WO2020234390A1 - Drum brake with reduced residual torque - Google Patents

Drum brake with reduced residual torque Download PDF

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Publication number
WO2020234390A1
WO2020234390A1 PCT/EP2020/064137 EP2020064137W WO2020234390A1 WO 2020234390 A1 WO2020234390 A1 WO 2020234390A1 EP 2020064137 W EP2020064137 W EP 2020064137W WO 2020234390 A1 WO2020234390 A1 WO 2020234390A1
Authority
WO
WIPO (PCT)
Prior art keywords
segment
drum brake
spring
hole
mounting
Prior art date
Application number
PCT/EP2020/064137
Other languages
French (fr)
Inventor
Alberto MOLINARO
Hwang SUNGCHANG
Gérard Luu
Ludovic LEVASSORT
Cédric GUIGNON
Original Assignee
Foundation Brakes France
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Foundation Brakes France filed Critical Foundation Brakes France
Publication of WO2020234390A1 publication Critical patent/WO2020234390A1/en

Links

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
    • F16D51/00—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like
    • F16D51/16—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis
    • F16D51/18—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes
    • F16D51/20—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes extending in opposite directions from their pivots
    • 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
    • F16D65/04—Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/08—Bands, shoes or pads; Pivots or supporting members therefor for internally-engaging brakes
    • F16D65/09—Pivots or supporting members therefor
    • F16D65/091—Pivots or supporting members therefor for axially holding the segments
    • 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
    • F16D65/10—Drums for externally- or internally-engaging brakes
    • 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
    • F16D2065/13—Parts or details of discs or drums
    • F16D2065/134—Connection

