Tolerance compensating hinge attachment

Abstract

A lift gate door having hinges installed for a predetermined position on a vehicle. And a method of attaching the lift gate door to a vehicle while maintaining a predetermined tolerance. A first fixture holds a set of hinges at a predetermined position corresponding to an assembly position on the vehicle body. The hinges are temporarily attached to a fixture corresponding to a predetermined vehicle position. A second fixture holds the lift gate at a final installation position for attaching the lift gate to the vehicle. Self-adjusting movable fixing nuts are provided in a set of holes in the hinge plate fixing area of ​​the lift gate. The first fixture moves in an orientation aligned with the second fixture, and the hinges are attached to the lift gate using fasteners. When the lift gate door having hinges is installed on the final vehicle, the hinges are aligned in a predetermined installation orientation to maintain the lift gate in the vehicle clearance with a predetermined tolerance.

Description

Technology Field

[0001] This application claims priority to United States Provisional Patent Application No. 62 / 727,171, filed September 5, 2018. The disclosures of said application are incorporated herein by reference.

[0002] The present invention relates to the alignment of hinges on a vehicle liftgate. Background Technology

[0003] Vehicle assembly is becoming increasingly important in a way that creates the highest consistency in the tolerances between outer body parts installed and finished on the exterior of the final vehicle.

[0004] SUV vehicles present several problems in this area due to the common use of rear liftgates, which are large, cumbersome, and require fitting and adjustment to provide a proper fit and finish. It has been found that it is difficult to properly maintain a desired constant gap between the liftgate door and the vehicle in the manufacture of SUV vehicles because slight variations in the hinges and hinge mounting structures cause installation and finish problems in other parts of the door. This is illustrated in FIG. 3, where misalignment between the vehicle (16p) and the liftgate (14p) using a conventional rivet nut fastener (F) results in misalignment in the area (T).

[0005] Current practice for mounting hinges on liftgates consists of fixed attachment surfaces, such as compression limiters or rivet nuts, where the hinge is bolted to a fixed attachment surface installed on the liftgate. Many discrepancies in these normal attachments can cause delays in custom fitting and adjustment of the liftgate.

[0006] Some of the reported issues include the following: potential mounting surface deformation; compression limiters may not be fully mounted; structural brackets may be displaced or internal panels may be distorted. All of these deformations may cause assembly difficulties.

[0007] Therefore, the goal of the industry is to provide a simple, more accurate, and cost-effective method for mounting hinges and liftgates on vehicles.

[0008] In a wide range of embodiments, the present invention comprises the following steps:

[0009] Step 1: The hinge is loaded into the fore-aft slide detail using body bolt studs as 4-way and 2-way positioning features. The stud positions are duplicated by drilling holes in the body for hinge mounting.

[0010] Step 2: The liftgate assembly maintains the fixture in a fixed state using data (datums) in a manner that optimizes clearance and leveling expectations when assembling to the vehicle.

[0011] Step 3: The front and rear slide details are rearranged to place the hinge in the nominal position in relation to the lift gate assembly data features fixture set.

[0012] Step 4: The hinge mounting bolts are driven by the adjustable elements of the liftgate fastener to secure the hinge.

[0013] According to the present invention, a method for attaching a liftgate door to a vehicle while maintaining a suitable tolerance is provided. A first fixture maintains a set of hinges at a predetermined position corresponding to an assembly position on the vehicle body. The hinges are temporarily attached to the fixture corresponding to a suitable vehicle position;

[0014] The second fastener holds the liftgate in a position that is the final installation position for attaching the liftgate to the vehicle. Self-adjusting movable fastening nuts are provided in a set of holes in the hinge plate fastening area of ​​the liftgate. The first fastener moves in an orientation aligned with the second fastener, and the hinge is attached to the liftgate using fasteners. When the hinged liftgate door is installed on the final vehicle, the hinge is aligned in an appropriate installation orientation to maintain the liftgate within the vehicle clearance with appropriate tolerances.

