WO2025029234A1

WO2025029234A1 - Internally threaded, self-threading fastener with a hole with a lobular structure

Info

Publication number: WO2025029234A1
Application number: PCT/TR2024/050718
Authority: WO
Inventors: Umut Ince; Muhammed Burak TOPARLI; Hatice SANDALLI YILDIZ; Burak Berk ARINCI; Niyazi Emrah Kilincdemir; Sarper DOGAN
Original assignee: Norm Izmir Civata Sanayi Ticaret Anonim Sirketi; Norm Somun Sanayi Ve Ticaret Anonim Sirketi
Priority date: 2023-07-28
Filing date: 2024-06-27
Publication date: 2025-02-06

Abstract

A fastener (1) having at least one body (10) for engagement with a counter fastener, at least one hole (12) in said body (10) suitable for insertion of the shaft of the counter fastener, and at least one threaded form (13) on the inner wall of said hole (12) allowing engagement with the counter fastener. It is characterized in that the threaded form (13) in the hole (12) for engagement of said fastener (1) with the counter fastener by threading comprises threading zones (21) allowing threading, having a point A (A), a point B (B), a point C (C), and a point D (D) tangent to a virtual circle with minor thread diameter (31), the center of which being the same as the center (30) of the hole (12) of said fastener, and relief zones (22) having a point A1 (A1), a point B1 (B1), a point C1 (C1), and a point D1 (D1), each between two sequential threading zones (21), around a virtual circle with major thread diameter (32) having a diameter larger than the virtual circle with minor thread diameter (31).

Description

INTERNALLY THREADED, SELF-THREADING FASTENER WITH A HOLE WITH A LOBULAR STRUCTURE

TECHNICAL FIELD

The invention relates to a fastener having at least one body for engagement with a counter fastener, at least one hole in said body for insertion of the counter fastener, and at least one threaded form on the inner wall of said hole allowing engagement with the counter fastener. The invention relates to an internally threaded, self-threading fastener with a hole with lobular structure that allows the connection to be established by threading the counter fastener during assembly in various sectors, in particular in the automotive industry.

PRIOR ART

In the state of the art, it is known to use internally threaded fasteners with self-threading capability to form a thread form on the shaft of male fasteners which have not yet been threaded. Due to the hole form and threaded structure with threading capability of such fasteners, with the effect of the high friction force that occurs when said fastener is rotated and advanced on the shaft of an unthreaded fastener, a thread form extending spirally around the shaft is formed as a result of the deformation of the material of said shaft. The frictional force generated during the threading process contributes to the clamping force that occurs between the two fasteners.

Patent application No. US3314326A known in the literature describes a nut threading a conical stud, and said nut consists of a rectangular opening with a major axis and a minor axis, containing threaded and unthreaded parts. The form of the opening is obtained by connecting the points where the axes intersect the rectangle with the curves.

In the patent application DE102018221101 A1 known in the literature, a fastener system consisting of two elements is mentioned. In said system, the first element has a protrusion, and the second element has a hole. There is at least one cutting surface on the outside the first element for cutting the inner surface of the second element and/or on the inner surface of the second element for cutting the outer surface of the first element.

When considering inventions with similar functions in the state of the art, only special taps and/or costly production methods such as machining may be required to obtain the desired thread form. Furthermore, depending on the lobular structure of the hole, obtaining the desired hole structure in the production process where the fastener is shaped is likely to cause an increase in cost.

As a result, all the above-mentioned problems have made it imperative to make an innovation in the relevant technical field.

SUMMARY OF THE INVENTION

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

The main object of the invention is to provide a self-threading, internally threaded fastener in order to overcome the disadvantages mentioned in the state of the art and to fulfill the needs.

Another object of the invention is to provide an internally threaded self-threading fastener that forms a thread in the counter fastener (preferably in the bolt) with a low threading torque and ensures that the torque applied to the fastener during assembly remains high in the connection system after assembly.

Another object of the invention is to provide a self-threading, internally threaded fastener that can form a secure connection with the counter fastener.

Another object of the invention is to form a thread in the counter fastener in unthreaded form with the self-threading, internally threaded fastener according to the invention, ensuring that said fastener becomes an externally threaded fastener.

Another object of the invention is to allow the reassembly with any standard internally threaded fastener of a compatible size, without the need for a fastener having a self- threading feature such as the internal threaded fastener of the invention, in the case that reassembly (need to disassemble and reassemble) is required after the thread form has been formed on the shaft of said externally threaded fastener with a self-threading, internally threaded fastener according to the invention.

Another object of the invention is to allow said fastener to ensure cleaning of the threads on the threaded part during assembly, in the case that the fastener according to the invention is assembled with an externally threaded fastener which is pre-threaded or threaded by the thread forming process (rolling or machining).

