve is a hollow rotary structural member with a stepped hole inside, and one end of the nail sleeve close to the local annealing zone is assembled with the thread of the core rod by rolling forming.

[0008] Furthermore, the cone is a hollow cone rotating structure, one end of the ring is provided with an inner cone surface matching with the outer cone surface provided on the cone, and the cone and the ring are matched and installed in the step hole of the nail sleeve.

[0009] Furthermore, the push bushing is a rotating structural member with a step hole opened inside, and the locking ring is installed at the end of the step hole with a larger aperture. In response to the extrusion force exceeding a limit value, the push bushing breaks at the position of the step hole to push the locking ring into the wedge-shaped locking hole.

[0010] Furthermore, an annular groove is provided on the core rod for interference fit with the inner hole of the push bushing.

[0011] Furthermore, the ring is made of special memory alloy material, and its hardness is between 110HV and 150HV.

[0012] Compared with the prior art, the high temperature resistant sealed blind rivet described in this application has the following beneficial effects: The high-temperature resistant sealed core-pulling rivet described in the present application is coordinated with structural parts such as a core rod, a locking sealing nut and a rivet sleeve, and has the characteristics of high temperature resistance, high sealing, a wider range of applicable interlayers, and greater clamping force. It can effectively solve the shortcomings of existing rivets in high sealing requirements, high temperature environments and high-strength applications, and has very broad prospects in high-end assembly fields such as aerospace, especially in applications involving complex connections and extreme working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is a cross-sectional view of the assembly of a high temperature resistant sealed blind rivet according to an embodiment of the present application; Figure 2 This is a schematic diagram of the core rod structure described in an embodiment of the present application; Figure 3 A cross-sectional view of a locking sealing nut and a sealing gasket according to an embodiment of the present application; Figure 4 A cross-sectional view of a nail sleeve according to an embodiment of the present application; Figure 5 A cross-sectional view of a locking ring and a push bushing according to an embodiment of the present application; Figure 6 A cross-sectional view of the cone and the ring described in the embodiment of the present application; Figure 7 This is a diagram of the riveting effect described in the embodiment of the present application.

[0014] Description of reference numerals: 1-core rod; 11-thread; 12-blocking step; 13-locking groove; 14-neck breaking groove; 15-circlip groove; 16-straight ring groove; 2-locking sealing nut; 3-nail sleeve; 31-local annealing belt; 32-locking cone hole; 4-locking ring; 5-push bushing; 6-cone; 7-ring; 8-sealing gasket. DETAILED DESCRIPTION

[0015] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0016] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The words "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprises" and other similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but can be Including electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0017] See also Figure 1 As shown, this embodiment provides a high temperature resistant sealed blind rivet, comprising a core rod 1, a locking sealing nut 2, a nail sleeve 3, a locking ring 4 and a pushing bushing 5; One end of the core rod 1 is installed in the chuck of the riveting gun, and the other end of the core rod 1 is provided with a blocking step 12; The nail sleeve 3 is sleeved on the core rod 1, and a local annealing band 31 is provided in the middle of the nail sleeve 3. A matching cone 6 and a ring 7 are installed between the nail sleeve 3 and the core rod 1. The end of the ring 7 abuts against the blocking step 12. The nail sleeve 3 and the core rod 1 are assembled by roll forming. The locking sealing nut 2 is arranged on the nail sleeve 3 to lock the core rod 1 and the nail sleeve 3. Under the extrusion of the blocking step 12 and the locking sealing nut 2, the ring 7 expands and deforms along the conical surface of the cone 6 to squeeze the local annealing band 31 to produce a bulging deformation; The other end of the nail sleeve 3 is provided with a locking cone hole 32, and the locking cone hole 32 cooperates with the locking groove 13 provided on the core rod 1 to form a wedge-shaped space. The locking ring 4 and the pushing bushing 5 are sleeved on the core rod 1, and the locking ring 4 is installed in the pushing bushing 5. In response to squeezing the pushing bushing 5, the pushing bushing 5 breaks, so that the locking ring 4 is squeezed and deformed into the wedge-shaped space; The control core rod 1 is broken from the neck breaking groove 14 provided thereon, and the riveting and locking is completed.

