Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
  • F16D69/02—Composition of linings ; Methods of manufacturing
  • F16D69/027—Compositions based on metals or inorganic oxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D23/00—Casting processes not provided for in groups B22D1/00 - B22D21/00
  • B22D23/003—Moulding by spraying metal on a surface
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/123—Spraying molten metal
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D65/00—Parts or details
  • F16D65/02—Braking members; Mounting thereof
  • F16D65/12—Discs; Drums for disc brakes
  • F16D65/127—Discs; Drums for disc brakes characterised by properties of the disc surface; Discs lined with friction material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
  • F16D69/04—Attachment of linings
  • F16D2069/0425—Attachment methods or devices
  • F16D2069/0491—Tools, machines, processes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D2250/00—Manufacturing; Assembly
  • F16D2250/0007—Casting

Definitions

• the invention relates to a brake disc for a disc brake device for automobiles and similar vehicles comprising a mainly disc-shaped cast-iron body having a hub portion integral with a surrounding peripheral edge portion having opposite side faces intended for engagement with the wearing parts of brake blocks and to which an increased hardness and wearability has been imparted.
• the wearing linings are designed as wearing plates composed of supporting parts of com- paratively thin sheet material which has a metallic surface layer of increased hardness and wearability provided by spray forming, applying the so-called "Osprey"-technology.
• the casting together of the wearing plates at the edge portion of the disc is, according to the above publication, carried out using the plates as core elements in casting the discs in disposable moulds produced by an automatic mould forming machine.
• said known technology will allow manufacture of brake discs which to a large extent can meet both the operational requirements of automobile disc braking devices and the above-mentioned environ ⁇ mental demands as concerns avoiding pollution of the atmosphere with asbestos fibres
• the fact that the wearing linings are designed as separate wear-resist- ant plates which are cast together with the cast-iron body of the disc, but may otherwise be of a different material, e.g. steel, may cause problems insofar as for example the tolerance differences may cause an imbalance of the brake disc.
• the invention is based on the recognition that a sufficient hardness and wearability for practical applications can be achieved without the usage of separate wearing plates that are cast together with the brake disc.
• this recognition has been realized in a brake disc of the above-mentioned design, which according to the invent ⁇ ion is characterized in that the said increased hard ⁇ ness and wearability has been achieved through a change of the structure in the surface zones of the said opposite side faces.
• the said surface zones will typically assume a cementite, pearlite or martensite structure or a mixture of these structures with a considerably increased hardness and wearability as compared with the the rest of the disc, which norm ⁇ ally consists of ordinary grey cast iron.
• Such a change of structure implies a binding of the carbon content of the cast iron, so that graphite does not occur in free form, and the said surface zones in themselves thus acquire improved frictional properties.
• Such a structural change can be brought about by applying a technology known per se, e.g. by expos ⁇ ing the said surface zones to accelerated cooling, placing elements which have a good heat conductivity at the corresponding walls of the mould cavity or by injection hardening of the finished product, whereby one or more additives such as, e.g. hard metal com ⁇ ponents are diffused into the said surface zones.
• the invention therefore relates to a brake disc for a disc brake device for automobiles and similar vehicles, compris ⁇ ing a mainly disc-shaped cast-iron body having a hub portion integral with a surrounding peripheral edge portion having opposite side faces intended for engagement with the wearing parts of brake blocks and to which wearing linings having a metallic surface layer with a considerably increased hardness and wear- ability have been applied.
• a brake disc is characterized in that said wear- ing linings have been applied to surface zones at said opposite side faces to which a change of structure has been imparted during manufacture of the disc.
• disc brakes can be produced having properties in respect of hardness and wearability which are on a par with the designs described in the above-mentioned international publication, but for which it has been avoided to use separate wearing plates in producing the wearing lin ⁇ ings.
• the binding of the carbon content of the cast iron that occurs during the change of structure elim ⁇ inates the particular phenomenon, namely the existence of carbon in free form, which has made conventional grey cast iron unsuited for direct application of wearing linings.
• the invention thus makes it possible to apply wearing linings directly on to the finished brake discs. This may be done by spray forming as described in the above-mentioned publication.
• the invention also relates to a method for manufacturing a brake disc by casting grey cast iron in a mould having a moulding cavity adapted to the shape of the brake disc. This method is characterized in that said opposite side faces of the edge portion of the brake disc is exposed to accelerated cooling to produce said changes of structure.
• the said accelerated cooling can be provided by arrangement of members hav ⁇ ing a high heat conductivity at the walls of the moulding cavity corresponding to said opposite side faces of the brake disc.
• brake discs can also be manufactured using a method which is characterized in that said opposite side faces of the edge portion of the brake disc of the finished product are exposed to injection hardening for producing the said change of structure by diffusion of an additive into said surface zones.
• brake discs can, according to the invention, be manufactured applying wearing linings direct on the brake disc, either by spray forming or friction weld ⁇ ing.
• the latter method ensures more freedom in the choice of material as the basis material in friction welding may be a known hard-metal alloy such as, e.g. Stellite or a member which in itself has been produc ⁇ ed, e.g. rod-shaped, by spray forming ("Osprey" tech ⁇ nology) .
