CN112659571A

CN112659571A - Riveting method of carbon fiber plate

Info

Publication number: CN112659571A
Application number: CN202110275997.1A
Authority: CN
Inventors: 张旭; 崔俊佳
Original assignee: Changsha University of Science and Technology
Current assignee: Changsha University of Science and Technology
Priority date: 2021-03-15
Filing date: 2021-03-15
Publication date: 2021-04-16

Abstract

The invention provides a riveting method of a carbon fiber plate, and belongs to the technical field of mechanical assembly. The rivet structure comprises a rivet, wherein the rivet comprises an inner cavity and a deformation cavity communicated with the inner cavity; the diameter of the pin is larger than the inner diameter of the deformation cavity, and the pin is inserted into the deformation cavity to enable the rivet to be subjected to plastic deformation to form a boss to lock the lower-layer plate; the riveting method comprises the following steps: s1, loading and pressing a rivet to enable the rivet to be completely pressed into a penetrating plate; s2, the pin is placed in the rivet cavity, and the pin is loaded and pressed down until the pin enters the deformation cavity, so that the rivet is subjected to plastic deformation. The method provided by the invention does not need to punch a prefabricated hole before riveting, loads a single surface during riveting, does not need to fix a mould, can save the design and manufacturing cost of the mould, and can also be suitable for riveting a single-side closed structural part.

Description

Riveting method of carbon fiber plate

Technical Field

The invention relates to the technical field of mechanical assembly, in particular to a riveting method of a carbon fiber plate.

Background

The problems of energy shortage, air pollution and the like brought to the environment by vehicles and other delivery vehicles are getting more serious. The light weight of the material contributes obviously to energy conservation and emission reduction, and the carbon fiber composite material has the advantages of higher specific strength, specific modulus, good designability, corrosion resistance and the like, can greatly reduce the weight of the structure and reduce the emission of harmful gas, and is an ideal material for development and popularization in the current manufacturing field. On the premise of ensuring good performance, the partial replacement of metal by the composite material can realize energy conservation and emission reduction to the maximum extent. In order to realize the wide application of the composite material, besides the design method and the manufacturing process, the connection with the metal is also one of the problems which must be solved.

At present, the riveting process for the carbon fiber composite board mainly comprises self-piercing riveting and conventional riveting after hole prefabrication. Conventional through-nail riveting process after prefabricating the hole needs to make the prefabricating hole before riveting, the process is more, the tolerance can not be controlled, and a plurality of problems still need to be solved at present in the carbon fiber plate drilling process. Self-piercing riveting is applied more in the automobile assembly field at present, but different specification products need be equipped with compatible nail mould, and design cost is higher, and the nail mould cooperates the use simultaneously with riveting loading end in addition, is not fit for enclosed space structure riveting.

Disclosure of Invention

In view of the above technical problems, an object of the present invention is to provide a method for riveting a carbon fiber sheet, which does not require drilling a pre-fabricated hole before riveting, and can reduce the corresponding drilling process and avoid error accumulation caused by drilling. During riveting, the single side is loaded, a fixed die is not needed, the design and manufacturing cost of the die can be saved, and the riveting die is also suitable for riveting a single-side closed structural part.

The invention provides a riveting method of a carbon fiber plate, which comprises a rivet structure, wherein the rivet structure comprises the following steps:

the rivet comprises a straight cylindrical inner cavity and a straight cylindrical deformation cavity communicated with the inner cavity;

the diameter of the pin is larger than the inner diameter of the deformation cavity, and the pin is inserted into the deformation cavity to enable the rivet to be subjected to plastic deformation to form a boss to lock the lower-layer plate;

the convex eaves are embedded into the riveted plate and are flush with the upper plate, and are used for locking the riveted plate together with the bosses;

the cutting edge structure is used for realizing that the rivet smoothly penetrates through the riveted plate;

the riveting method comprises the following steps:

s1, loading and pressing a rivet to enable the rivet to be completely pressed into a penetrating plate;

s2, the pin is placed in the rivet cavity, and the pin is loaded and pressed down until the pin enters the deformation cavity, so that the rivet is subjected to plastic deformation.

Preferably, a transition cavity in a circular truncated cone shape is arranged between the inner cavity and the deformation cavity, and an included angle between the side wall of the transition cavity and the side wall of the inner cavity is 120-150 degrees.

