Self-clinching fastener

Abstract

A self-clinching fastener for attachment to a plastically deformable metal substrate includes a body portion having a central axis, the body portion having an annular surface extending in a direction perpendicular to the central axis. The annular surface includes a first annular surface, a second annular surface, and a third annular surface. The third annular surface is located on an imaginary horizontal plane. A punch portion extends from the body portion. A plurality of spaced-apart lugs surround the punch portion. The first annular surface extends radially outward from an outer peripheral surface of the punch portion, and the second annular surface is radially disposed between the first and third annular surfaces. One of the plurality of lugs is inclined downward to the second annular surface.

Description

Technical Field

[0001] Cross - reference to Related Applications

[0001] None

[0002]

[0002] This application generally relates to self - attaching fasteners, and more specifically, to clinch nuts.

Background Art

[0003]

[0003] Self - attaching fasteners are used in many industries such as the automotive industry and the household appliance industry to fix various components to metal panels. When a clinch nut is attached to a metal panel, a screw or bolt is screwed into the clinch nut and tightened to a specified torque value. During installation, the clinch nut needs to have sufficient rotational resistance so that it does not rotate relative to the metal panel when the screw is inserted and tightened. During use, the clinch nut needs to have sufficient pull - out resistance so that it does not come out of the metal panel when external forces such as vibrations or other tensile forces act on it.

[0004]

[0004] A clinch nut typically includes a central pilot portion or punch portion that extends at least partially into an opening in a metal plate or panel. If the clinch nut is self-piercing, the central pilot portion works with a tool to form an opening in the metal panel when the clinch nut is attached to the metal panel. The clinch nut is attached to the metal panel by a die member that forms a mechanical connection between the clinch nut and the metal panel. Generally, the die member is a reflective die having a shape corresponding to the shape of the clinch nut. More specifically, such a reflective die member typically includes a raised portion that facilitates the deformation of the metal panel around the opening of the clinch nut into the annular groove surrounding the pilot portion, and / or deforms the pilot portion of the clinch nut on the metal panel to capture the metal panel. In such conventional applications, a force of 12 tons (or more) is required to physically connect the clinch nut to the metal panel. Furthermore, due to the amount of force used and the typical configuration of the reflective die, the reflective die often fails (i.e., breaks, deforms, etc.) after 100 to 1,000 uses. These elements repeatedly apply enough force to secure each clinch nut in place, continuously separating the metal panels, which often leads to failures, particularly at the raised areas of the reflective die.

[0005]

[0005] Therefore, there is a need in the art for an improved clinch nut that has sufficient extrusion strength and rotational resistance, extends the life of the tool (e.g., die component), and can be securely and consistently attached to a metal panel. Furthermore, there is a need for a clinch nut that can be manufactured relatively inexpensively and is relatively easy to use. [Overview of the project]

[0006]

[0006] According to one embodiment, a self-clinching fastener for attachment to a plastically deformable metal substrate is provided. The self-clinching fastener includes a body portion having a central axis. The body portion includes an outer circumferential surface extending in the direction of the central axis and an annular surface extending in a direction perpendicular to the central axis. The annular surface includes a first annular surface, a second annular surface and a third annular surface. The third annular surface is located on a virtual horizontal plane, and the first and second annular surfaces define a rim that protrudes away from the virtual horizontal plane in the direction of the central axis.

[0007]

[0007] The punch portion is coaxial with the central axis, and an annular surface extends from the main body portion so as to surround the punch portion. The punch portion includes an outer circumferential surface that extends in the direction of the central axis. A plurality of spaced lugs surround the punch portion and protrude outward from the annular surface in the axial direction. One of the lugs is inclined downward with respect to a virtual horizontal plane in the radially outward direction of the self-clinching fastener. The first annular surface extends radially outward from the outer circumferential surface of the punch portion. The second annular surface is positioned radially between the first annular surface and the third annular surface, and one of the lugs is inclined downward to the second annular surface.

