Self-clinching fasteners

Abstract

A self-clinching fastener is intended for attachment to a deformable metal panel. The self-clinching fastener comprises a body portion having a central axis and a punch portion extending from the body portion and coaxial with the central axis. The body portion forms a generally annular fastener face adjacent to the punch portion, and the punch portion has an inclined wall extending from the fastener face and forming a groove. A plurality of protrusions protrude from the fastener face, surround the punch portion, and are spaced apart from each other, and a plurality of recessed portions surround the punch portion and are spaced apart from each other within the fastener face. The plurality of protrusions and the recessed portions form abutments to improve the torsional resistance of the fastener.

Description

Technology Field

[0001] It is a self-clinching fastener. Background Technology

[0002] Self-clinching fasteners are a type of fastener (e.g., nut) installed within a substrate, such as sheet metal. This installation may involve pressing the self-clinching fastener into the substrate if it self-penetrates, or pressing it into a pre-punched or pre-drilled hole within the substrate. Self-clinching fasteners generally include geometric features, such as protrusions on the fastener face, which deform parts of the substrate and cause them to flow into areas of the self-clinching fastener (e.g., areas between protrusions). The result is that the substrate binds to the geometric features of the self-clinching fastener, creating a mechanical bond that holds the self-clinching fastener in place. Self-clinching fasteners may include female threads that accommodate screws or bolts to mount objects to the sheet metal substrate.

[0003] However, conventional self-clinching fasteners suffer from various defects, including but not limited to low push-out force thresholds, low torque-out force thresholds, and sometimes the requirement to pre-punch or pre-drill holes in the metal substrate to facilitate fastener installation. These defects lead to assembly costs and fastener failure.

[0004] In one aspect, the present disclosure relates to a self-clinching fastener for attachment to a deformable metal panel, wherein the self-clinching fastener comprises: a body portion having a central axis; a punch portion extending from the body portion and coaxial with the central axis, wherein the body portion forms a generally annular fastener face adjacent to the punch portion, and the punch portion has an inclined wall extending from the fastener face and forming a groove; a plurality of protrusions protruding from the fastener face and surrounding the punch portion and spaced apart from each other; and a plurality of spaced-apart recess portions within the fastener face surrounding the punch portion, wherein the plurality of protrusions and the recess portions form abutments to improve the torsional resistance of the fastener.

[0005] In embodiments of the present aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the fastener surface comprises 4 to 12 of the plurality of protrusions and 4 to 12 of the plurality of recessed portions.

[0006] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of protrusions and the plurality of recessed portions alternately surround the punch portion along the fastener surface.

[0007] In the embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of protrusions are Y-shaped structures on the fastener surface.

[0008] In embodiments of the present aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, each of the plurality of protrusions has a plurality of arms extending from a central portion of the protrusions, the plurality of arms form a plurality of wedges, and at least one of the plurality of wedges has a surface that is declining toward the fastener surface.

[0009] In embodiments of the present aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of arms includes a first arm extending from the center portion of the protrusions toward the inclined wall of the punch portion along the fastener surface, and the first arm has a first surface inclined downward toward the fastener surface.

[0010] In embodiments of the present aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of arms includes a second arm and a third arm extending from the center portion of the protrusions toward the outer perimeter of the fastener surface along the fastener surface, the second arm has a second surface that slopes downward in a direction away from the center portion of the protrusions, the third arm has a third surface that slopes downward in a direction away from the center portion of the protrusions, and the second arm and the third arm form a common surface that slopes downward in a direction away from the center portion of the protrusions between the second arm and the third arm.

[0011] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of recess portions include a surface that slopes progressively downward from the fastener surface to the flat bottom surface of the recess portions.

[0012] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the plurality of recess portions extend toward the inclined wall of the punch portion and meet the inclined wall.

[0013] In embodiments of the present aspect, a self-clinching fastener disclosed according to any one of the exemplary embodiments, wherein the plurality of recess portions have a recess volume corresponding to the protrusion volume of the plurality of protrusions.

[0014] In the embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inclined wall of the punch portion defines a first diameter of the punch portion at the fastener face and a second diameter at the opening of the punch portion.

[0015] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inclined wall of the punch portion includes a curved transition portion that meets the fastener surface.

[0016] In the embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inclined wall of the punch portion is a swallowtail's structure.

[0017] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inclined wall of the punch portion includes a flat portion forming an edge at the end portion of the punch portion.

[0018] In embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inclined wall of the punch portion includes a self-piercing edge for penetrating the deformable metal panel.

[0019] In the embodiments of this aspect, in the disclosed self-clinching fastener according to any one of the exemplary embodiments, the inner surface of the punch portion includes a female thread for mating to a bolt.

