Vertical air compliant hemming head

Abstract

The present invention pertains to a hemming head for performing a hemming operation which comprises a support housing adapted for securement to a robot arm on a first end, and having a first roller rotatably secured to a second end. The first roller has a cylindrical body, a head, and a groove between the body and head. The head has a diameter greater than the body, and the groove has a diameter less than the body. The groove also includes a canted surface that conjoins with the head. In use, the cylindrical body is adapted to engage and force a workpiece edge downwardly to a first position and the canted surface is adapted to engage and force the workpiece from the first position to a second position.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Application 61 / 209,931, which was filed on Mar. 12, 2009, the entire disclosure of which is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates to hemming sheet metal and more particularly to a hemming apparatus and method for forming a generally flat hem between two metal panels. Even more particularly, this invention relates to a roller-type hemming apparatus for edge hemming vehicle closure panels, such as hemming door, hood, trunk, and deck lid panels.[0004]2. Description of the Prior Art[0005]In the automotive industry, hemming machines are conventionally used to attach two metal panels together. These metal panels include, for example, the metal panels to form the automotive hood, door panels, quarter panels, and the like.[0006]Hemming machines are disclosed in the patent prior art, including U.S. Pat. Nos. 5,26...

AI Technical Summary

Benefits of technology

[0013]The present invention provides a method and apparatus for hemming a pair of panels together. In each, a robot controlled arm causes a roller-type hemming apparatus to hem a pair of upturned flanges together as a result of hemming rollers of the apparatus accurately following the configuration of the bent portion of a workpiece to be hemmed.

[0016]providing a hemming apparatus having a first and a second roller and a break plate associated with the first roller, each roller being disposed on a roller carriage and capable of completing a finished edge hem in successive passes of relative motion of the rollers along the length of the mated edges of the metal panels wherein the flange portion of the first metal panel is folded over in a gradual bend from one end to another of the mated edges to effectively engage the flange portion with the outer side of the mated edge portion of the second panel and thereby maintain the panels in an assembly; and

[0017]manipulating the hemming apparatus in a manner that the first roller and break plate engage opposite sides of the first panel and form a fulcrum break line that facilitates bending of the flange portion over the mated edge portion of the second metal panel and are then moved away from the flange portion followed by the second roller engaging and forcing the flange portion toward and into engagement with the second metal panel.

[0024]a hemming carriage having at least one roller capable of completing a finished edge hem along the length of the mated edges of the panels wherein the flange portion of the first panel is folded over in a gradual bend from one end to another end of the mated edges to effectively engage the flange with an outer side of the mated edge portion of the second panel and thereby maintain the panels in an assembly, and

[0031]The support housing and rollers are adapted to be rotated 180° relative to the axis of the slide shaft. Depending on the manipulator, such as the arm of a robotic machine, the first and second rollers are disposed in either of two positions for folding the flange portion, the first position positioning the second roller and break plate for folding engagement with the flange portion and the second position rotating the support housing and positioning the first roller into folding engagement with the flange portion to complete the hemming operation.

Problems solved by technology

However, a robot is not comprised of a perfectly rigid body.

This results in a fluctuation of the pressing force applied by the hem roller onto the edge of the workpiece, and therefore imperfect hemming of the workpiece.

However it has been observed that springs alone have proven to be inadequate.

In addition, traditional hemming rollers having a single roller only enable the user to hem simplistic workpiece such as those having open areas.

However single roller hemming apparatuses are not capable of hemming a workpiece with complex configurations.

Additionally, certain workpieces having complex geometry may be difficult to hem.

It is costly to reconfigure robot-controlled hemming apparatuses because it is time consuming with respect to labor expenses.

In addition, customized tooling required to reconfigure the mounting of the robot is expensive.

Additionally, as work progresses, oftentimes the circumference of the hemming roller may become nicked, thus resulting in an imperfect hemming.

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