[0018] In this embodiment, except for the push bushing 5, all other sub-parts are made of high-temperature resistant high-temperature alloy materials. The product is riveted on the skin surface of the hypersonic aircraft or the high-temperature area of ​​the tail nozzle of the engine, and can meet the long-term service under high-temperature conditions below 600°C. Among them, the ring 7 is made of high-temperature resistant special memory alloy material, and its hardness is between 110HV-150HV. Compared with the hardness of the nail sleeve 3, its hardness is lower, which can be conducive to forming. During the riveting process, it will be squeezed by the core rod 1 blocking step 12 and cone 6, so that it will be deformed until it is completely deformed, playing a filling role. After extrusion deformation, its hardness will be increased to between 200-250HV, which can further improve the strength of the rivet body; this material also has a significant characteristic that after the ambient temperature exceeds 400°C, it will have a tendency to return to the undeformed state. Since it is filled in the bulge foot composed of the nail sleeve 3 and the core rod 1, it will further increase the clamping force of the blind end bulge foot, and improve the service performance of the rivet body under high temperature conditions.

[0019] The high temperature resistant sealed core-pulling rivet described in this embodiment is coordinated with structural parts such as a core rod 1, a locking sealing nut 2 and a rivet sleeve 3, and has the characteristics of high temperature resistance, high sealing, a wider applicable interlayer range and a larger clamping force. It can effectively solve the shortcomings of existing rivets in high sealing requirements, high temperature environments and high-strength applications, and has very broad prospects in high-requirement fields such as aerospace, automobile engines, etc., especially in applications involving complex connections and extreme working environments.

[0020] like Figure 2 As shown, the core rod 1 is a slender rod structure, on which are provided a straight ring groove 16, a snap ring groove 15, a neck-breaking groove 14, a locking groove 13 and a blocking step 12. The specific explanation is as follows: The purpose of the straight ring groove 16 is to increase the friction between the core rod 1 and the rivet gun chuck. When the rivet gun is working, the rivet gun chuck clamps the straight part of the core rod 1 under the action of high-pressure gas and pulls the core rod 1 backward. The straight groove prevents the rivet gun chuck from slipping when clamping the core rod 1. The purpose of the snap ring groove 15 is to assemble the push bushing 5 together by interference fit during final assembly, so that it will not become loose during storage and transportation before the product is riveted for use.

[0021] The function of the blocking step 12 is to cooperate with the cone 6 and the blocking step 12 inside the nail sleeve 3 to limit the axial displacement of the core rod 1, so that the core rod 1 cannot be pulled further after being pulled to the corresponding position.

[0022] The locking groove 13 is used in conjunction with the locking hole of the nail sleeve 3. After the core rod 1 is pulled to the position, a wedge-shaped space will be formed between the core rod 1 and the nail body. The locking ring 4 will be squeezed into the wedge-shaped space under the pushing action of the sheared pushing bushing 5, thereby achieving the purpose of locking.

[0023] The function of the breaking neck groove 14 is to cause the core rod 1 to break at the breaking neck groove 14 when the tensile force it bears exceeds the strength of the core rod 1. After the axial displacement of the core rod 1 is restricted by the two blocking steps 12, the rivet gun chuck clamps the core rod 1 and cannot move further backward. When the tensile force value exceeds the limit value that the breaking neck groove 14 can withstand, it will break.

[0024] The purpose of providing the thread 11 on the head of the core rod 1 is to lock the nail sleeve 3 and the core rod 1 together by locking the sealing nut 2 to form a complete whole.

[0025] like Figure 3 As shown, the locking sealing nut 2 is a blind hole nut, and a section of the hole entrance is free of threads 11, which is a straight arm section. The size of the preload force can be controlled during riveting. The blind hole nut has a high overall hardness and is approximately a rigid body. There is a sealing groove at the bottom of the inner hole for placing a metal sealing gasket 8. The metal sealing gasket 8 is as shown in FIG. Figure 3 As shown, it is made of soft metal.