Preferably, the length of the inner cavity of the rivet is the same as the thickness of the plate to be riveted.

Further, the step S1 includes: before riveting, selecting a rivet with a proper size according to the thickness of the plate to be riveted and the requirement of the riveting degree, placing the rivet at a planned position, loading and pressing to enable the rivet to penetrate and penetrate through, and enabling the surface of the convex eaves and the upper plate to be smooth.

Further, the loading and pressing are carried out by adopting a riveter structure; the riveter structure includes:

the gun body shell is internally provided with a gun body inner cavity, a storage cavity and a valve cavity; a first sealing seat fixedly connected with the gun body shell is arranged in the gun body inner cavity; the high-pressure gas is stored in the storage cavity, the storage cavity is communicated with the valve cavity through a first connecting hole, and the valve cavity is communicated with the outside through a second connecting hole;

the punch is movably arranged in the inner cavity of the gun body, and one end of the punch is abutted against the sealing seat;

the sliding piston is attached to the inner cavity of the gun body through a piston sealing ring, a piston left movable cavity is formed between one end of the sliding piston and the first sealing seat, a piston right movable cavity is formed between the other end of the sliding piston and the inner cavity of the gun body, the piston left movable cavity is communicated with the storage cavity, and the piston right movable cavity is communicated with the valve cavity through a plastic hose 12;

one end of the trigger guide rod is connected with a trigger, the trigger guide rod comprises a rod body movably arranged in the second connecting hole, a second sealing seat arranged in the middle of the rod body and a trigger reset spring, the second sealing seat is positioned in the valve cavity, one end of the trigger reset spring is connected with the second sealing seat, the other end of the trigger reset spring is connected with the valve cavity, and the trigger reset spring initially provides elastic force for enabling the second sealing seat to seal the second connecting hole; when the trigger guide rod is driven to move towards the first connecting hole, the rod body seals the first connecting hole.

Preferably, the punch is of a two-end stepped shaft structure and comprises a thin shaft and a thick shaft, wherein the thin shaft is in sliding fit with the inner cavity of the gun body and is used for realizing sliding and guiding of the punch, and one end of the thin shaft is connected with one end of the thick shaft; the thick shaft and the inner cavity of the gun body are in sliding sealing through a punch sealing ring.

Preferably, the riveter structure further comprises:

the pressure relief hole penetrates through the gun body shell and is communicated with the inner cavity of the gun body and the outside;

and the punch reset spring is arranged in the inner cavity of the gun body, surrounds the thick shaft of the punch and is used for resetting the punch.

The technical scheme of the invention has the following advantages:

1. the traditional riveting process has the advantages that the two processes of hole prefabrication and riveting are separately carried out, the time for designing, clamping and machining the die is increased, and meanwhile, errors are accumulated due to the two processes. The invention provides a riveting mode without a prefabricated hole, which can shorten the processing flow, save the design and manufacturing time, save the investment cost of redundant molds and clamps, and most importantly solve the problem of error accumulation.

2. Compared with the self-piercing riveting process which is widely applied at present and does not need to prepare holes, the riveting process does not need a top die, not only can save the design and manufacturing cost of the die, but also can be suitable for riveting a single-side closed structural part.

3. According to the rivet structure provided by the invention, the sizes of all parts can be adjusted according to different rivet models, the design process is simple, the process size is small, and the production and the manufacture are easy.

4. The riveter structure provided by the invention can realize quick loading, is more favorable for the rivet to smoothly penetrate through the carbon fiber plate, can inhibit the defects of deformation, bending, layering and the like of the carbon fiber plate during riveting, and improves the construction efficiency.

5. According to the invention, by arranging the cutting edge structure and the convex eave structure, when the carbon fiber plate is riveted, the rivet is loaded and pressed down firstly, so that the cutting edge structure cuts and punches the carbon fiber plate, the composite material layering loss is effectively avoided, and the convex eave structure enables the rivet to be flush with the upper plate after penetrating through the carbon fiber plate, so that the surface of the carbon fiber plate is smoother, the aerodynamics is good, then the pin is loaded and pressed down, the straight cylindrical deformation cavity can be uniformly deformed, and the extra acting force on the carbon fiber plate is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a novel riveting method provided in a first embodiment of the invention;

FIG. 2 is a top view of a rivet structure provided in a second embodiment of the present invention;

FIG. 3 is a schematic view of a riveter according to a third embodiment of the present invention;

fig. 4 is a partially enlarged view of a portion a in fig. 3.