[0020] In one aspect, the present disclosure relates to a method for attaching a self-clinching fastener to a deformable metal panel. The method comprises the step of coaxially positioning the fastener and the die member on opposite sides of the metal panel at a position where the fastener is to be fixed to the metal panel, wherein the fastener comprises a body portion having a central axis, a punch portion extending from the body portion and coaxial with the central axis, wherein the body portion forms a generally annular fastener face adjacent to the punch portion, and the punch portion has an inclined wall extending from the fastener face and forming a groove, a plurality of protrusions protruding from the fastener face and surrounding the punch portion and spaced apart from each other, and a plurality of recess portions spaced apart from each other within the fastener face surrounding the punch portion, wherein the plurality of protrusions and the recess portions form abutments to improve the torsional resistance of the fastener; and includes the step of moving the die member and the fastener relative to each other in an axial direction so as to deform a portion of the panel into the groove of the fastener to improve the torsional resistance of the fastener until a secure mechanical interlock is formed between the fastener and the panel.

[0021] In embodiments of the present aspect, the disclosed method for attaching a self-clinching fastener according to any one of the exemplary embodiments comprises the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the plurality of protrusions press the deformed portion of the panel into the groove and the deformed portion of the panel into the plurality of recess portions.

[0022] A disclosed method for attaching a self-clinching fastener according to any one of the exemplary embodiments above comprises the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the plurality of protrusions press the deformed portion of the panel into at least three distinct directions away from the center portion of the plurality of protrusions.

[0023] A disclosed method for attaching a self-clinching fastener according to any one of the exemplary embodiments above includes the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the edge of the punch portion penetrates the deformable metal panel. Brief explanation of the drawing

[0024] To enable a detailed understanding of the cited features of the present disclosure, a more specific description of the present disclosure, which has been briefly summarized above, may be made by referring to exemplary embodiments, some of which are illustrated in the accompanying drawings. However, the accompanying drawings are intended to illustrate only exemplary embodiments of the present disclosure and should not be construed as limiting the scope thereof, as the present disclosure may allow for other equally effective embodiments. FIG. 1a shows a perspective view of a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 1b illustrates a front view of a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 1c illustrates a side view of a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 2a illustrates a cross-sectional view of an installation tool and a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 2b illustrates an installation tool and a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 2c illustrates a perspective view of an imprint in sheet metal caused by the installation of a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 2d illustrates an analysis of an imprint in a sheet metal caused by the installation of a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 3a shows a front view of the self-clinching fastener of FIG. 1a according to an exemplary embodiment of the present disclosure. FIG. 3b shows a front view of the self-clinching fastener of FIG. 1a according to an exemplary embodiment of the present disclosure. FIG. 3c shows a detailed front view of the self-clinching fastener of FIG. 1a according to an exemplary embodiment of the present disclosure. FIG. 3d illustrates a side view of the self-clinching fastener of FIG. 1a according to an exemplary embodiment of the present disclosure. FIG. 3e illustrates a side view of the self-clinching fastener of FIG. 1a according to an exemplary embodiment of the present disclosure. FIG. 3f illustrates an installation tool and a self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 4a shows a perspective view of another self-clinching fastener according to an exemplary embodiment of the present disclosure. FIG. 4b shows a front view of the self-clinching fastener of FIG. 4a according to an exemplary embodiment of the present disclosure. FIG. 4c illustrates another front view of the self-clinching fastener of FIG. 4a according to an exemplary embodiment of the present disclosure. FIG. 5 illustrates a flowchart illustrating the installation of the self-clinching fastener of FIG. 4a according to an exemplary embodiment of the present disclosure. FIG. 6 illustrates a block diagram of a die press according to an exemplary embodiment of the present disclosure. Specific details for implementing the invention

[0025] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of components and steps, formulas, and numerical values ​​defined in these exemplary embodiments do not limit the scope of the present disclosure unless specifically stated otherwise. The following description of at least one exemplary embodiment is by nature merely illustrative and is by no means intended to limit the present disclosure, its applications, or its uses. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but are intended to be part of the detailed description where appropriate. In all examples illustrated and discussed in this document, any specific values ​​should be interpreted as illustrative and non-limiting. Accordingly, other exemplary embodiments may have different values. It should be noted that similar reference numerals and letters refer to similar items in the following drawings, so once an item is defined in one drawing, it may not be necessary to discuss it further in the following drawings. Below, exemplary embodiments will be described with reference to the accompanying drawings.

[0026] The present disclosure relates to a solution for providing a self-clinching fastener (e.g., a nut) having various features that reduce installation costs and provide improved resistance to push-out forces and torque-out forces (i.e., torsion). One of these features is a self-piercing edge that allows the self-clinching fastener to be pressed directly into a substrate (e.g., sheet metal) without requiring pre-drilled or pre-punched holes. In other words, the self-clinching fastener can be installed in a single compressive motion in which a relative force is applied between the self-clinching fastener and the substrate, such that a portion of the self-clinching fastener pierces directly through the substrate and another portion of the self-clinching fastener deforms the substrate to be permanently attached to the substrate.

[0027] The self-clinching fastener disclosed in this document generally comprises three main geometric features to ensure a tight bond with a target substrate. These geometric features may include an anti-pushing punch portion, anti-rotation protrusions, and anti-rotation recess portions. The anti-pushing punch portion may include an inclined neck extending from an annular fastener face at the location of a groove toward the self-piercing edge of the fastener. The anti-rotation protrusions may include inclined and raised geometric shapes protruding from the fastener face. The anti-rotation recess portions may include recesses within the fastener face. In one configuration, the self-clinching fastener comprises a plurality of anti-rotation protrusions and anti-rotation recess portions alternately positioned as abutments around the fastener face.

