EP2032232A1 - Eléments de filtre formés de fil métallique enroulé - Google Patents

Eléments de filtre formés de fil métallique enroulé

Info

Publication number
EP2032232A1
EP2032232A1 EP07874492A EP07874492A EP2032232A1 EP 2032232 A1 EP2032232 A1 EP 2032232A1 EP 07874492 A EP07874492 A EP 07874492A EP 07874492 A EP07874492 A EP 07874492A EP 2032232 A1 EP2032232 A1 EP 2032232A1
Authority
EP
European Patent Office
Prior art keywords
filter
wire
wound
winding
core
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP07874492A
Other languages
German (de)
English (en)
Other versions
EP2032232A4 (fr
Inventor
George Greenwood
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ACS Industries Inc
Original Assignee
ACS Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ACS Industries Inc filed Critical ACS Industries Inc
Priority claimed from PCT/US2007/009152 external-priority patent/WO2008143606A1/fr
Publication of EP2032232A1 publication Critical patent/EP2032232A1/fr
Publication of EP2032232A4 publication Critical patent/EP2032232A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
    • B01D46/528—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using wound sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
    • B01D46/40—Particle separators, e.g. dust precipitators, using edge filters, i.e. using contiguous impervious surfaces
    • B01D46/403—Particle separators, e.g. dust precipitators, using edge filters, i.e. using contiguous impervious surfaces of helically or spirally wound bodies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
    • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
    • B60R21/16—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags
    • B60R21/26—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow
    • B60R21/264—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic
    • B60R21/2644—Inflatable occupant restraints or confinements designed to inflate upon impact or impending impact, e.g. air bags characterised by the inflation fluid source or means to control inflation fluid flow using instantaneous generation of gas, e.g. pyrotechnic using only solid reacting substances, e.g. pellets, powder

