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
  • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
  • F16D66/02—Apparatus for indicating wear
  • F16D66/021—Apparatus for indicating wear using electrical detection or indication means
  • F16D66/022—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness
  • F16D66/023—Apparatus for indicating wear using electrical detection or indication means indicating that a lining is worn to minimum allowable thickness directly sensing the position of braking members
  • F16D66/024—Sensors mounted on braking members adapted to contact the brake disc or drum, e.g. wire loops severed on contact
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/70—Insulation of connections
  • H01R4/72—Insulation of connections using a heat shrinking insulating sleeve

Definitions

• the present invention relates to a device for detecting wear of friction linings, in particular of brake pad linings and to a process for heat-sealing such a nozzle.
• friction linings are used which are intended to come into contact with moving parts in order to reduce their speed by friction.
• certain devices for detecting wear of brake pads include a tip which covers the end of an electrical conductor wire, said tip being inserted into a hole made for this purpose in the friction lining subject to the plate. -support of this garnish.
• the advantage of such a tip lies in the fact that it makes it possible to precisely position the end of the electrical conductor wire relative to the wear surface of the friction lining, which guarantees good precision in the detection of the minimum thickness from which it is necessary to replace the friction lining.
• the production of such a nozzle is generally carried out by overmolding of a plastic material at the end of the electrical conductor wire or else by molding of a nozzle or machining of a nozzle in a bar of plastic, then insertion and bonding of the wire inside the end piece.
• Such operations entail relatively high manufacturing costs because of the numerous manipulations they involve and also, for the bonding of the end piece, due to the price of the glue.
• the bonding of the wire poses problems of positioning the wire in the nozzle, said wire being able to move as long as the setting of the adhesive is not carried out.
• the present invention aims to provide a device for detecting wear of friction lining which does not have these drawbacks and which is, moreover, of a particularly simple and economical embodiment.
• the subject of the present invention is a device for detecting wear of friction lining, in particular of a brake pad, intended to be inserted into an orifice provided for this purpose in a friction lining or subject to a support plate carrying this lining, of the type comprising a hollow end piece and a sheathed electrical conductor wire fitted into this end piece, characterized in that the end piece is heat-sealed on the sheath of the electrical conductive wire.
• the tip can be obtained from molding, for example by injection or compression, or be obtained by machining a bar of plastic material.
• the tip of the device according to the invention has the advantage of being able to be placed at the end of an electrical conductor wire in a particularly simple manner, since it suffices to insert the electrical conductor wire inside the end piece without adding glue and then heat sealing the end piece on the wire.
• the tip can be used in a wear detection device with tangential wear or in a wear detection device with front wear.
• the electrical conductor wire can be provided with an electrical contact piece at its stripped end, for example the contact piece described by the Applicant Company in French patent application no. 93 01838 published under number 2 701 743.
• an electrical contact piece maintains the electrical conductor wire in the axial direction of the end piece and ensures frank electrical contact with the brake disc of the braking system when the pads are worn.
• the heat-sealed end piece is electrically insulating, watertight in the entire temperature range of use of the friction lining and mechanically resistant to the forces resulting from the expansion of the core of the electrically conductive wire. subject to temperature variations.
• the tip is made of thermoplastic material such as PA (polyamide), PEEK (polyetheretherketone), PCL (liquid crystal polymer), PTFE (polytetrafluoroethylene).
• the sheath of the electrical conductor consists of braided glass fibers and coated, individually or collectively, with a plastic material such as silicone.
• the external lateral surface of the end piece comprises means for retaining in the orifice provided for its insertion into the friction lining.
• the present invention also relates to a process for heat-sealing a nozzle as described above, characterized in that it consists in inserting the electric conducting wire into the nozzle and in applying the nozzle against a hot tool. to cause simultaneous fusion of the end cap and the sheath of the electrical conductor wire.
• the tip is applied against the hot tool by moving it axially in a frustoconical orifice of this tool.
• the tip is placed between two blocks constituting the tool and the two blocks are joined together.
• FIG. 1 represents a first end piece intended to be heat sealed on an electrical conductive wire
• FIG. 2 represents a second end piece intended to be heat sealed on an electrical conductive wire
• FIG. 3 represents a third end piece intended to be heat-welded on an electric conductive wire
• FIG. 4 is a perspective view of a half-heat-sealing tool provided for placing the end-piece of FIG. 1 on an electric conductor wire,
• FIG. 4A is a sectional view along IVA-IVA of FIG. 4,
• FIG. 5 is a perspective view of a half-tool allowing the heat-sealing the tip of FIG. 2 on an electrical conducting wire
• FIG. 5 A is a sectional view along NA-VA of FIG. 5,
• FIG. 6 is a perspective view of a half-tool for heat-welding the end piece of FIG. 3 on the electric conductive wire
• - FIG. 6A is a sectional view along NIA-VIA of FIG. 6,
• FIG. 7 is a perspective view of the nozzle of FIG. 1 and of the tool of FIG. 4 at the start of the heat-sealing operation
• FIG. 7A is a sectional view along VIIA-NIIA of FIG. 7,
• FIGS. 8 to 11 are sectional views along A- A of FIG. 7, limited to the vicinity of the end piece and showing four stages of the heat-sealing operation,
