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
• • 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
  • F16D13/00—Friction clutches
  • F16D13/58—Details
  • F16D13/60—Clutching elements
  • F16D13/64—Clutch-plates; Clutch-lamellae
• • 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
  • F16D2069/004—Profiled friction surfaces, e.g. grooves, dimples
• • 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
  • F16D2069/0433—Connecting elements not integral with the braking member, e.g. bolts, rivets
• • 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
  • F16D2069/045—Bonding
  • F16D2069/0466—Bonding chemical, e.g. using adhesives, vulcanising
• • 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

Definitions

• the present invention relates to a method of producing a friction lining, intended to equip a friction disc of an automobile clutch, in particular a double clutch.
• a double clutch can alternately couple the motor shaft of the vehicle with two coaxial input shafts of a gearbox, which can be of the robotic type.
• a dual clutch allows to change gears while maintaining the transmission of a torque engine to the vehicle wheels.
• the two clutches are respectively associated with even and odd gear ratios.
• a first clutch is disengaged while the second clutch is engaged, so that the engine torque is progressively transferred from the first to the second clutch.
• Each clutch comprises a mechanism comprising a diaphragm for cooperating with a pressure plate integral in rotation with the cover and the motor shaft.
• Each diaphragm is movable by means of a corresponding clutch abutment, between a rest position and an active position.
• the active position of the diaphragm corresponds to a coupling or decoupling of the shafts of the engine and the gearbox and the rest position of the diaphragm corresponds to a decoupling or a coupling of these shafts.
• These are respectively a normally open clutch and a normally closed clutch.
• the clutch stop is controlled by an actuator controlled by an electronic computer to exert a predetermined force on the diaphragm and move it over a given distance.
• each clutch urged by the corresponding diaphragm, is intended to clamp a friction disk, equipped with friction linings, on a reaction plate connected to the shaft. engine.
• a reaction plate may be provided for each clutch.
• the friction linings are intended to come into contact with the counter-materials of the pressure plates and the reaction plate or plates.
• Each friction disk is rotatably connected to an input shaft of the gearbox and each reaction plate is rotatably connected to a flywheel connected to the drive shaft.
• a liner conventionally comprises an annular friction body composed of a fibrous material, a binder and fillers.
• the friction body is fixed on a support formed by a metal ring foil, by pressing or gluing, for example.
• a lining is fixed on each of the radial faces of the friction disk, the counter-materials of the pressure plate and the corresponding reaction plate bearing against the friction bodies.
• the linings are fixed to the friction disk by rivets housed in the holes of the linings, the heads of the rivets bearing against either a countersink formed in the friction body, or against the foil.
• Each rivet can be used to attach one or both pads to the friction disc.
• holes located opposite the rivets must still be provided in the other lining, to allow the passage of a riveting tool.
• the free thickness of a rivet varies from one rivet to another, which can cause a lack of parallel friction lining and generate vibrations or a phenomenon called "chatter" when the rotation of the friction disc in operation.
• the friction body must have holes for housing the heads of the rivets or allowing the passage of a riveting tool.
• the foil must also have holes, serving either the passage of the rivet rod or the passage of the riveting tool, depending on the intended fastening mode of the linings.
• the holes of the friction body are made by drilling, using a drill or a milling cutter. In this case, it is a question of removing as much friction material as possible, without however damaging the foil which must serve to support the heads of the rivets.
• the holes of the friction body are formed directly during the overmolding or hot pressing operation.
• the movable piston has protruding areas for forming said holes after hot pressing.
• there is generally friction material downhole on the surfaces of the foil designed to form supports for the heads of the rivets.
• WO 201 1/009427 proposes to cover these areas of the foil with an interface layer aimed at reducing the adhesion of the friction material.
• the friction material remaining downhole can then be removed by evaporation with the aid of a laser beam.
• the power of the laser beam is determined so that the foil is not damaged by the heat produced. Such a process is relatively long and expensive.
• the invention aims in particular to provide a simple, effective and economical solution to this problem.
• the friction body is fixed on the support and comprises at least one hole passing through the friction body.
• the lining therefore does not include friction material down the hole, at the corresponding face of the support, intended to serve to support the head of a rivet.
• the holes to be formed in the support for the passage of the rivet rods or the passage of a riveting tool can be made thereafter, by drilling, punching, or by laser cutting, for example.
• said holes of the support can be made before fixing the friction body on the support. In this case, it is necessary to properly position the support relative to the friction body before fixing.
• the friction body is in the form of an annular friction body fixed on a ring-shaped support.
• the friction body is produced by pressure molding in a mold comprising a fixed part comprising a first cavity and a movable piston comprising a second cavity, at least one of said cavities comprising a projecting part able to form the hole during molding.
• the temperature inside the mold during the molding under pressure can be between 150 ° C and 250 ° C, preferably between 180 and 200 ° C.
• the pressure inside the mold can be increased gradually over time, this pressure being up to a maximum of between 200 and 300 bars.
• the friction body may comprise at least one fibrous material, at least one binder and at least one filler.
• the molding of the friction body can be carried out hot, so as to polymerize the binder, at least in part.
• the friction body must, after the die casting, have sufficient strength to be fixed on the support.
• the degree of polymerization at the end of this molding operation can be between 50 to 90%, and is preferably of the order of 70%.
• the support can be affixed to the first face of the friction body and then hot pressed against said friction body, until complete polymerization of said binder and adhesion of the friction body to the support.
