Patent Application
20250188981
This application relates generally to self-attaching construction elements (e.g., fasteners), and more particularly clinch nuts, studs, and non-threaded elements (e.g., spacers).
Self-attaching construction elements are used in many industries such as, for example, the automotive and appliance industries to secure various components to a metal substrate. During installation, the construction elements must have sufficient rotational resistance (i.e., torque-out resistance) to keep them from rotating relative to the metal substrate. Further, during service, the construction elements must have sufficient push-out resistance to keep them from separating from the metal substrate when external forces such as, for example, vibration or other tensile forces are applied.
Installing (i.e., attaching, joining, etc.) traditional construction elements to conventional substrates (e.g., metal panels) is generally accomplished by forcing the construction element into the substrate (i.e., sandwiching the construction element and the metal panel between a drive mechanism and an anchoring block) such that material of the substrate plastically deforms and conforms to select features and profiles of the construction element. This creates a joint between the construction element and the substrate.
Due to technological advances in the automotive and appliance industry, it is imperative for the joint to provide a sufficient fluid seal between the construction element and the substrate. For example, with reference to vehicles (and more particularly electric vehicles), it is important to hinder/prevent ingress of liquid/moisture within the vehicle compartment due to the corrosive effects as well as degradation of electrical systems if liquid/moisture is introduced thereto. As such, some automobile manufactures now set forth an air decay requirement, wherein a construction element must hold a loss of pressure (per construction element) that does not exceed 0.1 cm3/min.
Accordingly, there is a need in the art for improved construction elements which can be reliably and consistently attached to various substrates, wherein the attachment of the construction element to the substrate yields sufficient torque-out and push-out strength, as well as complying with the above-noted air decay requirement.
In accordance with one aspect, there is provided a self-clinching construction element for attachment to a plastically deformable metal substrate. The self-clinching construction element includes a body portion with a central axis, the body portion including an annular-shaped surface extending in a direction perpendicular to the central axis. A punch portion is coaxial with the central axis and extends from the body portion such that the annular-shaped surface encircles the punch portion. Further, the punch portion includes an outer peripheral surface extending in a direction of the central axis. A plurality of spaced apart lugs axially project outwards from the annular-shaped surface and extend radially outwards from the outer peripheral surface of the punch portion. The plurality of spaced apart lugs collectively encircle the punch portion. A lug of the plurality of spaced apart lugs has a maximum width that is less than a maximum width of the punch portion. Further, a percentage ratio between the maximum width of the lug and the maximum width of the punch portion is in a range of 10% to 22%.
In accordance with another aspect, there is provided a self-clinching construction element for attachment to a plastically deformable metal substrate. The self-clinching construction element includes a body portion with a central axis. The body portion includes an annular-shaped surface extending in a direction perpendicular to the central axis and an outer peripheral surface extending in a direction of the central axis. A punch portion is provided and is coaxial with the central axis and extends from the body portion such that the annular-shaped surface encircles the punch portion. The punch portion includes an outer peripheral surface that extends in the direction of the central axis and that has a cylindrical profile. Further, a plurality of spaced apart lugs axially project outwards from the annular-shaped surface and extend radially outwards from the outer peripheral surface of the punch portion. The plurality of spaced apart lugs collectively encircle the punch portion.
Moreover, a lug of the plurality of spaced apart lugs has a maximum width that is smaller than a maximum diameter of the punch portion. Further, a percentage ratio between the maximum width of the lug and the maximum diameter of the punch portion is in a range of 10% to 22%. Additionally, the annular-shaped surface of the body portion terminates at a peripheral edge which is coterminous with the outer peripheral surface of the body portion. Further still, the lug has opposite, first and second end portions, wherein the first end portion is disposed adjacent to the outer peripheral surface of the punch portion, and wherein the second end portion is provided at the peripheral edge. Moreover, a width of the lug increases with distance from the outer peripheral surface of the punch portion, and the maximum width of the lug is taken at the second end portion.
