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
  • F16D65/00—Parts or details
  • F16D65/02—Braking members; Mounting thereof
  • F16D65/12—Discs; Drums for disc brakes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22C—FOUNDRY MOULDING
  • B22C9/00—Moulds or cores; Moulding processes
  • B22C9/22—Moulds for peculiarly-shaped castings
• • 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
• • 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
  • F16D2250/0015—Casting around inserts

Definitions

• a braking member such as a brake disc or drum, casting model, core, mold, corresponding braking member and vehicle.
• the invention relates to the field of the automotive industry. More specifically, the invention relates to brake members, such as discs or brake drums, of the type of those mounted between a wheel and a wheel hub.
• brake members such as discs or brake drums
• the technology of the brake members has evolved considerably over the years, in particular as regards their mounting.
• the brake discs were fixed at the output of the gearbox, on the differential output plate, independently of the transmission. This solution had the advantage of reducing the unsprung mass of the vehicle.
• the brake discs were fixed behind the wheel hub, in the wheel assemblies and independently of it.
• this technique consists in implanting the brake disc 1 between the wheel 2 and the hub 3.
• the disc is tightened against the hub by the wheel using the fixing screws. 20 of the wheel.
• this disc is kept pressed against the hub using screws 31, generally two in number.
• the functions of the wheel bolts are therefore extended compared to the prior art, since these screws allow the disk to be immobilized with respect to: - the hub; - to the wheel to avoid any shearing of the wheel bolts due to a sliding of the disc under the effect of a braking torque.
• this mounting technique has the advantages of: - facilitating the mounting of the disc and reducing the corresponding times; - simplify the operation of changing the worn disc; - reduce assembly costs (in particular due to a reduced number of screws and tapping compared to the prior art); - improve the cooling of the disc by better exposure of it to fresh air; - do not increase the engine compartment temperature; - free up space in the engine compartment; - do not stress the transmission shafts and joints due to the braking torque.
• the development of the brake disc mounting technique has had no impact on the disc manufacturing techniques themselves.
• the invention aims to provide a technique for manufacturing brake members, such as discs or drums, which is less expensive than that of the prior art.
• the invention also aims to provide such a technique which makes it possible to envisage reducing manufacturing times and reducing certain indirect production costs.
• the invention also aims to provide such a technique which makes it possible to envisage new organizations for production workshops, in particular with a view to freeing up space on the ground.
• Another object of the invention is to provide such a technique which is simple in design and easy to implement.
• the invention therefore proposes a new approach to the manufacture of brake members, calling into question the principle consisting in considering, for the production of these members, that a hole is obtained by drilling. Indeed, with the disc mounting technique between the wheel and the hub, the holes in the disc act as a light, the diameter of which can be larger than that strictly necessary for the passage of the wheel bolts (M 12 or M14), and their diameter is not limited to ensure the support of a screw head as in the old solutions.
• the holes must only allow the passage (even wide) of screws ensuring the support of the hub and the wheel. Also, the dimensional limits of the holes in the case of previous solutions are pushed back, so that the precision obtained by a drilling technique is no longer necessary. On the contrary, it is conceivable to produce the lights in a diameter much greater than that of the wheel screws. This is why the invention proposes to advantageously produce these screw passages during the disc molding operation, this ensuring that machining equivalent to drilling will not be necessary because of the presence of burrs in these screw passages. The fact of providing for the production of these screw passages during molding makes it possible to envisage significant reductions in the cost of manufacturing the brake members.
• the manufacturing method according to the invention eliminates the machining step corresponding to drilling, which also eliminates the corresponding times as well as the operating costs associated with drilling machines. Furthermore, the invention makes it possible to considerably reduce the volume of material devoted to the production of brake disks or drums.
• the material gain is estimated at 11 cm 3 of cast iron per disc (for 5 cylindrical holes with a diameter of 16 mm), which corresponds to 44 m 3 of cast iron per year for a production of 4 million gross records in the year. By weight, this material gain amounts to 320 tonnes of cast iron per year, which corresponds to the weight necessary to manufacture 32,000 raw discs per year (for an average mass of 10 kg per raw disc).