[0026] During assembly, when the locking sealing nut 2 is screwed into the external threads 11 of the core rod 1 and the nail sleeve 3, when it is screwed to the bottom, the end surface of the thread 11 of the core rod 1 completely locks the metal sealing gasket 8 in the blind hole of the metal sealing nut, thereby completely sealing the core rod 1 and the nail sleeve 3.

[0027] like Figure 4 As shown, the nail sleeve 3 is a hollow rotary part with a stepped hole inside. The large hole part of the right half of the nail sleeve 3 is provided with a section of local annealing band 31. The hardness of this section is lower than that of other parts, which is used to guide the deformation of the bulge foot during riveting. The front half of the nail sleeve 3 is assembled together with the thread 11 of the core rod 1 by rolling forming, and finally the nail sleeve 3 and the core rod 1 are completely locked together by the locking sealing nut 2. A stepped hole and a locking cone hole 32 are provided inside the nail sleeve 3. The function of the stepped hole is to cooperate with the cone 6 and the blocking platform of the core rod 1. During the riveting process, after the core rod 1 is pulled to the position, the displacement will be limited by the cone 6 and the end face of the stepped hole. The locking cone hole 32 is used in cooperation with the locking groove 13 on the core rod 1. After the core rod 1 is pulled to the position, a wedge-shaped space will be formed between the locking cone hole 32 of the nail sleeve 3 and the locking groove 13 on the core rod 1, so that the lock ring 4 can be squeezed in to achieve the locking purpose.

[0028] like Figure 5 As shown, the lock ring 4 is an annular metal hoop; the push bushing 5 is a rotating part with a stepped hole inside, and the end with a larger hole diameter cooperates with the lock ring 4 to accommodate the lock ring 4. During riveting, the push bushing 5 will be squeezed by the rivet gun head and the end face of the nail body. When the squeezing force exceeds a certain limit value, the push bushing 5 will break at the position of the stepped hole, so that the lock ring 4 can be pushed into the wedge-shaped locking space.

[0029] like Figure 6 As shown, the cone 6 is a hollow cone 6 rotating part, which has a high hardness and is similar to a rigid body. Figure 6 As shown, the ring 7 is a hollow thin-walled part made of memory alloy, and its left end is an inner cone surface. When riveting, the outer cone surface of the cone 6 mainly cooperates with the inner cone surface of the memory alloy. During the riveting process of the memory alloy ring 7, under the extrusion of the blocking step 12 of the core rod 1 and the locking sealing nut 2, the end of the memory alloy ring 7 with a larger aperture will begin to expand and deform along the cone surface of the cone 6, thereby squeezing the nail sleeve 3 to bulge and deform on the blind end plate surface of the installation plate, and finally a bulge will be formed at the deformed end, thereby achieving the purpose of clamping; like Figure 7 As shown, the riveting process of the blind rivet is as follows: First, a rivet hole corresponding to the outer diameter of the blind rivet is drilled on the part to be riveted and the base; then the assembled blind rivet is inserted into the rivet hole of the part to be riveted, so that the nail cap of the nail sleeve 3 on the rivet body is pressed against the opening of the rivet hole of the part to be riveted; then the end of the core rod 1 is inserted into the chuck of the rivet gun, and the end face of the rivet gun head and the rivet sleeve is used to press the entire blind rivet against the mounting hole through the pushing sleeve 5 of the blind rivet.

[0030] Then, the trigger of the rivet gun is pressed, and the rivet gun starts to work. The rivet gun clamps the core rod 1 of the blind rivet through the chuck, and the chuck clamps the core rod 1 and retreats under the action of air pressure. During the retreat of the core rod 1, the core rod 1 drives the locking sealing nut 2 screwed on the external thread 11 on the head of the core rod 1 to retreat together. At the same time, the blocking step 12 on the core rod 1 compresses and drives the memory alloy ring 7 to retreat. When the memory alloy ring 7 retreats, it will retreat along the conical surface of the cone 6 and begin to expand and deform, thereby squeezing the local annealing zone 31 area of ​​the nail sleeve 3, causing the nail sleeve 3 to begin to bulge and deform along the hole of the mounting plate from the local annealing zone 31, thereby gradually driving the nail sleeve 3 to begin to produce a larger bulge on the blind end surface.