[0028] During installation, the self-clinching fastener may be pressed into the substrate, or vice versa. As the self-piercing edge of the fastener comes into contact with the substrate, the self-piercing edge pierces the substrate. Subsequently, as the anti-rotation protrusions come into contact with the substrate, the anti-rotation protrusions deform the substrate material and create indentations within the substrate. The mass of the substrate material deformed by the anti-rotation protrusions is forced (i.e., flows) into the groove (i.e., curved transition) formed between the fastener face and the anti-pushing neck, and into the anti-rotation recesses on the fastener face, thereby binding the substrate material to the fastener geometry. Consequently, the material within the groove formed between the fastener face and the anti-pushing neck resists the push-out force applied to the fastener, while the anti-rotation protrusions embedded in the substrate material resist the torque-out force applied to the fastener. The self-clinching fasteners described in this document may be installed in various products, including electric vehicles (EVs), to provide a fastening mechanism within EVs. For example, self-clinching fasteners may be installed within the metal panels (sheet metal) of an EV to provide mounting points for batteries, seats, etc. Although the application of self-clinching fasteners is described with reference to installation within an EV, it should be noted that self-clinching fasteners may be employed on any platform where self-clinching fasteners are required.

[0029] It should be noted that while the drawings and description of the present disclosure relate to self-clinching nuts for attachment to sheet metal substrates, the present disclosure is not limited to nuts or sheet metal substrates. Other types of self-clinching fasteners may utilize the self-penetrating and self-clinching features of self-clinching nuts. Such self-clinching fasteners may include, but are not limited to, self-clinching studs, self-clinching bolts, etc.

[0030] FIG. 1a illustrates a perspective view of a self-clinching fastener (100) comprising a body portion (114) and a punch portion (108). The body portion (114) comprises a plurality of protrusions (104) having various arms each comprising wedges (102), and a fastener surface (116) having a plurality of recessed portions (106). In this example, the plurality of protrusions (104) and the plurality of recessed portions (106) are formed circumferentially around the periphery of the fastener surface (116) of the self-clinching fastener (100). The punch portion (108) extends coaxially with the center axis from the fastener surface (116) and includes a center opening (112) having a female thread (110) and a self-penetrating edge (118). Self-clinching fasteners are generally formed from a metal (e.g., an alloy) through a process that may include the steps of cutting a piece of metal into the general shape of a nut, forging the nut into a desired shape including the self-penetrating and self-clinching features described above, thread rolling the nut to form threads for receiving and mating a screw or bolt, heat treatment to increase strength and durability, and finishing the surface, such as coating the nut with a protective finish. Structural and functional details of the self-penetrating and self-clinching features are now described with reference to the remaining drawings.

[0031] FIG. 1b illustrates a front view of a self-clinching fastener in which self-clinching features are illustrated and described in more detail. As previously mentioned, the fastener surface (116) includes protrusions (104) and recessed portions (106).

[0032] In this example, the protrusions (104) (i.e., ribs) are Y-shaped, comprising three arms (104A, 104B, 104C) radiating from the center portion (104D) of the protrusion toward the punch portion in one direction and toward the outer circumference of the fastener in the other direction. The arm (104A) is generally formed by a wedge surface (131) and inclined side surfaces (133, 137). The wedge surface (131) slopes from a maximum height above the fastener face (116) at the upper surface (132) to a minimum height above the fastener face (116) at the location of the groove where the fastener face (116) meets the punch portion (108). In other words, the wedge surface (131) slopes downward toward the groove where the fastener face (116) meets the punch portion (108). The arms (104B, 104C) are generally formed with a flat upper surface (132) and inclined side surfaces (133, 134, 135, 136, 137) extending from a maximum height above the fastener surface (116) on the upper surface (132) to the fastener surface (116). As shown in FIG. 1b, the protrusions (104) may be formed circumferentially and alternately around the perimeter of the fastener surface (116) of the self-clinching fastener. Although eight protrusions are shown in FIG. 1b, other configurations are possible and may fall within the range of four to twelve protrusions, but are not limited thereto.

[0033] In this example, the recess portions (106) are rectangular in shape and include a bottom portion (141) and side walls (142, 143, 144). The side walls (142, 143, 144) generally extend below the fastener face (116) and meet the bottom portion (141) at a set height below the fastener face (116). One or more of the side walls (142, 143, 144) may be straight or inclined with respect to the fastener face (116). The recess portions (106) may generally extend from a predefined point on the fastener face (116) toward the groove where the fastener face (116) meets the punch portion (108). As illustrated in FIG. 1b, recessed portions (106) may be formed circumferentially around the fastener face (116) of the self-clinching fastener in an alternating manner with respect to the protrusions (104). Although eight recessed portions are illustrated in FIG. 1b, other configurations are possible and may fall within the range of four to twelve recessed portions, but are not limited thereto.