• said transfer of said burrs is achieved by compressing parts of a casting model having means for molding said at least one lumen and / or parts of a core intended to integrate said casting model and having means for molding said aperture (s), said compression being, according to a preferred solution, permitted by a casting model and / or a core intended to integrate said casting model.
• a simple and effective means is obtained to avoid the presence of burrs in the disc openings provided for the passage of the wheel bolts. Any burrs are transferred to areas of the disc that can be machined other than by drilling. For example, burrs transferred to the periphery of the disc can be eliminated by turning.
• the manufacturing process comprises a step of producing at least one recess intended to form a reduced bearing surface against said hub or said wheel.
• said step of producing said one or more recesses is advantageously carried out during said molding step.
• other embodiments can be envisaged, in particular by planning to produce this or these recesses by turning.
• the fact of integrating this operation in the course of the molding makes it possible to simplify the ranges of finishing by machining of the disc, and therefore to reduce the corresponding times.
• said at least one lumen is inscribed in the surface of said at least one recess.
• the lights do not extend over the bearing surfaces.
• the method comprises at least one deburring step by turning a centering orifice of the braking member, said braking member preferably being clamped during said turning step by positioning the turning axis as a function of the position of said light (s).
• This ensures machining on a gross diameter concentric with the diameter in which the centers of the lights are inscribed. In this way, a good positioning of the lights is obtained with respect to the hub and the wheel.
• the invention also relates to a casting model, formed of two shells, for implementing the method as described above.
• the two shells of the casting model are dimensioned so as to present between them a negative clearance at least at the level of said molding means of said aperture (s), and / or in the vicinity thereof.
• the casting model has means for molding at least one recess intended to form a reduced bearing surface of said brake member with said hub or with said wheel.
• the invention also relates to a core intended to cooperate with a casting model as described above.
• the core is dimensioned so as to present a negative clearance with said casting model at least at the level of the said molding means of the said aperture (s), or in the vicinity thereof.
• the invention also relates to a mold for producing a shell of a casting model as described above, as well as a mold for producing a core as described above.
• Another object of the invention is a braking member, such as a disc or a drum, obtained by a method as described above.
• the centering diameter of the braking member is designed to be force fitted onto said hub. In this way, the screw for fixing the disc to the hub (screw 31 in FIG. 1) is no longer necessary.
• This characteristic combines perfectly with the object of the invention, in so far as the disc obtained makes it possible to eliminate any drilling operation. Therefore, the drilling stations implemented according to the prior art can be completely eliminated. New organization of production workshops can be envisaged, and space savings on the ground can be obtained.
• the braking member has a number of lights greater than the number of holes provided in said wheel for the passage of said fixing means.
• the number of additional lights may be used for the installation of indexes to achieve the tightening of the rocket nut (smooth holes being provided for this purpose in the hub), and may also contribute to the pairing of the disc with the hub in order to reduce the flapping of the brake tracks.
• the invention also relates to a vehicle equipped with at least one braking member as described above.
• FIG. 1 illustrates, in an exploded manner, the mounting of a disc between a wheel and a hub, with a disc of the prior art
• - Figure 2 illustrates in block diagram steps of a method of manufacturing a braking member according to the prior art
• - Figure 3 illustrates in block diagram steps of a method of manufacturing a braking member according to the invention
• - Figures 4 to 7 are each schematic views of the molding of a braking member using a casting model according to the invention
• - Figures 8 and 9 are perspective views respectively from the front and rear of a disc according to the invention
• - Figure 10 is a block diagram of a manufacturing range of a disc obtained with a method according to the prior art
• - Figure 11 is a block view of a range of presentation of a brake disc obtained with a method according to the invention
• a brake disc has: a braking track 11 on each of its faces; an outer diameter 12; a centering diameter (or hole) 13; - Several ventilation ducts 14, in the case of ventilated discs; bearing surfaces 15 intended to come into contact with a wheel hub for one face of the disc, and with the wheel for the other face of the disc.