• FIGS. 12 to 15 are top views of FIGS. 8 to 11,
• FIG. 16 is a view similar to Figure 7 illustrating another use of the heat-sealing tool, - Figure 16A is a sectional view along XNIA-XVIA of Figure 16.
• the end pieces 1, 2, 3 shown in Figures 1 to 3 each have the same front part 4 (on the left in the figures) constituted by a cylindrical sleeve 5 closed by a front wall 6 and provided with a flange 7 to the opposite of this front wall.
• the front wall 6 is the part of the end piece which is intended to come into contact with the disc (not shown) of a braking system and to wear out when the friction lining of the braking system reaches a level of wear requiring replacement.
• the disc comes into electrical contact with the electrical conductor wire introduced into the tip, or with a contact piece mounted on the stripped end of the wire introduced into the tip.
• the flange 7 serves as a shoulder when the tip is introduced into an orifice provided for this purpose in a friction lining, as is well known.
• the rear part 8, 9, 10 of the end piece differs between the three end pieces of figures 1, 2 and 3.
• this rear part 9 is frustoconical. In FIG. 2, it is cylindrical 9 and in FIG. 3, it is cylindrical and split 10. - -
• This rear part 8, 9, 10 is intended to be heat sealed on the sheath of the electrically conductive wire introduced into the end piece.
• FIGS. 4, 5 and 6 show tools 11, 12, 13 which can be used to heat seal the end pieces of FIGS. 1, 2 and 3.
• Each tool comprises two blocks 14, 15, 16, 17, as can be seen in FIGS. 7 and 16, only one 14, 16, 17 of these blocks being shown in perspective in FIGS. 4, 5 and 6.
• Each block comprises a first longitudinal channel 18 intended to receive heating cartridges 19 which bring each metal block to the temperature necessary for heat sealing the end piece on the sheath of the electrically conductive wire.
• Each block also comprises two transverse channels 20 intended to receive guide bars 21 by means of which the two blocks of the tool can move away or come closer while remaining in alignment with one another.
• each block On its face opposite the other block, each block has a semi-cylindrical clearance 22 of large diameter opening on its lower face 23, leaving on the upper face 24 a wall 25 of thickness slightly less than the length of the part rear 8, 9, 10 (to heat seal) of the nozzle.
• a groove 26, 27, 28 is formed, the shape of which corresponds to that of the rear part of the end piece 1, 2, 3.
• this groove 26 is semi-conical. It is semi-cylindrical 27 in FIG. 5.
• FIG. 6 it comprises, on the one hand, a semi-conical upper part directed upwards and extending over most of the thickness of the wall, on the other hand, a semi-conical lower part directed down. These two semi-conical parts 28 in opposition form a constriction.
• the facing grooves delimit an orifice 29 connecting the upper face 24 of the tool to the cylindrical clearance 22 of the lower face 23.
• the electrical conductor wire 30 provided at its stripped end with a contact piece 31 is fitted into the nozzle.
• the assembly thus prepared is engaged by the lower face 23 of the tool between its two separate blocks, until the flange 7 of the nozzle arrives above the upper wall 24 of the tool, while the part of the conductive wire 30 exiting the end piece is located between the grooves 26 and recesses 22 facing the two blocks, as shown in FIGS. 9 and 13.
• the two blocks 14, 15 are then brought together. .
• the guide bars 21 ensure a precise facing of the two grooves 26 which reconstitute the frustoconical orifice 29 enclosing the lower end of the end piece.
• the wire 30, trapped in this frustoconical orifice, is free to slide axially therein because the external diameter of its sheath 32 is smaller than that of the orifice 29.
• the tip is moved axially towards the tool, which brings its rear part 8 into contact with the walls of the orifice 29, as can be seen in FIG. 10, then a pressure on the endpiece to push it into the orifice 29 until the flange 7 comes to bear against the upper face 24 of the tool.
• the rear end of the end-piece is brought, by contact with the hot walls of the orifice, to its melting temperature and it deforms by being crushed on the sheath 32 of the electric conducting wire, which is, by conduction, also brought to its melting temperature.
• the two blocks are separated from each other (as shown in FIG. 15), the end piece being held between the two blocks so that the end piece and the wire sheath is no longer in contact with the tool, which allows them to cool and harden by welding together.
• the heat-sealed end cap and wire are then removed from the tooling.
• a second method is used to heat seal the end piece on the sheath of the electric conducting wire.
• the endpiece is positioned between the two separate blocks of the tooling with its collar 7 at the height of the upper face 24 of the two blocks, as seen in FIG. 16A.
• the rear part 8 of the end piece is therefore opposite the two grooves 26 of the blocks and protrudes beyond the grooves, opposite the semi-cylindrical recesses of large diameter.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing Of Electrical Connectors (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Braking Arrangements (AREA)
• Connections Effected By Soldering, Adhesion, Or Permanent Deformation (AREA)
• Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (2)

Family

ID=9546491

Family Applications (1)

Country Status (9)

Families Citing this family (1)

Citations (6)

• 1999
  • 1999-06-08 FR FR9907186A patent/FR2795470B1/fr not_active Expired - Fee Related
• 2000
  • 2000-06-08 WO PCT/FR2000/001581 patent/WO2000075526A1/fr active IP Right Grant
  • 2000-06-08 DE DE1101042T patent/DE1101042T1/de active Pending
  • 2000-06-08 CZ CZ20010494A patent/CZ296613B6/cs not_active IP Right Cessation
  • 2000-06-08 AU AU55401/00A patent/AU5540100A/en not_active Abandoned
  • 2000-06-08 SK SK177-2001A patent/SK1772001A3/sk unknown
  • 2000-06-08 EP EP00940467A patent/EP1101042A1/fr not_active Withdrawn
  • 2000-06-08 PL PL00345827A patent/PL345827A1/xx not_active Application Discontinuation
  • 2000-06-08 ES ES00940467T patent/ES2157188T1/es active Pending

Patent Citations (6)

Non-Patent Citations (1)

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