It is to be appreciated that the following description includes many features which can be utilized in various combinations that may include all or less than all of the features. All such combinations of features are intended to come within the scope of this application. Referring now to the drawings,
With reference to
In yet another example where the construction element 100 is a self-clinching spacer, upon installation of the construction element 100 to a plastically deformable metal substrate, a fastener (e.g., a bolt, threaded screw, etc.) can be inserted into the bore 106 such that a spaced distance is provided between either a head of the fastener and the metal substrate, or a corresponding nut (configured to be attached to the bolt, screw, etc.) and the metal substrate. That is, the construction element 100 provides a predetermined space between two distinct objects (i.e., the metal substrate and a separate fastener).
As further shown, the body portion 102 and the punch portion 104 are coaxial with a central axis ‘X.’ With reference to
The punch portion 104 is radially smaller than the body portion 102 such that the body portion 102 includes a generally annular-shaped surface 108 encircling the punch portion 104. That is, the punch portion 104 extends from the body portion 102 in a direction of the central axis ‘X,’ and is positioned such that the annular-shaped surface 108 encircles the punch portion 104. The annular-shaped surface 108 extends in a direction perpendicular to the central axis (i.e., extending in a radial direction ‘r’ of the construction element 100, as shown in
As further shown, the construction element 100 includes a plurality of spaced apart lugs 110 that collectively encircle the punch portion 104. As will be further discussed below, each of the lugs 110 axially projects outward from the annular-shaped surface 108 in a direction opposite to the first end surface 102a of the construction element 100. In one embodiment, as shown, the plurality of lugs 110 are equally spaced apart, one from the other, and all have the same configuration. Alternatively, the plurality of lugs 110 can be unequally spaced apart about the punch portion 104, one from the other, and/or can have varying configurations.
With respect to
With reference to
Notably, in the depicted example, the annular-shaped surface 108 is planar, and continuously inclines in the radially (outward) direction. More specifically, as the annular-shaped surface 108 radially extends from the outer peripheral surface 114 (i.e., in a direction from the first end portion 108a to the second end portion 108b), a (vertical) distance between the annular-shaped surface 108 and the imaginary horizontal plane “P” increases. Notably, the highest point of the annular-shaped surface 108 (i.e., at the second end portion 108b thereof) is provided at a first axial distance “H1” from a distal peripheral edge 117 of the punch portion 104 (described further below). In other words, the first axial distance “H1” represents a minimum distance (in a direction parallel to the central axis “X”) between the distal peripheral edge 117 of the punch portion 104 and the annular-shaped surface 108.
In an alternative example, the annular-shaped surface 108 need not be planar. For example, the annular-shaped surface 108 may be convex-or concave-shaped in cross-section. Additionally, in another alternative example, the annular-shaped surface 108 need not continuously incline from the first end portion 108a to the second end portion 108b. For example, the annular-shape surface 108 may include a section between the first and second end portions 108a, 108b that is parallel to the imaginary horizontal plane “P” or that declines relative to the imaginary horizontal plane “P.”
Moving back to
The outer peripheral surface 114 of the punch portion 104 having a cylindrical profile with no sharp edges greatly reduces or even eliminates the potential for imperfections (e.g., cracking) to form in the construction element 100 and/or the metal panel during installation. Specifically, because metal panels are now manufactured from relatively stronger, harder materials (e.g., hot-formed steel), the substrate does not flow (i.e., plastically deform) easily during installation. As such, sharp or pointed edges on the outer peripheral surface 114 of the punch portion 104 are susceptible to cracking due to the forces imparted thereon during installation. Accordingly, the construction element 100 described herein, having no sharp or pointed edges on the outer peripheral surface 114 of the punch portion 104, is removed from the above-noted problem and is less likely to yield a defective finished product.