[0008]

[0008] In another embodiment, a self-clinching fastener for attachment to a plastically deformable metal substrate is provided. The self-clinching fastener includes a body portion having a central axis. The body portion includes an outer circumferential surface extending in the direction of the central axis and an annular surface extending in a direction perpendicular to the central axis. The annular surface includes a first annular surface, a second annular surface and a third annular surface. The third annular surface is located on a virtual horizontal plane, and the first and second annular surfaces define a rim that protrudes away from the virtual horizontal plane in the direction of the central axis. The punch portion is coaxial with the central axis, and an annular surface extends from the main body portion so as to surround the punch portion. The punch portion includes an outer circumferential surface extending in the direction of the central axis and has a cylindrical contour located on a virtual circumferential surface. Multiple spaced lugs surround the punch portion and project outward axially from the annular surface. One of the multiple lugs is inclined downward radially outward of the self-clinching fastener with respect to a virtual horizontal plane. The first annular surface extends radially outward from the outer circumferential surface of the punch portion, and the second annular surface is radially positioned between the first and third annular surfaces. The first annular surface has a planar cross-section and is angled with respect to a virtual horizontal plane. The second annular surface has a concave cross-section such that it curves continuously toward the virtual horizontal plane in a radially outward direction. One of the multiple lugs is inclined downward to the second annular surface. [Brief explanation of the drawing]

[0009] [Figure 1]

[0009] A perspective view of the clinch nut. [Figure 2]

[0010] Figure 1 is a plan view of the clinch nut. [Figure 3]

[0011] This is a cross-sectional view along line 3-3 in Figure 2. [Figure 4]

[0012] This is a magnified view of the detailed area "4" shown in Figure 3. [Figure 5]

[0013] This is a magnified view of the detailed area "5" shown in Figure 3. [Figure 6]

[0014] Figure 1 is a perspective view of the stud, including the clinch mounting portion. [Figure 7]

[0015] This is a perspective view of an alternative clinch nut. [Modes for carrying out the invention]

[0010]

[0016] Referring to the drawings, Figure 1 shows a fastener 100 or nut for attachment to a plastically deformable metal plate or panel. The fastener 100 may be a self-clinching fastener that, when installed on the metal panel, is fastened to a pre-drilled hole formed in the metal panel. Preferably, the fastener 100 is a self-piercing and self-clinching fastener that, when installed, pierces an opening in the metal panel and fastens itself to the opening. Although the illustrated embodiment is a nut, it should be noted that other self-piercing and self-clinching fasteners, such as self-piercing and / or self-clinching studs (shown in Figure 6 and briefly described below), are within the scope of the present invention. For brevity, most of the following description will be in relation to self-clinching nuts and self-piercing nuts, but it should be understood that this disclosure is equally applicable to self-piercing studs and / or self-clinching studs.

[0011]

[0017] The fastener 100 has a body portion 102 and a pilot portion or punch portion 104 extending from one end of the body portion 102. A threaded hole or bore 106 penetrates both the body portion 102 and the punch portion 104 axially. Furthermore, the body portion 102 and the punch portion 104 are coaxial with the central axis "X". When installing the fastener 100 on a plastically deformable metal substrate, a matching threaded fastener (e.g., a bolt, screw, etc.) may be inserted into the threaded hole 106 and attached to the threaded hole 16. If the fastener is a self-piercing and self-clinching stud, the punch portion 104 is solid and does not have a through hole; instead, a threaded or unthreaded stud may extend outward from the opposite side of the body portion 102 (i.e., from the bottom or first end face 102a of the fastener 100). Preferably, such studs are positioned around the central axis "X" and coaxially with the central axis "X". The studs may be perpendicular to the first end face 102a, or, if necessary, may be positioned at a predetermined angle with respect to the central axis "X".

[0012]

[0018] Referring to Figures 1 to 3, the main body portion 102 extends to the bottom or first end face 102a of the fastener 100, corresponding to one end of the fastener 100 in the axial direction. The first end face 102a of the fastener 100 is shown to be substantially perpendicular to the central axis "X". However, the first end face 102a may have other geometric configurations, for example, the first end face 102a may be chamfered. Specifically, the first end face 102a may be inclined upward or downward with respect to the central axis "X". In other words, the first end face 102a may have a circumferential surface that gradually converges radially inward or gradually diverges radially outward with respect to the installation direction of the fastener 100. As further shown, the punch portion 104 extends to the upper end face or second end face 104a of the fastener 100, which corresponds to the other axial end of the fastener 100. The second end face 104a of the fastener 100 is similarly depicted as being substantially perpendicular to the central axis "X", but alternatively, as described above with respect to the first end face 102a, the second end face 104a may be chamfered.

[0013]

[0019] The punch portion 104 is radially smaller than the main body portion 102 such that the main body portion 102 includes a substantially annular surface 108 surrounding the punch portion 104. That is, the punch portion 104 extends from the main body portion 102 in the direction of the central axis "X", and the annular surface 108 is positioned to surround the punch portion 104. The annular surface 108 extends in a direction perpendicular to the central axis (i.e., extends in the radial direction "r" of the fastener 100, as shown in Figure 2), and is configured to engage with the metal panel to which the fastener 100 will be attached.