[0015] Using this process, the hinge(s) are positioned at a set point corresponding to the nominal vehicle body mounting location, while the liftgate is held within the fixture in a manner where the gap / flushness of the assembly is controlled. While driving the bolts to attach the hinges, the liftgate mounting surface compensates for mounting dimensional variation by adjusting to accommodate the fixed hinges. The result is improved gap / flushness between the liftgate assembly and the vehicle. When hinges are attached to the fixed liftgate mounting surface, a change in gap / flushness relative to the vehicle body occurs.

[0016] Therefore, the objective of the present invention is to compensate for changes in hinge mounting dimensions by using a tolerance compensating fastener together with part nesting to improve clearance conditions. The advantage of the present invention is that it is simple and inexpensive.

[0017] Accordingly, a vehicle lift gate is provided, comprising a lift gate frame including an inner panel. A hinge is positioned on a lift gate frame that is pre-positioned for installation on a vehicle. A tolerance compensating fastener system is interposed between the lift gate frame and the hinge to provide a predetermined position of the hinge that corresponds to a predetermined position of the vehicle opening to provide final installation on the vehicle that corresponds to a predetermined tolerance.

[0018] Further applications of the present invention will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples illustrating preferred embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of the invention. Brief explanation of the drawing

[0019] The present invention will be more fully understood from the detailed description and the accompanying drawings. Figures 1a-1e show a flowchart of a process according to the present invention. FIGS. 2a-2d is a partially exploded detailed perspective view to illustrate a fixed system used according to the present invention. FIG. 3 is a drawing of a standard rivet nut attachment of a liftgate showing the final tolerance problem in the area (T) where the liftgate (14p) is misaligned with the vehicle show surface (16p). Specific details for implementing the invention

[0020] The following description of preferred embodiment(s) is by nature merely illustrative and is not intended to limit the invention, application, or use.

[0021] Now, referring to the drawings and specifically FIGS. 1a-1e and 2a-2d, a method of attaching a hinge (12) to a liftgate door (14) is provided, which allows the liftgate door (14) to be installed on the vehicle body (16) while maintaining appropriate tolerances during final installation. A first fastener (18) holds a set of hinges (12) at a predetermined position corresponding to an assembly position on the vehicle body (16). The hinges (12) are attached to the first fastener (18) corresponding to an appropriate position on the vehicle body (16).

[0022] The second fastener (20) holds the liftgate door (14) in a position that is the final installation position for attaching the liftgate door (14) to the vehicle body (16). Self-adjusting movable fastening nuts, preferably tolerance-compensating fasteners (22), are provided in a set of holes of a hinge plate bracket (31) in a fixing area (33) of the liftgate door (14). The illustrated liftgate door includes an inner panel (35), which is typically a polymer panel such as a polypropylene-filled panel and a metal frame member (37). The hinge plate bracket is a reinforcement member, typically steel, to provide force support for the hinges. The opening for the hinge plate bracket (31), the inner panel (35), and the fasteners of the first fixture (18) is moved in an orientation aligned with the second fixture (20), and the hinge (12) is attached to the liftgate door (14) using the fastener (22). The gap (39, 41) facilitates the adjustable alignment of the hinges to a suitable position on the liftgate (14). When the liftgate door (14) with the hinges (12) is installed on the final vehicle, the hinge (12) is aligned in an appropriate installation orientation in the axial and longitudinal directions to maintain the liftgate door (14) in a suitable tolerance in the gap of the vehicle body (16).

[0023] In the first step, a first fixture (18) is provided to hold a set of hinges (12) at a predetermined position corresponding to the assembly position of the vehicle body (16). This is achieved by performing a computer machine scan of the vehicle opening of the desired vehicle, including detailed x, y, and z coordinates of surfaces on the vehicle body (16) associated with the hinge positions, fastener hole positions, and the edges of the liftgate door (14). Subsequently, a physical fixture is created that provides a model of the exact location of the hinge attachment. Using this fixture, the hinges (12) are temporarily attached to the fixture at an exact location that mimics the proper final installation vehicle location.