Another object of the invention is to contribute to the reduction of production cost and production time by eliminating the need for the thread forming process required to form the threaded part in the mass production of the externally threaded fastener.

Another object of the invention is to make it possible to produce a self-threading, internally threaded fastener according to the invention by a cold forming process.

Another object of the invention is to provide a self-threading fastener in which the use of only a special tap is not required for the formation of the thread form in the hole with lobular structure, after it is produced without threads by cold forming method.

In order to accomplish all the objects mentioned above and which will arise from the detailed description below, the present invention is a fastener having at least one body for engagement with a counter fastener, at least one hole in said body suitable for insertion of the shaft of the counter fastener, and at least one threaded form on the inner wall of said hole allowing engagement with the counter fastener. Accordingly, its novelty is that the threaded form in the hole for engagement of said fastener with the counter fastener by threading comprises threading zones allowing threading, having a point A, a point B, a point C, and a point D tangent to a virtual circle with minor thread diameter, the center of which being the same as the center of the hole of said fastener, and relief zones having a point A1 , a point B1 , a point C1 , and a point D1 , each between two sequential threading zones, around a virtual circle with major thread diameter having a diameter larger than the virtual circle with minor thread diameter. Thus, a self-threading, internally threaded fastener structure with a four-lobed hole form according to the invention is achieved. However, with the four-lobe hole design of the hole, the internally threaded, self-threading fastener of the invention form a thread in the counter fastener (preferably in the bolt) with low threading torque, and the torque applied to the fastener during assembly remains high in the connection system after assembly. Thus, a connection is formed between the two fasteners with a high clamping force and thus a high vibration resistance. The subject of the invention is a self-threading, internally threaded fastener, preferably a nut, and the fastener threaded with said nut is preferably a bolt or stud.

These threading zones and relief zones are located sequentially on the inner surface of the hole of the fastener with a four-lobed form. In a preferred embodiment of the invention, the relief zones are 4 and are disposed at an equal distance from each other around the four-lobed hole of the self-threading fastener according to the invention, while the threading zones are also 4 and are disposed at equal distances from each other around said four-lobed hole. The threading zone is the zone where the threaded parts of the fastener are located that are used to form threads in the counter fastener. Relief zones, on the other hand, are located at the corners of the fastener and consist of relief gaps.

A possible embodiment of the invention is that the relief zones are located at the corners of the hole of the fastener with a four-lobed form. During assembly, as the fastener according to the invention rotates and advances on the shaft of the counter fastener, the material on the surface of the shaft of the counter fastener, which is deformed to form a thread by means of the threading zones of the hole with a four-lobed form, is allowed to flow into the relief zones. Thus, the threading process can be carried out properly in the counter fastener.

A possible embodiment of the invention is characterized in that at point A1 , point B1 , point C1 , and point D1 , the corners are rounded.

A possible embodiment of the invention is characterized that the thread height in the threaded part in the threading zone is greater than the thread height in the relief zone.

A possible embodiment of the invention is characterized in that the thread height at the rounded corners at points A1 , B1 , C1 , and D1 , located in the relief zones, is almost zero. A possible embodiment of the invention is characterized in that, while moving from the threads in the threading zone to the threads in the thread relief zone, the sharpness of the apex of the threads decreases and becomes more rounded or almost flat.

A possible embodiment of the invention is characterized in that the thread height is maximum at point A, point B, point C, and point D located in the threading zones; and minimum at point A1 , point B1 , point C1 , and point D1 located in the relief zones.

A possible embodiment of the invention is characterized in that the thread height decreases while moving from point A to point A1 , from point B to point B1 , from point C to point C1 , and from point D to point D1 .

A possible embodiment of the invention is characterized in that the thread height increases while moving from point A1 to point B, from point B1 to point C, from point C1 to point D, and from point D1 to point A.

A possible embodiment of the invention is characterized in that the thread height decreases gradually while moving from the above-mentioned point A, point B, point C, or point D in the threading zones to point A1 , point B1 , point C1 or point D1 in the relief zones; and the thread height gradually increases while moving from the above- mentioned point A1 , point B1 , point C1 , or point D1 in the relief zones to the point A, point B, point C, or point D in the relief zones.

A possible embodiment of the invention is characterized in that the points A, B, C, and D in said threading zone are tangent to the virtual circle with minor thread diameter.

A possible embodiment of the invention is characterized in that it comprises at least one countersink formed to be compatible with the threading zone and the relief zone around the hole. Thus, it is ensured that the longitudinal axes of the fasteners are easily aligned before the fastener is engaged with the counter fastener.