• a disc has a series of slots 16 allowing the passage of fixing means ensuring the clamping of the disc between the wheel and its hub.
• the centering diameter is provided to be force fitted on the wheel hub, according to the technique described in the document published under the number FR - 2 816 018.
• a disc force fitted on the hub to: achieve a relatively short centering (on 1 to 2 mm) relative to the bearing surface of the disc on the hub which directs the brake track; dimension the geometrical defects of the bearing surfaces of the hub and of the disc so that the contacts between these two parts are established first on the largest common diameter.
• the bearing surfaces 15 can be obtained by making dimples 17, in the form of annular grooves, set back from the bearing surfaces 15 and consequently leaving the surfaces 15 in a prominent position. These recesses 17 are provided on either side of the disc so that the openings 16 are inscribed in the surface of the recesses.
• the slots 16 in the disc are obtained by molding the disc, this ensuring that no burrs detrimental to the free passage of the wheel bolts 21 will appear on the demolded disc.
• additional lights other than those necessary for the passage of the wheel bolts
• additional smooth holes also being provided in the hub so as to correspond with the additional lights of the disc. This makes it possible to introduce one or more indexes to establish a reaction to the tightening torque of the stub axle nut not passing through the disc.
• These additional lights may be of the same dimensions as the lights necessary for the passage of the wheel bolts, within the limit of the available bearing surfaces.
• the disc is molded, this molding providing, unlike the prior art , the realization of the lights 16, this by ensuring a transfer of any burrs in areas of the disc distinct from the lights 16.
• This transfer of burrs is achieved by compressing the parts of the casting model, at least at the lights 16 , this thanks to the adapted dimensioning of the casting model itself, or of the core which integrates the casting model. This is illustrated by FIGS. 4 to 7.
• FIG. 6 shows a casting model intended for molding a solid disc 1, the model comprising two shells 21, 22 one of which has forms of molding 211 of the lights 16
• these casting models and the possible corresponding cores are produced using a mixture of sand and a resin material molded using a mold comprising molding means for the formation, on the model or on the core, of negative molding means of the lights, this ensuring the transfer of any burrs in areas of the disc distinct from the lights.
• the local compression of the casting model at the level of the openings 16 of the disc is permitted while providing a negative clearance between the shell 22 and the zones 211.
• FIGs 4, 5 and 7 schematically illustrate the molding of a disc ventilated, the method using a model consisting of two shells 21, 22 and a core 23.
• Figures 4 and 5 show two alternative embodiments of a ventilated disc with inverted bowl, Figure 7 showing an exemplary embodiment a ventilated disc with a straight bowl.
• the molding forms 231 of the lights 16 are carried by the core 23.
• the negative clearance mentioned above is this time provided between the molding means 231 of the core and the corresponding shell, in l 'occurrence shell 21.
• the casting model is designed so that the disc is molded directly with the recesses 17.
• Step 1 molding the manufacturing process of a brake disc according to this mode followed by a turning step aimed at producing precisely: - the outside diameter 12 of the disc; - the centering orifice 13; - the braking surfaces 11.
• the disc is clamped by taking as axis of reference the axis of the circle defined by the lights 16.
• the operations of turning are carried out by considering that the correct positioning of the disc relative to the hub is a function of the position of the lights 16.
• FIG. 2 illustrates in a synoptic manner that the conventional method of the prior art also comprises turning, turning, balancing and protection molding steps, and adds thereto a drilling step 3.
• FIG. 9 illustrates a manufacturing range according to the prior art, comprising: - the loading of the raw disks; - a first stage of roughing; - a second stage of roughing; - a finishing filming stage; - geometric checks; - a balancing step; - a drilling phase; - a protection phase (painting); - unloading discs.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Braking Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34639672

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (4)

• 2003
  • 2003-12-29 FR FR0315516A patent/FR2864596B1/fr not_active Expired - Fee Related
• 2004
  • 2004-12-17 EP EP04816438A patent/EP1700051A1/de not_active Withdrawn
  • 2004-12-17 WO PCT/FR2004/003305 patent/WO2005073585A1/fr not_active Application Discontinuation
  • 2004-12-17 BR BRPI0417702-9A patent/BRPI0417702A/pt active Search and Examination

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events