As further shown, a plurality of spaced apart cutouts 118 are formed in the outer peripheral surface 114 of the punch portion 104 and are arranged so as to collectively encircle the punch portion 104. In one embodiment, the plurality of cutouts 118 are equally spaced apart, one from the other, and all have the same configuration. Specifically, each cutout 118 has a concaved surface with respect to the outer peripheral surface 114 of the punch portion 104. Alternatively, the plurality of cutouts 118 can have varying spacing and/or configurations, such as where only one cutout 118 has a concaved surface.
The outer peripheral surface 114 of the punch portion 104 further comprises a plurality of spaced apart column portions 120 (shown in
As mentioned above, in one embodiment, the plurality of cutouts 118 are shown as being equally spaced apart, one from the other. Specifically, it is the plurality of column portions 120 that provide the equal spacing between the plurality of cutouts 118. As such, the plurality of column portions 120 are likewise equally spaced, one from the other. As further mentioned above, the outer peripheral surface 114 of the punch portion 104 has a cylindrical profile with no sharp edges; this is a result of the column portions 120 being disposed between and spacing apart a respective pair of adjacently spaced apart cutouts 118. That is, if a pair of cutouts 118 were disposed directly adjacent one another, with nothing therebetween, there would be no surface having a cylindrical profile provided between the pair of adjacent cutouts 118, thus resulting in the formation of a sharp edge.
Still further, in one embodiment, the outer peripheral surface 114 of the punch portion 104 comprises a plurality of bridge portions 122 that are spaced apart, one from the other, and which collectively encircle the punch portion 104. Specifically, each bridge portion 122 is defined as an area of the cylindrically profiled outer peripheral surface 114 of the punch portion 104 disposed between a pair of adjacently spaced column portions 120. Further, each bridge portion 122 is positioned axially between the distal peripheral edge 117 of the outer peripheral surface 114 of the punch portion 104 and the cutout 118 which is bounded by the pair of adjacently spaced column portions 120. In this manner, each bridge portion 122 connects a respective pair of adjacently spaced apart column portions 120.
As further shown in
All of the components of the above-discussed construction element 100, specifically the body portion 102, the punch portion 104, and the lugs 110, are formed integrally with respect to one another. That is, the body portion 102, the punch portion 104 and the lugs 110 are all formed from the same stock material. For example, the construction element 100 can be manufactured from treated steal, and in one example specifically from 10B21 steel. However, the material selection is not limited to 10B21 steel, and other suitable materials may be used. Furthermore, it is preferable for the material of the construction element 100 to have a hardness greater than that of the substrate (e.g., metal panel) to which it is to be attached to.
Where the construction element 100 is a self-clinching stud, the stud would likewise be integrally formed of the same material. For example, with reference to
The geometric shape of a single lug 110 will now be discussed with the understanding that the below-disclosure likewise applies to the other lugs. With reference to
Notably, in the depicted example, the lug 110 does not have a uniform width between the first and second end portions 126a, 126b of the contact face 126. Rather, as best shown in
Moving on to
As further shown, the highest point of the lug 110 (i.e., at the second end portion 126b thereof) is provided at a second axial distance “H2” from the distal peripheral edge 117 of the punch portion 104. In other words, the second axial distance “H2” represents a minimum distance (in the direction parallel to the central axis “X”) between the distal peripheral edge 117 of the punch portion 104 and the lug 110. Notably, the second axial distance “H2” is less than the first axial distance “H1,” described above. Additionally, a ratio between the second axial distance “H2” and the first axial distance “H1” (expressed as a percentage) does not exceed 50%.
With reference to
In the depicted example, the maximum width “W1” of the lug 110 is provided at the second end portion 126b of the contact face 126 (i.e., at an end of the lug 110 distal from the punch portion 104). However, in other examples, the maximum width “W1” of the lug 110 may be at other radial locations. Of note, such dimensional differences are conventional. Specifically, with reference to
A crucial difference between the configuration of the new construction element 100 (as described herein) and those of old (e.g., the conventional element 100′) is the dimensional ratio between the maximum width “W1” of the lug 110 and the maximum diameter “D1” of the punch portion 104. For simplicity, the below-noted ratios will be expressed as percentages—i.e., the maximum width “W1” of the lug 110 divided by the maximum diameter “D1” of the punch portion 104, multiplied by one hundred.