Definitions

  • the present invention relates to a drum brake with reduced residual torque for a motor vehicle, and more particularly to a drum brake having a reduced residual torque for a motor vehicle actuated at least in part electrically or mechanically.
  • Motor vehicles are equipped with brakes at each wheel.
  • the rear wheels are equipped with either disc brakes or drum brakes.
  • the brakes fitted to the rear wheels provide the service braking function and the parking brake function.
  • the service braking function aims to slow down, or even stop, the motor vehicle.
  • the parking brake or parking brake function aims to immobilize a stationary vehicle and the emergency brake function is generally obtained with the system providing the parking brake.
  • a drum brake comprises a plate fixed to a knuckle carrier, and a drum integral in rotation with the wheel. It also comprises two segments mounted on the plate carrying brake linings intended to approach the drum in order to come into contact with the latter and brake it.
  • the movement of the segments is obtained by an actuator, for example a hydraulic wheel cylinder actuated by pressing the brake pedal in the service brake, and for example an electromechanical device actuated by pressing a button located on the control panel. board, or for example a lever for the parking brake.
  • the inventors have discovered that the springs for mounting the segments on the plate and ensuring their plating on the plate could be responsible for the appearance of at least part of a residual torque.
  • a mounting spring is a coil spring mounted in compression against the segments opposite the platen by means of an elongated piece referred to as a nail.
  • the axis of the spring is substantially perpendicular to the plate. Initially the nail is also perpendicular to the plate. As the segment moves, the nail tilts and tends to move the mounting spring which will then slide on the segment. The spring is then in a position offset from its initial position. However, this shift in position can generate a component on the segment that prevents it from returning to its rest position away from the drum. This results in a residual torque on the drum.
  • the inventors have therefore thought of adding means for maintaining the spring in a substantially fixed position relative to the segment in order to prevent this sliding and therefore the appearance of this component hindering the complete return of the segment to the rest position.
  • the spring retaining means comprise a cup interposed between the mounting spring and the segment, which is fixed relative to the segment and which receives an axial end of the mounting spring.
  • the rim of the cup keeps the spring in the plane of the segment. The cup advantageously maintains the spring in all directions of the plane.
  • the holding means are integrated directly into the segment, for example by a hollow shape or projections forming stops in one or more plane directions. This example has the advantage of not requiring any additional part.
  • the present invention therefore relates to a drum brake comprising a plate, two segments mounted to move relative to the plate, each segment comprising a core and a lining intended to come into contact with a drum, a device for applying the segments to the drum , mounting means for each segment on the plate, said mounting means comprising for each segment at least one mounting spring disposed on the segment opposite the plate, compression means cooperating with the plate to keep the assembly spring against the segment and thus press the segment onto the plate, the plate comprising at least one first hole, the core of the segment comprising a second hole, the first hole and the second hole being substantially opposite and being traversed by the means of compression.
  • the drum brake also comprises means for holding the mounting spring limiting the movement of the mounting spring relative to the segment.
  • the retaining means advantageously limit the movement of the mounting spring in all directions in the plane of the segment.
  • the holding means advantageously ensure the limitation of the displacement parallel to a main plane of the plate.
  • the retaining means cooperate with one end of the spring oriented towards the side of the segment, said means comprising at least one element fixed with respect to the segment limiting the movement of the spring.
  • the retaining means can be interposed between the mounting spring and the core of the segment.
  • the holding means comprise means cooperating with the core of the segment and means cooperating with the mounting spring.
  • the retaining means comprise a retaining cup comprising a bottom surrounded by a first flange cooperating with at least one end turn of the mounting spring, said bottom comprising a hole for the passage of the compression means and a second flange bordering said hole and cooperating with the second hole in the core of the segment.
  • the drum brake comprises means allowing easier visual detection of the presence of the holding means.
  • the means for facilitated visual detection of the retaining means comprise a shape projecting from the periphery of the mounting spring.
  • the holding means are integrated into the core of the segment.
  • the retaining means comprise at least one projection to limit at least in one direction and in one direction the movement of the mounting spring relative to the segment.
  • the retaining means may include several projections distributed around the second hole defining a housing for an end turn of the mounting spring.
  • the retaining means comprise an annular projection surrounding the second hole and having an outside diameter allowing it to penetrate into the end turn and to limit the movement of the mounting spring relative to the segment.
  • the retaining means comprise a housing bordering the second hole, the housing having an outside diameter making it possible to accommodate the end turn and to limit the movement of the mounting spring relative to the segment.
  • the holding means can be produced by stamping.
  • the drum brake may include for each segment two mounting springs and retaining means for each mounting spring.
  • the device for applying the segments against the plate comprises a mechanical actuator driven by an electric motor, said actuator being intended to provide at least the parking brake function.
  • the drum brake may also include a drum mounted around the segments.
  • FIG. 1 is a front view of an example of a drum brake to which the invention applies
  • FIG. 2A is a partial sectional view of a drum brake according to an exemplary embodiment at the level of a mounting spring and of the brake shoe of a first embodiment
  • Figure 2B is a perspective view of a segment with the two mounting springs, nails, mounting cups and retaining cups, the plate not being shown,
  • Figure 2C is an exploded view of Figure 2B
  • FIG. 3A is a top view of another example of a retaining cup according to the first embodiment
  • Figure 3B is a top view of a mounting spring and the retaining cup of Figure 3A,
  • FIG. 4A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to a second embodiment
  • Figure 4B is a perspective view of the brake shoe alone of Figure 4A
  • FIG. 5A is a sectional view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment
  • FIG. 5B is a perspective view of the brake shoe alone of FIG. 5A
  • FIG. 6A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the mounting springs of a segment according to the second embodiment
  • Figure 6B is a perspective view of the brake shoe alone of Figure 6A
  • FIG. 7 A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment
  • Figure 7B is a perspective view of the brake shoe alone of Figure 7A
  • FIG. 8A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment
  • FIG. 8B is a perspective view of the brake shoe alone of FIG. 8A.
  • the drum brake 1 comprises a drum T intended to be integral in movement with the wheel (not shown), a plate 2 of revolution of axis X equipped with a first and a second segment in an arc of circles S and 4 radially movable to be able to be pressed against the cylindrical internal face of the drum T.
  • the segments S and 4 each have a core Sa, 4a. in the form of a circular crown portion which carries a brake lining 3b, 4b.
  • the souls are flat and present a relief.
  • the segments are mounted diametrically opposed with their ends bearing both on a hydraulic wheel cylinder 6 and on a mechanical actuator 10 carried by the plate 2.
  • These segments 3 and 4 are further recalled one by one. towards the other by two return springs 8 and 9.
  • drum brake is understood to mean an assembly comprising at least one plate provided with segments, at least one device for moving the segments.
  • the drum brake arranged in a drum so that the linings are facing the skirt of the drum and configured to come into contact with the latter during a braking phase will also be referred to as a “drum brake”.
  • the segments are kept pressed against the platen with a possibility of moving relative to it by means of mounting springs 24.
  • the mounting springs 24 are coil springs.
  • each segment 3, 4 is held on the plate by two mounting springs 24.
  • the core of a segment having two holes (not visible) is placed on the plate which also has two holes (not visible). for each segment 3, 4, the holes in the segment facing those of the plate.
  • a mounting spring 24 having an inner diameter greater than the diameter of a segment hole is disposed on segment 3, 4 opposite the plate and surrounds the hole.
  • An elongated member 26 designated "nail”, having a head 25, is inserted from the plate through the holes and the spring, the head resting against the edge of the hole in the plate.
  • a mounting cup 28 is disposed on the free axial end of the spring.
  • the mounting cup comprises means of cooperation with the nail to ensure their axial connection and allow compression of the spring, for example it is a connection by quarter turn.
  • the mounting spring 24 is compressed, the free end of the nail 26 passes through the mounting cup 28, and the mounting cup 28 is rotated a quarter turn.
  • the mounting spring 24 is then kept compressed between the core of the segment and the mounting cup.
  • each segment 3, 4 is held by two mounting springs.
  • a single mounting spring is used.
  • a wear take-up link 7 extends along the wheel cylinder 6 having a first end resting on the web 3a of the first segment 3 and a second end resting on the web 4a of the second segment 4, when the brake is at rest.
  • the wheel cylinder 6 is intended to be actuated when using the drum brake 1 according to a first so-called “simplex" mode of operation, which provides progressive braking particularly suitable for braking the vehicle in service. It includes a hydraulic chamber closed at its ends by two pistons which move apart as hydraulic pressure increases and pushes the associated ends of segments 3 and 4.
  • the mechanical actuator 10 ensures, for its part, the parking or parking and emergency braking by separating the associated ends of the segments to ensure rapid and powerful locking of the vehicle wheels according to a so-called "duo-servo" operating mode. , in particular when the wheel cylinder 6 is inactive.
  • the wheel cylinder 6 comprises two opposed pistons, which each actuate one of the segments 3, 4 by moving their two opposite ends 3.1, 4.1 away from each other, c 'that is to say those located on the same side of the axis of rotation X, here called “movable ends” and located at the top of Figure 1.
  • each segment rests on the plate 2 by an anchoring element integral with the plate, and thus forming a stop for this segment.
  • the anchoring element transmits at least part of the braking torque between the segments and the plate.
  • the anchoring element of the two segments is produced by the actuator 10.
  • the actuator 10 extends along a Y axis perpendicular to the X axis of the plate and parallel to the plate. It comprises a housing 12 fixed on plate 2 on the side of the first face.
  • the housing comprises a housing formed by a through bore extending along the Y axis and opening at the two longitudinal ends of the housing 12.
  • a drive assembly is housed in the bore.
  • the drive assembly is for example of the screw-nut type, such as that described in application WO2015 / 101486. It comprises two support elements 16, 20 intended to form a fixed point for the ends 3.2, 4.2 of the brake segments 3, 4 respectively in service braking, and to apply a force to the ends 3.2, 4.2 in parking braking by being moved out of the housing along the Y axis.
  • the drum brake also comprises a drive device 22 of the actuator, fixed on the side on the other face of the plate opposite to the face on which the actuator 10 is mounted.
  • the drive device is a motor. electric which may or may not be associated with a reduction gear.
  • a passage (not visible) is made through the plate 2 to allow the transmission of the drive from the drive device 22 to the actuator 10.
  • the drum brake comprises a lever for providing the parking brake, which is connected to a cable moved by means of a hand brake lever located in the passenger compartment.
  • the mounting springs have a tendency to slide relative to the brake shoes and to take a position which can generate a force component hindering the return of the segments to a position away from the drum.
  • FIGS. 2A to 2C one can see an exemplary embodiment of means 30 for holding the mounting springs in position according to a first embodiment.
  • the retaining means designate the retaining means for a spring or more springs.
  • the holding means include at least one additional part attached to the brake shoe.
  • the first embodiment has the advantage of not requiring any modification of the segment and can be mounted on existing segments.
  • FIG. 2C one can see the various elements ensuring the assembly of the plated segment on the plate and described above.
  • the holes 32 in the core of the segment for the passage of the nails 26 are visible.
  • the retaining means 30 comprise a circular cup 34 comprising a bottom 36 and a first flange 38 extending transversely with respect to the bottom 36.
  • the internal diameter of the cup is such that it makes it possible to accommodate a free end of a mounting spring and limit its displacement in the plane of the segment.
  • the bottom 36 has a hole 40 of sufficient diameter for the passage of the nail 26.
  • the cup has a second flange 42 bordering the hole 40 and extending axially opposite the first flange 38.
  • the outer diameter of the second flange 38 is such that it can be inserted into the hole 32 of the segment and ensure immobilization of the retaining cup 34 in the plane of the segment.
  • segment plane is understood to mean the plane containing the face F of the core of the segment, not looking at the plate and on which the mounting spring (s) bear.
  • the plane of the segment is substantially parallel to the plane of the plate.
  • Segment 3 is placed on plate 2, hole 32 facing the hole in the plate.
  • the retaining cup 34 is mounted on segment 3, the second rim 42 penetrating into the hole 32.
  • the cooperation of the second rim 42 and the contour of the hole 32 ensures that the retaining cup 34 is immobilized with respect to the segment 3.
  • a axial end of mounting spring 24 is housed in retaining cup 34, the outer contour of end turn then cooperates with first flange 38 and secures mounting spring 24 in the plane of the segment.
  • the nail 26 is introduced into the mounting spring 24 from the plate 2, and the mounting cup 34 is disposed on the other axial end of the mounting spring 24.
  • the mounting spring 24 is compressed, the nail end is compressed. passes through the mounting cup 28 which is rotated a quarter turn.
  • the mounting spring 24 is kept compressed.
  • the mounting spring 24 can no longer slide on the face F of the web of the segment or has a limited displacement with respect to the web, under the action of the nail 26 which tilts during braking phases
  • the first and second flanges continuously surround the bottom 36 and the hole 40.
  • the first 38 and / or the second flange 42 are such that they surround the bottom 36 and the bottom in a discontinuous manner. hole 40 respectively while ensuring immobilization of the mounting spring 24 relative to the retaining cup and of the retaining cup relative to the segment.
  • the mounting springs most often slide substantially in a vertical direction, in one direction or the other depending on the segment stretched in forward or in reverse.
  • the flanges of the retaining cups are such that they ensure a limitation of the movement, or even an immobilization in the vertical direction only, or even only up or down.
  • the retaining means cooperate with the internal diameter of the mounting spring.
  • the holding means comprise a plate pierced with a hole and two tubes extending axially around the hole of the two faces of the plate, one tube entering the hole 32 of the brake shoe and the other in the spring.
  • the retaining means are configured to at least limit the sliding of the mounting spring relative to the segment. Therefore clearances between the spring and the first flange of the cup 34 and / or between the second flange of the cup and the hole in the segment are tolerated.
  • the cups are preferably made of a metallic material, for example of steel coated with zinc, for example of DC04 steel, coated with Z12FBR zinc.
  • the cups are made of stainless steel.
  • the holding means 130 which differs from the holding means 30 in that the holding cup 134 comprises means for easily detecting its presence.
  • the means 130 comprise a tongue 136 extending radially outwardly from the retaining cup 134.
  • the tongue 136 is visible and can be easily detected by control means. manual or automated to quickly and reliably ensure that the drum brake is complete
  • the first flange is interrupted at the level of the tongue without the function of maintaining the spring being damaged.
  • the retaining cup is for example produced by stamping a sheet.
  • two separate retaining cups are interposed between the segment and the mounting springs.
  • the two retaining cups are in one piece.
  • they are connected by a strip which can advantageously serve as means for detecting the presence of the cups.
  • FIGS. 4A and 4B one can see an exemplary embodiment of means 230 for holding the spring according to a second embodiment.
  • the holding means are integrated into the segment, i.e. they are formed integrally with the segment.
  • the second embodiment has the advantage of avoiding any risk of forgetting the holding means during assembly and facilitates assembly since no additional step, during assembly, is required.
  • the retaining means 230 comprise a housing 232 formed in the face F of the segment 3, of circular shape in diameter making it possible to accommodate an end turn of the mounting spring 24 and to ensure its relative immobilization in the plane of the segment. As can be seen in FIG. 4A, there may be a clearance between the outside of the coil and the inside of the housing. The edges of the recess ensure the immobilization of the spring and limit its sliding in the plane. The depth of the recess is preferably greater than the radius of the wire of the coil spring 24, and preferably less than 3 ⁇ 4 of the thickness of the web of the segment in which it is formed.
  • This example has the advantage of limiting the movement of the spring in all directions of the plane of the segment.
  • the recess is for example made by stamping the segment. Alternatively, the recess is machined in the web of the segment.
  • FIGS. 5A and 5B one can see another embodiment of the holding means 330 according to the second embodiment.
  • the retaining means 330 comprise an annular projection 332 on the face F of the segment, surrounding the hole 32.
  • the outside diameter of the annular projection 332 is such that the projection fits into the end turn of the mounting spring and ensures its relative immobilization in the plane of the segment.
  • the annular projection is for example produced by stamping the segment.
  • This example also has the advantage of limiting the movement of the spring in all directions of the plane of the segment.
  • FIGS. 6A and 6B one can see another exemplary embodiment of holding means 430 according to the second embodiment.
  • the retaining means 430 comprise pins 432 projecting from the face F of the segment 3 and arranged relative to each other around the hole 32 to form a housing for the end turn of the retaining spring.
  • At least three pins are distributed angularly in a regular manner around the hole 32 ensuring immobilization of the spring in all directions of the plane.
  • the three pins delimit an equilateral triangle whose bisectors intersect substantially at the center of the hole 32.
  • more than three pins are used.
  • the holding means 430 for the second hole 32 only have two pins due to the presence of the spring of the play-taking rod located nearby.
  • the spring of the play take-up link advantageously performs the function of immobilizing the third pin.
  • the pins are for example produced by stamping.
  • FIGS. 7A and 7B one can see another embodiment of the holding means 530 according to the second embodiment.
  • the holding means 530 include a groove 532 delimited by two parallel edges 534 extending over the entire width of the segment 3. The distance between the two edges 534 is such that it accommodates the end coil of the mounting spring and limits its movement in the plane of the segment.
  • the retaining means 530 immobilize the mounting spring 24 only in the X direction which is intended to be substantially vertical when the drum brake is mounted on the means.
  • the groove is for example produced by stamping.
  • FIGS. 8A and 8B one can see another exemplary embodiment of retaining means 630 according to the second embodiment.
  • the retaining means 630 comprises a projection disposed on one side of the hole 32 at a distance from the center of the hole corresponding substantially to the radius of the end coil of the mounting spring 24.
  • the projection 632 is oriented relative to the segment so as to form a stop in the most probable direction of movement of the spring.
  • the holding means 630 limit the sliding in one direction and one direction in the plane of the segment.
  • the protrusion has an oblong shape which extends in the direction of the width of the segment.
  • the holding means 630 are for example made by stamping.
  • the present invention is all the more advantageous in a drum brake in which several mounting springs are used for each segment, since the force component opposing the return to the rest position of the segments is all the greater.
  • the shape of the holding means is adapted to the section of the turns of the mounting springs.
  • the means for maintaining the mounting spring relative to the segments ensure that the mounting spring is held in order to prevent too great an amplitude sliding relative to the hole.
  • Maintaining the assembly springs in the plane of the segments has sufficient play to allow dispersions in the manufacture of the components and facilitate assembly, and absorb positioning errors, while reducing or even eliminating the component opposing the return of the components. segments in rest position.

