Gm Global Technolgoy Operations, Inc.

Romuald Gmurowski

Mircea M Ghiran

Bruce Steven Shimanovski

George Thomas Winterhalter

Glenn Mark Krcek

Eberhard E Wasserbaech

A Hadi Akeel

Gerald K Ruhlandt

The seal units that form part of a hydroforming apparatus that further includes dies for hydroforming parts are each provided with a tubular part locator for locating and clamping a tubular part in alignment with the seal unit. The part locator basically comprises a locator member, a pair of pivot arms and a backup member wherein the locator member and the pivot arms together with the seal unit are supported by an elevator that aligns the seal unit and the locator member with the hydroforming dies when the latter close on the tubular part. The locator member has a concave surface and guide surfaces wherein the concave surface has a shape conforming to the outer surface of the part and the guide surfaces are adapted to guide an end portion of the tubular part onto the concave surface of the locator member and thereby into alignment with the seal unit. The pivot arms each have a concave surface also conforming to the outer surface of the part and are adapted on pivoting to clamping positions to clamp the end portion of the part on the concave surface of the locator member. The backup member is adapted to hold the pivot arms in their clamping position during hydroforming of the part and may also include a concave surface that is adapted to clamp the end portion of the tubular part on the concave surface of the locator member in cooperation with the concave surface of the pivot arms.

Tubular part locator for hydroforming apparatus

Method and apparatus are disclosed wherein seal units sealingly connect a hydroforming fluid pressure source with the ends of a part to be hydroformed while the part is outside an intended die cavity and wherein the seal units are then conditioned with a relatively low sealing pressure capacity. The part is prefilled through the seal units with hydroforming fluid at a relatively low pressure sufficient to prevent later pinching, buckling, splitting and cracking of the part in the die cavity during hydroforming. The prefilled part, with the seal units remaining sealingly connected, is then enclosed in the die cavity and the seal units are conditioned with a relatively high pressure sealing capacity sufficient for the continued supply of hydroforming fluid to the part through the seal units at the considerably higher pressures required for hydroforming the part.

Method and apparatus for prefilling and hydroforming parts

Hydroforming method and apparatus are disclosed for preventing or minimizing thinning of a tubular part during its hydroforming in a die cavity. Seal units are employed which each have a docking rod that sealing docks at one end with the tubular part and is counterbalanced or overpowered at an opposite end with the same hydroforming pressure that acts in the tubular part on the docking end so that a hydraulic piston that operates the docking rod need only develop sufficient force to exceed the yield strength of the tubular part to effect its compression between the docking rods and thereby effect the addition of material in the tubular part to the portions of the tubular part being stretched during hydroforming.

Hydroforming method and apparatus

A die button flush mounted in the cavity surface of a lower one of two hydroforming dies has a backup plunger received therein that forms a part of this surface when the plunger is in a hydroforming position. A slug ejector received in the lower die also forms a part of this surface and with a tubular part enclosed in the cavity formed by the dies, hydroforming fluid under pressure is supplied to the interior of the part and also to separately act on the plunger. The fluid pressure moves and holds the plunger in its hydroforming position while forming the part to the die cavity surface. The fluid pressure on the plunger is then exhausted allowing the fluid pressure in the part to stretch a portion of the part into the die button while also forcing the plunger to a position that limits this stretching to prevent piercing. The fluid pressure in the part is then reduced to a pressure just sufficient to pierce the stretched portion and the plunger is then allowed to further retract to a position allowing the reduced pressure to pierce a slug onto the plunger. The part is then removed from the die cavity and the plunger is returned to its initial position with the slug thereon where the slug is then ejected from the lower die through an opening in the lower die cavity surface.

Hydroforming, in-die hydropiercing and slug-ejecting method and apparatus

A tube member is placed in a die having a plurality of nodules formed in the cavity thereof. A chamber is formed between a mandrel and end piece within the tube. The mandrel is positioned adjacent a first of the nodules and the chamber is pressurized during a hydroforming cycle to form a node on the tube by simultaneously expanding a portion of the tube outward and feeding the tube linearly into the die cavity. A mechanism for feeding the tube linearly is external to the die cavity and has a member in abutment with one end of the tube. During a positioning cycle, the pressure in the chamber is reduced and the mandrel is moved longitudinally within the tube to a position adjacent the next sequential nodule to permit a repeat of the hydroforming cycle. In one embodiment of the hydroforming process, a mandrel is positioned into the tube from each tube end and a feed mechanism is disposed adjacent each tube end. This permits the sequential simultaneous hydroforming of pairs of nodes on the tube.

Method and apparatus for sequential axial feed hydroforming

A chill device for combination with a vaporizable pattern for casting metal by a lost foam process comprises a chill body receivable within a bore of the pattern and including a plurality of outwardly extending fins. The fins define channels therebetween for packing with mold sand to shape the cast metal and for venting pattern decomposition vapors during casting to avoid pore-forming entrapment in the cast metal. Also, the fins contact the bore surface to conduct heat into the chill body from the cast metal about the bore to accelerate solidification and thereby reduce shrink porosity. Thus, the chill device of this invention produces pore-free metal in the casting region immediately about the bore.

Bore chill for lost foam casting pattern

A chuck for a chucking machine has a rotatably supported toroidal body having first and second sets of jaws projecting inward from its inner periphery, the first and second sets of jaws being axially spaced from one another. Each of the sets of jaws has its own actuating mechanism comprising a lead screw engaging each jaw for the movement thereof. All of the lead screws of a set are controlled by a ring gear actuable by a fluid pressure motor to simultaneously advance or withdraw all the jaws of a set. At least the second set of jaws has a slip clutch associated with each lead screw to allow engagement of all jaws with the workpiece regardless of irregularities in the workpiece surface. Separate locking means are provided for each sets of jaws comprising a collar associated with each lead screw, a locking member biased against each collar to apply locking force to the associated jaw and a fluid pressure motor to release the locking force of the locking members of a set to allow advance or withdraw of the jaws by the lead screw. Each jaw has an associated counterweight engaged through a pinion gear to help maintain clamping force at high rotational speeds. The chuck has fluid supply means to the fluid pressure motors including at least one annular channel in the toroidal body open on one axial side, a stationary annular face seal in the stationary portion of the chuck adjacent the open side of the annular channel, a fluid supply passage through the face seal and means for biasing the base seal toward the annular channel for sealing only during the passage of pressurized fluid therethrough for actuation of a fluid pressure motor.

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Rochester Hills, MI, United States of America

Romuald Gmurowski