Description of reference numerals:

d1: the diameter of the convex eaves; d2: the diameter of the inner cavity; d3: the diameter of the deformation cavity; d4: the diameter of the bottom end of the cutting edge; d5: diameter of the straight cylinder section.

1. A gun body housing; 2. a punch; 3. a punch return spring; 4. a pressure relief vent; 5. a punch head sealing ring; 6. a first seal seat; 7. fixing the pin; 8. a seal ring; 9. a piston seal ring; 10. a sliding piston; 11. a piston right movable cavity; 12. a plastic hose; 13. a piston left active cavity; 14. a storage chamber; 15. the air pump connecting pipe; 16. a valve cavity; 17. a trigger return spring; 18. a trigger guide bar; 19. a trigger; 20. the inner cavity of the gun body; 21. a first connection hole; 22. a second connection hole; 23. and a second seal seat.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1

A rivet structure for carbon fiber plates, which is described with reference to fig. 1 and 2, comprising:

the rivet comprises an inner cavity and a deformation cavity communicated with the inner cavity;

the diameter of the pin is larger than the inner diameter of the deformation cavity, and the pin is inserted into the deformation cavity to enable the rivet to be subjected to plastic deformation to form a boss to lock the lower-layer plate.

Wherein, the rivet still includes: and the convex eaves are embedded into the riveted plate and are parallel and level with the upper plate, and are used for locking the riveted plate together with the boss.

Wherein, be provided with the transition chamber of round platform form between inner chamber and the deformation chamber, the contained angle between the lateral wall of transition chamber and the inner chamber lateral wall is 120 ~ 150. Specifically, the included angle is set to be 135 degrees, so that the deformation cavity part of the blanking rivet in the rivet pressing process is prevented from being damaged, and the plastic expansion effect is not achieved. And an interference fit mode is adopted between the inner cavity of the rivet and the pin, so that the sealing effect is ensured.

Wherein, the cavity length of rivet is the same with by riveted plate thickness. The carbon fiber plate has poor interlaminar shear resistance, is easy to be layered and damaged when being extruded, and the length of the inner cavity of the rivet and the thickness of the plate are kept the same in order to avoid the defect. Therefore, when the pin is pressed down, the rivet is embedded in the middle of the plate, and radial expansion cannot occur to extrude the hole wall of the plate.

Wherein, the rivet still includes: and the cutting edge structure is used for realizing that the rivet smoothly penetrates through the riveted plate.

Wherein the diameter D1 of the convex eaves is larger than the diameter D5 of the straight cylinder section,

the working principle is as follows: in the process of pressing the pin downwards, the rivet deformation cavity is gradually pressed in, part of the rivet deformation cavity is extruded to be subjected to radial plastic expansion, the outer contour of the deformation cavity expands to form a boss and lock the next plate, and the riveting effect is achieved by embedding the convex brim of the upper plate and the boss expanded in the rivet deformation cavity on the lower plate. After the pin is fully pressed into the rivet cavity, the riveting is finished. The rear end of the pin is flush with the surface of the rivet convex eaves and the riveted plate, so that the surface is smooth. Adopt the better need not to dismantle of interference fit mode leakproofness between pin and the rivet inner chamber, if special demands such as air vent are left to the riveting position, the pin can also be loaded and demolishd and can not influence the riveting effect.

Example 2

A riveting method using the above rivet structure for carbon fiber sheets, described with reference to fig. 1, includes the following steps:

Further, step S1 includes: before riveting, selecting a rivet with a proper size according to the thickness of the plate to be riveted and the requirement of the riveting degree, placing the rivet at a planned position, loading and pressing to enable the rivet to penetrate and penetrate through, and enabling the surface of the convex eaves and the upper plate to be smooth.

Specifically, before riveting, a rivet with a proper size is selected according to the thickness of the plate to be riveted and the requirement of the riveting degree, the rivet is placed at a planned position, and loading and pressing are carried out to enable the rivet to penetrate into and penetrate through the rivet. In addition, the process of impressing can be according to by riveted plate intensity, and the rivet penetrates panel smoothly when adjusting the speed of pushing down, and after the rivet penetrated panel, its eaves part imbeds panel and panel parallel and level to guarantee that the panel surfacing. And the upper layer of the plate is locked through the convex eaves embedded into the plate, and the nailing process is finished.