A possible embodiment of the invention is characterized in that it is a nut with a four- lobed form, which, by rotating around itself, can tap the shaft of the counter fastener. A possible embodiment of the invention is characterized in that the threading zones are provided such that the hole has a 4-fold symmetry with respect to said hole center; and the thread heights in symmetrical threading zones are equal to each other.

A possible embodiment of the invention is characterized in that the relief zones are provided such that the hole has a 4-fold symmetry with respect to said hole center; and the thread heights in the symmetrical relief zones are equal to each other.

Thus, in the case that the self-threading fastener according to the invention is produced by traditional methods such as the cold forming process, the hole structure being in a uniform form as described contributes positively to tool life and process efficiency by ensuring that the loads caused by the forging process during cold forming are evenly distributed on the mold parts used in shaping the fastener.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a representative perspective view of the fastener of the invention.

Fig. 2 shows a representative top view of the fastener of the invention.

Fig. 3 shows a representative top view of the virtual circle with major thread diameter and the virtual circle with minor thread diameter on the fastener of the invention, and the position of the perimeter of the four-lobed hole of said fastener between these two circles.

Fig. 4 shows a representative geometric view of the circle with radius R1 drawn to form the first zone of the four-lobed hole of the fastener of the invention.

Fig. 5 shows a representative geometric view of the intersecting circles with radii R1 and R2 drawn to form the first zone of the four-lobed hole of the fastener of the invention.

Fig. 6 shows a representative geometric view of the intersecting circular arcs with radii R1 and R2 before the formation of the geometric shape of the first zone of the four-lobed hole of the fastener of the invention. Fig. 7 shows a representative view of the geometric shape of the first zone of the four- lobed hole of the fastener of the invention.

Fig. 8 shows a representative geometric view of the rounded corner of the four-lobed hole of the fastener of the invention with radius R3.

Fig. 9 shows a representative view of the center point of the circle with the radius R3 of the rounded corner in the first zone delimited by points A and D of the four-lobed hole of the fastener of the invention, and a representative geometric view of the point where the center of the circle with the radius R4 which is the center of said four-lobed hole and also of the virtual circle with minor thread diameter is located.

Fig. 10 shows a representative geometric view of the circle with radius R1 drawn to form the second zone of the four-lobed hole of the fastener of the invention.

Fig. 11 shows a representative geometric view of the intersecting circles with radii R1 and R5 drawn to form the second zone of the four-lobed hole of the fastener of the invention.

Fig. 12 shows a representative geometric view of the intersecting circular arcs with radii R1 and R5 before the formation of the geometric shape of the second zone of the four- lobed hole of the fastener of the invention.

Fig. 13 shows a representative view of the center point of the circle with the radius R6 of the rounded corner in the second zone delimited by points C and D of the four-lobed hole of the fastener of the invention, and a representative geometric view of the point where the center of the circle with the radius R4 which is the center of said four-lobed hole and also of the virtual circle with major thread diameter is located.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject of the invention is explained in detail by way of example only for a better understanding of the subject, without creating any limiting effect. Referring to Figs. 1 -13, the invention relates to an internally threaded, self-threading fastener (1 ) with a hole (12) with a four-lobed form (20). The fastener (1 ) of the invention can be used in assembly processes in various sectors, in particular in the automotive industry. The fastener (1 ) has an internally threaded, self-threading feature with a hole (12) with a four-lobed form (20) that allows the engagement with a counter fastener on the counter side by means of threading during assembly. The counter-fastener referred to herein is a fastener which has a cylindrical and unthreaded shaft before entering through the four-lobed hole of the fastener (1) of the invention; and which turns into an externally threaded structure by the creation of a threaded form on its shaft with the four- lobed hole form of the fastener of the invention as it advances with a relative rotational movement. Counter fasteners, without limitation and for exemplifying purposes, can be fasteners such as bolts, studs, etc. with their outer surfaces provided threadless. The fastener (1 ) of the invention may also preferably be a nut. The fastener (1 ) according to the invention, with its four-lobed hole and threaded part, is likely to have relatively higher strength than the counter fastener, allowing easy threading of the shaft of the counter fastener.

Referring to Fig. 1 , the fastener (1 ) of the invention has a body (10). On the outwardfacing side of said body (10), there is at least one wrench edge (11 ) suitable for contact with the wrench during tightening and loosening of the fastener (1 ). Said wrench edge

(11 ) is preferably located in multiple numbers on the outer side of the body (10) and allows the fastener (1) to be rotated around itself by means of a wrench. There is at least one hole (12) in the inner part of the body (10). Said hole (12) is the aperture through which the fastener (1 ) can be connected to the counter fastener by inserting the shaft of the counter fastener into said hole (12). On the inner wall of the hole (12) there is a threaded form (13) with at least one thread rotation. Said threaded form (13) in the hole

(12) with a four-lobed form (20) allows both threading the shaft of a counter fastener and assembling of the fastener (1 ) to the counter fastener as mentioned above.