Abstract

Drum brake comprising a drum, a backplate, two shoes (3), each shoe (3) comprising a web (3a) and a lining intended to come into contact with the drum, a device for applying the segments to the drum, means for mounting each shoe (3) on the backplate, said mounting means comprising, for each shoe (3), a spring (24) arranged on the shoe (3) on the opposite side to the backplate, and compression means cooperating with the backplate to maintain the spring (24) against the shoe (3), the backplate comprising a first hole, the web (3a) of the shoe comprising a second hole (32), the first hole and the second hole (32) facing one another and being traversed by the compression means. The drum brake comprises a cup (34) for retaining the spring (24) that limits the movement of the spring (24) relative to the shoe (3).

Description

FREIN À TAMBOUR A COUPLE RESIDUEL REDUIT REDUCED RESIDUAL TORQUE DRUM BRAKE
DESCRIPTIONDESCRIPTION
DOMAINE TECHNIQUE ET ÉTAT DE LA TECHNIQUE ANTÉRIEURE TECHNICAL FIELD AND STATE OF THE PRIOR ART
La présente invention se rapporte à un frein à tambour à couple résiduel réduit pour véhicule automobile, et plus particulièrement à un frein à tambour présentant un couple résiduel réduit pour véhicule automobile à actionnement au moins en partie électrique ou mécanique. The present invention relates to a drum brake with reduced residual torque for a motor vehicle, and more particularly to a drum brake having a reduced residual torque for a motor vehicle actuated at least in part electrically or mechanically.
Les véhicules automobiles sont équipés de freins au niveau de chaque roue. Les roues arrières sont équipées soit de freins à disque, soit de freins à tambour. Motor vehicles are equipped with brakes at each wheel. The rear wheels are equipped with either disc brakes or drum brakes.
Les freins équipant les roues arrière assurent la fonction de freinage de service et la fonction de freine de parking. La fonction de freinage de service vise à ralentir, voire arrêter, le véhicule automobile. La fonction de frein de parking ou de stationnement vise à immobiliser un véhicule à l'arrêt et la fonction de frein de secours sont généralement obtenues avec le système assurant le frein de parking. The brakes fitted to the rear wheels provide the service braking function and the parking brake function. The service braking function aims to slow down, or even stop, the motor vehicle. The parking brake or parking brake function aims to immobilize a stationary vehicle and the emergency brake function is generally obtained with the system providing the parking brake.
Un frein à tambour comporte un plateau fixé sur un porte-fusée, et un tambour solidaire en rotation de la roue. Il comporte également deux segments montés sur le plateau portant des garnitures de frein destinées à se rapprocher du tambour pour venir en contact avec celui-ci et le freiner. Le déplacement des segments est obtenu par un actionneur, par exemple un cylindre de roue hydraulique actionné par un appui sur la pédale de frein en frein de service, et par exemple un dispositif électromécanique actionné par l'appui sur un bouton situé sur le tableau de bord, ou par exemple un levier pour le frein de parking. A drum brake comprises a plate fixed to a knuckle carrier, and a drum integral in rotation with the wheel. It also comprises two segments mounted on the plate carrying brake linings intended to approach the drum in order to come into contact with the latter and brake it. The movement of the segments is obtained by an actuator, for example a hydraulic wheel cylinder actuated by pressing the brake pedal in the service brake, and for example an electromechanical device actuated by pressing a button located on the control panel. board, or for example a lever for the parking brake.
Lorsque l'action de freinage est relâchée, on cherche à ce qu'il n'y ait pas ou très peu de couple résiduel, qui résulterait d'un contact entre les segments et le tambour malgré la fin de l'action de freinage. Ce couple résiduel provoque une usure prématurée des garnitures de frein et une surconsommation en carburant. EXPOSÉ DE L'INVENTION When the braking action is released, it is sought that there is no or very little residual torque, which would result from contact between the segments and the drum despite the end of the braking action. This residual torque causes premature wear of the brake linings and excess fuel consumption. DISCLOSURE OF THE INVENTION
C'est par conséquent un but de la présente invention d'offrir un frein à tambour présentant un couple résiduel réduit. It is therefore an object of the present invention to offer a drum brake having a reduced residual torque.
Les inventeurs ont découvert que les ressorts de montage des segments sur le plateau et assurant leur plaquage sur le plateau pouvaient être responsables de l'apparition d'au moins une partie d'un couple résiduel. The inventors have discovered that the springs for mounting the segments on the plate and ensuring their plating on the plate could be responsible for the appearance of at least part of a residual torque.
Un ressort de montage est un ressort hélicoïdal monté en compression contre les segments à l'opposé du plateau au moyen d'une pièce allongée désignée clou. L'axe du ressort est sensiblement perpendiculaire au plateau. Initialement le clou est également perpendiculaire au plateau. Lors des déplacements du segment, le clou bascule et tend à déplacer le ressort de montage qui va alors glisser sur le segment. Le ressort se trouve alors dans une position décalée par rapport à sa position initiale. Or ce décalage en position peut générer une composante sur le segment qu'il l'empêche de revenir dans sa position repos écartée du tambour. Il en résulte un couple résiduel sur le tambour. A mounting spring is a coil spring mounted in compression against the segments opposite the platen by means of an elongated piece referred to as a nail. The axis of the spring is substantially perpendicular to the plate. Initially the nail is also perpendicular to the plate. As the segment moves, the nail tilts and tends to move the mounting spring which will then slide on the segment. The spring is then in a position offset from its initial position. However, this shift in position can generate a component on the segment that prevents it from returning to its rest position away from the drum. This results in a residual torque on the drum.
Les inventeurs ont alors pensé à ajouter des moyens pour maintenir le ressort dans une position sensiblement fixe par rapport au segment afin d'éviter ce glissement et donc l'apparition de cette composante gênant le retour complet du segment en position repos. The inventors have therefore thought of adding means for maintaining the spring in a substantially fixed position relative to the segment in order to prevent this sliding and therefore the appearance of this component hindering the complete return of the segment to the rest position.
Dans un exemple de réalisation, les moyens de maintien du ressort comportent une coupelle interposée entre le ressort de montage et le segment, qui est fixe par rapport au segment et qui reçoit une extrémité axiale du ressort de montage. Le rebord de la coupelle assure un maintien du ressort dans le plan du segment. La coupelle assure avantageusement le maintien du ressort dans toutes les directions du plan. In an exemplary embodiment, the spring retaining means comprise a cup interposed between the mounting spring and the segment, which is fixed relative to the segment and which receives an axial end of the mounting spring. The rim of the cup keeps the spring in the plane of the segment. The cup advantageously maintains the spring in all directions of the plane.
Dans un autre exemple, les moyens de maintien sont intégrés directement dans le segment, par exemple par une forme en creux ou des saillies formant des butées dans une ou plusieurs directions de plan. Cet exemple présente l'avantage de ne pas requérir de pièce supplémentaire. In another example, the holding means are integrated directly into the segment, for example by a hollow shape or projections forming stops in one or more plane directions. This example has the advantage of not requiring any additional part.
En d'autres termes, on ajoute des moyens limitant, voire empêchant le glissement du ressort sur le segment. La présente invention a alors pour objet un frein à tambour comportant un plateau, deux segments montés mobiles par rapport au plateau, chaque segment comportant une âme et un garniture destinée à venir en contact avec un tambour, un dispositif pour appliquer les segments sur le tambour, des moyens de montage de chaque segment sur le plateau, lesdits moyens de montage comportant pour chaque segment au moins un ressort de montage disposé sur le segment à l'opposé du plateau, des moyens de compression coopérant avec le plateau pour maintenir en compression le ressort de montage contre le segment et ainsi plaquer le segment sur le plateau, le plateau comportant au moins un premier trou, l'âme du segment comportant un deuxième trou, le premier trou et le deuxième trou étant sensiblement en regard et étant traversés par les moyens de compression. Le frein à tambour comporte également des moyens de maintien du ressort de montage limitant le déplacement du ressort de montage par rapport au segment. In other words, means are added which limit, or even prevent, the sliding of the spring on the segment. The present invention therefore relates to a drum brake comprising a plate, two segments mounted to move relative to the plate, each segment comprising a core and a lining intended to come into contact with a drum, a device for applying the segments to the drum , mounting means for each segment on the plate, said mounting means comprising for each segment at least one mounting spring disposed on the segment opposite the plate, compression means cooperating with the plate to keep the assembly spring against the segment and thus press the segment onto the plate, the plate comprising at least one first hole, the core of the segment comprising a second hole, the first hole and the second hole being substantially opposite and being traversed by the means of compression. The drum brake also comprises means for holding the mounting spring limiting the movement of the mounting spring relative to the segment.
Les moyens de maintien limitent avantageusement le déplacement du ressort de montage dans toutes les directions dans le plan du segment. The retaining means advantageously limit the movement of the mounting spring in all directions in the plane of the segment.
Les moyens de maintien assurent avantageusement la limitation du déplacement parallèlement à un plan principal du plateau. The holding means advantageously ensure the limitation of the displacement parallel to a main plane of the plate.
De manière très avantageuse, les moyens de maintien coopèrent avec une extrémité du ressort orientée du côté du segment, lesdits moyens comportant au moins un élément fixe par rapport au segment limitant le déplacement du ressort. Very advantageously, the retaining means cooperate with one end of the spring oriented towards the side of the segment, said means comprising at least one element fixed with respect to the segment limiting the movement of the spring.
Les moyens de maintien peuvent être interposés entre le ressort de montage et l'âme du segment. The retaining means can be interposed between the mounting spring and the core of the segment.
