FR2899296A1 - Guide pin for use in automobile industry, has guiding zone with rigid core or hub made of steel or fiber which is surrounded by intermediate layer in absorbent material for absorbing vibrations by shearing of layer, and fixation base - Google Patents

Abstract

The pin has a fixation base (29) and a cylindrical longitudinal bearing (27) of an axis forming a guiding zone of the pin. The guiding zone has a rigid core or hub (33) made of steel or fiber, which is surrounded by an intermediate layer (35) in an absorbent material for absorbing vibrations by shearing of the layer. The layer is locked in translation parallel to the axis and is extended on the zone by 75 percentage of length. Independent claims are also included for the following: (1) a method for fabricating a guide pin (2) a brake.

Description

DISC BRAKE HAVING FLEXIBLE GUIDING ELEMENTS

  The present invention relates to a floating disk brake comprising guiding elements, typically columns, of a member movable axially (with respect to a disk) or substantially axially, typically of a caliper, with respect to a fixed support , typically a screed.

  A disc brake of known type comprises a yoke attached to the rocket door provided with two parallel cylindrical bores, each receiving a column secured to a stirrup.

  The application of the brake linings on the opposite faces of a disk connected in rotation to a wheel of a vehicle generates a braking torque transmitted to the yoke by the lugs of the brake pads carrying the lining and possibly the driven lugs. by the stirrup itself driven by skates.

  In known manner, at least one of the columns has sufficient bending stiffness to minimize angular flexion (relative to the disk). Thus, for brakes of known type, the stirrup, the balusters and the yoke form a rigid assembly.

  In addition, a possible problem of parallelism between the balusters is remedied by increasing the diameter of the bores with respect to the diameter of the balusters. It limits the noise caused by the impact between the column and the wall of the bore at the beginning of braking by interposing a radial element relative to the axis of the column between the bore and the column. The main subject of the present invention is a floating caliper brake caliper comprising a fixing base and an axis guiding zone, characterized in that the guiding zone comprises a central core surrounded by a shear absorbing layer of said shear-absorbing layer. layer.

  The present invention also relates to a column characterized in that said layer is locked in translation parallel to the axis of the guide zone.

  The present invention also relates to a column characterized in that the vibration absorbing layer extends over at least 75% of the length of the guide zone. The present invention also relates to a column characterized in that the vibration absorbing layer is adhered to the web of the guide zone of the column.

  The present invention also relates to a pillar characterized in that the layer 45 absorbing vibration is adhered on at least 75% of the length of the guide zone. The present invention also relates to a column characterized in that it comprises a radially outer sleeve surrounding the vibration-absorbing layer. The present invention relates to a column characterized in that the sleeve is adhered to the vibration absorbing layer.

  The present invention also relates to a method of manufacturing a column characterized in that it comprises the steps of

  forming a metal monoblock piece forming a base for fixing the column and a core of a guide zone; - Cut a substantially rectangular piece of surface substantially equal to the developed surface of the web of the guide zone of the column, in a metal sheet coated with elastomer on at least one of its main faces; forming a substantially cylindrical sleeve with the piece cut in the preceding step and arranging it around the core of the guiding zone, an elastomer layer being interposed between said core and said metal sheet.

  The present invention also relates to a brake characterized in that it comprises a yoke comprising at least one bore in which slides a guide zone of a small column and in that a fixing base of the column is fixed to a floating caliper forming a suspended mass of a vibration damper.

  The present invention also relates to a brake characterized in that the vibration damper comprises two columns, in that the caliper has a mass of between 400 g and 3500 g and in that it attenuates vibrations between 100 Hz and 10000 Hz.

  The present invention also relates to a brake characterized in that the natural frequency of the vibration absorber formed by the stirrup and at least one column is between 100 Hz and 10000 Hz.

