MULTIPLE PIECE CONSTRUCTION AUTOMOTIVE DOOR HINGE

FIELD OF THE INVENTION

This invention applies to hinges, more particularly to automotive hinges, which facilitate motion of a closure panel relative to a fixed body structure, and simplify the configuration of the constitutive hinge components using a unique multiple piece construction.

BACKGROUND TO THE INVENTION

Automotive hinges are generally configured to include a door component that is rigidly attached to a closure panel and a body component that is rigidly attached to a body structure. This structural attachment of the components can be achieved by welding, riveting, bolting or similar mechanical fastening means. The simple rotary motion of the door component relative to the body component is normally achieved by a pivot pin and associated bearing surfaces. The pivot pin is configured to be rigidly attached to one of the hinge components while the other component freely rotates around the pivot pin via one or more bearing surfaces. It is normal practice to utilize two of these hinge assemblies, vertically offset with coaxially aligned pivot pins, to attach a closure panel to a body structure.

The body and door components of an automotive hinge are commonly constructed from either steel or aluminum using stamping, forging, casting, roll forming or extruding. Each component is generally configured with one or more mounting surfaces and a pair of pivot arms that contain pivot axis holes. The pivot arms are structurally connected by some form of bridge or by the mounting surface. It is common practice to create the required pivot bearing surface by assembling bushings into the pivot axis holes of the door component. A pivot pin is inserted through the pivot bushings of the door component and structurally attached to the body component through the pivot axis holes using knurling, interference fits, riveting, staking or similar means of material upsetting.

The body component is structurally attached to a vehicle body structure via its mounting surface using bolting, welding, bonding, riveting or similar fastening means. The door component is similarly structurally attached to a vehicle closure panel via its mounting surface using bolting, welding, bonding, riveting or similar fastening means.

Bolted automotive hinge systems typically utilize a minimum of two fasteners per hinge component. Complex formations are therefore required to provide the necessary pivot axis hole locations, mounting surfaces, structural integrity, fastener locations and clearance offsets in a single piece component. Forgings and casting are well suited to providing these necessarily complex shapes but carry a significant cost penalty in comparison to press formed metal stampings. Metal stamping is generally considered the most cost effective method of creating hinge components but formation shape is somewhat limited. Additionally, complex configurations generally result in large quantities of unused scrap material being produced during the press forming process.

Fig. 1 illustrates a common prior art embodiment of an automotive door hinge assembly (1) configured from a press formed body component (2), a press formed door component (3), a pivot pin (4) and two pivot bushings (25)(26). The body component (2) is configured with a pair of pivot arms (6)(7) and a large mounting surface (8) that is adapted to be structurally attached to a vehicle body structure via mounting holes (9)(10) and two corresponding threaded fasteners. These mounting holes (9)(10) are spaced at an adequate distance to assure sufficient load spreading into the vehicle body structure. The pivot arms (6)(7) are configured with a pair of pivot holes (11)(12) adapted to accept and rigidly capture the pivot pin (4) via knurling, interference fits, riveting, staking or similar means of material upsetting. The distance from the mounting holes (9)(10) to the pivot holes (11)(12) is dictated by the vehicle's closure panel and body configuration and can be substantial. The door component (3) is configured with a pair of pivot arms (13)(14), a structural bridge (21) and a pair of mounting surfaces (15)(16) that are adapted to be structurally attached to a vehicle closure panel via mounting holes (17)(18) and two corresponding threaded fasteners. These mounting holes (17)(18) are spaced at an adequate distance to assure sufficient load spreading into the vehicle closure panel. The pivot arms (13)(14) are configured with a pair of pivot holes (19)(20) adapted to accept

the pivot bushings (25)(26) that facilitate rotation around the pivot pin (4). The distance from the mounting holes (17)(18) to the pivot holes (19)(20) is dictated by the vehicle's closure panel and body configuration and can be substantial. Both the body component (2) and door component (3) are press formed from a flat sheet of steel and, due to their complex shapes a significant amount of scrap material is created during the stamping process. Fig. 2 illustrates the flat blank layout of both the prior art body component (2a) and the door component (3a) as well as the scrap material (22) shown cross hatched associated with the stamping process. Despite the considerable scrap material (22) generated in this configuration, the press formed manufacturing technique is still more cost effective than either casting or forging.