• Fig.l is a perspective view of an embodiment of a brake disc according to the invention.
• Fig.2 is an enlarged sectional view of a port ⁇ ion of the brake disc shown in Fig.l;
• Figs.3 and 4 are a sectional view and an en ⁇ larged section of a mould part for use in the manu ⁇ facture of a brake disc as shown in Figs.l and 2;
• Fig.5 shows the application of a wearing lining on a brake disc by spray forming
• Fig.6 shows the application of a wearing lining by friction welding
• Fig.7 is a section of Fig.2 of a brake disc with wearing lining.
• the brake disc 1 co-axially mounted on a vehicular wheel and co-rotating therewith in a con ⁇ ventional manner consists according to the invention of a mainly disc-shaped cast-iron body 2 with a hub portion 3 integral with a surrounding peripheral edge portion 4, the opposite side faces 5 of which according to the invention have a considerably in ⁇ creased hardness and wearability.
• Two uniform brake blocs are mounted in a caliper device known in the art at either side of the edge portion 4 of brake disc 2 so as to be displaceable towards each other, under the influence of the brake pressure power, in the axial direction of brake disc 1 for braking engage ⁇ ment with the opposite side faces 5 of the disc, whose radial width preferably is larger than the ex- tension of the brake blocs parallel to the plane of disc 1.
• the central body 2 of disc 1 may be made from a conventional cast-iron alloy, e.g. GG20.
• a brake disc may be made in a ventilated design in that from a central cavity, not shown in the Figure, in hub portion 3 a considerably number of radial ventilat ⁇ ion ducts 6 extend through the edge portion 4 of the cast-iron disc to the periphery of the disc.
• a considerably number of radial ventilat ⁇ ion ducts 6 extend through the edge portion 4 of the cast-iron disc to the periphery of the disc.
• an increased hardness and wearability has been imparted to the opposite side faces 5 of the peripheral edge portion 4 of disc 1 through a change of structure in surface zones 7 at the side faces 5.
• the adjacent material of the brake disc which may be conventional grey cast iron, especially cementite, pearlite or martensite structures or mixtures of same can be used.
• a change of structure to produce the desired surface properties can also be obtained by diffusion of one or more additives into the opposite side faces of the disc through a so-called injection hardening.
• the surface zones 7 may for example be made with a depth of 1-1.5 mm by exposing the side faces 5 to accelerated cooling during the casting process, thus generating a cementite structure.
• a cementite structure As shown in Figs.3 and 4 such an accelerated cooling can be ob ⁇ tained by placing elements, e.g. steel-plate rings 10, having a high heat conductivity at the walls 8 of a moulding cavity 9 corresponding to the surfaces 5 of the brake disc.
• elements e.g. steel-plate rings 10 having a high heat conductivity at the walls 8 of a moulding cavity 9 corresponding to the surfaces 5 of the brake disc.
• the side of each of the plate rings 10 facing the cavity 9 is blackened in a manner known per se.
• Fig.3 shows only a single mould part 12 for use in an automatic plant of the type as described in the above-mentioned international publication in which casting is done in disposable moulds made of sand or similar workable material, in which moulds the pouring cavity is provided between the opposite end walls of a number of uniform mould parts as shown in Fig.3.
• FIG.5 illustrates the method practised in the production of the wearing linings of the brake disc by spray forming, applying the so-called "Osprey" tech ⁇ nology.
• a furnace 20 contains a melt 21 of a met ⁇ allic material, in the actual case mainly aluminium oxide.
• the metallic melt is passed to an atomizer 22, in which by introduction of an inactive gas, e.g. nitrogen, at a high pressure, an atomization of liquid particles of the melt is generated.
• an inactive gas e.g. nitrogen
• the atomized material in the protective atmosphere provided by the inactive gas is directed in a conical cloud 23 towards a substrate 24 passed through the otherwise closed atomization chamber on a belt conveyor 25.
• the substrate 24 con- sists of cast brake discs having surface zones that have undergone a change of structure as described above.
• the parts of a brake disc that are not to be provided with wearing linings i.e. the hub portion 3 and possibly the peripheral edge portion, may be black ⁇ ened so as to be repellant to the atomized liquid particles.
• the liquid particles of the atomizing cloud 23 flatten out in flat blots and solidify instantaneously, where- by a homogeneous coherent surface coating 26 is pro ⁇ vided. Due to the great hardness and wearability of the deposited material the thickness of the surface coating 26 may be quite small, e.g. in the range of 75-100 u.
• a wearing lining made from hard metal or from a basis material produced by spray forming can be applied by pressing a rod-shaped body 30 of wearing lining material onto the side face 5 of the edge portion 4 of brake disc 1 at a high pressure P, e.g. 50 ton while the disc is rotating fast.
• the body 30 rotates on its own axis and a linear forwards and backwards movement in the radial direction of the brake disc is imparted over a length corresponding to the desired radial extension of the surface zone 7 onto which the wearing lining is to be applied.
• the body 30 can as already mentioned be made from a hard-metal alloy know per se, e.g. Stellite, but it preferably consists of a rod-shaped body prod ⁇ uced by applying the "Osprey” technology, having, e.g. aluminium oxide as its main component.
• a hard-metal alloy know per se, e.g. Stellite
• the "Osprey” technology having, e.g. aluminium oxide as its main component.
• the wearing lining 26 as shown in Fig.7 is applied in a quite thin layer, e.g. as mentioned above, a thickness in the range of of 50-100 ⁇ .

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Inorganic Chemistry (AREA)
• Braking Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8089472

Family Applications (1)

Country Status (4)

Cited By (12)

Citations (2)

• 1990
  • 1990-01-11 DK DK007790A patent/DK7790D0/da not_active Application Discontinuation
• 1991
  • 1991-01-10 WO PCT/DK1991/000008 patent/WO1991010840A1/en not_active Application Discontinuation
  • 1991-01-10 AU AU71475/91A patent/AU7147591A/en not_active Abandoned
  • 1991-01-10 EP EP91902858A patent/EP0510069A1/en not_active Withdrawn

Patent Citations (2)

Non-Patent Citations (3)

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