  The invention will be better understood with the aid of the following description and the appended figures among which:

  - Figure 1 is an explanatory perspective view; - Figure 2 is a sectional view of a detail of a known type of column; Figure 3 is a perspective view of the preferred embodiment of a pillar according to the invention; - Figure 4 is a top view partially broken away of a brake according to the present invention; FIG. 5 is a perspective view of an alternative embodiment of a column according to the invention; - Figure 6 is a perspective view of an alternative embodiment of a pillar according to the invention; Figure 7 is a perspective view of a sleeve that can be implemented by the manufacture of a pillar according to the invention; Figure 8 is a perspective view of an alternative embodiment of the sleeve of Figure 7; - Figure 9 is a longitudinal sectional view of an alternative embodiment of a pillar according to the invention. In Figures 1 to 9, the same references have been used to denote the same elements. FIG. 1 shows a disc 1 of axle brake 3. The disc 1 is capable of being rotatably connected to a wheel (not shown) rotating about the axis 3. In the remainder of this patent we will speak of an axial displacement (or force) relative to the disk to designate a displacement in rectilinear translation parallel to the axis 3 of the disk 1.

  In the remainder of this patent, reference will be made to a displacement or to an angular force 7 to designate a rotation about the axis 3 of the disk 1. In the remainder of this patent, reference will be made to a displacement or a radial force 9 to designate a displacement or a force along a radius of the disk 1.

  FIG. 2 shows a cylindrical column 11 of diameter D1 of known type arranged in a cylindrical bore 13 of diameter D2 greater than D1 of a yoke 15. A cylindrical sleeve 17 having a diameter at least equal to D2 is disposed in a groove 19 made near an end 21 of the pillar opposite the anchoring end of the column on the caliper. FIG. 3 shows the preferred embodiment of a pillar 11 'according to the invention comprising an advantageously cylindrical longitudinal bearing 27 of axis 23' forming the guide zone of the column, connected to a base of fixation 29 on its support, typically a stirrup ear, for example by a screw not shown. According to the invention, the longitudinal span of the column 11 'comprises transverse vibration damping means 31 with respect to the longitudinal axis 23' of the column 11 '.

  The various transverse vibration modes 31 come mainly from the transverse bends of the column 11 '. Thus, in the mode advantageously illustrated, the longitudinal span 27 of the column Il 'comprises a core or a rigid hub 33 preferably metal, preferably steel or fiber, included in a binder such as fiberglass or aramids included in an epoxy matrix, connected by a radially intermediate layer 35 (with respect to the axis 23 ') of shear vibration absorbing material such as lead or advantageously elastomer, plastomer or alloy and / or a mixture of the two . In a variant, the layer 35 comprises elastic means cooperating with the elastomer. For example, the layer 35 is formed by a cylindrical sleeve of elastomer in which is embedded a helical spring with non-contiguous turns. As a variant, the layer 35 is made of a solid material that is very finely divided so as to have a very large contact surface such as a heavy-weight and / or incompressible material of fine particle size or a small diameter wire intermixed and / or interlaced. In a first variant embodiment, a homogeneous layer of grains which are themselves homogeneous is used. In a second variant embodiment, the layer is formed by grains of hard and / or rigid material coated with flexible material, typically of elastomer.

  In a third variant embodiment, a homogeneous mixture of seeds of various grain sizes is used.

  In a fourth variant embodiment, the thinnest grains form a radially intermediate layer (along the axis 23 'of the column) between two boundary layers arranged, one around the core 33 of the column 11', 1 other in contact with a sleeve 37 radially external.

  In a fifth embodiment, the grains are embedded in the flexible matrix, for example elastomer.

  The nature, the particle size and / or the prestress exerted on the weighty material are chosen according to the frequencies to be damped of the natural frequencies of the mechanical system formed by the brake, the wheel and all or part of the chassis mechanically coupled by the suspension of the vehicle.

  Advantageously, the longitudinal door 27 of the column Il 'comprises, a sleeve 37 radially external, the axis 23' surrounding the layer 35.

  Advantageously, the intermediate layer 35 is adhered to the rigid core 33.

  Advantageously, the intermediate layer 35 is adhered to the radially outer sleeve 37.

  Advantageously, the core 33 and the attachment plate 29 of the column 11 'according to the invention form a single piece.