SUMMARY OF THE INVENTION

Accordingly, it would be advantageous to create a hinge assembly that is constructed utilizing press formed metal stampings but which reduces or eliminates the scrap associated with the complex shapes dictated by a vehicle's closure panel and body configuration. A great deal of the material used and scrapped in the press forming of a hinge component is directly attributable to shape complexity dictated by the required distances between the mounting holes and pivot pin support features. It would therefore be a significant improvement over the existing art if the interconnection of these features could be achieved in a more efficient manner.

The present invention is targeted at reducing the total material utilized in press formed metal stamped hinge components by utilizing the pivot pin as a primary structural component. In a conventionally configured automotive door hinge utilizing a single piece door component and single piece body component, the pivot pin performs two primary functions in that it structurally assembles the two components while facilitating relative rotary motion between them. The present invention utilizes the pivot pin for an additional primary function in that it also structurally connects multiple pieces of each individual component. A conventionally manufactured single piece press formed door component normally connects its two mounting surfaces and two pivot arms via an integral structural bridge. The present invention eliminates the structural bridge and

configures each mounting surface and associated pivot arm as an individual separate press formed angle bracket and structurally connects two of these angle brackets together using a uniquely configured pivot pin. Additionally, the present invention utilizes a unique body component configured from two simple press formed angle brackets that are structurally connected via a simple formed feature and the pivot pin.

The pivot pin of the present invention is configured with a central cylindrical pivot surface and two knurled opposing cylindrical ends stepped down in diameter from the central cylindrical pivot surface. The two press formed angle brackets of the body component are structurally connected via a simple formed feature on the pivot arms and a single pivot bushing is assembled in the pivot holes via a flanged arrangement. The pivot pin is arranged within the pivot bushing so that the central cylindrical pivot surface can freely rotate and the press formed angle brackets of the door component are configured to be structurally connected to the knurled opposing cylindrical ends of the pivot pin via riveting, staking or similar means of material upsetting.

In an alternative embodiment of the present invention, the opposing cylindrical ends of the pivot pin are configured without knurling and the step between the central cylindrical pivot surface and two opposing cylindrical ends is configured with a slight taper that compensates for the thickness tolerances of the body component during the assembly process. The material interference that creates the structural connection occurs between the tapered step and press formed angle brackets of the door components.

In another alternative embodiment of the present invention, the pivot pin is configured with a cantilevered feature to facilitate simple separation and reassembly of the door and body components as required in some vehicle assembly plants.

In accordance with a principle aspect of the invention, an automotive hinge assembly comprises: (a) a door component constructed from two press formed door angle brackets and adapted to be mounted to a vehicular closure panel; (b) a body component constructed from two press formed body angle brackets, configured to accept a single pivot bushing and adapted to be mounted to a vehicular body structure; (c) a pivot pin configured to structurally connect the press formed door and body angle brackets while

holding the door component and body component in structural assembly and facilitating rotary motion between the door component and body component; and (d) the pivot pin being configured with a central cylindrical pivot surface with a central diameter adapted to allow rotation of the pivot bushing thereabout, and ^' two knurled opposing cylindrical ends each with a diameter less than the central diameter adapted to structurally connect the door component angle brackets by material upset.

In accordance with further aspects of this invention, an automotive hinge assembly as described, wherein the press formed body angle brackets are structurally joined via a semi-shear feature and matching alignment hole using welding, bonding, riveting, staking or similar means of material upsetting.

In accordance with further aspects of this invention, an automotive hinge assembly as described, wherein a pair of hinge stop formations are provided in the body angle brackets that are adapted to interact with a pair of hinge stop surfaces provided on the door angle brackets so that the hinge assembly is structurally restrained from rotation at its full open position.

In accordance with further aspects of this invention, an automotive hinge assembly as described, wherein the pivot pin incorporates a tapered feature at a stepped interface between the central cylindrical pivot surface and the two knurled opposing cylindrical ends to compensate for thickness tolerances of the body component angle brackets during the assembly process.

In accordance with further aspects of this invention, an automotive hinge assembly as described, wherein the pivot pin is configured to structurally connect the press formed door angle brackets via a pivot bushing, washer and material upset while providing a cantilevered feature to facilitate simple separation and reassembly of the door and body components using a tapered nut and tapered pivot hole arrangement.