[0034] Note that although the protrusions (104) are depicted as Y-shaped, other shapes (e.g., various combinations of wedges and flat legs) are possible. For example, the protrusions (104) may have two I-shaped legs, four X-shaped legs, etc., as long as the legs force the deformed metal of the substrate to flow into the groove of the punch portion and into the recess portions. Note that although the recess portions (106) are depicted as rectangular in shape, other shapes are possible. For example, the recess portions (106) may be triangular shapes, circular shapes, etc., as long as the internal volume of the recess portions (106) is suitable for accommodating the deformed portion of the metal substrate flowing from the depressions caused by the protrusions (104). This configuration is advantageous because, as the metal substrate is deformed by the protrusions (104), a portion of the metal flows into the recessed portions (106) to form a solid mechanical bond between the substrate and the nut. This mechanical bond defines the torque-out force of the nut (i.e., how much force is required to rotate and remove the nut from the substrate after installation). Without the recessed portions (106), the portion of metal flowing away from the protrusions (104) would have nowhere to go but away from the fastener (100), resulting in the formation of unwanted bubbles of the substrate material outside the diameter of the fastener. In other words, the recessed portions (106) not only provide improved resistance to the torque-out force but also allow the substrate to deform in a more uniform manner.

[0035] FIG. 1c illustrates a side view of a self-clinching fastener in which self-clinching and self-penetrating features are illustrated and described in more detail. As illustrated, the self-clinching fastener comprises a side body surface (161), side punch portion surfaces (162, 163), and a self-penetrating edge (164). The side body surface (161) may form a rounded shape of the self-clinching fastener. However, the side body surface (161) is not limited to a rounded shape. The side punch portion surface (162) is a slanted surface (i.e., a slanted wall) having a shape (e.g., a swallowtail's structure) extending from the fastener face (116) toward the slanted surface (163). More specifically, the side punch portion surface (162) is slanted such that the diameter of the punch portion is minimum at the fastener face (116) and maximum at a height away from the fastener face (116) (e.g., the self-penetrating edge (164)). This configuration forms an annular groove (165) at the intersection of the side punch portion surface (162) and the fastener surface (116). The groove (165) is advantageous because, as the metal substrate deforms, a portion of the metal flows (i.e., is forced) into the groove (165) to form a solid mechanical bond between the substrate and the nut. This mechanical bond partially defines the push-out force of the nut (i.e., how much force is required to push the nut out of the substrate after installation).

[0036] Note that the self-penetrating edge (164) may be a sharpened edge that allows the nut to easily cut through the metal substrate during installation. In other words, the self-penetrating edge (164) assists the installation process by making a hole in the substrate when a relative force is applied between the nut and the substrate. This eliminates the need for pre-punched or pre-drilled holes within the metal substrate and allows the nut(s) to be installed by a single pressing action, which is described in more detail below.

[0037] FIG. 2a illustrates a cross-sectional view of a self-clinching fastener inserted into an installation tool (200). In this example, the installation tool (200) is a die press comprising an upper die member (201) having a hollow core (202) and a lower die member (205) having a recess (206) for receiving a self-clinching nut (100). Before compression, the self-clinching nut (100) is seated within the recess (206) of the lower die member (205), and a metal substrate (203) is positioned over the self-clinching nut (100). In this configuration, the self-penetrating edge (164) of the self-clinching nut (100) faces the substrate (203). During compression, a force is applied to at least one of the upper die member (201) and / or the lower die member (205) to force the dies toward each other. As the self-clinching nut (100) comes into contact with the substrate (203), the self-penetrating edge (164) penetrates the slug from the substrate to form a hole (204) within the substrate (203). The slug is received by the hollow core (202). As the substrate (203) subsequently comes into contact with the protrusions (104) on the fastener surface of the self-clinching nut (100), the protrusions (104) deform the substrate (203) so that parts of the substrate material flow away from the protrusions (104) and into the recessed parts (106) and groove (165), thereby creating a solid mechanical bond between the self-clinching nut (100) and the substrate (203). When the dies are retracted, the substrate (203) with the self-clinching nut (100) installed inside can be removed from the die as the installation of the nut is complete.

[0038] More specifically, during die pressing, as the substrate (203) comes into contact with the protrusions (104) on the fastener face of the self-clinching nut (100), the upper surface (132) of the protrusions (104) deforms the substrate (203) so that portions of the substrate material flow toward the recessed portions (106) away from the side surfaces (133, 134, 135, 137) of the protrusions. This excess material flows into the empty space defined by the recessed portions (106) because the geometry of the protrusions is designed (e.g., angle formation, etc.) to guide the excess material toward the recessed portions (106). Additionally, as the substrate (203) comes into contact with the protrusions (104) on the fastener surface of the self-clinching nut (100), the wedge surface (131) of the protrusions (104) deforms the substrate (203), causing parts of the substrate material to flow away from the wedge surface (131). Since the wedge surface (131) is inclined toward the annular groove (165), excess material flows into the groove due to the force generated by the wedge. The wedge surface (131) effectively pushes and squeezes a portion of the substrate into the groove.

