Abstract:
The invention concerns an arrangement ( 10 ) for fixing a tubular shift cylinder ( 12 ), between two mounting and locking positions in a motor vehicle body, comprising means for blocking the cylinder ( 12 ) in axial translation including, from the front rearwards, a transverse surface of the cylinder ( 12 ), axial elastic means, a body wall ( 20 ), pierced with an orifice ( 18 ), and a transverse eye mounting ( 34 ) of the cylinder ( 12 ) passing through a cutout ( 40 ) of the orifice ( 18 ) and enabling to immobilise the cylinder ( 12 ) axially when a rotation of the cylinder ( 12 ) locks it by squeezing the wall ( 20 ) between the support surface, the axial elastic means and the eye mounting ( 34 ). The invention is characterised in that the means immobilising the body ( 16 ) in rotation comprise a ferrule ( 56 ) linked with the cylinder ( 16 ) whereof an axial pin ( 68 ) passes through the wall ( 20 ) orifice ( 18 ) to be urged to stop against the wall ( 20 ) when the body ( 16 ) is locked in rotation, and whereof the axial teeth ( 72 ) bite into the wall ( 20 ) when the cylinder rotates ( 12 ) to immobilise it.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention concerns an arrangement for the fixing, to a body structure element of a motor vehicle, of a hydraulic control cylinder. 
     2. Description of the Related Art 
     The invention concerns more precisely an arrangement for the fixing, to a body structure element of a motor vehicle, of a hydraulic control cylinder with a tubular axial shape overall, notably for controlling a clutch or brakes on the vehicle, of the type in which the control cylinder is movable between a position of mounting in the body structure element of the vehicle, and a position of locking with respect to the body structure element of the vehicle in which it is immobilised with respect to the body structure element of the vehicle by immobilisation means, of the type in which means of immobilising it with respect to translation along the axis of the cylinder include, from front to rear, an abutment surface which extends transversely from a main body of the cylinder, axial elastic means, a wall fixed to the body structure element which has in it an orifice, and at least one bracket, which extends transversely from the main body, which, on mounting, passes through a complementary cutout extending radially from the orifice, the bracket allowing the translational immobilisation of the body with respect to the vehicle body when a rotation of the body about its axis brings it from its mounting position to its locking position and effects the gripping of the wall between the abutment surface, the elastic means and the bracket. 
     Many examples of arrangements for fixing a hydraulic control cylinder with a tubular axial shape overall to a body structure element of a motor vehicle are known. 
     First of all conventional arrangements are known, in which the control cylinder is fixed directly to a bulkhead on the vehicle, for example by studs, screws or nuts. 
     The arrangements of this type have the advantage of using control cylinders which are simple in shape, and therefore inexpensive to produce by casting. 
     However, these mountings are constraining, the mounting of a control cylinder of the abovementioned type requiring good coaxiality of the anchoring points on the control cylinder and the holes in the bulkhead. 
     To resolve this drawback, mountings of the type previously described have been conceived, often referred to as “bayonet” mountings, which allow a rapid mounting or demounting of the control cylinder in the body structure element in the vehicle, notably the vehicle bulkhead. 
     The document GB-B-2.163.475 describes an arrangement of this type in which the control cylinder has three brackets which simultaneously effect the translational immobilisation and the rotational immobilisation of the control cylinder. 
     To this end, the control cylinder has a U-shaped elastic pin which is slipped radially onto two parallel countersinks on the cylinder body, which is in abutment on a front face of the support and in abutment on a rear face of a radial collar on the body of the control cylinder. The control cylinder also has three brackets uniformly distributed angularly, whose front faces have teeth which are intended to cooperate with notches on a rear face of the support, when the elastic pin axially acts on the body of the control cylinder. 
     This arrangement has the drawback of requiring a suitable angular positioning of the teeth on the cylinder opposite the notches in the support, which makes mounting tricky. 
     In addition, the particular shape of the brackets requires a mould with a particularly complex shape and an expensive casting process, the surface state of the teeth being necessary to a good positioning of the control cylinder with respect to the vehicle bulkhead. 
     SUMMARY OF THE INVENTION 
     To remedy this drawback, the invention proposes a control cylinder arrangement in which the means of translational immobilisation and the means of rotational immobilisation are independent of each other. 
     To this end, the invention proposes an arrangement of the type described previously, characterised in that means of rotationally immobilising the body with respect to the wall include a dish, which is fixed with respect to rotation to the body, which is interposed between the axial elastic means and the wall, and which has at least one stud which extends axially through the orifice in the wall in order to come into abutment against the wall when the body is brought in rotation from its mounting position to its locking position, and include at least one tooth, fixed with respect to rotation to the body, which extends axially at the edge of the body in order to bite into the wall when the body is brought in rotation from its mounting position to its locking position, and to immobilise the body in the locking position. 
