Functionally adaptable special form capped press-in hybrid bolt

Abstract

The invention relates to an invention relates to a fastener (1) comprising at least one body (10) including a head (11). The novelty of the invention is in order to provide the desired function to the fastener (1) and to reduce weight, it comprises at least one cap (20) in a ring form, which passes over the head (11) so as to surround the head (11) and is connected thereto by an interference fit in a manner that prevents separation through plastic deformation of the head (11).

Description

[0001] FUNCTIONALLY ADAPTABLE SPECIAL FORM CAPPED PRESS-IN HYBRID BOLT

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a hybrid fastener capable of performing multiple functions such as weight reduction and enhancement of strength.

[0004] BACKGROUND OF THE INVENTION

[0005] Fasteners are mechanical components used to hold different parts together. They are widely used in many industrial fields, particularly in the automotive and construction sectors.

[0006] With today’s environmental and green transitions, there has been an increasing trend toward electrical vehicles and battery technologies in the automotive industry. In these sectors, where fasteners are used extensively, there is a significant need for functions such as electrical or thermal insulation, weight reduction, corrosion resistance, cosmetic appearance, sealing, and similar features. Although certain solutions have been considered to provide these functions to a standard bolt using current techniques, disadvantages still exist. The fastener to be produced for the desired function may need to be manufactured entirely from a material specific to that function, and one function may have to be sacrificed for another. For example, when a fastener to be produced for a weight reduction function is made of a light metal such as aluminum, a decrease in its mechanical strength will occur. Furthermore, different properties may be required in the shaft and head regions of the fastener. Hybrid bolts exist as solutions to produce fasteners in this way. At present, hybrid bolts are produced by combining different forms and materials through certain methods in order to impart functionality.

[0007] Patent number of US5338141A relates to hybrid bolts with caps functionalized for corrosion resistance. More specifically, a stainless steel sheet cap is placed on the bolt head and assembled by being compressed from beneath the flange. In addition, it is aimed to achieve sealing at the mounting area is intended to be achieved by means of an elastomer washer placed under the head. During installation of the bolt, the elastomer washer flows under the head and fills the gaps between the bolt, the cap, and the mountingarea. Corrosion resistance in the head region is improved through stainless steel caps that can be produced in the desired dimensions.

[0008] Another patent application, EP1409881 A1, relates to hybrid screws with seals functionalized for sealing. It is designed to prevent rainwater and atmospheric moisture from penetrating the screw during the fastening of the structures such as roofs. The screw consists of four parts: shaft, head, cap, and seal. The cap has standard hexagonal dimensions and is made from stainless material, while the shaft and head are made from a different material.

[0009] Patent application of FR2386722A1, on the other hand, relates to a decorative bolt cap for fasteners. The product consists of a cap made of plastic placed over a standard hexagonal bolt head. The cap and the bolt head are joined by deformable protruding tongues. These protrusions are present longitudinally along the central axis of each inner face of the cap.

[0010] In the prior art, hybrid bolts are produced by mounting a cap onto the head either by bending or by adhesive bonding, with the aim of providing features such as sealing, corrosion resistance, and cosmetic appearance. These mounting methods may require complex assembly machines, additional material use, adhesive chemicals, and thus additional costs.

[0011] In the prior art, weight reduction studies are carried out by removing / reducing parts of the bolt or changing the material. The amount of material that can be reduced from the product is limited. Moreover, the strength of light metals is lower compared to steel materials. Therefore, as weight is reduced, strength is also reduced simultaneously. This does not meet the expectations.

[0012] As a result, all the abovementioned problems have made it necessary to make an improvement in the relevant technical field.

[0013] SUMMARY OF THE INVENTION

[0014] The present invention relates to a fastener intended to eliminate the above-mentioned disadvantages and to bring new advantages to the relevant technical field.

[0015] An objective of the invention is to provide a hybrid fastener formed by joining two parts through a press fit operation, wherein the cap is made of a lightweight material in a hollowring form and the body form is made of steel materials, in order to overcome the disadvantages existing in the prior art.