• the temperature during this step may be between 150 ° C and 250 ° C, and preferably between 180 and 200 ° C.
• the pressure applied to the support may be between 200 and 300 bar.
• the friction body is fixed to the support by gluing.
• the friction body can be glued to the support with a phenolic resin glue.
• the face of the support on which the friction body is intended to be fixed is prepared by shot blasting or chemical etching, and / or is coated with a primer. hooking.
• the second surface of the friction body is machined by grinding, until said hole opens at the second surface of the friction body.
• all the holes can lead at one time to the level of the friction face, in a single grinding step.
• any particles present in the hole can be extracted, for example by suction.
• the invention also relates to a clutch friction lining comprising a friction body intended to be mounted on a support, said friction body comprising at least one groove devoid of material at the bottom of the groove and devoid of machining traces in the bottom and groove walls.
• the groove can be obtained by the manufacturing method described above.
• FIG. 1 is an exploded view, in perspective, of a friction disk of the prior art
• FIG. 2 to 7 are schematic views illustrating the various steps of the method of producing a friction lining according to the invention.
• FIG. 1 shows a friction disk 1 of the prior art, comprising a splined hub 2 extending along the axis A intended to be coupled to an input shaft of a gearbox, connected to a flange 3 extending radially outwardly from the splined hub 2.
• Annular friction linings 4 are mounted on either side of the flange 3, at its radially outer periphery.
• Each friction lining 4 comprises a support, formed by an annular foil 5, that is to say a sheet of composite material or a sheet of thin metal material, of thickness generally between 0.2 and 1 mm.
• Annular friction bodies 6 are mounted on the faces of the foils 5 which are opposed to the flange 3. These bodies 6 are conventionally composed of a fibrous material, a binder and fillers, as is known in particular from the document FR 2 941,758, in the name of the Applicant.
• Each friction body 6 has a radial fixing face 7, turned on the side of the corresponding foil, and a radial friction face 8, opposite to the fixing face 7.
• the attachment faces 7 are for example glued on the corresponding foils 5 and each foil 5 is fixed to the flange 3 by rivets 9.
• the friction faces 8 are intended to cooperate with a pressure plate and a reaction plate of a clutch mechanism, in particular a double clutch, so as to transmit a torque of one driving member, such as a crankshaft of a combustion engine, to a driven member, such as an input shaft of a gearbox.
• a clutch mechanism in particular a double clutch
• holes 10 are formed in the friction bodies, and serve to house the heads of the rivets.
• Holes 19, 20 are further provided in the foils 5 and serve respectively to pass the rods of the rivets 9, and the passage of a not shown riveting tool, as is known per se.
• the holes 19 have a smaller diameter than the holes 20.
• the heads of the rivets 9 bear on the foils 5, around the holes 19 serving for the passage of the rods of the rivets 9, said heads being moreover housed in the holes 10 of the friction bodies 6.
• FIGS. 2 to 7. These figures represent only a section B (FIG. 2) of an annular lining 4.
• the method comprises a first step of producing a friction body 6 having holes 10 opening only at the attachment face 7 of the body 6.
• the friction body 7 is made by pressure molding in a mold comprising a fixed annular portion 11 comprising a first cavity and a movable annular piston comprising a second cavity comprising cylindrical portions projection 13 able to form the holes 10 during molding.
• the friction body 6 comprises at least one fibrous material, at least one binder and at least one filler.
• the molding of the friction body 6 is carried out hot, so as to polymerize the binder, at least in part.
• the temperature inside the mold during the molding under pressure can be between 150 ° C and 250 ° C, preferably between 180 and 200 ° C.
• the pressure inside the mold can be increased gradually over time, this pressure being up to a maximum of between 200 and 300 bars.
• the polymerization rate at the end of this molding operation can be between 50 to 90%, and is preferably of the order of 70%.
• the method comprises a second step of fixing the friction body 6 on a support which, in this case, is an annular foil 5 of thickness between 0.2 and 1 mm.
• annular foil 5 is engaged in the fixed part 1 1 of the mold and placed on the attachment face 7 of the friction body 6.
• the preceding piston 12 is replaced by an annular piston 14 having a substantially flat face 15, facing the foil 5.
• the foil 5 is then pressed hot by the piston 14, against the friction body 6, until complete polymerization of said binder and adhesion of the friction body 6 to the foil 5.
• the face of the foil 5 on which the friction body 6 is intended to be fixed may be prepared by shot blasting or chemical etching, and / or may be coated with a primer, before hot pressing.
• the friction body 6 is fixed to the foil 5 by gluing, using a glue based on phenolic resin.
• the metal foil 5 is affixed to a magnetic table 16, so as to maintain in position the friction lining 4, the friction face 8 of the friction body 6 being machined using a cutter 17.
• the machined material thickness is between 0.2 and 1 mm, preferably between 0.3 and 0.5 mm.
• the friction body 6 has, after grinding, a thickness between 1, 5 and 5 mm. Any particles of friction material present in the holes are then extracted, for example by suction.
• the holes in the support and allowing the passage of the rivet rods or the passage of a riveting tool can be carried out subsequently, by drilling, punching, or by laser cutting for example.
• said holes of the support may be made before fixing the friction body on the support. In this case, it is necessary to properly position the support relative to the friction body before fixing.

Landscapes

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

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=47631457

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Citations (4)

Family Cites Families (7)

• 2012
  • 2012-01-12 FR FR1250318A patent/FR2985796B1/fr active Active
• 2013
  • 2013-01-10 KR KR1020147022180A patent/KR20140111700A/ko not_active Application Discontinuation
  • 2013-01-10 WO PCT/FR2013/050058 patent/WO2013104869A1/fr active Application Filing
  • 2013-01-10 CN CN201380010096.3A patent/CN104185744A/zh active Pending
  • 2013-01-10 DE DE112013000564.6T patent/DE112013000564T5/de active Pending
  • 2013-01-10 JP JP2014551665A patent/JP2015507150A/ja active Pending

Patent Citations (4)

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