[0039] Note that the force of the die is sufficient for the protrusions (104) to deform the substrate (203). However, an additional flange (207) on the upper die member (201) may also be included to increase the flow of the substrate material by increasing the force applied by the protrusions. In one example, the flange (207) is a protruding annular portion of the die that aligns with the recessed portions (106). The advantage of the flange (207) is that additional pressure is applied to specific portions of the substrate over the recessed portions (106), thereby ensuring that the substrate material is forced into the recessed portions (106) and the groove (165), thereby improving anti-rotation performance and mechanical bonding.

[0040] FIG. 2b illustrates a side view of the installation tool (220) and the self-clinching fastener when the substrate is deformed due to the action of the die press. As illustrated, the self-clinching nut (100) begins to press against the substrate (203) which begins to deform due to the force applied on one side of the substrate by the protrusions (104) and the force applied on the opposite side of the substrate by the upper die member (201). Parts of the substrate (203) begin to flow into the recessed parts (106) (not illustrated) and into the groove (165) between the surfaces (222, 224). FIG. 2b shows the groove (165) beginning to be filled with the substrate material (203), and after the compression is completed, most, if not all, of the empty space within the groove (165) is filled with the substrate material (203). Since the groove (165) is located on the smaller diameter of the punch portion (108), the material located in the groove (165) resists the push-out movement of the self-clinching nut (100) along the illustrated push-out axis (i.e., resists the nut coming out of the substrate). Additionally, most of the empty space within the recessed portions (106), if not all, is filled with substrate material (203), and the protrusions are embedded within the substrate material (203). Since the substrate material flows alternately in and out of the recessed portions (106) and over the protrusions (104), the material resists the torque-out movement of the self-clinching nut (100) along the illustrated torque-out axis (i.e., resists the nut rotating out of the substrate). FIG. 2c shows a perspective view of an imprint (240) in the substrate metal caused by the installation of the self-clinching fastener. As described, the base metal (241) includes impressions of protrusions (104), recessed portions (106), and grooves (165).Specifically, the imprint marks (242) are raised (i.e., embossed) features corresponding to the geometry of the recessed parts (106), whereas the imprint marks (243) are recessed (i.e., debossed) features corresponding to the geometry of the protrusions (104). Additionally, the imprint marks (244) take the form of an annular groove (165). These imprint marks are beneficial for resisting force from disengaging the self-clinching fastener (100) from the substrate. Specifically, the imprint marks / recesses (242, 243) press against the side surfaces (side walls) of the recessed parts (106) and protrusions (104) to resist torque-out force on the illustrated torque-out axis, whereas the imprint (244) presses against the surfaces of the groove (165) to resist push-out force on the illustrated push-out axis. The result is a self-clinching fastener (100) installed in a metal substrate in such a way that it creates a strong mechanical bond that resists common forces (e.g., push / pull and rotational forces) applied to self-clinching fasteners. FIG. 2d shows an enlarged analysis view (260) of the imprints in the sheet metal caused by the installation of the self-clinching fasteners as shown in FIG. 2c. More specifically, FIG. 2d shows the opposite side (e.g., bottom) of the substrate as shown in FIG. 2c, where the marks (242) are recessed (i.e., debossed) features corresponding to the geometry of the recessed parts (106), whereas the marks (243) are raised (i.e., embossed) features corresponding to the geometry of the protrusions (104).

[0041] FIGS. 3a through 3f are now described. These drawings are mechanical drawings showing the dimensions of a self-clinching fastener (100) from various perspective views. The dimensions are identified but are not limited to any specific range. In other words, the values ​​of each dimension and the relative sizes of the dimensions can be selected by the designer based on specific use cases.

[0042] FIG. 3a illustrates a front view (300) of a self-clinching fastener. The self-clinching fastener (100) may include various features and dimensions, including but not limited to an outer diameter (301), a radial spacing (302) between adjacent protrusions (104), a radial spacing (303) between adjacent recessed portions (106), and a radial spacing (304) between adjacent protrusions (104) and recessed portions (106). In the illustrated example, the self-clinching fastener (100) includes eight equally spaced protrusions (104) and eight equally spaced recessed portions (106), but it should be noted that the number of protrusions (104), the number of recessed portions (106), the spacing, and the dimensions are subject to the designer's needs based on the requirements of the use example.

[0043] FIG. 3b illustrates another front view (320) of a self-clinching fastener. The self-clinching fastener (100) may include various features and dimensions, including but not limited to: an outer width of the protrusion (321), a protrusion diffusion angle (322), a central axis of the protrusion (323), a protrusion arm sweep angle (324), an inner width of the protrusion (325), a fastener central axis (326), an inner dimension of the recess part (327), an outer dimension of the recess part (328), a vertical end of the recess part (329), a vertical top of the recess part (330), a recess part end (331), and a top of the recess part (332).

[0044] FIG. 3c illustrates a front view (340) of a self-clinching fastener. The self-clinching fastener (100) may include various features and dimensions, including but not limited to a protruding arm length (342) measured from a protruding arm line (341), a protruding arm separation distance (343), and a protruding arm sweep angle (344). FIG. 3d illustrates a side view (350) of a self-clinching fastener. The self-clinching fastener (100) may include various dimensions, including but not limited to a groove diameter (351), a punch portion height (352), a protrusion roundness (355), a recess portion depth (353) measured from the fastener face of the nut, and a protrusion height (354) measured from the rear of the nut.