[0014]

[0020] As further shown, the fastener 100 includes a plurality of spaced lugs 110 that collectively surround the punch portion 104. Each of the lugs 110 projects axially outward from the annular surface 108 in the direction opposite to the first end face 102a of the fastener 100. In one embodiment, as shown, the lugs 110 are spaced equally apart from each other and all have the same configuration. Alternatively, the lugs 110 may be unevenly spaced around the punch portion 104 and / or have various configurations.

[0015]

[0021] As shown in Figures 1 and 3, the main body portion 102 and the punch portion 104 each include outer circumferential surfaces 112 and 114 extending in the direction of the central axis "X". In one embodiment, the outer circumferential surface 112 of the main body portion 102 is planar and parallel to the central axis "X", providing a polygonal shape with flat sides that can be easily used in a machine tool. Alternatively, the outer circumferential surface 112 of the main body portion 102 may be curved in a convex or concave manner, and / or may be non-parallel to the central axis "X". In the example shown, the outer circumferential surface 112 of the main body portion 102 is polygonal and formed by multiple faces. Specifically, as shown in Figure 2, all of the multiple faces have the same dimensions (i.e., height and width) so that the outer circumferential surface 112 of the main body portion 102 is formed by eight faces. Alternatively, a total of 4 to 12 faces may form the outer circumferential surface 112 of the main body portion 102. Furthermore, it should be noted that the outer circumferential surface 112 of the main body portion 102 does not need to be polygonal and may have other geometric configurations (e.g., cylindrical). The height (i.e., axial dimension) and width (i.e., radial dimension) of the main body portion 102 are selected to provide sufficient thread engagement between the threaded hole 106 and the threaded male member (e.g., bolt) so that the engaging male threaded member can consistently engage with the threaded hole 106 without stripping the threads, and can also disengage from the threaded hole 106. If the fastener 100 has a self-clinching stud, the height and width of the main body portion 102 can similarly be selected to provide sufficient strength to the stud and the intended engaging fastener.

[0016]

[0022] Referring to Figures 2 and 4, Figure 4 is an enlarged detail view of the area enclosed by the circle of the fastener 100 shown in Figure 3, where the annular surface 108 is located on a virtual horizontal plane "P". Specifically, the virtual horizontal plane "P" is configured such that the central axis "X" is perpendicular to the virtual horizontal plane "P". Furthermore, the annular surface 108 comprises a first annular surface 108a, a second annular surface 108b, and a third annular surface 108c. The first annular surface 108a is surrounded by the second annular surface 108b (i.e., the first annular surface 108a is located closer to the punch portion 104 in the radial direction than the second annular surface 108b), and the second annular surface 108b is surrounded by the third annular surface 108c (i.e., the second annular surface 108b is located closer to the punch portion 104 in the radial direction than the third annular surface 108c). In other words, the first annular surface 108a, the second annular surface 108b, and the third annular surface 108c are arranged concentrically, with the second annular surface 108b positioned midway between the first annular surface 108a and the third annular surface 108c in the radial direction "r". In particular, each of the first annular surface 108a, the second annular surface 108b, and the third annular surface 108c continuously surrounds the punch portion 104 without interruption (i.e., surrounds it radially). However, it is conceivable that at least one of the first annular surface 108a, the second annular surface 108b, and / or the third annular surface 108c may have a separate (i.e., discontinuous) circumferential section that collectively surrounds the punch portion 104.

[0017]

[0023] As shown in Figure 4, the outer diameter of the third annular surface 108c (with respect to the central axis "X") intersects (i.e., crosses) the outer circumferential surface 112 of the main body portion 102 at the periphery 116 of the annular surface 108. That is, the outer diameter of the third annular surface 108c is adjacent to the main body portion 102 at the periphery 116. The inner diameter of the third annular surface 108c (with respect to the central axis "X") intersects (i.e., crosses) the outer diameter of the second annular surface 108b (with respect to the central axis "X"). Furthermore, the inner diameter of the second annular surface 108b (with respect to the central axis "X") intersects (i.e., crosses) the outer circumferential surface 114 of the punch portion 104.

[0018]

[0024] Further, as shown, the third annular surface 108c is planar (i.e., flat) and is located on the virtual horizontal plane “P”. Also, the first annular surface 108a has a planar (i.e., flat) cross-section and is angled with respect to the virtual horizontal plane “P”. Specifically, the first annular surface 108a may be convex with respect to the virtual horizontal plane “P”. That is, the first annular surface 108a is inclined upward toward the radially inner side of the fastener 100 with respect to the virtual horizontal plane “P”. As shown in FIG. 4, the first annular surface 108a has a convex angle θ (i.e., an angle of less than 180° with respect to the virtual horizontal plane “P”).