[0024] A second fixture (20) is manufactured using scan information of an opening on the vehicle to hold the lift gate (14) at a position that is the final installation position for attaching the lift gate (14) to the vehicle body (16). This final holding position is set so that the lift gate door (14) provides an accurate tolerance for the vehicle opening gap. A suitable computer measuring device is used to scan the opening to determine the appropriate fixture orientation.

[0025] A predetermined set of holes (24) is provided in the hinge plate fixing area of ​​the liftgate door (14). A movable fastener system is provided in each hole, as illustrated in more detail in FIGS. 2a-2d. The movable fastener system is preferably of the type of tolerance-compensating fastener. Such fastener systems are available from Bollhoff Inc., Troy, Michigan, and are marketed under the registered trademark Flexitol. Such fasteners include a fixed element (26) and an adjusting element (28). The fixed element (26) is fixed to each hole of the hinge mounting portion by means of a riveting structure, etc. The fixed element (26) includes a first set of threads (30) and a second set of threads (32) formed with opposite threads. In FIG. 2, the first thread (30) is a left-handed screw, and the second thread (32) is a right-handed screw. The adjusting element (28) includes a left-hand screw portion (34) that can be screwed into the thread (32) in the fixed element (26). The first thread (30) is compatible with the bolt (36) used to secure the hinge (12) in place. The adjustable element (28) includes a fixed head portion (38) that acts to support the hinge (12) in the final attachment position.

[0026] When operated, the adjustment element (28) is screwed flat with the fixing element (26) in each hole at each hinge position. Then, using dimensional calculations, the first fixing member (18) to which the hinge (12) is attached is finally installed in alignment with the first fixing member (18) holding the liftgate (14). The bolt (36) is inserted into each mounting hole by tightening it across the hinge (12). When the bolt (36) is tightened, the adjustable element (28) moves to a rear position of the hinge (12) to fix the position of the hinge (12) in the appropriate position. Then, the bolt (36) is snuged itself on the other side of the hinge (12) to fix the hinge (12) in the correct final axial orientation in place between the fixing head portion (38) of the adjustable element (28) (now in a fixed tolerance-adjusted orientation) and the bolt (36). This accurately aligns the hinge (12) in a proper installation orientation to maintain the liftgate door (14) in a vehicle clearance of appropriate tolerance when the liftgate door (14) having the hinge (12) is installed on the vehicle body (16). Then, the liftgate hinge (12) is properly configured when the liftgate door (14) is installed on the actual vehicle body (16). This provides an appropriate clearance between the liftgate door (14) and the vehicle body (16).

[0027] Accordingly, any gap between the fixed head portion (38) and the interfacing lift gate fastener (22) caused by dimensional change is compensated by an adjustable element (28) of the fastener (22) that is adjusted until the two surfaces come into contact and torque is applied. Compensating with the fastener adjustable element (28) prevents changes resulting in gap variation in the vehicle body (16).

[0028] In a preferred embodiment, the position of the hinge (12) on the liftgate door (14) has a form-fitting indentation for nesting the hinge (12). When a tolerance-compensating fastener (22) is used with the nesting of the parts, the appropriate assembly tolerance is further improved.

[0029] In one embodiment, the adjustable element (28) is a sub-gauge and is movable with respect to the opening, but can be fixed in a fixed position after alignment of the hinge (12) at a suitable position on the liftgate door (14). Accordingly, the diameter of the threaded shaft portion is smaller than the diameter of the mounting hole of the liftgate door (14) so ​​that alignment of the hinge (12) with respect to the liftgate door (14) is facilitated before the fixed head portion (38) of the adjustable element (28) on the liftgate is snugged.

[0030] The description of the present invention is essentially merely illustrative, and thus variations that do not depart from the essence of the invention are considered to be within the scope of the invention. Such variations should not be considered to be out of the spirit and scope of the invention.