[0016] Another objective of the invention is to provide a hybrid fastener that conforms to standards and has mechanical properties similar to those of standard bolts.

[0017] A further objective of the invention is to provide a fastener that eliminates the complexity of the joining method occurring during the production of hybrid bolts consisting of two parts including a cap in the prior art. Thanks to the ring structure of the cap with a central hole and the press fitting method used in the production process, torque transmission performance is increased and energy loss during tightening is reduced. As a result, efficiency of joining the cap and the body together in production is improved.

[0018] Another objective of the invention is to provide a fastener that enables the completion of production without the need for an adhesive chemical material during the joining of the hybrid bolt. Since the press fit method used in the production of hybrid bolts does not require additional adhesive chemicals, it offers ease of manufacturing and cost advantage.

[0019] Another objective of the invention is to provide a fastener that enables the production of a hybrid bolt with reduced weight when compared to standard dimensions.

[0020] A further objective of the invention is to provide a fastener that, in addition to having the cap form, allows the use of different materials in the cap and shaft parts, thereby providing functions such as sealing, insulation, corrosion resistance, and mechanical strength.

[0021] The invention relates to a fastener comprising at least one body including a head in order to achieve all the objectives mentioned above and those that will emerge from the detailed description below. The novelty of the invention is in order to provide the desired function to the fastener and to reduce weight, it comprises at least one cap in a ring form, which is fitted to the head so as to surround the head and is connected thereto by an interference fit in a manner that prevents separation through plastic deformation of the head. Thus, while ensuring that the fastener is lightweight, strength and joining reliability in production are improved.

[0022] A possible embodiment of the invention is that at least one curved form is located between the contact regions, and that the curved form has a radius extending away from the center of the cap. Thus, weight reduction can be achieved.A possible embodiment of the invention is that it consists of six contact regions and six curved forms. Thus, torque is distributed evenly during the tightening process, and surface pressure is reduced.

[0023] A possible embodiment of the invention is that a flange is included between the head and the shaft. Thus, the tightening force is distributed over a wider area, and the connection is reinforced without damaging the surface.

[0024] A possible embodiment of the invention is that the cap has a lower weight than the body. Thus, weight reduction is made possible.

[0025] A possible embodiment of the invention is that it is essentially a hybrid bolt. Thus, through the use of different materials together, requirements such as weight and strength can be addressed simultaneously.

[0026] A possible embodiment of the invention is that the cap is made of aluminum alloy. Thus, the lightness of the cap is maintained while also providing corrosion resistance and cost advantage.

[0027] A possible embodiment of the invention is that the body is made of steel. Thus, the fastener offers high mechanical strength and resistance to harsh conditions. The fact that the fastener is made of commonly available materials facilitates the production process and reduces cost.

[0028] A possible embodiment of the invention is that the head is hexagonal. Thus, joining is facilitated by compatibility with standard wrenches.

[0029] A possible embodiment of the invention is that the head has a recess at its center. Thus, the weight of the fastener can be reduced.

[0030] A possible embodiment of the invention is that, prior to being connected by interference fit, the length of the cap along the y-axis is shorter than the length of the head along the y-axis. Thus, after the press fitting process, the head and the cap align, enabling the product to have a more functional structure.

[0031] A possible embodiment of the invention is that, prior to being connected by interference fit, the width of the hollowed area in the center of the cap is greater than the width of the head.Thus, the cap can be easily placed over the head, and the joining process during production can be carried out more quickly and without issues.

[0032] A possible embodiment of the invention is that the excess volume of the head, resulting from the height difference between the head and the cap along the y-axis, is at least equal to the volume of the gap formed between the cap and the head when the cap is placed over the head. Thus, during the press fitting process, the head material completely fills the gap inside the cap, increasing the mechanical strength of the fastener.

[0033] BRIEF DESCRIPTION OF THE FIGURES

[0034] Figure 1 shows an isometric view of the fastener according to the invention.

