FR2566354A1 - BRAKING UNIT FOR MOTOR VEHICLE - Google Patents

Abstract

MECHANICALLY CONTROLLED BRAKING UNIT FOR AUTOMOTIVE VEHICLES, INCLUDING A MASTER CYLINDER AND AN AMPLIFIER USING THE PRESSURE DIFFERENCE BETWEEN A VACUUM AND THE ATMOSPHERIC PRESSURE, THESE AMPLIFIER CONSISTING OF THE ESSENTIAL OF A COQUERATED DEPRESSION BOX 3, 4 ASSEMBLED BY CRIMPING OR BY STAPLING, A DOUBLE VALVE 2 AND A PUSHBUTTON 18 SERVING TO PRIME THE BRAKING PROCESS, IN WHICH MEANS ARE PROVIDED FOR FIXING THE AMPLIFIER ON THE AWNING PANEL 33, 40, CHARACTERIZED IN THAT, THANKS TO A COLLAR 27, 36 SENSITIVELY CYLINDRICAL AND HOLLOW, SURROUNDING ONE OF THE SHELLS OF THE BOX 3, 4 AND WHOSE AXIS IS PARALLEL TO THE AXIS OF THE SAID SHELL, ONE OF THE ENDS DUDIT COLLAR BEING CONNECTED, FOR EXAMPLE SCREWED, RIVED OR WELDED, TO THE AWNING DECK 33, 40 WHILE ITS OTHER END IS CONNECTED TO THE RADIAL OUTER EDGE OF THE SAID CASE SHELL 3, 4 BY STAPLING OR BY CRIMPING OR IS DESIGNED TO BE U ONLY PART WITH ONE OF THE CASING SHELLS.

Description

The present invention relates to a controlled braking unit

  mechanically designed for a motor vehicle, comprising a master

  lindre and an amplifier using the pressure difference between a vacuum and the atmospheric pressure, said amplifier essentially consisting of a vacuum boot consisting of den :: boot shells joined by crimping or stapling, a valve double and a pusher used to start the process of

  braking -in which means are provided for fixing the am-

  plifier on the front apron The US patent 3,222,868 describes a braking unit essentially comprising a vacuum boot with two shells,

  a working piston fitted with a diaphragm moving in the box

  tier a depressiono A master cylinder of a hydraulic braking unit

  It is burnt on the end of one of the wood shells.

  tier Pins on the other housing shell are used to fix the assembly - braking unit and master cylinder - to the vehicle awning apron o

  In such an arrangement, the parts of the housing to be

  pressure are usually made of sheet steel and the master

  gray cast iron or light alloy cylinder.

  mechanical load tee, the components of the housing can be provided with reinforcement When the brake pedal is actuated,

  the force transmitted by the brake pedal as well as the force of Ampli

  fication a-issent in the rodo The total force acts on the piston of the

  anti-cylinder, but due to the resistance of the hydraulic fluid

  that compressed, there occurs in the master cylinder an opposite force component to hold the master cylinder

  app-roimatively in its position. This reaction force propagates

  ge from the master-cylinder through the building blocks of the

  vacuum housing to the awning apron which is usual-

  lerient fixr the pedal support, This reaction force results in an expansion of the vacuum housing in the axial direction and, gently, in a displacement of the master cylinder, which causes an additional dead stroke of the brake pedal It has therefore already been proposed (German patent application 28 14

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  372) to place the vacuum boot in a basket structure

  and attach the basket structure directly to the deck

  awning, this structure comprising a flange on which are

  xes both the vacuum unit and the master cylindero Cepen-

  However, this known braking unit has a drawback, namely that the basket structure is relatively heavy if it has to have the desired stiffness and resistance.

  part of the basket structure which is placed in the compartment

  motor-motor considerably increases the size of the unit, so that such a solution often turns out to be impractical for reasons of space.

  The object of the present invention is to eliminate the disadvantages

  specific to known devices and to provide a braking unit having excellent rigidity and low weight,

  can be easily mounted on the vehicle and allows replacement

  place the maitr-e-yliidre without the need to deposit the am-

  awning apron plifier Ccform.ment to the present invention, this object is achieved thanks to a substantially cylindrical and hollow collta which surrounds one of the housing ccquillas and whose axis is parallel to the axis of this shell one of the extremities of this collar being

  relid, for example screwed, riveted or welded, to the awning apron

  say that its other end is connected to the outer radial edge of a Soptier shell by stapling or crimping or is designed with a clamp sule with this shell. Given that the length of the cylindrical collar creup: can be changed during manufacture without requiring significant implementation of means at the level of

  manufacturing it is possible to provide a unique model of amplifier

  ficor for different vehicle modules (the collars being this-

  pendant of different sizes). In this case, the part of the amplifier

  The cator in the engine compartment has exactly the dimensions dictated by space requirements.

  of the amplifier boot may, for their part, present

  smooth faces, regardless of the type of amplifier support.