Claims

Claim 1 A method for attaching a liftgate door to a vehicle while maintaining a predetermined tolerance, comprising: a. providing a first fixing member for temporarily attaching the hinges to a first fixing member at an accurate position mimicking a predetermined installation position of the vehicle body, while maintaining a set of hinges at a predetermined position corresponding to the assembly position of the vehicle body; b. providing a second fixing member for maintaining the liftgate door at a final installation position for attaching the liftgate door to the vehicle—where the liftgate door is pre-positioned for installation on the vehicle—; c. providing a predetermined set of holes in a hinge plate fixing area of ​​the liftgate door and providing a movable fixing nut in each of the holes; and d. when the liftgate door is installed on the vehicle with the hinges, the first fixing member is moved in an alignment with the second fixing member by aligning the hinges in a predetermined installation orientation to maintain the liftgate door in a vehicle gap with a predetermined tolerance, and attaching the hinges to the liftgate door using fasteners; wherein c. A method for attaching a liftgate door to a vehicle, wherein, in the step, a tolerance compensation fastener system formed as a self-adjusting movable fixing nut is provided in the hole, and the tolerance compensation fastener system comprises a fixing element and an adjusting element, wherein the adjusting element is a sub-gauge and is movable with respect to the opening of the liftgate door but can be fixed in a fixed position after alignment of the hinge at a predetermined position on the liftgate door, and the adjusting element has a threaded shaft portion and a fixing head portion, and the diameter of the threaded shaft portion is smaller than the diameter of the liftgate mounting hole so as to facilitate the alignment of the hinge with respect to the liftgate door before the fixing head is snugged on the panel of the vehicle body. Claim 2 A method for attaching a liftgate door to a vehicle, characterized by further including the step of installing a liftgate door on the vehicle in claim 1. Claim 3 A method for attaching a liftgate door to a vehicle according to claim 1, wherein the movable fixing nut maintains the aligned position of the hinge together with the liftgate door to provide fixation of the hinge together with the liftgate door at the aligned position. Claim 4 A method for attaching a liftgate door to a vehicle according to claim 1, wherein positioning surfaces are provided on the liftgate door at the hinge position to assist in aligning the hinge, and the surface is formed as a form-fitting indentation for nesting the hinge. Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 A method for attaching a liftgate door to a vehicle, wherein the fixing element comprises a first set of threads in a radial portion in a first direction for fastening the threads of a bolt (36), and a second set of threads for fastening the corresponding threads of the adjusting element in the opposite direction so that the fastener can rotate the adjusting element in an axial direction toward the fixing element until the bolt is further pulled into the fixing element through the first set of threads and then tightened to a predetermined torque. Claim 9 delete Claim 10 A liftgate for a vehicle, comprising: a liftgate frame including an inner panel; a plurality of hinges positioned on a liftgate frame pre-arranged for installation on a vehicle, maintaining a hinge set at a predetermined position corresponding to an assembly position of the vehicle body, and attached by a fastener for temporarily attaching the hinges at an accurate position mimicking a predetermined installation vehicle position; A vehicle liftgate comprising a tolerance compensation fastener system interposed between the liftgate frame and the hinge to provide a predetermined position of the hinges corresponding to a predetermined position on the vehicle opening, wherein the tolerance compensation fastener system comprises a movable fixing nut formed of a self-adjusting movable fixing nut, wherein the tolerance compensation fastener system comprises a fixing element and an adjusting element, wherein the adjusting element is a sub-gauge and movable relative to the opening but can be fixed in a fixed position after alignment of the hinge at a predetermined position on the liftgate, and wherein the adjusting element has a threaded shaft portion and a fixing head portion, wherein the diameter of the threaded shaft portion is smaller than the diameter of the liftgate mounting hole so as to facilitate the alignment of the hinge with respect to the liftgate before the fixing head is snugged on the vehicle body panel. Claim 11 delete Claim 12 delete Claim 13 A vehicle liftgate according to claim 10, wherein the fixing element comprises a first set of threads in a radial portion in a first direction for engaging the threads of a bolt (36) and a second set of threads for engaging the corresponding threads of the adjusting element in the opposite direction so that the fastener can rotate the adjusting element in an axial direction toward the fixing element until the bolt is further pulled into the fixing element through the first set of threads and then tightened to a predetermined torque. Claim 14 delete

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