[0045] FIG. 3e illustrates a side view (360) of a self-clinching fastener. The self-clinching fastener (100) may include various dimensions, including but not limited to a punch portion diameter (361), groove sweep angles (362, 363) of a groove (364), a thread size (365), a punch portion bevel height (366), and a protrusion height (367).

[0046] FIG. 3f illustrates a drawing (370) of an installation tool and a self-clinching fastener. The installation tool may include various dimensions, including but not limited to the outer flange diameter (371), inner flange diameter (372), and flange height (374) of the upper die member (376), and the void width (373) and void height (375) of the lower die member (377).

[0047] FIGS. 3a through 3e are mechanical drawings showing the dimensions of a self-clinching fastener (100) from various perspective views. However, note that other fastener configurations (e.g., different body shapes / sizes, different numbers / shapes / distances of protrusions and recesses, etc.) are possible. For example, FIGS. 4a and 4b are mechanical drawings showing the dimensions of a different self-clinching fastener (400) from various perspective views. The dimensions are identified but are not limited to any specific range. In other words, the values ​​of each dimension and the relative sizes of the dimensions can be selected by the designer based on specific use cases.

[0048] FIG. 4a illustrates a perspective view of a self-clinching fastener (400) comprising a body portion (414) and a punch portion (408). The body portion (414) comprises a plurality of protrusions (404) having various arms each comprising wedges (402), and a fastener surface (416) having a plurality of recessed portions (406). The body portion (414) may be similar to or different from the body shown in FIG. 3a through 3e. For example, the body portion (414) may have a hexagonal shape as illustrated. The protrusions (404) may be similar to or different from the protrusions shown in FIG. 3a through 3e. For example, the arms of the protrusions may have curved or inclined surfaces on the outer perimeter edges as illustrated. Likewise, the recessed portions (406) may be similar to or different from the recessed portions illustrated in FIGS. 3a through 3e. For example, the shapes of the recessed portions (406) may have more curved shapes and curved walls as illustrated. In either case, a plurality of protrusions (404) and a plurality of recessed portions (406) are formed circumferentially around the perimeter of the fastener face (416) of the self-clinching fastener (400). The punch portion (408) extends coaxially with the center axis from the fastener face (416) and includes a center opening (412) having a female thread (410) and a self-penetrating edge (418). Self-clinching fasteners are generally formed from metal (e.g., alloy) through a process that may include the steps of cutting a piece of metal into the general shape of a nut, forging the nut into a desired shape including the self-penetrating and self-clinching features described above, thread-rolling the nut to form threads for receiving and engaging a screw or bolt, heat treatment to increase strength and durability, and finishing the surface, such as coating the nut with a protective finish.Structural and functional details of the self-penetrating and self-clinching features are now described with reference to the remaining drawings.

[0049] FIG. 4b illustrates a front view (420) of a self-clinching fastener. The self-clinching fastener (400) may include various dimensions, including but not limited to an outer diameter (421), a radial spacing (423) between adjacent protrusions, an outer perimeter (425), a radial spacing (422) between adjacent recessed portions, and a radial spacing (424) between adjacent protrusions and recessed portions. In the illustrated example, the self-clinching fastener (400) includes six equally spaced protrusions and six equally spaced recessed portions, but it should be noted that the number of protrusions, the number of recessed portions, and the spacing are subject to the designer's needs based on the requirements of the use example.

[0050] FIG. 4c illustrates another front view (440) of a self-clinching fastener (400). The self-clinching fastener (400) may include various dimensions, including but not limited to: an outer width of the protrusion (441), a protrusion diffusion angle (442), a center axis of the protrusion (443), a protrusion arm sweep angle (444), an inner width of the protrusion (445), a fastener center axis (446), an inner dimension of the recess part (447), an outer dimension of the recess part (448), a vertical end of the recess part (449), a vertical top of the recess part (450), a top of the recess part (451), and a end of the recess part (452).

[0051] FIGS. 3a through 3f and FIGS. 4a through 4c illustrate various features and dimensions of a self-clinching fastener (100) and an installation tool. Note that the size of the fastener, the number of features (e.g., protrusions, recessed parts, etc.), their shapes, their spacing, and their dimensions are to be determined by the designer based on the needs of the use case. For example, self-clinching fasteners may be manufactured in metric or standard fastener (e.g., nut) sizes. Some metric fastener sizes useful for automotive applications may include, but are not limited to, M5 to M12 nuts, while their standard equivalent fastener sizes may be 3 / 16 inch to 1 / 2 inch nuts. Likewise, the number of features (e.g., protrusions, recessed parts, etc.), their shapes, their spacing, and their dimensions may be based on the overall size of the fastener and / or the desired torque-out and push-out forces. For example, an M5 fastener may have the same number and spacing of protrusions and recesses as an M12 fastener, but the protrusions and recesses of the M12 fastener may be larger than those of the M5 fastener. In another example, the M12 fastener may also be designed with a greater number of protrusions and recesses to resist greater torque-out and push-out forces. In other words, the number of features (e.g., protrusions, recesses, etc.), their shapes, spacing, and dimensions may be designed based on various factors, including but not limited to the size of the fastener, the desired torque-out and push-out forces, the fastener material, the substrate material, and other use case factors.