[0019]

[0025] This convex angle 9 provides a technical advantage of generating an appropriate surface with which the metal panel can engage during attachment. Specifically, conventional fasteners have a concave angle provided between the annular surface and the virtual horizontal plane. Such a configuration is acceptable for previously configured metal panels. However, currently, metal panels are manufactured from new lightweight materials (e.g., aluminum, steel, etc.) that have been strengthened (e.g., heat-treated) to improve their strength characteristics. These new metal panels are thinner, lighter, and stronger, but due to the relatively hard substrate of such metal panels, the material is less likely to stretch during installation. That is, the substrate (i.e., the metal panel) does not easily flow (i.e., plastically deform) during the installation of the fastener, and thus a gap (i.e., an empty space) is formed between the punch portion and / or the annular surface and the engaging substrate (i.e., the metal panel). These gaps or voids reduce the attachment strength between the fastener and the metal panel, and ultimately result in an insufficient joint between them. The configuration of the fastener 100 described herein, specifically, the configuration of the convex angle described above, significantly reduces or completely eliminates the potential voids formed between the fastener 100 and the metal panel. That is, there is no need for the substrate to flow into the undercut region formed by the angle between the annular surface and the outer peripheral edge of the punch portion.

[0020]

[0026] As shown, the first annular surface 108a does not continuously slope downward from the outer peripheral surface 114 of the punch portion 104 to the third annular surface 108c. Rather, as described above, the second annular surface 108b is disposed (radially) between the first annular surface 108a and the third annular surface 108c and is curved gradually downward in the radial direction "r" (i.e., toward the virtual horizontal plane "P"). That is, the second annular surface 108b follows the radius of curvature connecting the outer diameter of the first annular surface 108a and the inner diameter of the third annular surface 108c in cross-section. Thus, due to the curved design described above, the second annular surface 108b has a concave cross-section.

[0021]

[0027] In particular, by providing the curved second annular surface 108b between the first annular surface 108a and the third annular surface 108c of the plane (cross-section), the radial occupied area of the first annular surface 108a is reduced. That is, the first annular surface can hold the convex angle θ with respect to the virtual horizontal plane "P" and there is no need to continuously reduce the convex angle to the virtual horizontal plane "P". Rather, the curved second annular surface 108b provides a smooth / efficient transition between the first annular surface 108a and the third annular surface 108c.

[0022]

[0028] However, it should be understood that the second annular surface 108b may have a cross-sectional configuration other than curved. For example, the second annular surface 108b has a planar (i.e., flat) cross-section and is angled with respect to the virtual horizontal plane "P". In another example (e.g., as shown in FIG. 7, described later), the second annular surface 108b has a planar (i.e., flat) cross-section and is disposed perpendicular to the third annular surface 108c (i.e., perpendicular to the virtual horizontal plane "P").

[0023]

[0029] In summary, the first annular surface 108a and the second annular surface 108b define the rim 109 of the annular surface 108, which protrudes axially outward from the virtual horizontal plane "P" and away from the virtual horizontal plane "P", and protrudes toward the second end face 104a of the fastener 100 along the central axis "X". Furthermore, the rim 109 protrudes radially outward from the outer circumferential surface 114 of the punch portion 104 (for example, the virtual circumferential surface "C" shown in Figure 5).

[0024]

[0030] Returning to Figure 1, the outer circumferential surface 114 of the punch portion 104 extends in the direction of the central axis "X" between the annular surface 108 of the main body portion 102 and the distal periphery 117 of the punch portion 104 (i.e., the edge where the second end face 104a and the outer circumferential surface 114 of the punch portion 104 intersect). In particular, the height of the punch portion 104 is lower than the height of the main body portion 102. Furthermore, the outer circumferential surface 114 of the punch portion 104 has a cylindrical contour. That is, it is preferable that the outer circumferential surface 114 of the punch portion 104 has rounded corners that form a rounded surface overall. In other words, it is preferable that the outer circumferential surface 114 does not have sharp edges that extend beyond the virtual circumferential surface "C" (for example, shown in Figure 5) that surrounds (i.e., encloses) the outer circumferential surface 114 of the punch portion 104.