[0035] Figure 2 shows a front view of the fastener according to the invention.

[0036] Figure 3 shows a front cross-sectional view of the fastener according to the invention.

[0037] Figure 4 shows another isometric view of the fastener according to the invention.

[0038] Figure 5 shows a top view of the fastener according to the invention.

[0039] Figure 6 shows a front view of the body of the fastener according to the invention.

[0040] Figure 7 shows an isometric view of the body of the fastener according to the invention.

[0041] Figure 8 shows a top view of the body of the fastener according to the invention.

[0042] Figure 9 shows an isometric view of the cap of the fastener according to the invention.

[0043] Figure 10 shows a top view of the cap of the fastener according to the invention.

[0044] Figure 11 shows a front view of the cap of the fastener according to the invention.

[0045] DETAILED DESCRIPTION OF THE INVENTIONIn this detailed description, the fastener (1) according to the invention is explained by means of examples provided solely for a better understanding of the subject, without having any limiting effect.

[0046] The present invention relates to a fastener (1) developed to meet the above-mentioned needs concerning fasteners, to overcome the identified problems, and to achieve the stated objectives. The said fastener (1) is a hybrid fastener (1) comprising a body (10) and at least one cap (20).

[0047] Although the fastener (1) is preferably in the form of a hybrid bolt, it may also be a male external threaded fastener (1) such as a screw or lug bolt. Accordingly, since it is formed by joining components made of different materials and configured to meet the desired properties, it can provide superior performance in areas where high strength, lightweight, insulation, corrosion resistance, or aesthetic requirements are prioritized. They find extensive application across a broad spectrum of industries, including automotive, aerospace, construction, maritime, energy, electronics, and medical devices, where they are utilized in accordance with specific requirements.

[0048] The fastener (1) comprises at least one body (10). The said body (10) consists of a head (11) and a shaft (13). In the preferred embodiment, the body (10) may also comprise a flange (12). The body (10) is manufactured from steel material. However, in alternative embodiments, it may also be made of different metals or alloys.

[0049] The threads on the shaft (13) part of the body (10) are continuously extending in a helical manner. Additionally, the body (10) can be mounted into a female fastener such as a nut with internal threads, or into a female fastener with a hole that has no threads formed, or even into a workpiece without a pre-drilled hole to establish a connection.

[0050] As mentioned above, the body (10) includes at least one head (11). The said head (11) is the part of the fastener (1) that transmits the torque. The term head (11) refers to the portion of the fastener (1) located above the flange (12) and onto which the cap (20) is mounted.

[0051] The head (11) may be in various polygonal forms such as square or pentagon, or in special socket forms, and is preferably in a hexagonal head form. In the preferred embodiment, a recess is formed in the center of the head (11) by removing a part of material. This recessenables weight reduction without affecting the overall mechanical strength of the fastener (1)-

[0052] The body (10) preferably includes a shaft (13). The said shaft (13) allows the fastener (1) to be mounted onto a desired part. The shaft (13) is located below the head (11) with respect to the y-axis (y) and may include threads. In the preferred embodiment, it has a helical thread section starting at any height along the y-axis (y).

[0053] The body (10) preferably includes a flange (12). The said flange (12) distributes the tightening force over a wider area, thereby increasing the strength of the connection and reducing surface damage during assembly.

[0054] The above-mentioned cap (20) is the component that transmits the torque applied by a driver (such as a wrench) during assembly of the fastener (1) to the shaft (13). After the cap (20) is placed over the head (11), it is fixed to the body (10) by plastically deforming the head (11). That is, once the cap (20) is placed over the head (11), a pressing process is applied to the head (11). Under the applied pressing force, the head (11) undergoes plastic deformation and becomes fixed inside the cap (20). In this way, a hybrid fastener (I) according to the invention is formed as a result of an interference fit achieved by the press applied to both the cap (20) and the head (11 ). To achieve this, the center of the cap (20) is hollowed out in the same geometry as the form of the head (10). Since the head (I I) is preferably in a hexagonal form, the cap (20) is also hollowed in a hexagonal form.