The hole (1 ) of the self-threading, internally threaded fastener (12) according to the invention has a four-lobed form (20). This is one of the characteristic features of the invention. With the four-lobed form (12) of said hole (20), a thread is formed in the shaft of the counter fastener in the unthreaded form. The fastener (1 ) according to the invention has at least one countersink (14) located at the entrance and exit edges of the hole (12). Said countersink (14) contributes to the alignment of the longitudinal axes of said fastener (1 ) and the counter fastener before starting the threading process by rotating and advancing the fastener (1 ) of the invention on the shaft of the counter fastener in order to engage with the counter fastener. After the longitudinal axes of the fasteners are aligned, the threaded form is formed on the shaft of the counter fastener by continuing the rotational movement of the fastener (1 ) according to the invention on the shaft of the counter fastener. By continuing the rotational movement of the fastener (1) according to the invention on said shaft, the fastener (1 ) according to the invention, on one hand, advances on the counter fastener while forming a thread, and on the other hand, assembles onto the counter fastener. In the threading process, as the fastener (1 ) continues its rotation and advancement movement in the direction of assembly with a certain thread angle on the shaft of the counter fastener, a threaded part consisting of at least one thread rotation is formed on the shaft of the counter fastener.

The technical features of the self-threading, internally threaded fastener (1 ) according to the invention are explained in detail below with reference to the figures.

Fig. 2 shows a representative top view of the fastener (1 ) of the invention. Accordingly; the fastener (1 ) has threading zones (21) and relief zones (22) around the hole (12). Said threading zones (21) are positioned closer to the hole center (30) than said relief zones (22). As shown in Fig. 2, the threading zones (21) and relief zones (22) are positioned sequentially on the inner surface of the hole (12) of the fastener (1) with a four-lobed form (20). In other words, they are positioned sequentially, with a relief zone (22) between the two threading zones (21 ). In a possible embodiment of the invention, there are 4 threading zones (21 ) and 4 relief zones (22) on the inner surface of the hole (12). The threading zones (21 ) referred to herein are the parts that form threads by applying pressure to the shaft of the counter fastener. Said relief zones (22) has gaps for easy flow of the material on the surface of the shaft of the counter fastener, which the fastener (1) according to the invention deforms to form a thread by means of the threading zones (21 ) in its hole (12) with a four-lobed form (20) as it rotates and advances on the shaft of the counter fastener. In this way, the threaded part is formed on said shaft without causing any jamming of the material deformed on the shaft surface due to the pressure applied on the shaft of the counter fastener by said threading zones (21 ) to form threads and the continuity of the rotation and advancement movement of the fastener element (1) according to the invention on the counter fastener is ensured. According to the height of the threaded form (13) intended to be formed on the shaft of the counter fastener, the thread heights in the threading zones (21 ) and relief zones (22) in the fastener (1) according to the invention are determined.

The threading zones (21 ) are provided such that the hole (12) has a 4-fold symmetry with respect to said hole center (30). The thread heights in the symmetrical threading zones (21 ) are equal to each other. For example, point A (A) is symmetrical to point C (C) with respect to the center of the hole (30). Point D (D) is also symmetrical to point B (B) with respect to the center of the hole. Point D (D) and point B (B) are also provided with a radial angle of 90 degrees between them and point A. Thus, it is ensured that the threading zones (21 ) have a fourfold symmetry.

The relief zones (22) are provided such that the hole (12) has a 4-fold symmetry with respect to said hole center (30). The thread heights in the symmetrical relief zones (22) are equal to each other. The above explanation similarly applies to relief zones. For example, point A1 (A1 ) is symmetrical to point C1 (C1 ) with respect to the center of the hole (30). Point D1 (D1 ) is also symmetrical to point B1 (B1 ) with respect to the center of the hole. Point D1 (D1 ) and point B1 (B1 ) are also provided with a radial angle of 90 degrees between them and point A1. Thus, it is ensured that the threading zones (21 ) have a fourfold symmetry.