[0025]

[0031] Since the outer circumferential surface 114 of the punch portion 104 has a cylindrical contour without sharp edges, the possibility of defects (e.g., cracks) occurring in the fastener 100 and / or metal panel during installation is greatly reduced, and in some cases completely eliminated. That is, sharp or pointed edges on the outer circumferential surface 114 of the punch portion 104 are prone to cracking due to the force applied during installation. Therefore, since the fastener 100 described herein does not have sharp or pointed edges on the outer circumferential surface 114 of the punch portion 104, the aforementioned problems are eliminated and the possibility of defects occurring in the finished product is reduced.

[0026]

[0032] As shown, the outer circumferential surface 114 of the punch portion 104 has a plurality of spaced-apart notches 118 that collectively surround the punch portion 104. In one embodiment, the plurality of notches 118 are spaced equally apart from each other and all have the same configuration. Specifically, each notch 118 has a concave surface relative to the outer circumferential surface 114 of the punch portion 104. Alternatively, the plurality of notches 118 may have varying spacings and / or configurations, such as only one notch 118 having a concave surface.

[0027]

[0033] The outer circumferential surface 114 of the punch portion 104 further comprises a plurality of spaced-apart column portions 120, as shown by dashed lines in Figure 1. Each column portion 120 is defined as a region of the outer circumferential surface 114 having the cylindrical contour of the punch portion 104, between pairs of adjacent, spaced-apart notches 118. The plurality of spaced-apart column portions 120 collectively surround the punch portion 104, and each column portion 120 extends from the annular surface 108 to the distal periphery 117 of the outer circumferential surface 114 of the punch portion 104. Specifically, each column portion 120 is positioned between pairs of adjacent, spaced-apart notches 118, and separates those pairs of notches 118.

[0028]

[0034] As mentioned above, in one embodiment, it is shown that the multiple notches 118 are spaced equally apart from each other. Specifically, the multiple column portions 120 provide the equal spacing between the multiple notches 118. Therefore, the multiple column portions 120 are also spaced equally apart from each other. Furthermore, as mentioned above, the outer surface 114 of the punch portion 104 has a cylindrical contour without sharp edges; this is a result of the column portions 120 being positioned between pairs of adjacent, spaced-apart notches 118, and the pairs of notches 118 being spaced apart. In other words, if a pair of notches 118 are positioned directly adjacent to each other with nothing between them, there will be no surface with a cylindrical contour between a pair of adjacent notches 118, and sharp edges will be formed.

[0029]

[0035] Furthermore, in one embodiment, the outer circumferential surface 114 of the punch portion 104 is provided with a plurality of bridge portions 122 that are spaced apart from each other and collectively surround the punch portion 104. Specifically, each bridge portion 122 is defined as a region of the cylindrical outer circumferential surface 114 of the punch portion 104, positioned between a pair of adjacent and spaced-apart column portions 120. Furthermore, each bridge portion 122 is axially positioned between the distal periphery 117 of the outer circumferential surface 114 of the punch portion 104 and a notch 118 surrounded by a pair of adjacent and spaced-apart column portions 120. In this way, each bridge portion 122 connects a pair of adjacent and spaced-apart column portions 120.

[0030]

[0036] Moving to Figure 5, one of the lugs 110 has a contact surface 124 with a rounded contour (as shown in Figure 1). That is, the contact surface 124 is curved with respect to a virtual axis extending radially "r" of the fastener 100 (i.e., rounded in the lateral, left-right direction). Preferably, the highest point of the contact surface 124 (with respect to the virtual horizontal plane "P") is at its midpoint, but other shapes are also possible. In one embodiment, the contact surface 124 is configured to engage with a metal panel to which the fastener 100 will be attached, and is inclined downward in the radially outward direction of the fastener 100 with respect to the virtual horizontal plane "P". As shown in the illustrated embodiment, the contact surface 124 is inclined continuously downward with respect to the virtual horizontal plane "P" in the radially outward direction of the fastener 100. This particular configuration (i.e., the contact surface 124 being inclined continuously downward in the radially outward direction) creates a suitable mating surface with respect to the metal panel. In other words, as mentioned above, since the substrate (i.e., metal panel) does not easily flow (i.e., plastically deform) during installation, it is important to provide a fastener fitting surface that does not require the substrate to flow into the cavity and / or void. Accordingly, the contact surface 124 of the fastener 100 described herein allows the substrate to flow efficiently and fit into the annular surface 108 during installation. Furthermore, the configuration of the contact surface 124 (i.e., its spatial orientation and having a rounded contour) eliminates the possibility of deformation of the lug 110 during installation.