[0055] The width of the hollowed area in the center of the cap (20) is greater than the width of the head (11). Thus, during production, the cap (20) can be easily placed onto the head (11). When the cap (20) is placed on the head (11), a gap remains between the head (11) and the cap (20). This gap is closed after the pressing process. In other words, after the cap (20) is placed over the head (11) leaving a gap between them, the head (11) undergoes plastic deformation, as mentioned, and by being pressed so that it fills the gap between the cap (20) and the head (11). Thus, an interference fit is achieved between the cap (20) and the head (11).

[0056] The fit tolerance between the cap (20) and the head (11) is preferably set based on the fit tolerance between standard heads and tightening tools in the present invention, although alternative fit tolerances may also be used.The length of the cap (20) along the y-axis (y) is shorter than the length of the head (11) along the y-axis (y). Thus, during the press fit process, the pressed head (11) undergoes plastic deformation inside the cap (20), and the height of the cap (20) along the y-axis (y) becomes equal to the height of the head (11). The difference in height between the head (11) and the cap (20) is determined according to the volume filled during the press fitting process. In other words, the excess volume of the head (11) resulting from the height difference between the head (11) and the cap (20) is at least equal to the volume of the gap formed between the cap (20) and the head (11) when the cap (20) is placed over the head (11). Thus, when pressure is applied to the head (11), the excess material of the head (11) completely fills the gap inside the cap (20), ensuring the cap (20) is fixed onto the head (11). As a result, although the resulting fastener (1) has a hybrid structure, it possesses the same mechanical strength as a one-piece standard fastener.

[0057] The cap (20) includes at least two contact regions (21) and at least one curved form (22) located between these contact regions (21). The contact regions (21) ensure that the torque applied by a driving tool to the fastener (1) is efficiently transmitted. The curved form (22) provides equal distribution of torque and reduction of surface pressure during the tightening process in the cap (20). This structure facilitates joining in production while also allowing a reduction in the weight of the cap (20).

[0058] The body (10) and cap (20) constituting the fastener (1) in accordance with the present invention are manufactured using a conventional cold forming process. The mentioned cap (20) and body (10) forms can be produced by cold forming as a production preference or by machining. During production, when the cap (20) and head (11) are joined to each other, the applied press fit process which is carried out through a simple process based on the expansion of the head (11) by localized crushing. As a result, there is no need for any adhesive material or use of chemical, and a fastener (1) according to the present invention can be produced by interference fitting without high cost.

[0059] The cap (20) being a part independent from the body (10) allows it to be made of a lightweight material without affecting the strength of the body (10), thereby enabling weight reduction and the incorporation of various functions as needed. In summary, thanks to the special ring form of the cap (20), weight reduction is achieved, and the fastener (1) can be assembled using standard drivers. Thus, the fastener (1) is made lighter without the need for a different driving tool.Although 6082-T6 aluminum alloy is preferably used as the material of the cap (20), it may also be made of other aluminum alloys or any lightweight material to achieve additional functions and features besides weight reduction. The important point here is that the material used for the cap (20) must be lighter than the material used for the body (10). In other words, the density of the cap (20) material is lower than the density of the body (10) material. This enables achieving one of the objectives of the invention, which is to reduce the weight of fasteners. Although the present invention has been developed specifically for the function of weight reduction, it is possible to add other functions by making changes to the shape and material of the cap (20).

[0060] The cap (20) enables the torque applied by a driver (tightening tool) such as a wrench to be transmitted to the shaft (13). Due to its form, the cap (20) can be tightened and / or loosened using conventional socket drivers and sockets. The torque applied during the process is transferred from the cap (20) to the body (10), and then to the threads, enabling tightening and loosening. The cap (20) and the head (11) are fixed by interference fitting following the press fit process in the production, which allows the fastener (1) to be repeatedly tightened and loosened without any loosening occurring. That is, the width of the cavity in the cap (20) must be narrow enough to achieve an interference fit with the head (11).