[0052] As described above, an installation tool such as a die press is used to install one or more self-clinching fasteners into a substrate such as sheet metal. FIG. 5 illustrates a flowchart (500) illustrating an exemplary installation of a self-clinching fastener. Generally, a die press may be structured to include one or more die presses, each configured to install a self-clinching nut into a substrate. An exemplary die press is illustrated in the block diagram (600) of FIG. 6 and comprises an upper die bolster (606) comprising one or more upper die members (606A, 606B), a lower die bolster (608) comprising one or more self-clinching nuts (608A, 608B) seated in empty spaces within the lower die bolster, and an actuator (604) (e.g., a pneumatic actuator) that is controlled by a controller (602) (e.g., a processor, memory, software, input / output terminals, etc.) to move the upper die bolster (606) and / or the lower die bolster (608) toward each other so that a substrate (610) is squeezed between one or more upper die members (606A, 606B) and one or more self-clinching nuts (608A, 608B) that are axially aligned with each other. Various sensors (not shown) are also included and monitored by the controller to determine the pressure and positioning of the die members relative to each other.

[0053] For example, during assembly, a selected material (610) (e.g., sheet metal) is placed into a die press machine in step (501). The material (610) may be placed into the die press machine by a human worker, a robot, or a combination of both. In step 502, the material (610) is positioned between the self-clinching nuts (608A, 608B) and the upper die members (606A, 606B) such that the self-clinching nuts are oriented on one side of the material (610) and the upper die members (606A, 606B) having flanges are positioned on the opposite side of the material (610). More specifically, the material (610) is positioned so that the self-clinching nuts are placed at desired installation locations on the material (610). The nut locations may be predetermined within the press machine based on the design of the final product. For example, the nuts and dies may be placed at locations set by the specific floor design of the EV. Note that the dies may be positioned at fixed locations or may be movable by a robot arm. In either case, at step 503, the controller (602) controls the actuator (604) to move the nuts and upper die members toward each other, thereby forcing the self-penetrating edges of the nuts to punch holes in the substrate (610) and forcing the protrusions to deform the sheet metal, causing parts of the sheet metal to be displaced and flow into both the groove and recess parts. As previously mentioned, the upper die members (606A, 606B) may each include flanges that increase pressure around the groove positions of the nuts to force more substrate material into the grooves. After the upper die members reach a stop point and the nut is fully embedded within the substrate (610), the controller (602) controls the actuator (604) in step 504 to retract the upper die members so that the substrate (610) can be removed in step 505. The final product is a metal panel containing one or more embedded self-clinching nuts at desired locations.The metal panel can then proceed to the next stage of assembly, such as integration into the EV.

[0054] Although self-clinching fasteners have been described in the context of self-clinching nuts having female threads for use in EVs, it should be noted that self-clinching fasteners can take other forms and be used in other applications. For example, a self-clinching fastener may include male threads and function as a self-clinching bolt that accommodates female threaded nuts. Additionally, self-clinching fasteners may be used in any application where self-clinching fasteners are advantageous. These applications may include, but are not limited to, furniture applications, home appliance applications, etc.

[0055] The advantages of the disclosed self-clinching fastener include, but are not limited to, reducing installation time by providing a self-clinching fastener installed in a single clinching motion. Pre-drilled or pre-punched holes are not required. Furthermore, the self-clinching fastener has improved resistance to push-out force and torque-out force compared to conventional self-clinching fasteners.

[0056] It should be noted that self-clinching fasteners are generally made of a material harder than the substrate material. This ensures that the self-clinching fastener can penetrate the substrate with its self-penetrating edge and use protrusions to deform parts of the substrate and force it to flow into grooves and recesses. For example, if the substrate is an aluminum alloy, the self-clinching fastener may be a steel alloy. Additionally, the overall design (number / size of protrusions, recesses, grooves, threads, etc.) and dimensions of the self-clinching fastener, including but not limited to nut diameter, nut height, protrusion dimensions, recess dimensions, punch height, groove dimensions, etc., can be selected based on the target substrate and performance thresholds based on push-out force and torque-out force for a specific application (e.g., mounting devices in an EV).

[0057] Additionally, the geometry of the protrusions, recesses, and annular grooves may be designed relative to one another. In one example, the dimensions of the protrusion arms (e.g., length, height, angle, displacement volume, etc.) may be designed to force a predetermined volume of deformed metal to flow toward the recesses and annular grooves. Likewise, the dimensions of the recesses and annular grooves (e.g., shape, depth, volume, etc.) may be designed to accommodate a predetermined volume of deformed metal flowing from the protrusions. In other words, the protrusions, recesses, and annular grooves may be designed to work in cooperation to ensure proper deformation and engagement (i.e., interlocking) of the geometric features of the self-clinching nut and the substrate. While the foregoing relates to exemplary embodiments described herein, other additional exemplary embodiments may be devised without departing from the basic scope of the disclosure. It will be understood by those skilled in the art that the preceding examples are exemplary and not limiting. All orders, improvements, equivalents, and improvements thereof that are apparent to a person skilled in the art when reading the detailed description and studying the drawings are intended to be included within the true spirit and scope of the present disclosure. Accordingly, the following appended claims are intended to include all such modifications, orders, and equivalents that fall within the true spirit and scope of these teachings.