[0031]

[0037] The contact surface 124 has a first end 124a and a second end 124b. The first end 124a is positioned adjacent to the outer circumferential surface 114 of the punch portion 104, and the second end 124b is positioned radially outward from the outer circumferential surface 114 of the punch portion 104. Preferably, the first end 124a is formed together with the outer circumferential surface 114 of the punch portion 104. In particular, the second end 124b does not extend to the outer circumferential surface 112 of the main body portion 102. That is, the second end 124b of the contact surface does not form a boundary with the outer circumferential surface 112 of the main body portion 102. Rather, the second end 124b is positioned radially between the virtual circumferential surface "C" (i.e., defining the boundary of the outer circumferential surface 114 of the punch portion 104) and the periphery 116 of the annular surface 108.

[0032]

[0038] As further shown in Figures 1 and 5, each lug 110 has an outer surface 125 (distal to the punch portion 104) that tapers radially outward toward a virtual horizontal plane "P". Similar to the contact surface 124, the outer surface 125 of the lug 110 does not extend to the outer circumferential surface 112 of the body portion 102. Rather, the outer surface 125 extends from the second end 124b of the contact surface 124 to the second annular surface 108b of the rim 109. In particular, in one embodiment, the outer surface 125 of the lug 110 is continuously inclined downward radially outward with respect to the virtual horizontal plane "P" and has an inclination angle that allows the distal end of the outer surface 125 to smoothly transition with the inner diameter of the second annular surface 108b. Furthermore, in contrast to the contact surface 124, the outer surface 125 of the lug 110 is planar (for example, as shown in Figure 1). In other words, the outer surface 125 is not curved with respect to a virtual axis extending in the radial direction "r" of the fastener 100 (i.e., it is not rounded in the lateral or left-right direction). However, the outer surface 125 may have a surface contour other than a plane.

[0033]

[0039] As described above, in one embodiment, the contact surface 124 is continuously inclined downward in the radially outward direction of the fastener 100 with respect to the virtual horizontal plane "P". This is because the surface of the first end 124a of the contact surface 124 is spaced a first distance d1 from the virtual horizontal plane "P" in a direction perpendicular to the virtual horizontal plane "P", and the first distance d1 is greater than any other distance (e.g., d2) between the contact surface 124 and the virtual horizontal plane "P" in a direction perpendicular to the virtual horizontal plane "P". Furthermore, as shown, the angle α between the contact surface 124 and the outer peripheral surface 114 of the punch portion 104 is obtuse (i.e., the angle α is greater than 90° and less than 180°).

[0034]

[0040] In one embodiment, as shown in Figure 1, each of the multiple lugs 110 may have the same configuration. Furthermore, as shown, each lug 110 is radially aligned with one of the multiple notches 118. In this way, a notch 118 is formed at the first end 124a of each lug 110, which the lug 110 is radially aligned with. Therefore, the first end 124a of each lug 110 is radially positioned between the radial center point of the fastener 100 (i.e., the central axis "X") and the virtual circumferential surface "C" that defines (i.e., surrounds) the boundary of the outer circumferential surface 114 of the punch portion 104. Furthermore, the total number of radially aligned lugs 110 and notches 118 is determined according to the total number of surfaces on the outer circumferential surface 112 of the main body portion 102, and each may be radially aligned with the outer circumferential surface 112. That is, for example, in Figures 1 and 2, the fastener 100 has a total of eight surfaces that collectively constitute the outer circumferential surface 112 of the main body portion 102. Thus, the fastener 100 further comprises a total of eight lugs 110 and notches 118, each lug 110 and notch 118 being radially aligned with one of the eight surfaces that constitute the outer circumferential surface 112 of the main body portion 102. Alternatively, the total number of lugs 110 may differ from the total number of notches 118 and / or surfaces of the outer circumferential surface 112 of the main body portion 102. Furthermore, the lugs 110, notches 118 and / or surfaces of the outer circumferential surface 112 of the main body portion 102 do not need to be radially aligned. For example, one lug 110 may be radially aligned with an edge formed between a pair of adjacent surfaces of the outer circumferential surface 112 of the main body portion 102.

[0035]

[0041] All components of the fastener 100 described above, specifically the body portion 102, punch portion 104, rim 109, and lug 110, are integrally formed from each other. That is, the body portion 102, punch portion 104, rim 109, and lug 110 are all formed from the same material. However, the choice of material is not limited to this, and other suitable materials may be used. Furthermore, it is preferable that the material of the fastener 100 has a higher hardness than the hardness of the metal panel to which the fastener 100 will be attached. If the fastener is a self-clinching stud, the stud is also integrally formed from the same material.

