PROCESS ASSEMBLY AND ARTICLE FOR FORMING AN EDGE CLINCHING OF OVERLAPPING PANELS AS A WEIGHT SAVINGS ENABLER

Abstract

A clinch forming assembly and associated process for joining first and second panels including a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface. An overlapping arrangement of the first and second panels defines a center line of the punch aligning with an edge of the upper panel. Initial downward motion of the punch results in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel. Following a degree of initial deformation of the upper panel, the bottom most profile surface of the punch contacting an upper surface of the lower panel, with continued downward deformation of the punch against an opposing die located underneath the bottom panel resulting in clinching of the layers.

Description

FIELD OF THE INVENTION

The present invention relates generally to clinch molding techniques. More specifically, the present invention teaches a novel process, assembly and article for forming a clinched edge between overlapping panels, such as including any of steel, aluminum or other suitable metals, which results in significant weight savings owing to reduced overlap of the panels.

BACKGROUND OF THE INVENTION

Prior art edge clinching describes various techniques for joining two panels of a ductile metal using a variety of die and punch designs, such as alternate to resistance spot welding and self-piercing riveting operations. A most commonly known clinching arrangement contemplates a punch and a radially sprung die, which is employed to cause the panels to flow outward at the bottom of the stroke, with a resultant overhang locking the panels together. As further noted, the joining force achieved by traditional clinching is generally weaker than that associated with the conventional spot welding or self-piercing rivets.

With reference to FIG. 1 of the attached illustrations, depicted is a cross sectional cutaway view of standard clinch operation according to the Prior Art for joining overlapping edges of first 2 and second 4 panels. As shown, a line edge 5 established between the clinch deformed layers 2/4 defines a joining profile.

FIG. 2 provides a corresponding Prior Art view of a standard clinch material stack-up defining a fastener center line relative to a designed overlap of the sheet metal panels 2 and 4 to be joined and based on the fastener type employed. As further shown, a material overlap 6 between the panels 2/4 is defined by a fastener center line 8 through which the punch and die are employed on opposite sides of the overlapped sheets.

Typical advantages of clinching relate to costs and operational simplicity, such as for non-visible surfaces associated with high volume products which do not require high strength joints. Other advantages, such as when compared to welding, include allowing dissimilar materials (such as steel and aluminum) to be joined together and, unlike with welding, clinching does not require the surfaces to be treated before fastening nor does it produce any heat effects in the parts.

Other examples of known clinching devices include such as those described in Scott, U.S. Pat. No. 9,656,318, which teaches a clinch forming operation for joining together multiple panels. Other references of note include Kagami U.S. Pat. No. 11,077,886, which depicts a similar arrangement for crimp joining a pair of plate shaped members by mechanical clinching from a side at which the first member is disposed, with a reinforcing portion being inflected toward a normal direction in a vicinity of the crimped portions.

Bartig, US 2015/0121679 teaches a punch riveting die combining first and second work pieces (layers), a semi-hollow punch rivet and a punch-riveting die for driving the rivet between the first and second workpieces. Wang, US 2003/0167620 teaches another rivet design for joining first and second panels or layers, the rivet including an adhesive formed in the passages thereof for assisting in fastening the sheets to each other with greater strength.

SUMMARY OF THE INVENTION

The present invention discloses a novel process, assembly and article for forming a clinched edge between overlapping panels (this again including any of a steel, aluminum or other suitable material), such as which results in significant weight savings owing to reduced overlap of the panels. In comparison to existing clinching techniques, the present invention provides the ability to reduce the overlap of the stacked panels which, in combination with a novel redesigning of the punch and die components, results in significant material and weight savings through the ability to reduce the material overlap in comparison to prior clinching applications.

The clinch assembly includes a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface. A die having an upper profile surface with stepped support surfaces corresponds with the stepped surfaces of the punch.

An overlapping arrangement of the first and second panels are positioned between the punch and die and define a center line aligning with an edge of the upper panel. Initial downward motion of the punch results in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel. Following a degree of initial deformation of the upper panel, the bottom most profile surface of the punch contacts an upper surface of the lower panel, with continued downward deformation of the punch against the opposing underside die located underneath the bottom panel resulting in clinching of the layers.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:

FIG. 1 is a Prior Art cross sectional view of standard clinch operation for joining overlapping edges of first and second panels;

FIG. 2 is a corresponding Prior Art view of a standard clinch material stack-up defining a fastener center line relative to a designed overlap of the panels to be joined and based on the fastener type employed;

FIG. 3 is a cross sectional depiction of an edge clinching operation according to a non-limiting embodiment of the present invention and utilizing a redesigned punch and reduced overlapping edge;

FIG. 4 is a depiction similar to FIG. 2 of a clinch material arrangement defining a reduced designed overlap between the panels prior to joining and further referencing material saved by this arrangement;

FIG. 5 is an illustration of a clinch joined article according to the present invention; and

FIG. 6 is an illustration similar to FIG. 1 and depicting a clinch operation according to the present invention for joining overlapping edges of first and second panels.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the attached illustrations, the present invention discloses a novel process, assembly and article for forming a clinched edge between overlapping panels, which results in significant weight savings owing to reduced overlap of the panels. Without limitation, the definition of panels is interpreted to include any suitable ductile material not limited to any grade steel or aluminum.