Example 3

In example 2, the loading and pressing of the rivet in step S1 and the loading and pressing of the pin in step S2 were performed by using a riveter.

The riveter structure provided in this embodiment is described with reference to fig. 3 and 4, and includes:

the gun body shell 1 is internally provided with a gun body inner cavity 20, a storage cavity 14 and a valve cavity 16; a first sealing seat 6 fixedly connected with the gun body shell 1 is arranged in the gun body inner cavity 20; high-pressure gas is stored in the storage cavity 14, the storage cavity 14 is communicated with the valve cavity 16 through a first connecting hole 21, and the valve cavity 16 is communicated with the outside through a second connecting hole 22;

the punch 2 is movably arranged in the inner cavity 2 of the gun body, and one end of the punch is abutted against the first sealing seat 6;

the sliding piston 10 is attached to the gun body inner cavity 20 through a piston sealing ring 9, a piston left movable cavity 13 is formed between one end of the sliding piston 10 and the first sealing seat 6, a piston right movable cavity 11 is formed between the other end of the sliding piston and the gun body inner cavity 20, the piston left movable cavity 13 is communicated with the storage cavity, and the piston right movable cavity 11 is communicated with the valve cavity 16 through a plastic hose 12;

the trigger guide rod 18, one end connects the trigger 19, including the body of rod placed in the second attachment hole 22 movably, set up in the second seal receptacle 23 of the middle part of the body of rod, and trigger reset spring 17, the second seal receptacle 23 locates in the valve cavity 16, one end of the trigger reset spring 17 is connected with second seal receptacle 23, another end is connected with valve cavity 16, the trigger reset spring 17 provides the elasticity making the second seal receptacle 23 seal the second attachment hole 22 at first; when the trigger guide 18 is driven to move toward the first coupling hole 21, the rod seals the first coupling hole 21.

The punch 2 is of a two-end stepped shaft structure and comprises a thin shaft and a thick shaft, wherein the thin shaft is in sliding fit with the inner cavity 20 of the gun body and used for realizing sliding and guiding of the punch 2, and one end of the thin shaft is connected with one end of the thick shaft; the thick shaft and the gun body inner cavity 20 are in sliding seal through a punch head seal ring 5, and the punch head seal ring 5 is arranged in an annular groove of the thick shaft part.

Wherein, the riveter structure still includes:

the pressure relief hole 4 penetrates through the gun body shell 1 and is communicated with the gun body inner cavity 20 and the outside;

and the punch reset spring 3 is arranged in the gun body inner cavity 20 and surrounds the thick shaft of the punch for resetting the punch 2. The high-pressure air on the right side of the punch 2 pushes the punch to move leftwards, and after the primary loading is finished, the punch 2 is moved back to the initial position through the punch return spring 3. When drift 2 right-hand member moved and crossed pressure release hole 4, drift 2 right side inner chamber communicates with each other the pressure release with the external world, takes place danger in order to prevent that gas pressure is too high on the one hand, and drift 2 resets through drift reset spring 3 during on the other hand is for the pressure release.

Wherein, the gun body shell 1 is fixedly connected with the first sealing seat 6 through a fixing pin 7.

The high-pressure air on the right side of the punch 2 pushes the punch to move leftwards, and after the primary loading is finished, the punch 2 is moved back to the initial position through the punch return spring 3.

The working principle is as follows: compressed air of the air pump is led into a storage cavity 14 of the gun body shell 1 through an air pump connecting pipe 15, the high-pressure air storage cavity 14 is communicated with a piston left movable cavity 13 and a valve cavity 16 at the same time, and the valve cavity 16 is connected and communicated with a valve cavity 16 and a piston right movable cavity 11 through a plastic hose, so that the piston right movable cavity 11 and the piston left movable cavity 13 are in a balanced state under the same pressure. At the moment, the sliding piston 10 is attached and sealed with the first sealing seat 6, the first sealing seat 6 is connected and fixed with the gun body shell 1 through the fixing pin 7 and is sealed with the gun body shell 1 through the sealing ring 8, and the cavity on the right side of the punch 2 is balanced with the external air pressure and keeps still because no high-pressure control exists in the cavity.