A comparison will now be made with respect to the new construction element 100 (as described above) and a conventional construction element (such as the construction element 100′ depicted in
With respect to the conventional construction element 100′ (and others not discussed herein), a ratio between the maximum width “W2” of the lug 110′ and the maximum diameter “D2” of the punch portion 104 is generally greater than or equal to 28%. During installation, this yields a joint between the conventional construction element 100′ and the substrate that provides sufficient torque-out and push-out strength. However, that dimensional ratio (i.e., between the maximum width “W2” of the lug 110′ and the maximum diameter “D2” of the punch portion 104) produces a joint that is susceptible to air decay “leaking.” That is, the joint between the conventional construction element 100′ and the substrate provides a “leak” path, permitting ingress of moisture and/or liquid. As expressed above, this “leak” path can have detrimental effects for the overall product. For example, in the automotive industry, such “leak” paths can lead to corrosion of the substrate at the joint, reducing its torque-out and/or push-out strength, potentially to the point of failure.
The new construction element 100 (discussed above) has a ratio (i.e., between the maximum width “W1” of the lug 110 and the maximum diameter “D1” of the punch portion 104) within a range of 10% to 22%. In comparison to the above-noted ratio of the conventional construction element 100′, this new ratio range of 10% to 22% amounts to about a 42% reduction as compared to the conventional construction element 100′. It has been determined that this ratio reduction is directly correlated to a vast improvement in resistance to air decay (or the joint's susceptibleness to leaking). Indeed, the above-noted changes in the new construction element 100 (with respect to the conventional construction element 100′) yield substantially similar torque-out and push-out strength, while providing a superior sealed joint.
With reference to Table 1 (shown above), experimental data is shown for a conventional construction element (i.e., the conventional construction element 100′ having a ratio roughly equal to 28%) underwent various testing to determine its torque-out, push-out, and air-decay performance. As shown, the conventional construction element 100′ has an average torque-out specification of 50.1 Nm, an average push-out specification of 3.6 kN, and an average air decay specification of 0.094 cm3/min. While the above-noted torque-out and push-out specifications provide satisfactory torque-out and push-out strength, the results of the air decay specification are concerning. Specifically, while the resulting average value of the air decay testing (i.e., 0.094 cm3/min) falls below the (required) standard of 0.1 cm3/min (set forth by auto-manufacturers), multiple test results exceeded that standard. More specifically, out of the twenty-five trials, the conventional construction element 100′ exceeded the standard 0.1 cm3/min a total of six times. Said differently, 24% of the trials did not meet the standard set forth by auto-manufacturers.
In comparison, with reference to Table 2 (shown below), experimental data is shown for the new construction element 100 (i.e., having a ratio within a range of 10% to 22%) has similar (i.e., satisfactory) torque-out and push-out performance with respect to the conventional construction element 100′, however, its air decay performance has greatly improved. More specifically, the average value of the air decay testing for the new construction element resulted in 0.00 cm3/min. Indeed, none of the trials exceeded, or even came close to meeting, the 0.1 cm3/min standard.
To further evidence how vast this improvement is, the testing results for each of the conventional and new construction elements (i.e., as represented in Table 1 and Table 2, respectively) have been plotted in respective bar graphs. With respect to
Consequently, the empirical data (both numerically and graphically represented) shows that the configuration of the new construction element 100 provides a much greater sealing capability than conventional construction elements. Indeed, this advantage is a direct correlation of the reduction in the (maximum) lug-width to (maximum) punch portion width ratio. Not only does this new design provide improved performance, but it also meets, and greatly exceeds, a now recognized industrial standard.
The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Example embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.