With reference to FIG. 3, a cross sectional depiction is generally shown at 10 of an edge clinching operation according to a non-limiting embodiment of the present invention and utilizing a redesigned punch 12, in combination with a reduced overlapping edge 14 (see further FIG. 4) of the panels 2 and 4, as compared to that shown in FIG. 2. The punch 12 as depicted includes a bottom most profile surface 16, in combination with an inwardly stepped surface 18 which is separated by a vertical edge surface 19. As further again shown in FIG. 4, the clinch material arrangement defines a reduced designed overlap (again at 14) between the panels 2/4 prior to joining and further references an amount of material 20 saved by this arrangement.

In operation, the redesign punch depicted in FIG. 3 is exerted from an upper direction through the overlapping panel arrangement of FIG. 3 so that along a relocated center line 22 (see as compared to at 8 in FIG. 2) of the downwardly descending punch 12 is defined. Initial downward motion of the punch 12 results in the inwardly stepped surface 18 contacting the upper surface of the upper stacked panel 2, with the vertical edge surface 19 of the punch overlapping in close contact the adjoining side edge 24 of the upper stacked panel 2.

Following a degree of initial deformation of the upper panel 2, the bottom profile surface 16 contacts an upper surface of the lower stacked panel, with subsequent downward deformation of the punch 12 against the opposing die shown at 21 in FIG. 3 positioned underneath the bottom panel 4. The die 21 is located in alignment with the center line 22 and includes stepped support surfaces 23/25 which correspond with the downward stepped surfaces 18/16 of the punch 12, resulting in clinching of the layers in the manner best shown in FIGS. 5-6. Specifically, FIG. 5 is an illustration of a clinch joined article according to the present invention and by which a redesigned an inwardly deformed clinch profile 24 is created between the overlapping location of the panels 2/4.

As further shown in FIG. 6 (which is an illustration similar to FIG. 1) depicted is the clinch operation according to the present invention for joining overlapping edges of first and second panels and by which the a modified line edge 26. As further shown, the reconfigured edge clinch joint provides adequate holding force with significantly reduced weight and material saving.

Additional embodiments can include providing first and second panels or layers of differing strength or hardness, this affecting overall ductility. As part of the clinching operation, the overlapping portion of the higher strength panel can optionally be heated to an adequate temperature to induce a desired degree of flow-ability and such that, upon placing against the lower hardness panel and subsequently clinching the two panels together, the flowable material integrates with the surface layer matrix of the lower hardness panel to create a stronger clinch therebetween.

Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims. The detailed description and drawings are further understood to be supportive of the disclosure, the scope of which being defined by the claims. While some of the best modes and other embodiments for carrying out the claimed teachings have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims.

The foregoing disclosure is further understood as not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims.

In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as one skilled in the art will appreciate, various embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description is to be considered as illustrative and is for the purpose of teaching those skilled in the art the manner of making and using various embodiments of the disclosure. It is to be understood that the forms of disclosure herein shown and described are to be taken as representative embodiments. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. All joinder references (e.g., attached, affixed, coupled, connected, and the like) are only used to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the systems and/or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other.

Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification.

It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Additionally, any signal hatches in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically specified.

Claims

1. An clinch assembly for joining first and second panels, comprising: a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface;a die having an upper profile surface with stepped support surfaces which correspond with the stepped surfaces of the punch;an overlapping arrangement of the first and second panels positioned between the punch and die and defining a center line aligning with an edge of the upper panel, with initial downward motion of the punch resulting in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel; andfollowing a degree of initial deformation of the upper panel, the bottom most profile surface of the punch contacting an upper surface of the lower panel, with continued downward deformation of the punch against the opposing underside die located underneath the bottom panel resulting in clinching of the layers.

2. A process for clinch joining first and second panels, comprising the steps of: providing a punch having a bottom most profile surface in combination with an inwardly stepped surface which is separated by a vertical edge surface;providing a die having an upper profile surface with stepped support surfaces which correspond with the stepped surfaces of the punch;positioning overlapping portions of the first and second panels between the punch and die to define a center line aligning with an edge of the upper panel;exerting an initial downward motion of the punch, resulting in the inwardly stepped surface contacting an upper surface of the upper panel, with the vertical edge surface of the punch overlapping in close contact an adjoining side edge of the upper panel;initially deforming the upper panel with the bottom most profile surface of the punch contacting an upper surface of the lower panel;applying continued downward deformation of the punch against the opposing underside die located underneath the bottom panel resulting in clinching of the layers.

3. The process of claim 2, further comprising the step of providing the first and second panels of differing strength or hardness.

4. The process of claim 3, further comprising the step of heating the overlapping portion of the higher strength panel to an adequate temperature to induce a desired degree of flow-ability and such that, upon placing against the lower hardness panel and subsequently clinching the two panels together, the flowable material integrates with the surface layer matrix of the lower hardness panel to create a stronger clinch therebetween.