Definitions

  • This invention relates to filter elements and their manufacture by winding a wire about a mandrel.
  • Filters have long been made by helically winding a strip of material, such as paper or wire, about a form to make a filter.
  • US 2,122,582 describes an intake air filter for an internal combustion engine made by helically winding a gimped wire.
  • Helically wound polymeric fibers have been used to manufacture various filtering or separation apparatus, such as described in US 4,048,074.
  • filters are used to control and cool the hot explosion products produced by the gas generator.
  • US 5,230,726 describes a hollow cylindrical core having helically wrapped thereabout various layers of material, including a filter layer; the wrapped core is then cut into filters of the desired size. Ceramic fibers have been helically wrapped about a core to make an air bag inflator filter, as in US 5,702,494 and US 5,908,481.
  • wire filters WO05/065811 describes a filter having copper-plated iron wires knit together and then heat treated between the melting point of copper and its sintering temperature to adhere the wires to each other where they cross.
  • WO05/065999 describes a helically wound wire filter with two layers in which the pitch angles of the first layer superimposed on itself in the radial direction is symmetrical, and a second layer having finer filtration by using a thinner wire.
  • Winding machines are well-known, from machines for winding wire about pre- stressed pipe having diameters of meters, to machines for winding thread on bobbins or tubes having diameters of centimeters. It is also known to provide computer control for such machines.
  • this invention provides wound wire filters having geometries other than a right rectangular cylinder, wound wire files having improved strength, and wound wire filters having another material provided as a radially intermediate portion disposed between adjacent layers of wires.
  • This invention provides a cylindrical wound wire filter with an inner bore, suitable for use with an airbag inflator, having at least two different outer diameters and/or at least two different inner diameters.
  • Wires in adjacent layers can be bonded together brazing, or have a sheet-like material therebetween, such as a ceramic filter paper.
  • the brazing material is an example of an adjuvant, which could be an adhesive, or a strip of braided or non-woven material such as the ceramic filter paper fed along with the wire.
  • this invention provides a wound wire filter having a first inner diameter and a first outer diameter, and at least one second (different) inner diameter (different from the first) or one second (different) outer diameter (different from the first).
  • Fig. 1 depicts the winding device.
  • Fig. 2 depicts a wound wire filter in a dumbbell shape.
  • Fig. 3 depicts a cross section of a filter having multiple inner diameters and a sacrificial member.
  • Fig. 4 depicts the device in Fig. 1 with a set of crimping rolls and an applicator for a paintable or sprayable adjuvant material.
  • Figs. 5-7 depict wound wire filter devices having a smooth exterior, a helically- wound interior, and more than one internal diameter.
  • Fig. 8 depicts a wound wire filter having an expanded metal core.
  • a typical winding machine has a mandrel 1 and a source 2 of an indefinite length material, wire 3 in this invention, that is wound onto the mandrel.
  • the wire is preferably a flat wire, although a round, oval, or any other cross section can be used.
  • the mandrel is preferably a collapsible mandrel, like a chuck for a drill.
  • the position L of the source is controlled with respect to the speed of rotation R of the mandrel.
  • the angle ⁇ (helix angle) between the wire and the center line (axis of rotation) of the mandrel is typically kept constant and the source moves regularly in one direction, or regularly back and forth shuttling between the ends of the mandrel (or over whatever length is desired to make the part).
  • the dwell time is typically zero at the ends; that is, once the source reaches one end of the mandrel it shuttles back to the other end.
  • the angle ⁇ is altered and the movement of the source is varied to achieve a desired geometry.
  • the helix angle and the dwell time are adjusted to make geometries other than a simple right rectangular cylinder.
  • a wind ratio can be specified; the "wind ratio" is the number of windings per linear length taken parallel with the axis of rotation of the mandrel. Because the circumference changes as the wire is wound, a fixed helix angle will result in a changing wind ratio as the device grows, and similarly a fixed wind ratio will result in a changing helix angle as the device grows.
  • the dwell time during a particular axial length can be altered to change the thickness of the wound layer over that length.
  • the apparatus is relatively simple to make from off-the-shelf parts or by modification of a conventional wire winding machine.
  • Fig. 2 depicts a wound wire filter 10 in the shape of a dumbbell, having a central cylinder 12 and disk-shaped ends 13 each with a greater radius than the central cylinder.
  • the computer is programmed to wind a central cylindrical portion for the entire length of the filter, then to wind one of the dumbbell ends, then to traverse to the other end and wind that end. If the traverse speed is sufficiently slow, the wire at the outer circumference of the first dumbbell will wind onto the central portion first, and is cosmetically almost indistinguishable from the wires in the central portion.
  • the filter shown in Fig. 2 thus has a geometry other than a simple right rectangular cylinder. Rather, the device as two outer diameters, one for the central portion and one for the dumbbell ends, and a single inner diameter.
  • filters can be used for air bag inflators, as are wire mesh filters, such as described in US 6,277,166, the disclosure of which is incorporated herein by reference.
  • wire mesh filters such as described in US 6,277,166, the disclosure of which is incorporated herein by reference.
  • a wire mesh tube is compressed in a mold to form an annular filter having ribs running axially on the outside of the filter.
  • a filter having multiple ribs running transversely can be made, effectively like the dumbbell design in Fig. 2 with additional larger disk(s) between the outermost disks (that is, a plurality of two different outer diameters).
  • the explosive charge is provided in a short length of solid tube, with the ends sealed, and openings around the circumference of the tube for the gases to escape.
  • a sacrificial band can be placed on the mandrel and a filter wound in the desired geometry. The device is then removed from the mandrel and the band removed.
  • the band can be a polymer, such as neoprene that is removed mechanically or by hand, or polystyrene that is burned off or dissolved chemically, or a water-soluble polymeric compound.
  • the resulting filter 31 has a bore 32, a band of sacrificial material 33 forcing the wound material to form a cavity 35.
  • the filter shown in Fig. 3 has a single outer diameter and multiple inner diameters. Surprisingly, it has been found that even the wire is wound under tension, the cavity does not deform to any noticeable extent when the sacrificial material is removed. In use, the cavity acts as a manifold for the explosive gases. Also shown in Fig. 3 is an continuous (axially) outer layer 37, formed by successive windings being side-by-side; that is, the outer layer approximates putting a wound right cylindrical filter into a tube. With the continuous layer, the explosive gases exit axially from the filter.
  • Fig. 4 depicts modifications that can be made to the wire prior to winding.
