Gm Global Technolgoy Operations, Inc.

Chih-chang Chen

Daniel C Hutchinson

Michael J Bland

Hongliang Wang

Teresa J Rinker

Chi-Mou Ni

Pei-chung Wang

Wayne Cai

Roger Michael Brisbane

Erik B Golm

Robert H Dietze

Michael G Poss

Peter C Sun

Nikolay Kondratyev

Stephen R Smith

Alexander Michael Turley

Steven Daniel Lorentz

Eric G Hartnagle

Peter A Tropper

Jacob W Disbro

Corey Simone

Presented are metalworking systems for joining metallic workpieces, methods for forming and welding such workpieces, and lithium-ion battery pouch cells with anodized aluminum tabs joined via knurling and laser welding. A method for laser welding abutting sections of a workpiece or stackup of workpieces includes receiving, via a workpiece support frame, one or more metallic workpieces each with a surface having applied thereto a treatment layer. This treatment layer releases a gas during welding. A metalworking device forms a knurl pattern into the workpiece surface with the treatment layer. The knurl pattern includes a network of channels, such as one or more series of mutually parallel, rectilinear vent channels, designed to exhaust therethrough the gas released from a welded section of the treatment layer. A laser welding device thereafter welds a joint region of the surface(s) of the one or more metallic workpiece with the knurl pattern.

Welding systems and methods with knurled weld interfaces for metallic workpieces

A method and associated device for joining a battery cell tab to a plurality of foils associated with a plurality of electrodes of a battery cell are described. This includes arranging the plurality of foils in a stack, and joining, via a first joining device, the plurality of foils, wherein the first joining device defines a joining region. A portion of the battery cell tab is arranged on the plurality of foils, and joined, via a second joining device, to the plurality of foils. The second joining device generates a weld joint that is encompassed within the joining region defined by the first joining device. In doing so, weld quality and strength of internal welds in a battery cell may be improved by reducing the occurrence of porosities and cracks in the foil/tab weld joints.

Method and apparatus for welding foils

A method and fixture for welding a battery foil-tab assembly is disclosed. The fixture includes a first clamp member having a first clamping surface defining an opening extending into the first clamp member and a second clamp member having a protrusion surrounding a weld slot. The opening of the first clamp member is configured to receive a portion of the protrusion with the battery foil-tab assembly disposed therebetween. The second clamp member is moveable toward the first clamp member to align the weld slot of the second clamp member with the opening of the first clamp member, thereby causing the protrusion to cooperate with the opening of the first clamp to deflect a portion of the battery foil-tab assembly out of a plane parallel with the battery foil-tab assembly. A laser beam is directed at the out of plane portion to laser weld the battery foil-tab assembly.

Method and clamping fixture for laser welding battery foils to a battery tab

A battery assembly includes a plurality of battery cells each including a cell tab and a bus bar connected to the cell tabs of adjacent battery cells. The bus bar including a pair of 180 degree bend regions that each define a channel for receiving a respective cell tab and a cut-out region defining an opening having opposing edge portions that allows direct access to the cell tab within the cut-out region. A weld line connects the cell tab to at least one of the opposing edge portions within the cut-out region.

Battery bus bar design and laser welding

A method of ultrasonically bonding a plurality of prismatic battery cell tabs to a bus bar within a battery section. The method includes arranging numerous prismatic battery cells such that cell tabs that extend from their lateral edge are substantially aligned along a stacking dimension defined within the battery section, and positioning a free end of at least one of the plurality of cell tabs in contact with a surface of the bus bar. The method is completed by contacting a bonding tool to no more than one surface of the positioned cell tab free end and ultrasonically bonding the positioned cell tab free end to a bus bar with the bonding tool. The one-sided bonding tool has a bonding tip cooperative with an ultrasonic excitation source.

One-sided ultrasonic bonding for applications to join battery tabs to bus bars

A bonded structure of aluminum and copper is formed by bonding a copper workpiece and an aluminum workpiece together along a joint via an arc welding process. The copper workpiece has a first coating, having a lower melting point than copper, applied to at least a portion of it. The first coating allows the copper workpiece to be wetted and brazed, while the aluminum workpiece is melted and fused along the joint. The arc welding process involves the cyclic alternating of a first stage, in which an electric current is supplied to a welding wire as it is moved toward the workpieces, and a second stage, in which the electric current is reduced and the welding wire is moved away from the workpieces, to generate and detach a plurality of molten droplets along the joint. Each molten droplet is formed from the welding wire in the first stage.

Structure and method of bonding copper and aluminum

A resistance spot welding manufacture includes a first metal layer having a first thickness, a second metal layer having a faying surface defining an embossed region, wherein the second metal layer has a second thickness that is less than the first thickness so that a ratio of the first thickness to the second thickness is greater than about 2:1, a third metal layer sandwiched between the first metal layer and the embossed region, wherein the third metal layer has a third thickness that is greater than the second thickness, and a weld joint penetrating each of the first metal layer, the third metal layer, and the faying surface at the embossed region to thereby join each of the first metal layer and the second metal layer to the third metal layer. A method of forming a resistance spot welding manufacture is also disclosed.

Resistance spot welding manufacture and method of forming same

A method of joining the ends of wire windings for a motor stator or the like includes preparing a surface at each end (e.g., by removing any enamel coating), deforming the surfaces to produce knurls, striations, and the like, and then ultrasonically bonding the two surfaces to produce the bond between windings, thereby providing a joint with improved strength.

Methods and apparatus for a motor stator

A method of single sided spot welding includes the steps of providing a metal tube having a convex surface portion and providing a metal sheet for welding to the metal tube. The method also includes the steps of contacting the metal sheet with the convex surface portion of the metal tube and contacting the metal sheet with a welding electrode. The method further includes the steps of supplying power to the welding electrode for melting metal and solidifying the molten metal to form a weld nugget between the metal sheet and the metal tube.

Method for single sided spot welding

The present invention is for a method of lap joining two tubular members and then hydroforming the tubular assembly. An insert end of the first tubular member is inserted into a receiver end of the second tubular member to form a lap joint. A filler metal ring is placed about the outer periphery of the insert end so that it is adjacent the opening of the receiver end of the second tubular member. Heat is applied to braze or solder the lap joint, forming a tubular assembly. The tubular assembly is then hydroformed during which time a supplementary mechanical lock may be formed in the lap joint.

Joining and forming of tubular members

In attempting to reduce deformity when joining vehicle frame components, a riveting/brazing process has been proposed. This process includes joining tubular members, such as hydroformed parts, by cutting at least one flange into one end of a first body member, shaped in conformance with the surface of a second body member. Location holes are formed into each flange as well as into the surface of the second member in suitable alignment with each other. A brazing filler material is fixed into a side of the flange, usually within a pocket, intending to lie on the surface of the second member when the two structures are attached. The flange(s) are initially attached to the surface of the second member by means of a rivet to formed an actual vehicle body assembly. Heat is then applied to the assembly to form a brazed T-joint.

Growing community of inventors

Rochester Hills, MI, United States of America

Chih-chang Chen