[0036]

[0042] In particular, the aforementioned configuration of fastener 100 results in improvements that extend tool life and reduce manufacturing costs, which ultimately benefit consumers. Specifically, as mentioned above, the rim 109 of the annular surface 108 and the lug 110, which does not extend radially outward to the outer peripheral surface 112 of the main body portion 102, allow the material of the base material (i.e., metal panel) to flow (i.e., undergo plastic deformation) more easily compared to conventional fastener designs. In particular, as mentioned above, the specific configuration of the rim 109 and lug 110 promotes material flow, resulting in a force reduction of up to 50%, or in some cases even more (during installation), compared to conventional designs. Furthermore, the need to use a reflective die is eliminated. Rather, a flat (i.e., planar) die can only be used as a backstop during installation to reduce potential wear points on the tool. More specifically, the common weakness of conventional reflective dies (i.e., the raised portion) is eliminated, and the function of the raised portion is incorporated into the fastener 100 via the configuration of the rim 109. That is, the rim 109 provides the same technical advantages as the aforementioned raised portion, but is formed as part of the fastener 100 itself (rather than the die) and is therefore used only once. Thus, since the die is flat (i.e., no longer a reflective die with a raised portion) and is provided as a backstop, the life of the flat die is significantly extended to 5 to 50 times that of conventional manufacturing dies, which is a substantial improvement due to the new fastener design of the present invention. Consequently, tool life is extended and manufacturing costs are reduced.

[0037]

[0043] As briefly mentioned above and as described with respect to Figure 6, the fastener 100 may be a self-piercing and / or self-clinching stud. In such a configuration, the fastener 100 comprises a body portion 102 and a punch portion 104. The shank 126 extends outward from the second end face 104a of the fastener 100 along the central axis "X". In other examples, the shank 126 may extend outward from the first end face 102a of the fastener 100 along the central axis "X". As shown, threads may be formed on at least a portion of the shank 126. Alternatively, the shank 126 may not be threaded.

[0038]

[0044] Moving briefly to Figure 7, an alternative fastener 100 is shown. As mentioned above, the second annular surface 108b of the annular surface 108 does not need to have a radius of curvature. Rather, the second annular surface 108b may have a linear cross-section and extend perpendicularly to the virtual horizontal plane "P". Alternatively, the second annular surface 108b may have a linear cross-section and be oriented at a predetermined angle (other than 90°) with respect to the virtual horizontal plane "P". As further shown in Figure 7, the outer surface 125 of each lug 110 may have the same orientation as the second annular surface 108b with respect to the virtual horizontal plane "P". Specifically, as shown, the outer surface 125 extends perpendicularly to the virtual horizontal plane "P" and coincides with the second annular surface 108b. However, the outer surface 125 may be oriented at a predetermined angle (other than 90°) with respect to the virtual horizontal plane "P".

[0039]

[0045] The present invention has been described with reference to the exemplary embodiments described above. Changes and modifications will be made by reading and understanding this specification. Exemplary embodiments incorporating one or more aspects of the present invention include all such changes and modifications, insofar as they fall within the scope of the appended claims.

Claims

1. A self-clinching fastener for attachment to a plastically deformable metal substrate, wherein the self-clinching fastener is A main body portion having a central axis, comprising an outer circumferential surface extending in the direction of the central axis and an annular surface extending in a direction perpendicular to the central axis, wherein the annular surface includes a first annular surface, a second annular surface and a third annular surface, the third annular surface is located on a virtual horizontal plane, and the first and second annular surfaces define a rim protruding from the virtual horizontal plane in the direction of the central axis, A punch portion, wherein the punch portion is coaxial with the central axis, and the annular surface extends from the main body portion so as to surround the punch portion, and the punch portion includes an outer peripheral surface extending in the direction of the central axis, The punch portion is surrounded by a plurality of spaced lugs that protrude axially outward from the annular surface, wherein one of the plurality of lugs is inclined downward in the radially outward direction of the self-clinching fastener with respect to the virtual horizontal plane, and the plurality of spaced lugs are provided, A self-clinching fastener wherein the first annular surface extends radially outward from the outer circumferential surface of the punch portion, the second annular surface is radially positioned between the first annular surface and the third annular surface, and one of the plurality of lugs is inclined downward to the second annular surface.

2. The self-clinching fastener according to claim 1, wherein the inner diameter of the first annular surface intersects the outer circumferential surface of the punch portion, the outer diameter of the first annular surface intersects the inner diameter of the second annular surface, and the outer diameter of the second annular surface intersects the inner diameter of the third annular surface.