[0031] As the core rod 1 continues to retreat, the memory alloy ring 7 continues to be squeezed and deformed, driving the bulge caused by the deformation of the nail sleeve 3 to become larger and larger, until the core rod 1 finally retreats to the point where the blocking step 12 of the core rod 1 contacts the right top surface of the cone 6. At this time, the bulge of the nail sleeve 3 reaches its maximum, and the cone 6 cannot retreat because it is blocked by the blocking step 12 of the nail sleeve 3, resulting in the core rod 1 being unable to retreat further.

[0032] As the pulling force exerted by the rivet gun puller on the tail of the core rod 1 becomes greater and greater, the rivet gun will shear off the push bushing 5 under the action of the reaction force. The sheared push bushing 5 pushes the locking ring 4 to move toward the formed locking wedge space, and finally squeezes and deforms it completely into the wedge space. When the pulling force on the core rod 1 continues to increase and exceeds the force that the neck breaking groove 14 of the core rod 1 can withstand, the core rod 1 will break from the neck breaking groove 14, completing the riveting locking process.

[0033] The applicable installation thickness range of the blind rivet can be adjusted by setting different lengths of the cone 6. For example, when the length of the cone 6 is 3mm, the product can meet the single-sided connection of the sandwich plate with a thickness of 12mm-14mm, and when the length of the cone 6 is 5mm, the product can meet the single-sided connection of the sandwich plate with a thickness of 12mm-16mm.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0035] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A high temperature resistant sealed blind rivet, characterized in that: It includes a core rod, a locking sealing nut, a nail sleeve, a locking ring and a push bushing; One end of the core rod is installed in the chuck of the riveting gun, and the other end of the core rod is provided with a blocking step; The nail sleeve is sleeved on the core rod, a local annealing zone is provided in the middle of the nail sleeve, a matching cone and an annulus are installed between the nail sleeve and the core rod, the end of the annulus abuts against the blocking step, the nail sleeve and the core rod are assembled by roll forming, the locking sealing nut is provided on the nail sleeve, and is used to lock the core rod and the nail sleeve, and under the extrusion of the blocking step and the locking sealing nut, the annulus expands and deforms along the conical surface of the cone to squeeze the local annealing zone to produce a bulging deformation; The other end of the nail sleeve is provided with a locking cone hole, and the locking cone hole cooperates with the locking groove provided on the core rod to form a wedge-shaped space. The locking ring and the pushing bushing are sleeved on the core rod, and the locking ring is installed in the pushing bushing. In response to squeezing the pushing bushing, the pushing bushing breaks, so that the locking ring is squeezed and deformed to enter the wedge-shaped space; The core rod is controlled to break from the breaking neck groove arranged thereon to complete the riveting and locking.

2. A high temperature resistant sealed blind rivet according to claim 1, characterized in that: The locking sealing nut is a blind hole nut, the hole entrance of which is a straight arm section, and a sealing groove is provided at the bottom of the inner hole, and a sealing gasket is installed in the sealing groove.

3. The high temperature resistant sealed blind rivet according to claim 1, characterized in that: The head of the core rod is provided with threads, the nail sleeve is a hollow rotary structural member with a stepped hole opened inside, and one end of the nail sleeve close to the local annealing zone is assembled with the threads of the core rod by rolling forming.

4. A high temperature resistant sealed blind rivet according to claim 3, characterized in that: The cone is a hollow cone rotating structural member, one end of the ring is provided with an inner cone surface matched with the outer cone surface provided on the cone, and the cone and the ring are matched and installed in the step hole of the nail sleeve.

5. The high temperature resistant sealed blind rivet according to claim 1, characterized in that: The push bushing is a rotating structural part with a stepped hole inside. The locking ring is installed at the end of the stepped hole with a larger aperture. In response to the extrusion force exceeding the limit value, the push bushing breaks at the position of the stepped hole to push the locking ring into the wedge-shaped locking hole.

6. The high temperature resistant sealed blind rivet according to claim 1, characterized in that: The core rod is also provided with an annular groove for interference fit with the inner hole of the push bushing.

7. The high temperature resistant sealed blind rivet according to claim 1, characterized in that: The ring is made of special memory alloy material, and its hardness is between 110HV and 150HV.

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