In accordance with further aspects of this invention, an automotive hinge assembly as described in the paragraph immediately above, wherein a rivet is adapted to provide the

hinge stop on the body component while also structurally joining the press formed body angle brackets.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an exploded perspective view of a prior art press formed automotive door hinge assembly;

Fig. 2 is a plan view of a developed flat blank layout associated with the press form stamping of the components of the prior art automotive door hinge assembly of Fig. 1;

Fig. 3 is a perspective view of a pair of the inventive hinge assemblies in a typical automotive installation;

Fig. 4 is a perspective view of the inventive hinge assembly;

Fig. 5 is an exploded perspective view of the inventive hinge assembly;

Fig. 6 is a partial sectional view of the inventive hinge assembly through the centreline of the pivot pin;

Fig. 7 is a side view of the pivot pin of the inventive hinge assembly;

Fig. 8 is an exploded perspective view of the door component of the inventive hinge assembly;

Fig. 9 is an exploded perspective view of the body component of the inventive hinge assembly;

Fig. 10 is a plan view of a developed flat blank layout associated with the press form stamping of the components of the inventive hinge assembly;

Fig. 11 is a side view of an alternative tapered step embodiment of the pivot pin of the inventive hinge assembly;

Fig. 12 is a side view of an alternative fixed head embodiment of the pivot pin of the inventive hinge assembly

Fig. 13 is a perspective view of an alternative lift-off embodiment of the inventive hinge assembly;

Fig. 14 is a partial _^ sectional view of an alternative lift-off embodiment of the inventive hinge assembly through the centreline of the pivot pin.

DETAILED DESCRIPTION QF THE INVENTION

Referring to Figs. 3, 4, 5, and 6, an automotive hinge assembly (30) is substantially constructed from a door component (40) and a body component (60). The door component is configured with a mounting surface (41) and two pivot arms (42). Each pivot arm (42) contains a pivot axis hole (43). The door component (40) is structurally attached to a vehicle closure panel (27) via its mounting surface (41) using bolting, welding, bonding, riveting or similar fastening means. The body component (60) is configured with a mounting surface (61) and a pivot arm (62). The pivot arm (62) contains a pivot axis hole (63). The body component is structurally attached to a vehicle body structure (28) via its mounting surface (61) using bolting, welding, bonding, riveting or similar fastening means. The pivot axis hole (63) of the body component (60) is fitted with a pivot bushing (80) that contains an internal cylindrical bearing surface (81) and two opposing thrust flanges (82). Referring to Fig. 7, a pivot pin (90) is configured with a central cylindrical pivot surface (91) and two knurled opposing cylindrical ends (92) each with a diameter less than the central cylindrical pivot surface diameter. The central cylindrical pivot surface (91) is adapted to freely rotate within the internal cylindrical bearing surface (81) of the pivot bushing and the two knurled opposing cylindrical ends (92) are adapted to be inserted and structurally connected to the to the door component (40) pivot axis holes (43) via riveting, staking or similar means of material upsetting, In this way the door component (40) and body component (60) are held in structural assembly but are free to rotate relatively to each other.

Referring to Fig. 8, the door component (40) is constructed from two press formed door angle brackets (46)(47) that are both configured with a mounting surface (41) and a pivot arm (42). The pivot arms (42) each contain a pivot axis hole (43). When the two knurled opposing cylindrical ends (92) of the pivot pin (90) are pressed into the pivot axis holes

(43) and structurally attached via riveting, staking or similar means of material upsetting a single unitary door component (40) is created. The pivot pin (40) therefore replaces the structural bridge normally required to create a single, unitary door component significantly reducing the amount of material required and associated cost.

Referring to Fig. 9, the body component (60) is constructed from two press formed body angle brackets (66)(67) that are both configured with a mounting surface (61) and a pivot arm (62). The pivot arms (62) each contain a pivot axis hole (63). The two body angle brackets (66)(67) are configured so that the two pivot arms (62) are arranged surface to surface and aligned via a semi-shear feature (68) fitted within a matching alignment hole (69). When the semi-shear feature (68) is structurally connected within the alignment hole (69) via press fitting, welding, bonding, riveting, staking or similar means of material upsetting a single unitary body component (60) is created. The semi-shear (68) and alignment hole (69) are arranged so that the pivot axis holes (63) are in alignment. The pivot axis hole (63) is fitted with a pivot bushing (80) that contains an internal cylindrical bearing surface (81) and two opposing thrust flanges (82). In this way the two press formed body angle brackets (66)(67) create a single, unitary door component significantly reducing the amount of material required and associated cost in comparison to a single piece configuration.