Dans un mode de réalisation, les moyens de maintien comportent des moyens coopérant avec l'âme du segment et des moyens coopérant avec le ressort de montage. Par exemple, les moyens de maintien comportent une coupelle de maintien comportant un fond entouré par un premier rebord coopérant avec au moins une spire d'extrémité du ressort de montage, ledit fond comportant un trou pour le passage des moyens de compression et un deuxième rebord bordant ledit trou et coopérant avec le deuxième trou de l'âme du segment. In one embodiment, the holding means comprise means cooperating with the core of the segment and means cooperating with the mounting spring. For example, the retaining means comprise a retaining cup comprising a bottom surrounded by a first flange cooperating with at least one end turn of the mounting spring, said bottom comprising a hole for the passage of the compression means and a second flange bordering said hole and cooperating with the second hole in the core of the segment.
De manière avantageuse, le frein à tambour comporte des moyens permettant une détection visuelle facilitée de la présence des moyens de maintien. Par exemple les moyens permettant une détection visuelle facilitée des moyens de maintien comportent une forme faisant saillie de la périphérie du ressort de montage. Advantageously, the drum brake comprises means allowing easier visual detection of the presence of the holding means. Through For example, the means for facilitated visual detection of the retaining means comprise a shape projecting from the periphery of the mounting spring.
Dans un autre mode de réalisation, les moyens de maintien sont intégrés à l'âme du segment. In another embodiment, the holding means are integrated into the core of the segment.
Dans un exemple, les moyens de maintien comportent au moins une saillie pour limiter au moins dans une direction et dans un sens le déplacement du ressort de montage par rapport au segment. Les moyens de maintien peuvent comporter plusieurs saillies réparties autour du deuxième trou délimitant un logement pour une spire d'extrémité du ressort de montage. In one example, the retaining means comprise at least one projection to limit at least in one direction and in one direction the movement of the mounting spring relative to the segment. The retaining means may include several projections distributed around the second hole defining a housing for an end turn of the mounting spring.
Dans un autre exemple, les moyens de maintien comportent une saillie annulaire entourant le deuxième trou et présentant un diamètre extérieur lui permettant de pénétrer dans la spire d'extrémité et de limiter le déplacement du ressort de montage par rapport au segment. In another example, the retaining means comprise an annular projection surrounding the second hole and having an outside diameter allowing it to penetrate into the end turn and to limit the movement of the mounting spring relative to the segment.
Dans un autre exemple, les moyens de maintien comportent un logement bordant le deuxième trou, le logement présentant un diamètre extérieur permettant de loger la spire d'extrémité et de limiter le déplacement du ressort de montage par rapport au segment. In another example, the retaining means comprise a housing bordering the second hole, the housing having an outside diameter making it possible to accommodate the end turn and to limit the movement of the mounting spring relative to the segment.
Les moyens de maintien peuvent être réalisés par emboutissage. The holding means can be produced by stamping.
Le frein à tambour peut comporter pour chaque segment deux ressorts de montage et des moyens de maintien pour chaque ressort de montage. The drum brake may include for each segment two mounting springs and retaining means for each mounting spring.
Selon une caractéristique additionnelle, le dispositif pour appliquer les segments contre le plateau comporte un actionneur mécanique entraîné par un moteur électrique, ledit actionneur étant destiné à assurer au moins la fonction de frein de parking. According to an additional characteristic, the device for applying the segments against the plate comprises a mechanical actuator driven by an electric motor, said actuator being intended to provide at least the parking brake function.
Le frein à tambour peut également comporter un tambour monté autour des segments. The drum brake may also include a drum mounted around the segments.
BRÈVE DESCRIPTION DES DESSINS BRIEF DESCRIPTION OF THE DRAWINGS
La présente invention sera mieux comprise sur la base de la description qui va suivre et des dessins en annexe sur lesquels: La figure 1 est une vue de face d'un exemple de frein à tambour auquel s'applique l'invention, The present invention will be better understood on the basis of the description which follows and the appended drawings in which: FIG. 1 is a front view of an example of a drum brake to which the invention applies,
La figure 2A est une vue en coupe partielle d'un frein à tambour selon un exemple de réalisation au niveau d'un ressort de montage et du segment de frein d'un premier mode de réalisation, FIG. 2A is a partial sectional view of a drum brake according to an exemplary embodiment at the level of a mounting spring and of the brake shoe of a first embodiment,
La figure 2B est vue en perspective d'un segment avec les deux ressorts de montage, les clous, les coupelles de montage et les coupelles de maintien, le plateau n'étant pas représenté, Figure 2B is a perspective view of a segment with the two mounting springs, nails, mounting cups and retaining cups, the plate not being shown,
La figure 2C est une vue en éclaté de la figure 2B, Figure 2C is an exploded view of Figure 2B,
La figure 3A est une vue de dessus d'un autre exemple de coupelle de maintien selon le premier mode de réalisation, FIG. 3A is a top view of another example of a retaining cup according to the first embodiment,
La figure 3B est une vue de dessus d'un ressort de montage et de la coupelle de maintien de la figure 3A, Figure 3B is a top view of a mounting spring and the retaining cup of Figure 3A,
La figure 4A est une vue en perspective d'un détail d'un frein à tambour selon un autre exemple de réalisation au niveau des ressorts de montage d'un segment selon un deuxième mode de réalisation, FIG. 4A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to a second embodiment,
La figure 4B est une vue en perspective du segment de frein seul de la figure 4A Figure 4B is a perspective view of the brake shoe alone of Figure 4A
La figure 5A est une vue en coupe d'un détail d'un frein à tambour selon un autre exemple de réalisation au niveau des ressorts de montage d'un segment selon le deuxième mode de réalisation, FIG. 5A is a sectional view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment,
La figure 5B est une vue en perspective du segment de frein seul de la figure 5 A, FIG. 5B is a perspective view of the brake shoe alone of FIG. 5A,
La figure 6A est une vue en perspective d'un détail d'un frein à tambour selon un autre exemple de réalisation au niveau des ressorts de montage d'un segment selon le deuxième mode de réalisation, FIG. 6A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the mounting springs of a segment according to the second embodiment,
La figure 6B est une vue en perspective du segment de frein seul de la figure 6 A Figure 6B is a perspective view of the brake shoe alone of Figure 6A
La figure 7 A est une vue en perspective d'un détail d'un frein à tambour selon un autre exemple de réalisation au niveau des ressorts de montage d'un segment selon le deuxième mode de réalisation, La figure 7B est une vue en perspective du segment de frein seul de la figure 7 A FIG. 7 A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment, Figure 7B is a perspective view of the brake shoe alone of Figure 7A
La figure 8A est une vue en perspective d'un détail d'un frein à tambour selon un autre exemple de réalisation au niveau des ressorts de montage d'un segment selon le deuxième mode de réalisation, FIG. 8A is a perspective view of a detail of a drum brake according to another exemplary embodiment at the level of the springs for mounting a segment according to the second embodiment,
La figure 8B est une vue en perspective du segment de frein seul de la figure 8A. FIG. 8B is a perspective view of the brake shoe alone of FIG. 8A.
EXPOSÉ DÉTAILLÉ DE MODES DE RÉALISATION PARTICULIERS DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS
Sur la figure 1, on peut voir un frein à tambour 2 "bi-mode" auquel s'applique la présente. In Figure 1, we can see a drum brake 2 "dual mode" to which the present applies.
Le frein à tambour 1 comporte un tambour T destiné à être solidaire en mouvement de la roue (non représentée), un plateau 2 de révolution d'axe X équipé d'un premier et d'un second segment en arc de cercles S et 4 mobiles radialement pour pouvoir être pressés contre la face interne cylindrique du tambour T. The drum brake 1 comprises a drum T intended to be integral in movement with the wheel (not shown), a plate 2 of revolution of axis X equipped with a first and a second segment in an arc of circles S and 4 radially movable to be able to be pressed against the cylindrical internal face of the drum T.
Les segments S et 4 comportent chacun une âme Sa, 4a. en forme de portion de couronne circulaire qui porte une garniture de freinage 3b, 4b. Les âmes sont planes et présentent un relief. Dans l'exemple représenté, les segments sont montés diamétralement opposés avec leurs extrémités en appui à fois sur un cylindre de roue 6 hydraulique et sur un actionneur mécanique 10 portés par le plateau 2. Ces segments 3 et 4 sont en outre rappelés l'un vers l'autre par deux ressorts de rappel 8 et 9. The segments S and 4 each have a core Sa, 4a. in the form of a circular crown portion which carries a brake lining 3b, 4b. The souls are flat and present a relief. In the example shown, the segments are mounted diametrically opposed with their ends bearing both on a hydraulic wheel cylinder 6 and on a mechanical actuator 10 carried by the plate 2. These segments 3 and 4 are further recalled one by one. towards the other by two return springs 8 and 9.
Dans le cas d'un frein à tambour dans lequel la fonction frein de parking est activée via un levier ce frein, les extrémités 3.2 et 4.2 des segments 3 et 4 respectivement sont en appui sur un point fixe eu plateau. In the case of a drum brake in which the parking brake function is activated via a lever this brake, the ends 3.2 and 4.2 of segments 3 and 4 respectively are supported on a fixed point on the plate.
Dans la présente demande, on entend par « frein à tambour » un ensemble comportant au moins un plateau muni de segments, d'au moins un dispositif pour déplacer les segments. Le frein à tambour disposé dans un tambour de sorte que les garnitures soient en regard de la jupe du tambour et configurés pour venir en contact avec celle-ci lors d'une phase de freinage sera également désigné « frein à tambour ». Les segments sont maintenus plaqués sur le plateau avec une possibilité de se déplacer par rapport à celui-ci au moyen de ressorts de montage 24. Les ressorts de montage 24 sont des ressorts hélicoïdaux. In the present application, the term “drum brake” is understood to mean an assembly comprising at least one plate provided with segments, at least one device for moving the segments. The drum brake arranged in a drum so that the linings are facing the skirt of the drum and configured to come into contact with the latter during a braking phase will also be referred to as a “drum brake”. The segments are kept pressed against the platen with a possibility of moving relative to it by means of mounting springs 24. The mounting springs 24 are coil springs.
