Apparatus and method for forming shaped articles

Abstract

A method and apparatus for forming shaped articles such as heat exchanger plates and fuel cell plates from a strip of material. The apparatus includes a feed mechanism for feeding the strip; one or more forming devices which form peripheral features and / or discontinuities in the strip; and an alignment device which maintains constant spacing between the discontinuities and thereby avoids accumulation of incremental feeding errors. Preferably, the strip is re-aligned once for each plate produced. The alignment device comprises a pilot pin and a pilot hole punch for forming index holes in the strip, and can be integral with or separate from the forming devices. One preferred apparatus utilizes a forming device comprising a plurality of punches mounted on a reciprocating frame or gantry structure.

Description

FIELD OF THE INVENTION [0001] The invention relates to apparatus and methods for production of shaped articles, more particularly to apparatus and methods for performing a number of stamping and / or punching operations on a strip of material. BACKGROUND OF THE INVENTION [0002] Heat exchangers are commonly formed from stacks of flat plates. In such heat exchangers, spaces between adjacent plates define internal flow passages. Heat exchangers of this type are described in U.S. Pat. No. 5,794,691 (Evans et al.) and U.S. Pat. No. 6,244,334 (Wu et al.). This type of stacked plate construction is also used in fuel cells and electrolyzers. In these applications, individual plates (bipolar plates) may be bonded together in pairs containing spaced apart passages for coolant flow between them, and outer facing passages for reactant fluid flow. The bipolar plate pairs are then assembled into a stack comprising catalyst-coated membranes and gas diffusion layers sandwiched between each of the bip...

AI Technical Summary

Benefits of technology

[0007] In one aspect, the present invention provides an apparatus for forming a plurality of shaped articles from a strip of material, the apparatus comprising: a feed mechanism for incrementally feeding the strip of material in a forward direction along a strip feed axis; a forming device which receives the strip of material from the feed mechanism and which forms discontinuities in the strip of material at axially-spaced intervals; an alignment device for maintaining constant axial spacing between the discontinuities, the alignment device being located in fixed axial relation to both the forming device and the feed mechanism, the alignment device comprising a frame structure having a first portion and a second portion betwee...

Problems solved by technology

In such operations it is difficult to ensure that the discontinuities formed by the various punching operations are properly spaced from each other and from the periphery of the plate.

In particular, small errors in feeding the strip are repeated for each incremental advance of the strip.

These errors are compounded during the course of a production cycle and may result in parts which do not meet specifications and must be scrapped or may contribute to small incremental assembly errors that are initially undetected but can result in decreased product yield in the downstream assembly process, resulting in even greater losses.

Moreover, traditional progressive dies can be extremely expensive for plates that require forming sections to produce the intricate patterns of formed channels and bosses typically required for fluid passages in the intended product applications.

To produce products of this type by conventional means, two different progressive dies must be purchased at a substantial cost increment.

Moreover to maintain balanced production flow in a continuous production setting, the two dies would need to be run in parallel on two presses, further compounding the cost and complexity of operation.

To date, it has not been possible to produce different types of plates from a single strip of material, in a mass production environment, without using complex and expensive manufacturing equipment as described above.

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