Fig. 3 shows a representative top view of a virtual circle with minor thread diameter (31 ) and a virtual circle with major thread diameter (32) of the fastener (1 ) of the invention. As can be seen in Fig. 3, the center (31 ) of said virtual circle with minor thread diameter, the center (32) of the virtual circle with major thread diameter, and the center (30) of the hole (12) of the fastener according to the invention with a four-lobed form (20) coincide. The threaded part of the hole of the fastener (1 ) according to the invention with a four- lobed form is located along the hole between the virtual circle with minor thread diameter (31 ) and the virtual circle with major thread diameter (32). In the fastener (1 ) according to the invention, the thread height of the threading zones (21) is greater than the thread height of the relief zones (22). In a possible embodiment of the invention, the thread height at the rounded corners at point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ) located in the relief zones can be almost zero. The hole center (30) of the fastener (1 ) according to the invention is also the center of the virtual circle with minor thread diameter (31 ) and the virtual circle with major thread diameter (32). The points where the thread height is greatest in the hole (12) of the fastener (1 ) of the invention with a four-lobed form (20) are point A (A), point B (B), point C (C), and point D (D) in the threading zones (21 ) where the perimeter of said hole is tangent to the virtual circle with minor thread diameter (31). Said points are points closest to the center of the hole (12) of the fastener (1 ) of the invention with a four-lobed form. The points where the thread height is lowest in said fastener (1 ) are point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ) in the relief zones (22) where the perimeter of the hole is closest to the virtual circle with major thread diameter (32). Said points are the points furthest from the hole center (30) of the hole (12) of the fastener (1 ) of the invention with a four-lobed form.

In a possible embodiment of the invention, the thread height when proceeding clockwise starting from point A (A) in a four-lobed form (20) hole (12) of the fastener according to the invention (1 ) decreases while moving from point A (A) in the threading zone, where it is at maximum, to point A1 (A1 ) in the relief zone (22), and is minimum at point A1 (A1 ); while moving from point A1 (A1 ) to point B (21 ) in another threading zone (21 ), it increases again and reaches the maximum height at point B (B). The thread height decreases again while moving from point B (B), where it is maximum, to point B1 (B1 ) in another relief zone, where it is minimum, and reaches a minimum at point B1 (B1 ); while moving from point B1 (B1 ) to point C (C) in another threading zone (21 ) it increases towards the maximum value and reaches the maximum value at point C (C) in another threading zone (21 ). The thread height decreases again as while moving from point C (C) to point C1 (C1 ) in the other relief zone and decreases to its minimum value at point C1 (C1 ). While moving from C1 (C1 ), where the thread height is minimum, to point D (D) in the other threading zone, the thread height increases again and reaches the maximum value at point D (D), then decreases again to the minimum value while moving towards point D1 (D1 ), and increases again towards the maximum value while moving towards point A (A) and reaches its maximum value at point A (A).

The thread height of the threaded form (13) in the hole (12) of the fastener according to the invention in a four-lobed structure (20) has the maximum height at point A (A), point B (B), point C (C), and point D (D) in the threading zones (21 ), and the height value is the same. The thread height of the threaded form (13) in the hole (12) of the fastener according to the invention in a four-lobed structure (20) has the minimum height at point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ) in the relief zone (22), and the thread height value is the same. With the gradual and continuous change of the thread height of the threads in the threaded part (13) in the four-lobed (20) hole (12) of the fastener according to the invention between the threading zones (21 ) and the relief zones (22) from the maximum value to the minimum value and from the minimum value to the maximum value as described in detail above, the thread formation process is carried out on the shaft of the counter fastener in accordance with the object of the invention.

Each of the relief zones (22) is located between the sequential threading zones (21 ) of the hole (12) of the fastener (1 ) in a four-lobed form (20). During assembly, as the fastener (1 ) rotates and advances on the shaft of the counter fastener, the material it has deformed on the shaft of the counter fastener to form a thread by means of the threading zones (21 ) of the hole (12) with a four-lobed form (20) is allowed to flow into the relief zones (22). Thus, the threading process is carried out properly in the counter fastener. The relief zones (22) provide a gap for the material to flow to form threads, while at the same time contributing to provision of optimum levels of contact between the fastener (1) and the counter fastener so that the post-installation connection has the desired vibration resistance. With the above-mentioned four-lobed form (20) of the hole (12) of the fastener, a thread can be formed on the shaft of the counter fastener with a low threading torque and a connection with a high clamping force can be obtained postassembly by transferring the torque applied to the fastener (1) of the invention for assembly to the counter fastener at a higher level.

The thread root of the threads at point A (A), point B (B), point C (C), and point D (D) located in the threading zones (21 ), and the thread root of the threads at point A1 (A1 ), point B1 (B1), point C1 (C1 ), and point D1 (D1 ) located in the relief zones (22) of the hole (12) of the fastener according to the invention with a four-lobed form (20) fall on the virtual circle with major thread diameter (32). Point A (A), point B (B), point C (C), and point D (D) located in the threading zones (21 ) on the inner surface of the hole (12) of the fastener (1 ) with a four-lobed form (20) has fully formed threads, while moving from point A (A), point B (B), point C (C), and point D (D) towards point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ) in the relief zones (22), the thread height of the threads decreases and while the thread height decreases, the sharpness of the thread apex also gradually decreases and incomplete thread forms are formed. At point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ) in the relief zones (22) where the thread height is minimum, the sharpness and tapering form of the apex of the threads decreases and takes a more rounded or flat shape.