Dans l'exemple représenté chaque segment 3, 4 est maintenu sur le plateau par deux ressorts de montage 24. L'âme d'un segment comportant deux trous (non visibles) est disposée sur le plateau qui comporte également deux trous (non visibles) pour chaque segment 3, 4, les trous du segment étant en regard de ceux du plateau. Un ressort de montage 24 présentant un diamètre intérieur supérieur au diamètre d'un trou de segment est disposé sur le segment 3, 4 à l'opposé du plateau et entoure le trou. Sur les figures 2A à 2C, on peut voir un exemple de montage des ressorts de montage. Un élément allongé 26 désigné « clou », comportant une tête 25, est inséré à partir du plateau à travers les trous et le ressort, la tête venant en appui contre le bord du trou du plateau. Une coupelle de montage 28 est disposée sur l'extrémité axiale libre du ressort. La coupelle de montage comporte des moyens de coopération avec le clou pour assurer leur solidarisation axiale et permettre une compression du ressort, par exemple il s'agit d'une liaison par quart de tour. Par exemple, le ressort de montage 24est comprimé, l'extrémité libre du clou 26 traverse la coupelle de montage 28 et la coupelle de montage28 est tournée d'un quart de tour. Le ressort de montage 24 est alors maintenu comprimé entre l'âme du segment et la coupelle de montage. Le ressort de montage le plaquage du segment sur le plateau. In the example shown, each segment 3, 4 is held on the plate by two mounting springs 24. The core of a segment having two holes (not visible) is placed on the plate which also has two holes (not visible). for each segment 3, 4, the holes in the segment facing those of the plate. A mounting spring 24 having an inner diameter greater than the diameter of a segment hole is disposed on segment 3, 4 opposite the plate and surrounds the hole. In FIGS. 2A to 2C, one can see an example of the mounting of the mounting springs. An elongated member 26 designated "nail", having a head 25, is inserted from the plate through the holes and the spring, the head resting against the edge of the hole in the plate. A mounting cup 28 is disposed on the free axial end of the spring. The mounting cup comprises means of cooperation with the nail to ensure their axial connection and allow compression of the spring, for example it is a connection by quarter turn. For example, the mounting spring 24 is compressed, the free end of the nail 26 passes through the mounting cup 28, and the mounting cup 28 is rotated a quarter turn. The mounting spring 24 is then kept compressed between the core of the segment and the mounting cup. The spring for mounting the segment on the plate.
Dans l'exemple représenté, chaque segment 3, 4 est maintenu par deux ressorts de montage. Dans un autre exemple un seul ressort de montage est mis en oeuvre. In the example shown, each segment 3, 4 is held by two mounting springs. In another example, a single mounting spring is used.
Une biellette de rattrapage d'usure 7 s'étend le long du cylindre de roue 6 en ayant une première extrémité en appui sur l'âme 3a du premier segment 3 et une seconde extrémité en appui sur l'âme 4a du second segment 4, lorsque le frein est au repos. A wear take-up link 7 extends along the wheel cylinder 6 having a first end resting on the web 3a of the first segment 3 and a second end resting on the web 4a of the second segment 4, when the brake is at rest.
Le cylindre de roue 6 est destiné à être actionné lors d'une utilisation du frein à tambour 1 selon un premier mode de fonctionnement dit "simplex", qui assure un freinage progressif particulièrement adapté pour freiner le véhicule en service. Il comprend une chambre hydraulique fermée à ses extrémités par deux pistons qui s'écartent l'un de l'autre lorsque la pression hydraulique augmente et pousse les extrémités associées des segments 3 et 4. The wheel cylinder 6 is intended to be actuated when using the drum brake 1 according to a first so-called "simplex" mode of operation, which provides progressive braking particularly suitable for braking the vehicle in service. It includes a hydraulic chamber closed at its ends by two pistons which move apart as hydraulic pressure increases and pushes the associated ends of segments 3 and 4.
L'actionneur mécanique 10 assure, quant à lui, le freinage de stationnement ou de parking et de secours en écartant les extrémités associées des segments pour assurer un blocage rapide et puissant des roues du véhicules selon un mode de fonctionnement dit "duo-servo", notamment quand le cylindre de roue 6 est inactif. The mechanical actuator 10 ensures, for its part, the parking or parking and emergency braking by separating the associated ends of the segments to ensure rapid and powerful locking of the vehicle wheels according to a so-called "duo-servo" operating mode. , in particular when the wheel cylinder 6 is inactive.
Dans l'exemple représenté, le cylindre de roue 6 comporte deux pistons opposés, qui actionnent chacun l'un des segments 3, 4 en écartant l'une de l'autre leurs deux extrémités 3.1, 4.1 en vis-à-vis, c'est-à-dire celles situées d'un même côté de l'axe de rotation X, ici appelées "extrémités mobiles" et situées en haut de la figure 1. A son extrémité opposée 3.2, 4.2, dite extrémité de butée, chaque segment s'appuie sur le plateau 2 par un élément d'ancrage solidaire du plateau, et formant ainsi une butée pour ce segment. L'élément d'ancrage transmet au moins en partie le couple de freinage entre segments et plateau. L'élément d'ancrage des deux segments est réalisé par l'actionneur 10. In the example shown, the wheel cylinder 6 comprises two opposed pistons, which each actuate one of the segments 3, 4 by moving their two opposite ends 3.1, 4.1 away from each other, c 'that is to say those located on the same side of the axis of rotation X, here called "movable ends" and located at the top of Figure 1. At its opposite end 3.2, 4.2, called the stop end, each segment rests on the plate 2 by an anchoring element integral with the plate, and thus forming a stop for this segment. The anchoring element transmits at least part of the braking torque between the segments and the plate. The anchoring element of the two segments is produced by the actuator 10.
L'actionneur 10 s'étend le long d'un axe Y perpendiculaire à l'axe X du plateau et parallèle au plateau. Il comporte un boîtier 12 fixé sur plateau 2 du côté de la première face. Le boîtier comporte un logement formé par alésage traversant s'étendant le long de l'axe Y et débouchant aux deux extrémités longitudinales du boîtier 12. Un ensemble d'entrainement est logé dans l'alésage. The actuator 10 extends along a Y axis perpendicular to the X axis of the plate and parallel to the plate. It comprises a housing 12 fixed on plate 2 on the side of the first face. The housing comprises a housing formed by a through bore extending along the Y axis and opening at the two longitudinal ends of the housing 12. A drive assembly is housed in the bore.
L'ensemble d'entrainement est par exemple du type vis-écrou, tel que celui décrit dans la demande W02015/101486. Il comporte deux éléments d'appui 16, 20 destinés à former un point fixe pour les extrémités 3.2, 4.2 des segments de freinage 3, 4 respectivement en freinage de service, et à appliquer un effort sur les extrémités 3.2, 4.2 en freinage de parking en étant déplacés vers l'extérieur du boîtier le long de l'axe Y. The drive assembly is for example of the screw-nut type, such as that described in application WO2015 / 101486. It comprises two support elements 16, 20 intended to form a fixed point for the ends 3.2, 4.2 of the brake segments 3, 4 respectively in service braking, and to apply a force to the ends 3.2, 4.2 in parking braking by being moved out of the housing along the Y axis.
Le frein à tambour comporte également un dispositif d'entraînement 22 de l'actionneur, fixé du côté sur l'autre face du plateau opposée à la face du côté de laquelle est monté l'actionneur 10. Le dispositif d'entrainement est un moteur électrique qui peut être associé ou non à un réducteur. Un passage (non visible) est pratiqué à travers le plateau 2 pour permettre la transmission de l'entraînement du dispositif d'entraînement 22 à l'actionneur 10. The drum brake also comprises a drive device 22 of the actuator, fixed on the side on the other face of the plate opposite to the face on which the actuator 10 is mounted. The drive device is a motor. electric which may or may not be associated with a reduction gear. A passage (not visible) is made through the plate 2 to allow the transmission of the drive from the drive device 22 to the actuator 10.
Dans un autre exemple, le frein à tambour comporte un levier pour assurer le frein de stationnement, qui est relié à un câble déplacé au moyen d'un levier de frein à main situé dans l'habitacle. In another example, the drum brake comprises a lever for providing the parking brake, which is connected to a cable moved by means of a hand brake lever located in the passenger compartment.
Lorsque la pression hydraulique dans le cylindre de roue et/ou l'actionneur 10 revient en position repos, les segments de frein sont rappelés en position repos sous l'action des ressorts de rappel 8, 9. Comme cela a été expliqué ci-dessus un couple résiduel peut être constaté. Les inventeurs ont déterminé une des sources de ce couple résiduel et ont alors ajouté au frein à tambour des moyens de maintien des ressorts de montage en position par rapport aux segments. When the hydraulic pressure in the wheel cylinder and / or the actuator 10 returns to the rest position, the brake shoes are returned to the rest position under the action of the return springs 8, 9. As explained above. a residual torque can be observed. The inventors have determined one of the sources of this residual torque and then added to the drum brake means for maintaining the mounting springs in position with respect to the segments.
En effet, les inventeurs ont découvert que les ressorts de montage avaient tendance à glisser par rapport aux segments de frein et à prendre une position pouvant générer une composante de force gênant le retour des segments dans une position écartée du tambour In fact, the inventors have discovered that the mounting springs have a tendency to slide relative to the brake shoes and to take a position which can generate a force component hindering the return of the segments to a position away from the drum.
Sur les figures 2A à 2C, on peut voir un exemple de réalisation de moyens de maintien 30 en position des ressorts de montage selon un premier mode de réalisation. Les moyens de maintien désignent les moyens de maintien pour un ressort ou plusieurs ressorts. In FIGS. 2A to 2C, one can see an exemplary embodiment of means 30 for holding the mounting springs in position according to a first embodiment. The retaining means designate the retaining means for a spring or more springs.
Selon le premier mode de réalisation, les moyens de maintien comportent au moins une pièce supplémentaire rapportée sur le segment de frein. Le premier mode de réalisation présente l'avantage de ne pas requérir de modification du segment et peut être monté sur des segments existants. According to the first embodiment, the holding means include at least one additional part attached to the brake shoe. The first embodiment has the advantage of not requiring any modification of the segment and can be mounted on existing segments.