  Advantageously, the core 33 has a small diameter to allow its flexion when the brake is subjected to radial 9 and / or angular vibrations 7, for example when a portion of the braking torque passes through the columns 11 ', so as to to promote the absorption of vibrations by the shearing of the layer 35 during the deformation or transverse flexion 31 of the longitudinal portion 27 of the column 11 '.

  Advantageously, over at least a portion of its length, the bore 13 '(Figure 4) formed in the yoke 15' to a diameter slightly greater than the diameter of the longitudinal door 27 of the column 11 'not to oppose flexing said longitudinal door.

  In Figure 4, one can see a brake according to the invention comprising at least one, preferably two columns 11 'according to the invention slidably mounted in the yoke 15' similar to the clevis 15 of known type. Columns 11 'are secured with a floating stirrup 39 of disk brake 41.

  In known manner, said fastening is provided by screws 43 passing through openings in ears 45 of the stirrup 39 and are screwed into threads formed in the fixing fuse 29 of the columns 11 '. In known manner, the stirrup 39 overlaps the disc 41. On typically hydraulic control, the stirrup applies friction linings on the opposite major faces of the disc 41 generating a braking torque.

  This braking torque can cause unwanted noises and vibrations.

  According to the invention, the mass of the stirrup is suspended by balusters 11 'and in particular by the layer 35, the bore assembly 13' of the clevis 15 ', columns 11' and stirrup 39 acting as a shock absorber. vibration.

  The mass of the stirrup is for example between 300 g and 5 kg, preferably between 400 g and 3900 g.

  The natural frequency of the vibration absorber formed by the stirrup and at least one column is preferably between 100 Hz and 10 kHz. Thus, it may be advantageous to damp the vibrations in a low acoustic frequency band, for example between 100 Hz and 500 Hz and / or in an average acoustic frequency band of between 1.5 kHz and 10 kHz.

  However, it will be understood that a brake comprising columns Il 'fixed on the yoke and sliding in bores made in the caliper are not outside the scope of the present invention.

  FIG. 5 shows an alternative embodiment of the column 11 'according to the invention of rectangular cross-section made by alternating stacking of sheets 47 of steel or the like and of layers 35' bonded with a damping material, typically elastomer. The multilayer laminar structure makes it possible to increase the shear damping of the elastomer between the sheets 47.

  Advantageously, the plates 47 are perpendicular to the angular movement 7 and parallel to the radial movement 9.

  The thickness of the plates 47 is sufficient to ensure the translation of the yoke 39 with respect to the yoke 15 'and in particular to support a possible transmission of the braking torque by the columns 11' with a desired bending amplitude.

  Advantageously, the plates 47 all have the same thickness. Advantageously, the layers 35 'of damping material have the same thickness.

  40 The implementation of column 11 'of Figure 5 of rectangular section requires the machining of complementary shape bores. It may be advantageous to be able to achieve the bores 13 'by simple drilling to implement balusters 11' with a light structure having a circular section as shown in Figure 6.

  Columns 11 'of FIGS. 5 and 6 may, without departing from the scope of the present invention, receive a core 33 and / or a radially outer sleeve 37 (not shown).

  In FIG. 7, it is possible to see a metal sheet, for example made of stainless steel 37 'covered with a layer of rubber 35 ", folded back on itself along an axis 23' 50 to form a sleeve opened by a parallel slot 49 to the axis 23'.15 By forcing an axis 33 into the sleeve of Figure 7, a column 11 'is produced according to the invention Advantageously, the main face of the sheet opposite to that receiving the rubber layer is varnished or receives a layer of PTFE or the like to avoid the formation of electrical torque with the bore 13 'made in the yoke typically made of cast iron.

  Alternatively, the sleeve is made by folding the rubber sheet around the core 33 of the column. In Figure 8, we can see an advantageous embodiment of the sleeve of Figure 7 closed for example by a stapling 50 in the example shown in the complementary cuts 50.1 and 50.2 preferably dovetail.