Claims

Claim 1 A self-clinching fastener for attachment to a deformable metal panel, comprising: a body portion having a central axis; a punch portion extending from the body portion and coaxial with the central axis, wherein the body portion forms a generally annular fastener surface adjacent to the punch portion, and the punch portion has an inclined wall extending from the fastener surface and forming a groove; a plurality of protrusions protruding from the fastener surface and surrounding the punch portion and spaced apart from each other; and a plurality of spaced-apart recess portions within the fastener surface surrounding the punch portion, wherein the plurality of protrusions and the recess portions form abutment portions to improve the torsional resistance of the fastener. Claim 2 A self-clinching fastener according to claim 1, wherein the fastener surface comprises 4 to 12 of the plurality of protrusions and 4 to 12 of the plurality of recessed portions. Claim 3 A self-clinching fastener according to claim 1, wherein the plurality of protrusions and the plurality of recess portions alternately surround the punch portion along the fastener surface. Claim 4 A self-clinching fastener according to claim 1, wherein the plurality of protrusions are Y-shaped structures on the fastener surface. Claim 5 A self-clinching fastener according to claim 4, wherein each of the plurality of protrusions has a plurality of arms extending from a central portion of the protrusions, the plurality of arms form a plurality of wedges, and at least one of the plurality of wedges has a surface that slopes downward toward the fastener surface. Claim 6 A self-clinching fastener according to claim 4, wherein the plurality of arms include a first arm extending from the center portion of the protrusions toward the inclined wall of the punch portion along the fastener surface, and the first arm has a first surface inclined downward toward the fastener surface. Claim 7 A self-clinching fastener according to claim 4, wherein the plurality of arms include a second arm and a third arm extending from the center portion of the protrusions toward the outer perimeter of the fastener surface along the fastener surface, the second arm having a second surface that slopes downward in a direction away from the center portion of the protrusions, the third arm having a third surface that slopes downward in a direction away from the center portion of the protrusions, and the second arm and the third arm forming a common surface that slopes downward in a direction away from the center portion of the protrusions between the second arm and the third arm. Claim 8 A self-clinching fastener according to claim 1, wherein the plurality of recess portions include a surface that gradually slopes downward from the fastener face to the flat bottom surface of the recess portions. Claim 9 In claim 8, the plurality of recess portions extend toward the inclined wall of the punch portion and meet the inclined wall, a self-clinching fastener. Claim 10 A self-clinching fastener according to claim 8, wherein the plurality of recess portions have a recess volume corresponding to the protrusion volume of the plurality of protrusions. Claim 11 A self-clinching fastener according to claim 8, wherein the inclined wall of the punch portion defines a first diameter of the punch portion at the fastener surface and a second diameter at the opening of the punch portion. Claim 12 A self-clinching fastener according to claim 8, wherein the inclined wall of the punch portion includes a curved transition portion that meets the fastener surface. Claim 13 A self-clinching fastener according to claim 1, wherein the inclined wall of the punch portion is a swallowtail's structure. Claim 14 A self-clinching fastener according to claim 13, wherein the inclined wall of the punch portion includes a flat portion forming an edge at the end portion of the punch portion. Claim 15 In paragraph 13, the inclined wall of the punch portion comprises a self-penetrating edge for penetrating the deformable metal panel, a self-clinching fastener. Claim 16 In paragraph 13, the inner surface of the punch portion comprises a female thread for mating to a bolt, a self-clinching fastener. Claim 17 A method for attaching a self-clinching fastener to a deformable metal panel, comprising the step of coaxially positioning the fastener and the die member on the opposite side of the metal panel at a position where the fastener is to be fixed to the metal panel, wherein the fastener comprises: a body portion having a central axis; a punch portion extending from the body portion and coaxial with the central axis, wherein the body portion forms a generally annular fastener surface adjacent to the punch portion, and the punch portion has an inclined wall extending from the fastener surface and forming a groove; a plurality of protrusions protruding from the fastener surface and surrounding the punch portion and spaced apart from each other; and a plurality of recess portions spaced apart within the fastener surface surrounding the punch, wherein the plurality of protrusions and the recess portions form abutment portions to improve the torsional resistance of the fastener; and the step of coaxially positioning the fastener and the die. A method comprising the step of moving the die member and the fastener relative to each other in an axial direction so as to deform a portion of the panel into a groove of the fastener to improve the torsional resistance of the fastener until a secure mechanical interlock is formed between the fastener and the panel. Claim 18 A method according to claim 17, comprising the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the plurality of protrusions press the deformed portion of the panel into the groove and the deformed portion of the panel into the plurality of recess portions. Claim 19 A method according to claim 17, comprising the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the plurality of protrusions press the deformed portion of the panel into at least three distinct directions away from the center portion of the plurality of protrusions. Claim 20 A method according to claim 17, comprising the step of moving the die member and the fastener relative to each other in a direction along the central axis so that the edge of the punch portion penetrates the deformable metal panel.

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