Sur la figure 2C, on peut voir les différents éléments assurant le montage du segment plaqué sur le plateau et décrits ci-dessus. Les trous 32 dans l'âme du segment pour le passage des clous 26 sont visibles. In FIG. 2C, one can see the various elements ensuring the assembly of the plated segment on the plate and described above. The holes 32 in the core of the segment for the passage of the nails 26 are visible.
Les moyens de maintien 30 comportent une coupelle 34 circulaire comprenant un fond 36 et un premier rebord 38 s'étendant transversalement par rapport au fond 36. Le diamètre intérieur de la coupelle est tel qu'il permet de loger une extrémité libre d'un ressort de montage et limiter son déplacement dans le plan du segment. The retaining means 30 comprise a circular cup 34 comprising a bottom 36 and a first flange 38 extending transversely with respect to the bottom 36. The internal diameter of the cup is such that it makes it possible to accommodate a free end of a mounting spring and limit its displacement in the plane of the segment.
Le fond 36 comporte un trou 40 de diamètre suffisant pour le passage du clou 26. En outre la coupelle comporte un deuxième rebord 42 bordant le trou 40 et s'étendant axialement à l'opposé du premier rebord 38. Le diamètre extérieur du deuxième rebord 38 est tel qu'il permet d'être insérer dans le trou 32 du segment et d'assurer une immobilisation de la coupelle de maintien 34 dans le plan du segment. The bottom 36 has a hole 40 of sufficient diameter for the passage of the nail 26. In addition, the cup has a second flange 42 bordering the hole 40 and extending axially opposite the first flange 38. The outer diameter of the second flange 38 is such that it can be inserted into the hole 32 of the segment and ensure immobilization of the retaining cup 34 in the plane of the segment.
On entend par « plan du segment » le plan contenant la face F de l'âme du segment, ne regardant pas le plateau et sur laquelle vient en appui le ou les ressort(s) de montage. Le plan du segment est sensiblement parallèle au plan du plateau. The term “segment plane” is understood to mean the plane containing the face F of the core of the segment, not looking at the plate and on which the mounting spring (s) bear. The plane of the segment is substantially parallel to the plane of the plate.
Le montage d'un ressort de montage 24 va maintenant être décrit en considérant le segment 3. The mounting of a mounting spring 24 will now be described with regard to segment 3.
Le segment 3 est disposé sur le plateau 2, le trou 32 en regard du trou du plateau. La coupelle de maintien 34 est montée sur le segment 3, le deuxième rebord 42 pénétrant dans le trou 32. La coopération du deuxième rebord 42 et du contour du trou 32 assure une immobilisation de la coupelle de maintien 34 par rapport au segment 3. Une extrémité axiale du ressort de montage 24 est logée dans la coupelle de maintien 34, le contour extérieur de la spire d'extrémité coopère alors avec le premier rebord 38 et assure une immobilisation du ressort de montage 24 dans le plan du segment. Le clou 26 est introduit dans le ressort de montage 24 à partir du plateau 2, et la coupelle de montage 34 est disposée sur l'autre extrémité axiale du ressort de montage 24. Le ressort de montage 24 est comprimé, l'extrémité du clou traverse la coupelle de montage 28 qui est pivotée d'un quart de tour. Le ressort de montage 24 est maintenu comprimé. Segment 3 is placed on plate 2, hole 32 facing the hole in the plate. The retaining cup 34 is mounted on segment 3, the second rim 42 penetrating into the hole 32. The cooperation of the second rim 42 and the contour of the hole 32 ensures that the retaining cup 34 is immobilized with respect to the segment 3. A axial end of mounting spring 24 is housed in retaining cup 34, the outer contour of end turn then cooperates with first flange 38 and secures mounting spring 24 in the plane of the segment. The nail 26 is introduced into the mounting spring 24 from the plate 2, and the mounting cup 34 is disposed on the other axial end of the mounting spring 24. The mounting spring 24 is compressed, the nail end is compressed. passes through the mounting cup 28 which is rotated a quarter turn. The mounting spring 24 is kept compressed.
Du fait de l'ajout de coupelle de maintien 34, le ressort de montage 24 ne peut plus glisser sur la face F de l'âme du segment ou a un déplacement limité par rapport à l'âme, sous l'action du clou 26 qui s'incline lors des phases de freinage Due to the addition of the retaining cup 34, the mounting spring 24 can no longer slide on the face F of the web of the segment or has a limited displacement with respect to the web, under the action of the nail 26 which tilts during braking phases
Dans cet exemple, puisque les ressorts de montage glissent peu ou ne glissent plus par rapport aux segments, la composante de force gênant le retour des segments en position repos est réduite, voire annulée. Le freinage résiduel est donc réduit voire supprimé. Dans l'exemple représenté, les premier et deuxième rebords entourent de manière continue le fond 36 et le trou 40. En variante, le premier 38 et/ou le deuxième rebord 42 sont tels qu'ils entourent de manière discontinue le fond 36 et le trou 40 respectivement tout en assurant une immobilisation du ressort de montage 24 par rapport à la coupelle de maintien et de la coupelle de maintien par rapport au segment. In this example, since the mounting springs slide little or no longer slide relative to the segments, the force component hindering the return of the segments to the rest position is reduced, or even canceled. Residual braking is therefore reduced or even eliminated. In the example shown, the first and second flanges continuously surround the bottom 36 and the hole 40. As a variant, the first 38 and / or the second flange 42 are such that they surround the bottom 36 and the bottom in a discontinuous manner. hole 40 respectively while ensuring immobilization of the mounting spring 24 relative to the retaining cup and of the retaining cup relative to the segment.
Les inventeurs ont constaté que les ressorts de montage glissaient le plus souvent sensiblement dans une direction verticale, dans un sens ou dans l'autre en fonction du segment tendu en marche avant ou en marche arrière. Dans un exemple, les rebords des coupelles de maintien sont tels qu'ils assurent une limitation du déplacement, voire une immobilisation dans la direction verticale uniquement, voire uniquement vers le haut ou vers le bas. The inventors have found that the mounting springs most often slide substantially in a vertical direction, in one direction or the other depending on the segment stretched in forward or in reverse. In one example, the flanges of the retaining cups are such that they ensure a limitation of the movement, or even an immobilization in the vertical direction only, or even only up or down.
Dans un autre exemple, les moyens de maintien coopèrent avec le diamètre intérieur du ressort de montage. Par exemple, les moyens de maintien comportent un plateau percé d'un trou et deux tubes s'étendant axialement autour du trou des deux faces du plateau, un tube pénétrant dans le trou 32 du segment de frein et l'autre dans le ressort. In another example, the retaining means cooperate with the internal diameter of the mounting spring. For example, the holding means comprise a plate pierced with a hole and two tubes extending axially around the hole of the two faces of the plate, one tube entering the hole 32 of the brake shoe and the other in the spring.
Les moyens de maintien sont configurés pour au moins limiter le glissement du ressort de montage par rapport au segment. Par conséquent des jeux entre le ressort et le premier rebord de la coupelle 34 et/ou entre le deuxième rebord de la coupelle et le trou dans le segment sont tolérés. The retaining means are configured to at least limit the sliding of the mounting spring relative to the segment. Therefore clearances between the spring and the first flange of the cup 34 and / or between the second flange of the cup and the hole in the segment are tolerated.
Les coupelles sont de préférence en matériau métallique, par exemple en acier recouvert de zinc, par exemple en acier DC04, recouvert de zinc Z12FBR. En variante les coupelles sont en acier inox. The cups are preferably made of a metallic material, for example of steel coated with zinc, for example of DC04 steel, coated with Z12FBR zinc. As a variant, the cups are made of stainless steel.
Sur les figures 3A et 3B, on peut voir un exemple avantageux de réalisation de moyens de maintien 130 qui diffère des moyens de maintien 30 en ce que la coupelle de maintien 134 comporte des moyens pour détecter facilement sa présence. Dans cet exemple les moyens 130 comportent une languette 136 s'étendant radialement vers l'extérieur de la coupelle de maintien 134. Lorsque le montage est terminé (figure 3B), la languette 136 est visible et peut être facilement détectée par des moyens de contrôle manuels ou automatisés permettant de s'assurer rapidement et de manière fiable que le frein à tambour est complet Dans cet exemple, le premier rebord est interrompu au niveau de la languette sans que la fonction de maintien du ressort ne soit détériorée. In FIGS. 3A and 3B, one can see an advantageous embodiment of the holding means 130 which differs from the holding means 30 in that the holding cup 134 comprises means for easily detecting its presence. In this example the means 130 comprise a tongue 136 extending radially outwardly from the retaining cup 134. When the assembly is completed (FIG. 3B), the tongue 136 is visible and can be easily detected by control means. manual or automated to quickly and reliably ensure that the drum brake is complete In this example, the first flange is interrupted at the level of the tongue without the function of maintaining the spring being damaged.
Il sera compris que toute forme visuellement détectable est envisageable pour assurer une vérification de la présence de la coupelle de maintien. It will be understood that any visually detectable shape can be envisaged for verifying the presence of the retaining cup.
La coupelle de maintien est par exemple réalisation par emboutissage d'une tôle. The retaining cup is for example produced by stamping a sheet.
Dans les exemples des figures 2A à 3B, dans lesquels plusieurs ressorts de maintien sont mis en oeuvre sur le même segment, deux coupelles de maintien distinctes sont interposés entre le segment et les ressorts de montage. En variante, les deux coupelles de maintien sont d'un seul tenant. Par exemple, elles sont reliées par une bande qui peut avantageusement servir de moyens de détection de la présence des coupelles. In the examples of Figures 2A to 3B, in which several retaining springs are implemented on the same segment, two separate retaining cups are interposed between the segment and the mounting springs. As a variant, the two retaining cups are in one piece. For example, they are connected by a strip which can advantageously serve as means for detecting the presence of the cups.
Sur les figures 4A et 4B, on peut voir un exemple de réalisation de moyens de maintien 230 du ressort selon un deuxième mode de réalisation. In FIGS. 4A and 4B, one can see an exemplary embodiment of means 230 for holding the spring according to a second embodiment.
Selon le deuxième mode de réalisation, les moyens de maintien sont intégrés au segment, i.e. ils sont formés d'un seul tenant avec le segment. According to the second embodiment, the holding means are integrated into the segment, i.e. they are formed integrally with the segment.