     According to other characteristics of the invention: 
     the body has at its periphery at least one bracket, which is associated with a complementary cutout in the orifice, the dish has a cylindrical shape overall, and has a rear transverse wall, which has a circular orifice and a cutout, identical to that in the body, to enable it to be mounted on the body, 
     the dish has a rectilinear ridge arranged tangentially to the edge of its circular orifice, and which is intended to cooperate with a complementary flat, arranged on the periphery of the body, to fix the dish to the body with respect to rotation, 
     the stud is arranged on a rear face of the rear transverse wall of the dish, at the edge of a substantially radial ridge on the cutout, 
     the dish is produced by moulding from a plastics material, 
     the dish is produced by pressing from a metal sheet, 
     the stud is formed by an axial fold in the sheet metal of the dish and is oriented towards the rear, 
     the tooth extends from a front face of the bracket on the body, 
     the tooth is carried by the rear face of the rear transverse wall of the dish, 
     the tooth is formed by an axial fold in the metal sheet of the dish, which is arranged at the edge of the cutout, and which is oriented towards the rear, 
     the abutment surface of the body forms part of a radial annular collar, 
     the elastic means include an elastic washer which bears on a rear face of the collar and on a front internal face of the dish, 
     the dish is able to slide on the body between two extreme positions, a first front position in which the front internal face of the dish is acted on by the elastic washer, and a second rear abutment position in which a radial protrusion, carried by an internal wall of the dish, extends in the direction of the axis of the cylinder in order to immobilise the dish nesting on the collar, 
     the wall is carried by a support which is arranged opposite an opening formed in the body structure element, and has two lugs with holes at their ends, which enable the support to be mounted on the body structure element by screwing, 
     the body has at its periphery at least two brackets of different shapes, uniformly distributed, which are associated with at least two complementary cutouts in the orifice, to allow angular location of the body when it is inserted in the orifice, 
     the rectilinear ridge connects together two consecutive cutouts in their area of junction with the orifice. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the invention will emerge from a reading of the following detailed description, for an understanding of which reference should be made to the accompanying drawings, in which: 
     FIG. 1 is an exploded perspective view of an arrangement according to the invention; 
     FIG. 2 is a side view of an arrangement according to FIG. 1 depicted assembled; 
     FIG. 3 is an end view of the cutouts of the orifice in the support according to the invention; 
     FIG. 4 is an end view of a dish according to the invention; 
     FIG. 5 is an end view of a control cylinder according to the invention; 
     FIG. 6 is an end view illustrating a control cylinder according to the invention with its engagement through the orifice; 
     FIG. 7 is an end view illustrating a control cylinder according to the invention during its engagement in the orifice; 
     FIG. 8 is an end view illustrating a control cylinder according to the invention after its engagement in the orifice and after its rotation; 
     FIG. 9 is a perspective view of a corrugated elastic washer for a second embodiment of the control cylinder according to the invention; 
     FIG. 10 is a perspective view of an elastic washer made from wire arched and split for the first embodiment of the control cylinder according to the invention; 
     FIG. 11 is a perspective view of an elastic washer made of elastomer material for the first embodiment of a control cylinder according to the invention; 
     FIG. 12 is a perspective view of a split elastic washer for the first embodiment of the control cylinder according to the invention; 
     FIG. 13 is a perspective view of a dish made of plastics material for the second embodiment of the control cylinder according to the invention; 
     FIG. 14 is a detail view in axial section illustrating the mounting of the control cylinder according to the second embodiment of the invention. 
     FIG. 15 is a detail view in axial section illustrating the mounting of the control cylinder wherein the tooth extends from the bracket toward the abutment surface. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the description which follows, identical reference numerals designate identical parts or those having similar functions. 
     In FIG. 1 the whole of an arrangement  10  for fixing a hydraulic control cylinder  12  to a body structure element  14 , notably a bulkhead, of a motor vehicle (not shown) can be seen. The element  14  is fixed. 
     In a known fashion, the control cylinder  12  has a body  16  with a tubular axial shape overall produced for example by casting a metallic material or moulding a plastics material. 
     In a known fashion, the body  16  of the control cylinder  12  is intended to be mounted through an orifice  18  in a wall  20  which is fixed to the body structure element  14  of the vehicle. The wall  20  can be made in one piece with the body structure element  14 , as is the case, for example, when the wall  20  forms part of a vehicle bulkhead. 
     However, in the preferred embodiment of the invention, the wall  20  belongs to a support  22  fixed to the body structure element  14  of the vehicle. 
     To this end, the support  22  has a substantially cylindrical body  24  intended to receive the control cylinder  12 , and a flat base  26 , which has two lugs  28  each with, at their end, axial holes  30  intended to allow passage of screws (not shown) for fixing to the vehicle bulkhead  14 . 