According to the final thread dimensions of the threads in the threaded part desired to be obtained in the shaft of the counter fastener to be threaded, the radius dimensions in the hole (12) of the fastener (1 ) with a four-lobed form (20) are adjusted and the thread form is created in the dimensions determined with the help of the standard or special tap used in the machining method or the rolling process.

Below are geometric descriptions of the portions forming the four-lobed form (20) of the hole (12) of the fastener (1 ) according to the invention. The four-lobed form of the hole (12) of the self-threading fastener (1 ) according to the invention is defined as follows:

As can be seen in Figure 4, inside a regular hexagon drawn symmetrically on the X-axis (X) and Y-axis (Y), a circle with a radius R1 (R1 ) with a center point in the -Y direction (- Y) of the Y axis (Y) is formed. On the Y axis (Y), there is a +Y direction (+Y) on the opposite side of the -Y direction (-Y). As shown in Figure 5, another circle with radius R2 (R2) with the same radius value as R1 , the center of which being in the -X direction (-X), is drawn. In Figure 5, both circles with R1 radius (R1) and R2 radius (R2) are tangent to the intersection points of the circles with R1 radius (R1 ) and R2 radius (R2) which seem to intersect in the first zone (1 .B) and the 3rd zone (3.B). The R part (R) and the S part (S) shown in Figure 6 are removed from the intersection point of the circles with R1 radius (R1 ) and R2 radius (R2) in order to form the relief zone (22) in a first zone (1 .B). As can be seen in Figure 7, after removing the R part (R) and the S part (S), the form of the first zone (1.B) located between point A (A) and point D (D) is defined in the hole (12) of the fastener (1 ) with a four-lobed form (20).

In the first region (1 .B) defined as described, there is provided a corner of the hole (12) with said four-lobed form (20), which is located in one of the relief zones (22) of the fastener (1 ), this corner, as shown in Figure 8, is rounded to form the arc of a circle with radius R3 (R3), the center of which located in the first zone (1 .B). Point A (A) and point D (D) located in the first zone (1.B) of the fastener (1 ) are also located on a circle with radius R4 (R4), the center of which coinciding ( the same) with the center of the hexagon, as shown in Figure 9. The circle described here with radius R4 (R4) also overlaps the virtual circle with minor thread diameter (31 ) shown in Figure 3, the radius values are equal to each other, and the point C (C) and point B (B) shown in Figure 3 are also on the same circle. The center (30) of the hole of the fastener (1 ) according to the invention in a four-lobed form also coincides with the center of the virtual circle with minor thread diameter (31 ) and the center of the circle with radius R4, and the location of said three centers is the same. The steps carried out for defining the first zone (1.B) described in detail above are also carried out in a similar way for defining the third zone (3.B) which is symmetrical with the first zone (1 .B) according to the center of the circle (30). Inside a regular hexagon drawn symmetrically on the X-axis (X) and Y-axis (Y), a circle with the same radius as the circle with radii R1 and R2 described above and with a center point in the +Y direction (+Y) of the Y-axis (Y) is formed. A second circle with its center in the direction of +X (+X) and with the same radius is also drawn. At the same time, said circles are tangent to the intersection point of these circles in the third zone (3.B). In order to form the relief zone (22) in the third zone (3.B), from the point where the circles intersect, the parts included for the same purpose as R part (R) and S part (S) described above are removed. Accordingly, the form of the third zone (3.B) located between point B (B) and point C (C) in the hole (12) of the fastener (1 ) with a four-lobed form (20) is defined.