Le deuxième mode de réalisation présente l'avantage d'éviter tout risque d'oubli des moyens de maintien lors du montage et facilite le montage puisqu'aucune étape supplémentaire, lors du montage, n'est requise. The second embodiment has the advantage of avoiding any risk of forgetting the holding means during assembly and facilitates assembly since no additional step, during assembly, is required.
Les moyens de maintien 230 comportent un logement 232 formé dans la face F du segment 3, de forme circulaire de diamètre permettant de loger une spire d'extrémité du ressort de montage 24 et d'assurer son immobilisation relative dans le plan du segment. Comme on peut le voir sur la figure 4A, un jeu peut exister entre l'extérieur de la spire et l'intérieur du logement. Les rebords de l'évidement assurent l'immobilisation du ressort et limitent son glissement dans le plan. La profondeur de l'évidemment est de préférence supérieure au rayon du fil du ressort hélicoïdal 24, et de préférence inférieure à ¾ de l'épaisseur de l'âme du segment dans laquelle il est formé. The retaining means 230 comprise a housing 232 formed in the face F of the segment 3, of circular shape in diameter making it possible to accommodate an end turn of the mounting spring 24 and to ensure its relative immobilization in the plane of the segment. As can be seen in FIG. 4A, there may be a clearance between the outside of the coil and the inside of the housing. The edges of the recess ensure the immobilization of the spring and limit its sliding in the plane. The depth of the recess is preferably greater than the radius of the wire of the coil spring 24, and preferably less than ¾ of the thickness of the web of the segment in which it is formed.
Cet exemple présente l'avantage de limiter le déplacement du ressort dans toutes les directions du plan du segment. L'évidement est par exemple réalisé par emboutissage du segment. En variante, l'évidement est usiné dans l'âme du segment. Sur les figures 5A et 5B, on peut voir un autre exemple de réalisation de moyens de maintien 330 selon le deuxième mode de réalisation. This example has the advantage of limiting the movement of the spring in all directions of the plane of the segment. The recess is for example made by stamping the segment. Alternatively, the recess is machined in the web of the segment. In FIGS. 5A and 5B, one can see another embodiment of the holding means 330 according to the second embodiment.
Les moyens de maintien 330 comportent une saillie annulaire 332 sur la face F du segment, entourant le trou 32. Le diamètre extérieur de la saillie annulaire 332 est tel que la saillie se loge dans la spire d'extrémité du ressort de montage et assure son immobilisation relative dans le plan du segment. The retaining means 330 comprise an annular projection 332 on the face F of the segment, surrounding the hole 32. The outside diameter of the annular projection 332 is such that the projection fits into the end turn of the mounting spring and ensures its relative immobilization in the plane of the segment.
La saillie annulaire est par exemple réalisée par emboutissage du segment. The annular projection is for example produced by stamping the segment.
Cet exemple présente également l'avantage de limiter le déplacement du ressort dans toutes les directions du plan du segment. This example also has the advantage of limiting the movement of the spring in all directions of the plane of the segment.
Sur les figures 6A et 6B, on peut voir un autre exemple de réalisation de moyens de maintien 430 selon le deuxième mode de réalisation. In FIGS. 6A and 6B, one can see another exemplary embodiment of holding means 430 according to the second embodiment.
Les moyens de maintien 430 comportent des picots 432 en saillie de la face F du segment 3 et disposés les uns par rapport aux autres autour du trou 32 pour former un logement pour la spire d'extrémité du ressort de maintien. The retaining means 430 comprise pins 432 projecting from the face F of the segment 3 and arranged relative to each other around the hole 32 to form a housing for the end turn of the retaining spring.
De manière avantageuse, au moins trois picots sont répartis à angulairement de manière régulière autour du trou 32 assurant une immobilisation du ressort dans toutes les directions du plan. Dans l'exemple représenté, les trois picots délimitent un triangle équilatéral dont les bissectrices se croisent sensiblement au centre du trou 32. Advantageously, at least three pins are distributed angularly in a regular manner around the hole 32 ensuring immobilization of the spring in all directions of the plane. In the example shown, the three pins delimit an equilateral triangle whose bisectors intersect substantially at the center of the hole 32.
En variante, plus de trois picots sont mis en oeuvre. As a variant, more than three pins are used.
Dans l'exemple représenté, les moyens de maintien 430 du deuxième trou 32 ne comportent que deux picots du fait de la présence du ressort de la biellette de rattrapage de jeu situé à proximité. Le ressort de la biellette de rattrapage de jeu assure avantageusement la fonction d'immobilisation du troisième picot. In the example shown, the holding means 430 for the second hole 32 only have two pins due to the presence of the spring of the play-taking rod located nearby. The spring of the play take-up link advantageously performs the function of immobilizing the third pin.
Les picots sont par exemple réalisés par emboutissage. The pins are for example produced by stamping.
Sur les figures 7A et 7B, on peut voir un autre exemple de réalisation de moyens de maintien 530 selon le deuxième mode de réalisation. In FIGS. 7A and 7B, one can see another embodiment of the holding means 530 according to the second embodiment.
Les moyens de maintien 530 comportent une rainure 532 délimitée par deux bords parallèles 534 s'étendant sur toute la largeur du segment 3. La distance entre les deux bords 534 est telle qu'elle permet de loger la spire d'extrémité du ressort de montage et de limiter son déplacement dans le plan du segment. The holding means 530 include a groove 532 delimited by two parallel edges 534 extending over the entire width of the segment 3. The distance between the two edges 534 is such that it accommodates the end coil of the mounting spring and limits its movement in the plane of the segment.
Les moyens de maintien 530 immobilisent le ressort de montage 24 uniquement dans la direction X qui est destinée à être sensiblement vertical lorsque le frein à tambour est monté sur le moyen. The retaining means 530 immobilize the mounting spring 24 only in the X direction which is intended to be substantially vertical when the drum brake is mounted on the means.
La rainure est par exemple réalisée par emboutissage. The groove is for example produced by stamping.
Sur les figures 8A et 8B, on peut voir un autre exemple de réalisation de moyens de maintien 630 selon le deuxième mode de réalisation. In FIGS. 8A and 8B, one can see another exemplary embodiment of retaining means 630 according to the second embodiment.
Les moyens de maintien 630 comportent une saillie disposée sur un côté du trou 32 à une distance du centre du trou correspondant sensiblement au rayon de la spire d'extrémité du ressort de montage 24. La saillie 632 est orientée par rapport au segment de sorte à former une butée dans le sens de déplacement le plus probable du ressort. Les moyens de maintien 630 limitent le glissement dans une direction et un sens dans le plan du segment. Dans cet exemple, la saillie a une forme oblongue qui s'étend dans la direction de la largeur du segment. The retaining means 630 comprises a projection disposed on one side of the hole 32 at a distance from the center of the hole corresponding substantially to the radius of the end coil of the mounting spring 24. The projection 632 is oriented relative to the segment so as to form a stop in the most probable direction of movement of the spring. The holding means 630 limit the sliding in one direction and one direction in the plane of the segment. In this example, the protrusion has an oblong shape which extends in the direction of the width of the segment.
Les moyens de maintien 630 sont par exemple réalisés par emboutissage. The holding means 630 are for example made by stamping.
La présente invention est d'autant plus avantageuse dans un frein à tambour dans lequel plusieurs ressorts de montage sont mis en oeuvre pour chaque segment, puisque la composante de force s'opposant au retour en position repos des segments est d'autant plus grande. The present invention is all the more advantageous in a drum brake in which several mounting springs are used for each segment, since the force component opposing the return to the rest position of the segments is all the greater.
Il sera compris que la forme des moyens de maintien est adaptée à la section des spires des ressorts de montage. It will be understood that the shape of the holding means is adapted to the section of the turns of the mounting springs.
Les moyens de maintien du ressort de montage par rapport aux segments assurent un maintien du ressort de montage afin d'éviter un glissement de trop grande amplitude par rapport au trou. The means for maintaining the mounting spring relative to the segments ensure that the mounting spring is held in order to prevent too great an amplitude sliding relative to the hole.
Le maintien des ressorts de montage dans le plan des segments présente un jeu suffisant pour autoriser les dispersions de fabrication des composants et faciliter l'assemblage, et absorber des défauts de positionnement, tout en réduisant voire en supprimant la composante s'opposant au retour des segments en position repos. REFERENCESMaintaining the assembly springs in the plane of the segments has sufficient play to allow dispersions in the manufacture of the components and facilitate assembly, and absorb positioning errors, while reducing or even eliminating the component opposing the return of the components. segments in rest position. REFERENCES
1 frein à tambour 1 drum brake
2 plateau 2 tray
3 premier segment 3 first segment
4 second segment 4 second segment
3a, 4a âmes 3a, 4a souls
3b, 4b garnitures de freinage 3b, 4b brake linings
6 cylindre de roue hydraulique 6 hydraulic wheel cylinder
7 biellette de rattrapage d'usure 7 wear take-up link
8, 9 ressorts de rappel 8, 9 return springs
10 actionneur mécanique 10 mechanical actuator
12 boîtier de l'actionneur 12 actuator housing
16 premier élément 16 first element
18 deuxième élément 18 second element
24 ressort de montage 24 mounting spring
25 tête du clou 25 nail head
26 clou 26 nail
28 coupelle de montage 28 mounting cup
30 moyens de maintien 30 holding devices
32 trou 32 hole
34 coupelle de maintien 34 holding cup
36 fond de la coupelle 36 bottom of the cup
38 premier rebord 38 first ledge
40 trou de la coupelle 40 cup hole
42 deuxième rebord 42 second ledge
130 moyens de maintien 130 means of maintenance
134 coupelle de maintien 134 holding cup
136 languette 136 tab
230 moyens de maintien 230 holding devices
232 logement 232 accommodation
330 moyens de maintien 330 means of maintenance
332 saillie annulaire 332 annular protrusion
430 moyens de maintien 430 means of maintenance
432 picot 432 picot
530 moyens de maintien 530 holding devices
532 rainure 532 groove
534 bords 534 edges
630 moyens de maintien 630 holding devices
632 saillie 632 projection
F face de l'âme du segment 3 F face of segment 3 web
X, Y axes X, Y axes