  The other usual holes for fixing screws placed

3 2566354

  on the pedal-side boot shells are not necessary on

  the amplifier according to the present invention, which further reduces

tagging the risk of leaks.

  In an advantageous embodiment, one of the two co-

  housing pins has, in the region of its circumferential outer radial edge, a hollow cylindrical collar which extends to the awning apron and one end of which is provided with a flange screwed or riveted on the apron d awning, while the other end of the substantially cylindrical and hollow collar has notches or notches which engage behind the outer edge or in

  hollows or grooves in the other housing shell.

  The other end of the hollow cylindrical collar is advantageous.

  screwed, riveted or welded to the awning apron while the collar

  let overlap9 speaks folded edge provided at its other end :, the crimped or stapled joint of the two housing shells and has notches or notches which cooperate with the outer edge of one of the housing shells while the edge of this shell of the case is in turn fixed to that of the other case shell by means, for example, of notcheso In an embodiment comprising a collar separate from the two shell cases, the hollow cylindrical collar surrounding the

  crimped or stapled joint of the two shell shells has molds

  lures, folded edges or notches extending radially inwardly which abut against the edges of the curved edges radially outward or the folded edges of the

  housing shells and which prevent any axial displacement of the collar

  let. The different objects and characteristics of the invention

  will now be detailed in the description which follows, made

  by way of nonlimiting example, with reference to the appended figures which represent:

  Figure 1, a longitudinal sectional view of an amplifier

  braking force generator screwed to the front apron, fitted with its fixing device, - Figures 2 to 5, partial cross-sectional views of the edges of the shells of the shells of different force amplifiers

  braking fixed in different ways to the front apron of the vehicle

  the. As shown in Figure 1, the braking force amplifier consists of an amplifier housing 3, 4 with two shells

  the, of the rolling diaphragm 7 dividing the interior of the case into a chamber

  bres 5, 6, the diaphragm plate 8, the depression orifice 9, the spring 10 cooperating with the master cylinder not shown in detail as well as the control unit 2 shown in position

released.

  The spring 10 pushes the diaphragm plate 8 with the plunger

  tone of amplifier 11, via the sealing seat of the control case, against the disc valve 12 or, as the case may be, against the sealing surface 13 as well as, via the washer stop 17, against the housing shell 3 while it

  is supported on the inner wall of the shell 4.

  The return spring 15 of the pusher pushes the valve piston.

  ve 6, via the sealing seat of the valve piston, against the disc valve 12 and, via the washer

  stop 17, against the boot of amplifier 3 (the return spring

  pel 15 of the pusher is therefore supported via the seat

  valve piston).

  When the pusher 18 is actuated in the direction of the arrow

  che, the force of the return spring 15 of the pusher is exceeded and the sealing seat of the valve piston opens immediately without dead travel. The force of the spring 19 of the disc valve then acts

  on the sealing seat of the control case and maintains its

  tightness. The outside air flows over the sealing seat of the valve piston and the channel 20 enters the working chamber.

  5 and applies an exit force on the rod 21 due to the diff-

  pressure reference by Report to chamber 6. The dia-

  sentence 8 associated with the amplifier piston moves in the direction of the arrow and the sealing seats adopt the so-called "venting" position. The reaction is determined by a reaction disc

  22 which can also be replaced by a lever mechanism. Above

  there from the valve's maximum open position, the valve piston 16 bears against the surface 25 of the amplifier piston 11 and the input force is transmitted directly via

  the stop The sealing seat of the valve piston is then complete.

  fully open If the unit adopts its relaxed position, that is to say in the absence of the input force, the valve piston 16 is returned by the return spring 15 of the pusher until the disc 23 is pressed against the amplifier piston 11o Via the sealing seat of the valve piston, the valve piston 16 brings back the disc valve 12 so that the sealing seat of the control box s opens and outside air can be drawn out of chamber S through channel 24 to be sent to chamber 6 The sealing seat of the control case remains open until the amplifier piston 11 associated with the valve piston 16 and the disc valve 12 either returned to its initial position and is in abutment against the stop of the washer 17o The sealing seat of the control unit is then closed by the action of the spring 10 which

  is supported on the washer 17 via the watertight seat

  cheite. The unit has returned to the released position and can be

calf operated without dead stroke.