  • the wire is passed through a set of crimping rolls 42, so that the wound wire is crimped. It is preferred to place the crimped wire on the outside if the filter is to be placed into a tubular structure; the crimped wire is more compressible (radially) than the uncrimped wire of the bulk filter, so a filter with crimped wire on the outside can be more easily force fit into a cylinder. Likewise, a crimped layer can be formed directly adjacent the mandrel to enable a tubular structure (such as the above mentioned airbag charge) to be forced into the bore of the filter.
  • FIG. 4 Another embodiment shown in Fig. 4 is the application of a adjuvant to the surface of the wire prior to winding.
  • an applicator 44 adjacent the wire is used to apply a paintable or sprayable fluid from a reservoir 46 to the wire.
  • the applicator can be a brush or a spray nozzle.
  • the adjuvant need not be used in combination with crimping, and may be applied to either or both sides of the wire.
  • the adjuvant can be an adhesive, adding shear strength to the wound structure.
  • the adjuvant can be a paste used for brazing.
  • the filter as wound can be sintered to provide a diffusion bond where the wire cross. A stronger bond can be achieved by using a brazing adjuvant, such as copper powder (e.g.
  • the filter will be brazed and a stronger bond will be formed between crossing wires. It may be desirable to keep the filter on the mandrel during sintering or other heat treatment, in which case the mandrel can be coated with a non- reactive material ⁇ e.g., SiN, BN) that will allow the heat-treated filter to be easily removed from the mandrel after the heat treatment.
  • a non- reactive material e.g., SiN, BN
  • a strip of sheet-like material can be fed along with the wire during winding.
  • Suitable sheet-like materials include braided metal or glass fiber, a non-woven matt (such as glass or carbon fiber, or a ceramic filter paper (such as described in US 4,890,860, and US 6,913,059, the disclosure of which is incorporated herein by reference), stainless steel microfibers (such as in mesh form); the width of the filter paper is preferably wider than the wire width.
  • a non-woven strip or filter paper enables filtering relatively finer particles.
  • a pyrolyzable polymeric fiber or strip can be fed in with the wire and the strip pyrolyzed to a ceramic or carbon during heat treatment of the filter.
  • Figs. 5-7 depict wound wire filter devices having a smooth exterior, where the wire is wrapped side-by-side, an interior where the wire is wrapped helically, and a smaller interior diameter.
  • Fig. 5 is a close up view of a wound wire filter having an innermost diameter 501 wherein the wires are wound side-by-side to make a smooth or flat surface, and intermediate portions where the wire winding changes to helical 503.
  • Fig. 6 depicts a similar device, where the outer surface 601 of the filter is smooth (side-by-side winding) and ends 603 at a small shelf where the winding becomes helical 605, as seen on the larger diameter interior surface.
  • Fig. 7 is another perspective view of a similar device having a smooth outer surface 701 overlying a helically-wound interior 703, the device having both a larger diameter inner diameter (ID) at 703 and a smaller diameter ID ending at shelf 705. From the devices seen in Figs.
  • a wound filter can be made with multiple inner and/or outer diameters, and that the innermost and/or outermost surfaces can be made with a smooth winding (i.e., side-by-side winding) or more porous with helical winding.
  • an expanded metal sleeve can be positioned on the inner diameter and/or the outer diameter.
  • the axial strength of the filter can be augmented by orienting the diamond-shaped opening of the expanded metal sleeve along the axis of the filter.
  • the sleeve acts as a heat sink, protecting the smaller wires.
  • the expanded metal sleeve can be manufactured from carbon steel, stainless steel, or any other metallic substance. The sleeve can be in place if the device is sintered, whereby the sleeve will become fused with any wires with which it is in contact.
  • a wire winding on a mandrel can be paused at one end of the unfinished winding, an insert placed over the existing winding, and then the winding continued to effectively encase the insert between relatively inner and outer windings.
  • This operation can be done multiple times, and can include in inner porous sleeve like the expanded metal sleeve described above.
  • the insert can be in the form of a porous sheet (metal or polymeric, including weaves like screens and fabric), a preformed tube (like an expanded metal tube), a mesh (plastic or metal, preferably knitted), or any combination.
  • the filter preferably has an internal diameter of about one to three inches (2.5-7.5 cm) and a length of about one to two inches (20-50 cm), suitable for installation in the steering wheel of a vehicle as part of a driver's side airbag.
  • a filter for the airbag safety device on the passenger's side is typically much longer (about 12-18 cm) and has a smaller diameter (about 15-40 cm).
  • the airbag curtain device that protects against contact with the side window has an even smaller inner diameter (5-20 mm) and length (about 20-30 mm). The thickness of the filter depends on the particular application and the charge used.
  • Front (driver and passenger) airbags typically use an explosive material for the charge, whereas side (curtain) airbags use either an explosive charge ignited during a collision or a stored gas canister ruptured to release the gas in a collision.
  • a front airbag for the passenger side of a vehicle typically is much larger than the driver's front airbag, and so more gas generation is required.
  • the passenger's front airbag may have up to five equivalent charges, including charges of different sizes (not all of which are ignited, as in "smart" airbag technology where the weight of the passenger is sensed to determine the explosive force needed).
  • this invention provides a filter especially useful for a passenger's front airbag, wherein the wire is wound around a hollow core having a multiplicity of openings.
  • the core can be any material that will withstand the explosion and provides filtering.
  • a woven or knitted wire mesh can be used as the core.
  • a woven metal wire sheet or screen is rolled into a tube or cylinder and welded with abutting ends.
  • a wire mesh is typically knitted as a tube, and where knitted wires are overlapping they can be spot welded to give the mesh integrity; thereafter, the mesh can be cut to the desired tube length.
  • Another alternative is an expanded metal sheet; like a woven sheet, the expanded metal sheet is cut to size and welded with abutting edges to provide a cylinder. Because the explosion is essentially isotropic, and wire is wound around the core, abutting edges are preferred to overlapping edges.
  • an expanded metal sheet is rolled into a cylinder and welded with abutting edges to provide a core 801. Each end 803 of the core is preferably flared out. The core is then placed on a mandrel, and the wire 805 is wrapped around the core to provide the filter.
  • the end of the wire is preferably spot welded to the winding and then broken off to assure the wire does not ravel (unwind).
  • the wound wire can be made to provide various patterns or structures in the winding.
  • the core is preferably made of stainless steel, has a thickness of about 0.1 mm to about 1.0 mm (in the figure the thickness is about 0.5 mm) and has about 5% to about 50% void space (i.e., the multiplicity of opening as a fraction of the area of one side).
  • Figs. 9A-9C are side, plan, and perspective views of a filter wherein the inner surface 901 is relatively smooth and the outer surface 903 is made using a relatively large angle so that the helical winding provides a relatively open pattern.
  • the shelf 905 is more sharply defined due to the winding pattern shown in these figures, and thus forms a flange with good tolerance for mating with the housing in which the filter will be used.