Claims

REVENDICATIONS
1. Frein à tambour comportant un plateau (2), deux segments (3, 4) montés mobiles par rapport au plateau (2), chaque segment (3, 4) comportant une âme (3a, 4a) et un garniture (3b, 4b) destinée à venir en contact avec un tambour (T), un dispositif pour appliquer les segments sur le tambour, des moyens de montage de chaque segment (3, 4) sur le plateau (2), lesdits moyens de montage comportant pour chaque segment (3, 4) au moins un ressort de montage (24) disposé sur le segment (3, 4) à l'opposé du plateau (2), des moyens de compression coopérant avec le plateau (2) pour maintenir en compression le ressort de montage (24) contre le segment (3, 4) et ainsi plaquer le segment (3, 4) sur le plateau (2), le plateau (2) comportant au moins un premier trou, l'âme (3a, 4a) du segment comportant un deuxième trou (32), le premier trou et le deuxième trou (32) étant sensiblement en regard et étant traversés par les moyens de compression, caractérisé en ce que le frein à tambour comporte également des moyens de maintien (30, 130, 230, 330, 430, 530, 630) du ressort de montage (24) limitant le déplacement du ressort de montage (24) par rapport au segment (3, 4), dans lequel les moyens de maintien (30) assurent la limitation du déplacement parallèlement à un plan principal du plateau et dans lequel les moyens de maintien coopèrent avec une extrémité du ressort orientée du côté du segment, lesdits moyens comportant au moins un élément fixe par rapport au segment limitant le déplacement du ressort. 1. Drum brake comprising a plate (2), two segments (3, 4) mounted movable relative to the plate (2), each segment (3, 4) comprising a web (3a, 4a) and a lining (3b, 4b) intended to come into contact with a drum (T), a device for applying the segments to the drum, means for mounting each segment (3, 4) on the plate (2), said mounting means comprising for each segment (3, 4) at least one mounting spring (24) arranged on the segment (3, 4) opposite the plate (2), compression means cooperating with the plate (2) to keep the mounting spring (24) against the segment (3, 4) and thus press the segment (3, 4) on the plate (2), the plate (2) having at least a first hole, the core (3a, 4a ) of the segment comprising a second hole (32), the first hole and the second hole (32) being substantially opposite and being traversed by the compression means, characterized in that the drum brake also comprises holding means (30, 130, 230, 330, 430, 530, 630) of the mounting spring (24) limiting the movement of the mounting spring (24) relative to the segment (3, 4), in which the means (30) ensure the limitation of the displacement parallel to a main plane of the plate and in which the retaining means cooperate with one end of the spring oriented towards the side of the segment, said means comprising at least one element fixed relative to the segment limiting the spring displacement.
2. Frein à tambour selon la revendication 1, dans lequel les moyens de maintien (30, 130, 230, 330) limitent le déplacement du ressort de montage (24) dans toutes les directions dans le plan du segment. 2. A drum brake according to claim 1, wherein the retaining means (30, 130, 230, 330) limit the movement of the mounting spring (24) in all directions in the plane of the segment.
3. Frein à tambour selon la revendication 1 ou 2, , dans lequel les moyens de maintien (30, 130) sont interposés entre le ressort de montage (24) et l'âme du segment (3a, 4a). 3. Drum brake according to claim 1 or 2, wherein the retaining means (30, 130) are interposed between the mounting spring (24) and the core of the segment (3a, 4a).
4. Frein à tambour selon la revendication 3, dans lequel les moyens de maintien (30, 130) comportent des moyens coopérant avec l'âme du segment (3a) et des moyens coopérant avec le ressort de montage (24). 4. Drum brake according to claim 3, wherein the holding means (30, 130) comprise means cooperating with the web of the segment (3a) and means cooperating with the mounting spring (24).
5. Frein à tambour selon la revendication 4, dans lequel les moyens de maintien comportent une coupelle de maintien (34) comportant un fond (36) entouré par un premier rebord (38) coopérant avec au moins une spire d'extrémité du ressort de montage (24), ledit fond (36) comportant un trou (40) pour le passage des moyens de compression et un deuxième rebord (42) bordant ledit trou (40) et coopérant avec le deuxième trou (32) de l'âme (3a) du segment. 5. Drum brake according to claim 4, wherein the retaining means comprise a retaining cup (34) comprising a bottom (36) surrounded by a first flange (38) cooperating with at least one end turn of the spring. assembly (24), said bottom (36) comprising a hole (40) for the passage of the compression means and a second flange (42) bordering said hole (40) and cooperating with the second hole (32) of the core ( 3a) of the segment.
6. Frein à tambour selon l'une des revendications 3, 4 et 5, comportant des moyens permettant une détection visuelle facilitée de la présence des moyens de maintien. 6. Drum brake according to one of claims 3, 4 and 5, comprising means for facilitated visual detection of the presence of the holding means.
7. Frein à tambour selon la revendication 6, dans les moyens permettant une détection visuelle facilitée des moyens de maintien comportent une forme (136) faisant saillie de la périphérie du ressort de montage. 7. A drum brake according to claim 6, wherein the means for facilitated visual detection of the retaining means comprise a shape (136) projecting from the periphery of the mounting spring.
8. Frein à tambour selon la revendication 1, dans lequel les moyens de maintien (230, 330, 430, 530, 630) sont intégrés à l'âme (3a, 4a) du segment. 8. Drum brake according to claim 1, wherein the retaining means (230, 330, 430, 530, 630) are integrated into the web (3a, 4a) of the segment.
9. Frein à tambour selon la revendication 8, dans lequel les moyens de maintien (430, 630) comportent au moins une saillie (432, 632) pour limiter au moins dans une direction et dans un sens le déplacement du ressort de montage (24) par rapport au segment (3, 4). 9. A drum brake according to claim 8, wherein the retaining means (430, 630) comprise at least one projection (432, 632) for limiting at least in one direction and in one direction the movement of the mounting spring (24). ) with respect to segment (3, 4).
10. Frein à tambour selon la revendication 9, dans lequel les moyens de maintien(430) comportent plusieurs saillies (432) réparties autour du deuxième trou (32) délimitant un logement pour une spire d'extrémité du ressort de montage (24). 10. Drum brake according to claim 9, wherein the retaining means (430) comprise several projections (432) distributed around the second hole (32) defining a housing for an end turn of the mounting spring (24).
11. Frein à tambour selon la revendication 8, dans lequel les moyens de maintien (330) comportent une saillie annulaire (332) entourant le deuxième trou (32) et présentant un diamètre extérieur lui permettant de pénétrer dans la spire d'extrémité et de limiter le déplacement du ressort de montage (24) par rapport au segment (3, 4). 11. A drum brake according to claim 8, wherein the retaining means (330) comprise an annular projection (332) surrounding the second hole (32) and having an outer diameter allowing it to penetrate into the end turn and to limit the movement of the mounting spring (24) relative to the segment (3, 4).
12. Frein à tambour selon la revendication 8, dans lequel les moyens de maintien (230) comportent un logement (232) bordant le deuxième trou (32), le logement présentant un diamètre extérieur permettant de loger la spire d'extrémité et de limiter le déplacement du ressort de montage (24) par rapport au segment (3, 4). 12. Drum brake according to claim 8, wherein the holding means (230) comprise a housing (232) bordering the second hole (32), the housing having an outer diameter making it possible to accommodate the end turn and to limit the movement of the mounting spring (24) relative to the segment (3, 4).
13. Fein à tambour selon l'une des revendications là 12, dans lequel les moyens de maintien sont réalisés par emboutissage. 13. Fein drum according to one of claims 1 to 12, wherein the holding means are produced by stamping.
14. Frein à tambour selon l'une des revendications 1 à 13, comportant pour chaque segment (3, 4) deux ressorts de montage(24) et des moyens de maintien pour chaque ressort de montage (24). 14. Drum brake according to one of claims 1 to 13, comprising for each segment (3, 4) two mounting springs (24) and holding means for each mounting spring (24).
15. Frein à tambour selon l'une des revendications 1 à 14, dans lequel le dispositif pour appliquer les segments contre le plateau comportant un actionneur mécanique (10) entraîné par un moteur électrique, ledit actionneur étant destiné à assurer au moins la fonction de frein de parking. 15. Drum brake according to one of claims 1 to 14, wherein the device for applying the segments against the plate comprising a mechanical actuator (10) driven by an electric motor, said actuator being intended to provide at least the function of parking brake.
16. Frein à tambour selon l'une des revendications 1 à 15, et un tambour monté autour des segments. 16. Drum brake according to one of claims 1 to 15, and a drum mounted around the segments.
PCT/EP2020/064137 2019-05-23 2020-05-20 Drum brake with reduced residual torque WO2020234390A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1905437A FR3096422B1 (en) 2019-05-23 2019-05-23 REDUCED RESIDUAL TORQUE DRUM BRAKE
FRFR1905437 2019-05-23

Publications (1)

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WO2020234390A1 true WO2020234390A1 (en) 2020-11-26

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FR (1) FR3096422B1 (en)
WO (1) WO2020234390A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2999566A (en) * 1959-08-24 1961-09-12 Gen Motors Corp Brake shoe spring
JPS62204045U (en) * 1986-06-18 1987-12-26
WO1993012356A1 (en) * 1991-12-10 1993-06-24 Kelsey-Hayes Company Dual mode drum brake assembly
WO2015086958A2 (en) * 2013-12-09 2015-06-18 Chassis Brakes International B.V Drum brake provided with a member for holding a brake segment
WO2015101486A2 (en) 2013-12-30 2015-07-09 Chassis Brakes International B.V. Drum brake device including a parking brake operating in duo servo mode, associated vehicle and assembly methods

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2999566A (en) * 1959-08-24 1961-09-12 Gen Motors Corp Brake shoe spring
JPS62204045U (en) * 1986-06-18 1987-12-26
WO1993012356A1 (en) * 1991-12-10 1993-06-24 Kelsey-Hayes Company Dual mode drum brake assembly
WO2015086958A2 (en) * 2013-12-09 2015-06-18 Chassis Brakes International B.V Drum brake provided with a member for holding a brake segment
WO2015101486A2 (en) 2013-12-30 2015-07-09 Chassis Brakes International B.V. Drum brake device including a parking brake operating in duo servo mode, associated vehicle and assembly methods

Also Published As

Publication number Publication date
FR3096422A1 (en) 2020-11-27
FR3096422B1 (en) 2021-07-02

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