Similar to the description above for defining the first zone (1.B), in order to define a second zone (2.B) of the hole (12) part of the fastener (1 ) in a four-lobed form (20), inside a regular hexagon drawn symmetrically on the X axis (X) and Y axis (Y), a circle with radius R1 (R1 ) with a center point in the -Y direction (-Y) of the Y axis (Y) is drawn as shown in Figure 10. As shown in Figure 11 , another circle with radius R5 (R5) with a center in the +X direction (+X) is drawn symmetrically to the center of the circle with radius R2 (R2) shown in Figure 5 with respect to the intersection of the X-axis (X) and the Y-axis (Y). In Figure 1 1 , both circles with R1 radius (R1 ) and R5 radius (R5) are tangent to the intersection points of the circles with R1 radius (R1 ) and R5 radius (R5), whose radii are the same, which seem to intersect in the second zone (2.B) and the fourth zone (4.B). The U part (U) and the T part (T) shown in Figure 12 are removed from the intersection point of the circles with R1 radius (R1 ) and R5 radius (R5) in order to define the relief zone (22) in the second zone (2.B). After removing the U part (U) and the T part (T), as shown in Figure 13, the second zone (2.B) located between point C (C) and point D (D) is formed in the hole (12) of the self-threading fastener (1) according to the invention with a four-lobed form (20). In the second region (2.B) formed as described, there is provided a corner of the hole (12) with said four-lobed form (20), which is located in another one of the relief zones (22) of the fastener (1 ), this corner is rounded to form the arc of the circle with radius R6 (R6), the center of which located in the second zone (2.B) (Fig. 13). The radius of said circle with radius R6 (R6) has the same value as the radius of the circle with radius R3 (R3) mentioned above. Point C (C) and point D (D) located in the second zone (2.B) of the fastener (1 ) are also located on the circle with radius R4 (R4), the center of which coinciding (i.e. the same) with the center of the hexagon, as shown in Figure 13. The circle with radius R4 (R4) overlaps the virtual circle with minor thread diameter (31 ) shown in Figure 3. The center (30) of the hole of the fastener (1) according to the invention in the four-lobed form also coincides with the center of the virtual circle with minor thread diameter (31 ) and the center of the circle with radius R4, and the location of said three centers is the same. The steps carried out for defining the second zone (2.B) described in detail above are also carried out in a similar way for defining the fourth zone (4.B) which is symmetrical with the second zone (2.B) according to the center of the circle (30). Inside a regular hexagon drawn symmetrically on the X-axis (X) and Y-axis (Y), a circle with the same radius as the circle with radii R1 , R2 and R5 and with a center point in the +Y direction (+Y) of the Y-axis (Y) is formed. A second circle with its center in the direction of -X (-X) and with the same radius is also drawn. At the same time, said circles are tangent to the intersection point of these circles in the fourth zone (4.B). In order to form the relief zone (22) in the fourth zone (4.B), from the point where the circles intersect, U part (U) and T part (T) described above; the parts included for the same purpose as R part (R) and S part (S), are removed. Accordingly, the form of the fourth zone (4.B) located between point A (A) and point B (B) in the hole (12) with a four-lobed form (20) of the fastener (1) is defined.

In each of the relief zones (22) of the hole (12) of the fastener (1 ) according to the invention with a four-lobed form (20), there is one rounded corner formed to represent the arc of the circles with a certain radius value. In the detailed explanation given above for forming 1st zone (1.B) and 2nd zone (2.B), the radii of these rounded corners are shown with reference to R3 and R6, and these radii are equal to each other. The radius values of the rounded corners in the 3rd and 4th zones (3.B, 4.B) are also equal to the radius value of the radius R3 and R6. The rounded corners in the relief zones of the hole (12) of the fastener (1) according to the invention with a four-lobed form (20) are represented by the arcs of the circle with equal radii to each other, and the radius values of these arcs are equal to each other. In addition, the radius values of the circles used in the formation of the zones (1.B, 2.B, 3.B, 4.B) of the fastener (1) according to the invention described in detail above are also equal to each other.

The self-threading, internally threaded fastener (1) with a hole (12) with a four-lobed form (20) whose geometric features are described above can be obtained by traditional methods, but preferably by cold forming method. With the four-lobed form of the hole (12) of the fastener according to the invention, the torque applied to said fastener (1 ) during the assembly of said fastener (1 ) according to the invention with the counter fastener remains high in the connection system. Furthermore, when threading the counter fastener, since the damages or deformations such as stripping in the thread form, plastic deformation of the bolt, failure of the bolt can be detected quickly and easily in the threaded fastener (1 ) during and/or after the assembly, a secure connection can be provided while forming a thread form on the shaft of the counter fastener. Thus, with the quick detection of possible deformation of the counter fastener (e.g., bolt) during or after assembly, the assembly conditions are readjusted and the connection security is maintained.

In the case that reassembly (need to disassemble and reassemble) is required when the threaded form (13) is formed once on the unthreaded counter fastener with the selfthreading, internally threaded fastener (1 ) of the invention, reassembly can be performed with a standard nut without the need for a self-threading, internally threaded fastener such as the fastener (1 ) of the invention. In the case that the fastener (1 ) according to the invention is assembled with an externally threaded counter-fastener (1 ) which is prethreaded or threaded by the thread forming process, said fastener (1 ) also ensures the cleaning of the threads in the thread form of the counter fastener during assembly. The fastener (1) of the invention contributes to the reduction of production cost and production time by eliminating the need for the thread forming process required to form the threaded part in the mass production of the externally threaded counter fastener (1 ).