  FIG. 9 shows an exemplary embodiment of the balancer according to the invention with fluid damping, in the form of a sealed cartridge, the advantageously cylindrical outer casing 51 of which is forcefully inserted into the bore 13 '. . The outer casing 51 can receive inking means 53, typically lugs of the column 11 'in the bore 13'. The cartridge comprises a rod 33 forming the core of the column whose diameter is smaller than the internal diameter of the outer wall 51 and at least two guide elements 55 whose diameter is substantially equal to the internal diameter of the outer wall 51.

  The guide elements 55 are integral in translation with the core 33. The guide elements 55 form shoulders of the core or, advantageously, have the form of disks secured to the core 33. Each guide element comprises less a calibrated opening 57 allowing the flow of a fluid 35 ', typically oil filling the cartridge. The flow through the aperture calibrated during the displacement of the rod 33 ensures the damping of vibrations. As a variant, the outer diameter of the guide elements 55 is slightly smaller than the internal diameter of the wall 51 so as to allow, when the rod 33 moves relative to the outer wall 51, the flow of fluid at the periphery. guide elements.

  A seal 59 ensures the confinement of the oil in the cartridge.

  Advantageously, a spring 61 axially pushes the core 33 so as to move, in the absence of brake control, the pads of the disk 41.

  The present invention applies in particular to the automotive industry.

  The present invention applies mainly to the braking industry. 35 40 45 50

Claims (11)

claims   Floating caliper bracket (39) having a fixing base (29) and a guide zone (27) with an axis (23 '), characterized in that the guide zone comprises a central core (33) surrounded by per layer (35, 35 ', 35 ", 35"') absorbing shear vibrations of said layer (35, 35 ', 35 ", 35"'). 10   2. Column according to claim 1 characterized in that said layer (35, 35 ', 35 ", 35') is locked in translation parallel to the axis (23 ') of the guide zone (27).   Column according to claim 1 or 2, characterized in that the vibration-absorbing layer (35, 35 ', 35 ", 35"') extends over at least 75% of the length of the guide zone (27). .   4. Column according to claim 2 or 3 characterized in that the vibration absorbing layer (35, 35 ', 35 ") is adhered to the web (33) of the guide zone (27) of the column (1). l ').   Column according to claim 4, characterized in that the vibration-absorbing layer (35, 35 ', 35 ") is adhered over at least 75% of the length of the guide zone 27.   6. Column according to any one of the preceding claims characterized in that it comprises a radially outer sleeve (37) surrounding the vibration absorbing layer (35, 35 ', 35 ", 35'").   7. Column according to claim 6 characterized in that the sleeve (37) is adhered to the vibration absorbing layer (35, 35 ', 35 ").   8. A method of manufacturing a column characterized in that it comprises the steps of: shaping a one-piece metal part forming a mounting base (29) of the column and a core (33) of a zone guide (27); cutting a substantially rectangular piece of surface substantially equal to the developed surface of the web (33) of the guide zone (27) of the column (11 '), in a metal sheet coated with elastomer (35 ") on at least one of its main faces - forming a substantially cylindrical sleeve with the piece cut in the preceding step and arranging it around the core (33) of the guiding zone (27) a layer 45 of elastomer (35) ") being interposed between said core (33) and said metal sheet. 30 2899296 s   9. Brake characterized in that it comprises a yoke (45) comprising at least one bore (13 ') in which slides a guide zone (27) of a pillar (11') according to any one of claims 1 to 7 and in that a fixing base (29) of the column (11 ') is fixed to a floating stirrup (39) forming a suspended mass 5 of a vibration damper.   10. Brake according to claim 9 characterized in that the vibration damper comprises two posts (11 ') according to any one of claims 1 to 6, in that the stirrup (39) has a mass of between 400 g and 3500 g and in that it attenuates vibrations between 100 Hz and 10000 Hz.   11. Brake according to claim 9 or 10, characterized in that the natural frequency of the vibration absorber formed by the stirrup (39) and at least one column (11 ') is between 100 Hz and 10000 Hz. 30 35 40 45 50