3. The self-clinching fastener according to claim 2, wherein the first annular surface has a planar cross-section and is angled with respect to the virtual horizontal plane, and the second annular surface has a curved cross-section such that the second annular surface curves continuously toward the virtual horizontal plane in a radially outward direction.

4. The self-clinching fastener according to claim 1, wherein the second annular surface has a concave cross-section.

5. The self-clinching fastener according to claim 1, wherein one of the plurality of lugs includes a contact surface having a first end and a second end, the first end is positioned adjacent to the outer circumferential surface of the punch portion, and the second end is positioned radially outward from the outer circumferential surface of the punch portion.

6. The self-clinching fastener according to claim 5, wherein the punch portion has a cylindrical contour located on a virtual circumferential surface, the first end is radially positioned between the central axis and the virtual circumferential surface, the second end is radially outward from the virtual circumferential surface, and the contact surface is continuously inclined downward from the first end to the second end.

7. The self-clinching fastener according to claim 5, wherein one of the plurality of lugs further includes an outer surface that tapers continuously toward the virtual horizontal plane in a radially outward direction.

8. The self-clinching fastener according to claim 7, wherein the outer surface extends from the second end of the contact surface to the second annular surface.

9. The self-clinching fastener according to claim 8, wherein the contact surface has a rounded contour and the outer surface has a flat contour.

10. The self-clinching fastener according to claim 1, wherein a screw through hole is formed in at least one of the main body portion and the punch portion.

11. The self-clinching fastener according to claim 1, wherein the rim and one of the plurality of lugs do not have a boundary with the outer circumferential surface of the main body portion.

12. The outer circumferential surface of the punch portion has a cylindrical contour, and the outer circumferential surface of the punch portion is Multiple spaced notches surrounding the punch portion, The self-clinching fastener according to claim 1, comprising: a plurality of spaced-apart column portions surrounding the punch portion, each of which column portions is positioned between each pair of adjacent spaced-apart notches and spaced apart from each pair of notches.

13. The self-clinching fastener according to claim 12, wherein each column portion extends from the rim to the distal periphery of the outer surface of the punch portion.

14. The self-clinching fastener according to claim 13, wherein the outer circumferential surface of the punch portion further comprises a plurality of bridge portions surrounding the punch portion, and each bridge portion connects each pair of adjacent spaced-apart column portions.

15. The self-clinching fastener according to claim 14, wherein each bridge portion is arranged axially between the distal periphery of the outer surface of the punch portion and each of the notches of the plurality of notches.

16. The self-clinching fastener according to claim 14, wherein a screw through hole is formed in at least one of the main body portion and the punch portion.

17. A self-clinching fastener for attachment to a plastically deformable metal substrate, wherein the self-clinching fastener is A main body portion having a central axis, comprising an outer circumferential surface extending in the direction of the central axis and an annular surface extending in a direction perpendicular to the central axis, wherein the annular surface includes a first annular surface, a second annular surface and a third annular surface, the third annular surface being located on a virtual horizontal plane, and the first and second annular surfaces defining a rim protruding from the virtual horizontal plane in the direction of the central axis, A punch portion, wherein the punch portion is coaxial with the central axis, and the annular surface extends from the main body portion such that it surrounds the punch portion, and the punch portion includes an outer surface having a cylindrical contour that extends in the direction of the central axis and is located on a virtual circumferential surface, The punch portion is surrounded by a plurality of spaced lugs that project outward axially from the annular surface, wherein one of the plurality of lugs is inclined downward radially outward with respect to the virtual horizontal plane, and comprises a plurality of spaced lugs, The first annular surface extends radially outward from the outer circumferential surface of the punch portion, and the second annular surface is radially positioned between the first annular surface and the third annular surface. The first annular surface has a planar cross-section and is angled with respect to the virtual horizontal plane, and the second annular surface has a concave cross-section such that the second annular surface is continuously curved radially outward toward the virtual horizontal plane. A self-clinching fastener in which one of the plurality of lugs is inclined downward to the second annular surface.

18. The self-clinching fastener according to claim 17, wherein one of the plurality of lugs includes a contact surface having a first end and a second end, the first end being radially positioned between the central axis and the virtual circumferential surface, the second end being radially outward from the virtual circumferential surface, and the contact surface being continuously inclined downward from the first end to the second end.

19. The self-clinching fastener according to claim 18, wherein one of the plurality of lugs further includes an outer surface that tapers continuously from the second end of the contact surface to the second annular surface.

20. The self-clinching fastener according to claim 19, wherein the rim and one of the plurality of lugs do not have a boundary with the outer circumferential surface of the main body portion.

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