  The amplifier housing 11, 33 with two shells is joined by means of notches 26 (hollow, indentations) and the housing shell

  3 surrounding the chamber 5 is therefore provided, on its outer edge ra-

  dial, a cylindrical and hollow collar 27 which hangs on the ar3te

  radially curved outwards 28 from the other box shell

  tier 4a The two shell shells 3, 4 close the bead

  lateral 29 of the rolling diaphragm 7 while the notches 26 pre-

  seen on the hollow cylindrical collar 27 are placed so as to push the curved edge 28 of the housing shell 4, with a predetermined load, against the lateral bead 29, and the latter against the hollow 30 of the housing shell 3. The hollow cylindrical collar 27 is provided with a flange 31 which is connected to the front apron

  33 by means of several screws 32 distributed around its periphery

  the amplifier on the front apron 33 of the vehicle at

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  means of a clamping piece 31 placed on the hollow cylindrical collar 27 of one of the housing shells 3 has an advantage,

  know that, on the one hand, the extreme surfaces of the box shells

  tier 3, 4 can be designed without taking into account the fixing means

  tion and that, on the other hand, at least one of the two shell shells 3 or 4 can be designed with thinner walls and less weight insofar as the forces exerted through

  of the brake pedal and by push button 18 are transmitted by the

  end of the flange directly to the front panel 33 In the embodiment of the shells 3, 4 shown in FIG. 1, the housing shell 3 which surrounds the double valve or, as the case may be, the control unit 2 and which is close to the brake pedal is held and fixed to the front apron33 by means of the flange 31; conversely, Figures 4 and 5

  show embodiments of housing shells in the-

  which the flange 31c, 31d fixed to the front apron 33 is not designed in one piece with the corresponding housing shell 3c, 3d or 4c, 4d, but is designed as a separate component which is connected to a housing shells by means of notches 41 or, as the case may be, 422 In the embodiment according to FIG. 5, the flange 31d is provided, on its side close to the housing shell 3d, with an edge 34 folded inwards, this edge surrounding the circumferential folded edge 43 of the housing shell 3do In addition, the housing shell 3d is fixed to the housing shell 4d close to the master cylinder by means of notches 35 while the lateral flange 29 of the diaphragm roller 7 is firmly pinched between the edges, extending outwards, of the housing shells 3d, 4do The embodiment shown in FIG. 2 corresponds to

  that of f igure 1 with, however, an important difference, except

  see that the hollow cylindrical collar 36 is not part of the co-

  housing keel 3a close to the pedal, but part of the co-

  bootsteel keel 4a close to the master cylinder 0 In this case, the housing shell 3a is completely released from the forces exerted by the pedal to the extent that these forces act on the pusher 18 and via the valve piston 16, from the reaction disc 22 and the rod 21, on the piston of the master cylinder are transmitted directly, via the housing of the master cylinder (not shown in detail), to the housing shell 4a and therefore to the flange 37 and to the front apron 33. The embodiment in accordance with FIG. 3 differs from that in accordance with FIG. 2 insofar as the cylindrical collar 44 does not have a clamping part, but this hollow cylindrical collar 44 is directly connected to a part of the front apron 33

  designed there as tubing 39.

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Claims (4)

  1. Mechanically controlled braking unit for vehicle   automobile, comprising a master cylinder and an amplifier   sant the pressure difference between a vacuum and atmospheric pressure, said amplifier consisting essentially of a vacuum housing consisting of two housing shells (3, 4) joined by crimping or stapling, a valve double (2) and a pusher (18) used to initiate the braking process, in which are provided means for fixing the amplifier on   the front apron (33, 40), characterized in that, thanks to a collar   let (27, 36) substantially cylindrical and hollow which surrounds one of the shells of the housing (3, 4) and whose axis is parallel to the axis of said shell, one of the ends of said collar   being connected, for example screwed, riveted or welded, to the apron of   wind (33, 40) while its other end is connected to the outer edge   radial laughing of said housing shell (3, 4) by stapling or   by crimping or is designed in one piece with one of the co- housing pins.   2. Mechanically controlled braking unit according to claim 1, characterized in that one of the two shell shells (3, 4) comprises, in the region of its outer circumferential radial edge, a hollow cylindrical collar (27, 36 ) which extends to the front apron (33) and one end of which is provided with a flange (31, 37) screwed or riveted on the front apron (33), while the other end of the collar substantially cylindrical and hollow (27, 36) has notches or notches (26, 41) which engage behind the outer edge or in hollows or grooves in the other housing shell 3. Mechanically controlled braking unit according to claim 1, characterized in that one of the ends of the hollow cylindrical collar (38) is advantageously screwed, riveted or welded to the front apron (33) while the collar (38) overlaps, by folded edge (34) provided at its other end, the crimped joint 9 2566354   OR stapled (43) of the two housing shells (3d, 4d) and comprises   notches or notches (41) which cooperate with the outer edge   laughing at one of the housing shells (3d), the edge of this co-   bootsteel keel (3d) being in turn fixed to that of the other   be the shell of the bootmaker (4d) by means, for example, of notches (35).   4. Mechanically controlled braking unit conforming to the   any of the preceding claims, characterized in that   the hollow cylindrical collar surrounding the crimped or stapled joint of the two housing shells has moldings, folded edges or notches extending radially inwardly which bear against the edges of the edges curved radially outward or folded edges of the boot shells and which   prevent axial movement of the collar.