Abstract

L'invention concerne un filtre cylindrique formé de fil métallique enroulé qui comporte un trou intérieur, peut être utilisé avec un système de gonflage de coussin gonflable de sécurité et comporte au moins deux diamètres extérieurs différents et/ou au moins deux diamètres intérieurs différents. Les fils métalliques de couches adjacentes peuvent être liés ensemble par un adhésif ou par brasage, ou comportent entre eux une matière du type feuille, par ex. papier filtre céramique.
EP07874492A 2006-04-15 2007-04-13 Eléments de filtre formés de fil métallique enroulé Withdrawn EP2032232A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US79215306P 2006-04-15 2006-04-15
US25957606A 2006-05-11 2006-05-11
PCT/US2007/009152 WO2008143606A1 (fr) 2006-04-15 2007-04-13 Eléments de filtre formés de fil métallique enroulé

Publications (2)

Publication Number Publication Date
EP2032232A1 true EP2032232A1 (fr) 2009-03-11
EP2032232A4 EP2032232A4 (fr) 2010-03-24

Family

ID=40328875

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07874492A Withdrawn EP2032232A4 (fr) 2006-04-15 2007-04-13 Eléments de filtre formés de fil métallique enroulé

Country Status (1)

Country Link
EP (1) EP2032232A4 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2392801A1 (fr) 2010-06-07 2011-12-07 Ford Global Technologies, LLC Procédé et dispositif pour détecter le nombre de cétane

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002306914A (ja) * 2001-04-17 2002-10-22 Fuji Filter Kogyo Kk 巻線型フィルター装置の製造方法
JP2006159153A (ja) * 2004-12-10 2006-06-22 Chuo Spring Co Ltd 濾過部材及び濾過部材の製造方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002306914A (ja) * 2001-04-17 2002-10-22 Fuji Filter Kogyo Kk 巻線型フィルター装置の製造方法
JP2006159153A (ja) * 2004-12-10 2006-06-22 Chuo Spring Co Ltd 濾過部材及び濾過部材の製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2008143606A1 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2392801A1 (fr) 2010-06-07 2011-12-07 Ford Global Technologies, LLC Procédé et dispositif pour détecter le nombre de cétane

Also Published As

Publication number Publication date
EP2032232A4 (fr) 2010-03-24

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