When the trigger 19 is pressed, the right end face of the second seal provided on the trigger guide 18 compresses the trigger return spring 17, and the rightmost end of the trigger guide 18 is inserted into the first connection hole 21 and blocks the first connection hole 21 by the second seal 23 so that the high-pressure gas in the storage chamber 14 does not enter the valve chamber 16. At this time, the valve chamber 16, the plastic hose 12 and the piston right movable chamber 11 are isolated from the high pressure gas storage chamber 14. The trigger guide rod 18 moves rightwards to separate the second sealing seat 23 from the second connecting hole 22 to remove the sealing, and at the moment, the high-pressure gas in the valve cavity 16, the plastic hose 12 and the piston right movable cavity 11 is quickly decompressed to be balanced with the outside air. After the pressure of the piston right movable cavity 11 is relieved, the pressure in the piston left movable cavity 13 is higher than that of the piston right movable cavity 11, the sliding piston 10 is pushed to move rightwards to be separated from the first sealing seat 6 to remove sealing, high-pressure air in the high-pressure air storage cavity 14 quickly flows into contact with the right end face of the punch 2, and the punch is pushed to move leftwards quickly to impact a rivet or an expansion pin.

During riveting, the trigger 19 is held by hand continuously for loading; after riveting, the trigger 19 is loosened, the trigger guide rod 18 is pushed to move leftwards by the trigger return spring 17, the second sealing seat 23 on the trigger guide rod 18 is attached to the second connecting hole 22 for sealing again, and meanwhile, the right end of the trigger guide rod 18 is separated from the first connecting hole 21 for releasing sealing. At the moment, the valve cavity 16, the plastic hose 12 and the piston right movable cavity 11 are communicated with the storage cavity 14, so that the pressure in the piston right movable cavity 11 is greater than that in the piston left movable cavity 13 after pressure relief, the sliding piston 10 is pushed by the pressure difference to move leftwards to be attached and sealed with the sealing seat 6 again, and the riveter is restored to the state before riveting to prepare for next riveting.

It should be understood that the above-described embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A riveting method of a carbon fiber plate is characterized by comprising a rivet structure, wherein the rivet structure comprises the following steps:

the riveting method comprises the following steps:

2. The riveting method of the carbon fiber plate as claimed in claim 1, wherein a truncated cone-shaped transition cavity is arranged between the inner cavity and the deformation cavity, and an included angle between the side wall of the transition cavity and the side wall of the inner cavity is 120-150 °.

3. The method for riveting carbon fiber plates according to claim 1, wherein the length of the inner cavity of the rivet is the same as the thickness of the plate to be riveted.

4. The method for riveting a carbon fiber plate material as defined in claim 1, wherein the step S1 comprises: before riveting, selecting a rivet with a proper size according to the thickness of the plate to be riveted and the requirement of the riveting degree, placing the rivet at a planned position, loading and pressing to enable the rivet to penetrate and penetrate through, and enabling the surface of the convex eaves and the upper plate to be smooth.

5. A riveting method according to claim 1, wherein the loading and pressing down is performed using a riveter configuration; the riveter structure includes:

the trigger guide rod comprises a rod body movably arranged in the second connecting hole, a second sealing seat arranged in the middle of the rod body and a trigger reset spring, the second sealing seat is positioned in the valve cavity, one end of the trigger reset spring is connected with the second sealing seat, the other end of the trigger reset spring is connected with the valve cavity, and the trigger reset spring initially provides elastic force for enabling the second sealing seat to seal the second connecting hole; when the trigger guide rod is driven to move towards the first connecting hole, the rod body seals the first connecting hole.

6. The riveting method of carbon fiber plates as claimed in claim 5, wherein the punch is of a two-end stepped shaft structure and comprises a thin shaft and a thick shaft, wherein the thin shaft is in sliding fit with the inner cavity of the gun body and is used for realizing sliding and guiding of the punch, and one end of the thin shaft is connected with one end of the thick shaft; the thick shaft and the inner cavity of the gun body are in sliding sealing through a punch sealing ring.

7. The method of claim 5, wherein the riveter structure further comprises:

and the pressure relief hole penetrates through the gun body shell and is communicated with the inner cavity of the gun body and the outside.