Fig. 10 illustrates the flat blank layout of both the press formed body angle brackets (66a)(67a) and the press formed door angle brackets (46a)(47a) of the present invention as well as the scrap material (58) associated with the stamping process. In comparison with the flat blank layout of the prior art hinge assembly illustrated in Fig. 2 it is evident that the present invention offers superior overall material efficiency and lower scrap content than the prior art configuration.

In a preferred embodiment of the present invention a pair of hinge stop formations (70) are provided on the pivot arms (62) of the body angle brackets (66)(67) that are adapted to interact with a pair of hinge stop surfaces (50) provided on the pivot arms (42) or the door angle brackets (46)(47). When the door hinge assembly (30) is rotated to its full

open position the hinge stop surfaces (50) contact the hinge stop formations (70) and prevent further rotation.

Fig. 11 illustrates an alternative embodiment of the pivot pin (100) of the present invention that incorporates two opposing cylindrical ends (102) that are configured without knurling. The pivot pin (100) is configured with tapered steps (105) between the larger diameter of the central cylindrical pivot surface (101) and the smaller diameters of two opposing cylindrical ends (102) that allow compensation for a range of body angle bracket material thickness. In the primary embodiment of the present invention the steps are configured to be square and without taper so that the door angle brackets (46)(47) are pressed on to the two knurled opposing cylindrical ends (92) to a fixed distance defined by the steps. Due to the material tolerances associated with the thickness of the two body angle brackets (66)(67) the two opposing thrust flanges (82) of the pivot bushing (80) can be under or over compressed resulting in inadequate structural assembly or poor relative rotational movement. The tapered steps (105) of the alternative embodiment allow the door angle brackets (46)(47) to be pressed onto the taper to a range of distances while allowing the riveting, staking or similar means of material upsetting to occur against a resistive base. The material interference between the two door angle brackets (46)(47) and the tapered steps (105) creates the structural connection between these components. Increased press loading allows the two door angle brackets (46)(47) to be set to a distance that properly compresses the two opposing thrust flanges (82) of the pivot bushing (80) so that adequate structural assembly and correct rotational movement can be achieved.

Fig. 12 illustrates an alternative embodiment of the pivot pin (110) of the present invention that is configured with a fixed head (116) to facilitate single sided riveting. The pivot pin (110) is configured with a central cylindrical pivot surface (111) and two knurled opposing cylindrical ends (112)(113). The knurled cylindrical end (112) adjacent to the fixed head (116) is of a larger diameter than the central cylindrical pivot surface (111) and the knurled cylindrical end (113) at the opposing end of the pivot pin (110) is of a smaller diameter than the central cylindrical pivot surface diameter. The fixed head (116) is of a larger diameter than the knurled cylindrical ends (112)(113) and the central cylindrical pivot surface (111). In this way the assembly process of the automotive hinge

assembly (30) is simplified to a single pivot pin (110) insertion and riveting, staking or similar means of material upsetting of one end. A slight degradation of the structural attachment of the two door angle brackets (46)(47) may occur using this configuration.

Figs. 13 and 14 illustrate an alternative embodiment of the present invention in that the pivot pin (190) is configured to facilitate ease of separation of the door component (140) and body component (160). This type of separation and reassembly is required in some vehicle assembly plants and is generally referred to as a lift-off process. Both the door component (140) and body component (160) are constructed in the same manner as the main embodiment of the present invention using two press formed door angle brackets (146)(147) and two press formed body angle brackets (166)(167). However, the pivot pin (190) is configured to be structurally connected to the two door angle brackets (146)(147) through a pivot bushing (180) and washer (184) via riveting, staking or similar means of material upsetting. The end of the pivot pin (190) opposite the washer and material upset is configured with a tapered feature (195) and threaded end (196) adapted to interface with a mating cylindrical pivot axis hole (163) in the body angle brackets (166). When the door component (140) is interleaved over the body component (160) a tapered nut (187) is provided that threads onto the threaded end (196) and interfaces with the mating cylindrical pivot axis hole (163) in the body angle bracket (167) achieving correct structural assembly between the door component (140) and body component (160) while the bushing arrangement assures adequate rotational movement. A stop rivet (170) is adapted to structurally connected the two body angle brackets (166)(167) while also interacting with a hinge stop surface (150) provided on the door angle brackets (146)(147) so that when the door hinge assembly (130) is rotated to its full open position the hinge stop surfaces (150) contact the hinge stop formations (170) and prevent further rotation.