[0061] In light of all the above, the operation of the invention is as follows: the opening in the ringshaped cap (20) is larger than the diameter of the head (11) on the body (10), and the initial height of the head (11) along the y-axis (y) is greater than the height of the cap (20) along the y-axis (y). In the first stage of production of the fastener (1), the cap (20) is tightly placed onto the head (11). Then, pressure is applied to the head (11) to deform it, and the excess material of the head (11 ) fills the gap between the cap (20) and the head (11 ). After the press fit process, the cap (20) and the head (11) are aligned. As a result, the cap (20) and the body (10) are firmly joined together to form a hybrid fastener (1 ).

[0062] Therefore, weight reduction has been achieved in the production of the hybrid fastener (1). The problems encountered in the prior art have been overcome, and a fastener (1) has been developed which can be functionalized for different properties (such as corrosion resistance, electrical insulation, etc.) and has mechanical strength at the same level as conventional products, has reduced weight, without a complex press fitting process. More specifically, by using hybrid fastener (1) technology consisting of two different parts, namely the cap (20) and the body (10), weight reduction has been achieved withoutcompromising the mechanical properties of the material. Furthermore, this process is carried out without the use of a complex joining mechanism or adhesive chemicals.

[0063] The scope of the invention is specified in the appended claims and cannot be limited to the description made for illustrative purposes in this detailed description. Likewise, it is clear that a person skilled in the art can put forward similar embodiments in the light of the above descriptions without departing from the main theme of the invention.REFERENCE NUMBERS THAT GIVEN IN THE FIGURE

[0064] 1 Fastener

[0065] 10 Body

[0066] 11 Head

[0067] 12 Flange

[0068] 13 Shaft

[0069] 20 Cap

[0070] 21 Contact Region

[0071] 22 Curved Form

[0072] (y) Y-Axis

Claims

CLAIMS1. A fastener (1) comprising at least one body (10) including a head (11), characterized in that in order to provide the desired function to the fastener (1) and to reduce weight, it comprises at least one cap (20) in a ring form, which passes over the head (11) so as to surround the head (11) and is connected thereto by an interference fit in a manner that prevents separation through plastic deformation of the head (11 ).

2. The fastener (1) according to claim 1, characterized in that the length of the cap (20) along the y-axis (y) is shorter than the length of the head (11) along the y-axis (y) prior to being connected by interference fit.

3. The fastener (1 ) according to claim 1 , characterized in that the width of the hollow in the center of the cap (20) is greater than the width of the head (11) prior to being connected by interference fit.

4. The fastener (1) according to claim 1 , characterized in that the excess volume of the head (11) resulting from the difference in height between the head (11) and the cap (20) along the y-axis (y) is at least equal to the volume of the gap formed between the cap (20) and the head (11) when the cap (20) is placed over the head (11).

5. The fastener (1) according to claim 1, characterized in that the density of the material of the cap (20) is lower than the density of the material of the body (10).

6. The fastener (1 ) according to claim 1 , characterized in that the cap (20) comprises at least two contact regions (21).

7. The fastener (1) according to claim 6, characterized in that at least one curved form (22) is located between the contact regions (21).

8. The fastener (1) according to claim 1, characterized in that the head (11) has a recess at its center.

9. The fastener (1 ) according to claim 1 , characterized in that a shaft (13) is provided below the head (11 ) on the body (10).

10. The fastener (1) according to claim 1, characterized in that a flange (12) is provided between the head (11) and the shaft (13).

11. The fastener (1) according to claim 9, characterized in that at least a portion of the shaft (13) is helically threaded.

12. The fastener (1) according to claim 1, characterized in that it is essentially a hybrid bolt.

13. The fastener (1) according to claim 1 , characterized in that the cap (20) is made of 6082-T6 aluminum alloy.

14. The fastener (1) according to claim 1, characterized in that the body (10) is made of steel.

15. The fastener (1) according to claim 1, characterized in that the head (11) is hexagonal.

Images