The internally threaded fastener (1 ) of the invention can be manufactured by one of the traditional methods that are well known in the art. In a possible embodiment of the invention, the fastener (1 ) is produced threadless by cold forming process. With the cold forming process, the stability of the desired tolerance values and surface quality is ensured. In order to bring the hole (12) of the fastener (1 ) into the internally threaded form (13), threading process can be done by rolling or machining method using standard or special taps.

The scope of protection of the invention is specified in the appended claims and cannot be limited to what is described for illustrative purposes in this detailed description. It is clear that a person skilled in the art can produce similar embodiments in the light of what is explained above, without deviating from the main theme of the invention.

REFERENCE NUMERALS IN DRAWINGS

I Fastener

10 Body

I I Wrench Edge

12 Hole

13 Threaded Form

14 Countersink

20 Four-Lobed Form

21 Threading Zone

22 Relief Zone

30 Hole Center

31 Virtual Circle with Minor Thread Diameter

32 Virtual Circle with Major Thread Diameter

(A) Point A

(B) Point B

(C) Point C

(D) Point D

(A1 ) Point A1

(B1 ) Point B1

(C1 ) Point C1

(D1 ) Point D1 (1.B) First Zone

(2.B) Second Zone

(3.B) Third Zone

(4.B) Fourth Zone

(R1 ) Radius R1

(R2) Radius R2

(R3) Radius R3

(R4) Radius R4

(R5) Radius R5

(R6) Radius R6

(R) R Part

(S) S Part

(U) U Part

(T) T Part

(X) X-Axis

(-X) -X Direction

(+X) +X Direction

(Y) Y-Axis

(+Y) +Y-axis

(-Y) -Y-axis

Claims

1. A fastener (1 ) having at least one body (10) for engagement with a counter fastener, at least one hole (12) in said body (10) suitable for insertion of the shaft of the counter fastener, and at least one threaded form (13) on the inner wall of said hole (12) allowing engagement with the counter fastener, characterized in that t e threaded form (13) in the hole (12) for engagement of said fastener (1) with the counter fastener by threading comprises threading zones (21 ) allowing threading, having a point A (A), a point B (B), a point C (C), and a point D (D) tangent to a virtual circle with minor thread diameter (31 ), the center of which being the same as the center (30) of the hole (12) of said fastener, and relief zones (22) having a point A1 (A1 ), a point B1 (B1 ), a point C1 (C1 ), and a point D1 (D1 ), each between two sequential threading zones (21 ), around a virtual circle with major thread diameter (32) having a diameter larger than the virtual circle with minor thread diameter (31 ).

2. A fastener (1 ) according to Claim 1 , characterized in that the corners are rounded at point A1 (A1 ), point B1 (B1 ), point C1 (C1 ), and point D1 (D1 ).

3. A fastener (1 ) according to Claim 1 , characterized in that the thread height in the threaded part in the threading zone (21 ) is greater than the thread height in the relief zone (22).

4. A fastener (1 ) according to Claim 3, characterized in that while moving from the threads in the threading zone (21 ) to the threads in the thread relief zone (22), the sharpness of the threads decreases.

5. A fastener (1 ) according to Claim 1 , characterized in that the thread height decreases while moving from point A (A) to point A1 (A1 ), from point B (B) to point B1 (B1 ), from point C (C) to point C1 (C1 ), and from point D (D) to point D1 (D1 ).

6. A fastener (1 ) according to Claim 1 , characterized in that the thread height increases while moving from point A1 (A1 ) to point B (B), from point B1 (B1 ) to point C (C), from point C1 (C) to point D (D), and from point D1 (D) to point A (A).

7. A fastener (1 ) according to Claim 1 , characterized in that the threading zones (21 ) are provided such that the hole (12) has a 4-fold symmetry with respect to said hole center (30), and the thread heights in symmetrical threading zones (21 ) are equal to each other.

8. A fastener (1 ) according to Claim 1 , characterized in that the relief zones (22) are provided such that the hole (12) has a 4-fold symmetry with respect to said hole center (30), and the thread heights in the symmetrical relief zones (22) are equal to each other.

9. A fastener (1 ) according to Claim 1 , characterized in that the points A, B, C, and D in said threading zone (22) are tangent to the virtual circle with minor thread diameter (31).

10. A fastener (1 ) according to Claim 1 , characterized in that it comprises at least one countersink (14) formed to be compatible with the threading zone (21 ) and the relief zone (22) around the hole (12).

11 . A fastener (1 ) according to Claim 1 , characterized in that it is a nut with a four- lobed form (20), which, by rotating around itself, can tap the shaft of the counter fastener.