     The cylinder  12  is able to move between a position of mounting in the support  22 , and a position of locking in the support  22 . 
     In a known manner, the body  16  of the cylinder  12  has at its rear end  32  at least one transverse bracket  34  which is intended, as will be seen subsequently, to allow the fixing of the control cylinder  12  in the support  22 . In the preferred embodiment of the invention, and non-limitatively of the invention, the body  16  has four brackets  34 , regularly distributed angularly, and which are made in the one piece with the cylinder  12 . Good mechanical strength of the brackets  34  with respect to the body  16  made of castable material is advantageously ensured by ribs  36  which extend between rear faces  38  of the brackets  34  and the periphery of the body  16 . The brackets  34  and their ribs  36  are also depicted in FIG. 5, which illustrates the body  16  of the cylinder  12 , here based on fiber-reinforced plastics material 
     When mounting, the cylinder  12  is first of all engaged from front to rear so that the brackets  34  pass through cutouts  40  in the orifice  18 , which have a shape complementary to the brackets  34 . The orifice  18 , enlarged by the cutouts  40 , therefore has substantially the shape of a four-pointed star. Advantageously, as depicted in FIGS. 1 and 5, the brackets  34  are each different from each other, and the same applies to the associated cutouts  40  in the support  22 , visible in FIG.  3 . This arrangement gives rise, on mounting, to a single possible angular orientation of the cylinder  12  with respect to the support  22 , which is particularly advantageous for the positioning of any connections which may be made to the cylinder  12  during the remainder of the assembly of the vehicle. This is because, the cylinder  12  being intended to be connected to different hydraulic pipes in the vehicle, the definition of its angular position and mounting must be clearly defined so that a correct connection of the pipes can be made. 
     On mounting, the body  16  and brackets  34  pass from front to rear through the cutouts  40  in the orifice  18 , and then the body  16  is pivoted about its axis by approximately one eighth of a turn. The body  16  is elastically returned towards the rear, so that, after this rotation of the body  16 , the brackets come into abutment by means of their front faces  35  on the material returns  42  arranged on the support  22  between the cutouts  40  in the orifice  18 . 
     For this purpose, the body has a collar  44 , which extends radially in front of the brackets  34 , and which has a diameter greater than the radial dimension of the brackets  34 , so that it can provide a support surface, formed by a rear face  46 , for an elastic washer  48 , which is interposed before mounting between the collar  44  and the support  22 , which is also depicted in FIG.  2 . 
     The elastic washer  48  has four cutouts  52  complementary to the brackets  34 , to enable it to come into abutment on the rear face  46  of the collar  44  after having the brackets  34  of the body  16  pass through it. Advantageously, the washer  48  is a tapered elastic washer of the “Belleville” type, depicted in FIG. 1, but can also be a corrugated elastic washer of the “Onduflex” type, depicted in FIG. 9, a washer made of arched and split wire, depicted in FIG. 10, a washer made of elastomer material, depicted in FIG. 11, or a split washer, depicted in FIG.  12 . The details of these washers will be described subsequently. 
     When the cylinder  12  is brought into the mounting position, the washer  48  is compressed between the rear face  46  of the collar  44  and a rear face  54  of a dish  56  interposed between the washer  48  and the support  22 . 
     The dish  56  is a dish made of pressed sheet metal or a plastics material, substantially cylindrical in shape, a rear transverse wall  58  of which also has a circular orifice  69  and four cutouts  60 , and which is intended to be slipped axially onto the body  16  of the cylinder  12  and onto the washer  48 . The dish  56  is depicted in FIGS. 1 and 4. The dish  56  has a diameter greater than that of the washer  48 , so that, when the washer  48  and dish  56  are slipped axially from rear to front onto the body  16  of the cylinder  12 , the washer  48  is received in the dish  56 . 
     The dish  56  has an inside diameter substantially equal to the outside diameter of the collar  44  of the body  16  and has, on its internal wall  59 , a protrusion  61 , which extends radially towards the inside, to enable the dish  56  to nest on the collar  44 . In this way, the dish  56  is able to move axially with respect to the body  16  between two axial stop positions, a front position in which its rear face  54  is in abutment against the washer  48  when it is compressed, and a rear position in which the protrusion  61  holds the dish on the collar  44 , the washer  48  being relaxed. 
     On mounting, the body  16 , provided with the elastic washer  48  and the dish  56 , depicted in FIG. 1, is presented opposite the cutouts  40  in the support  22  and then inserted from front to rear in the support  22 . FIG. 6 illustrates a non-conforming position of the body  16  with respect to the cutouts  40  which prevents its being mounted in the support  22 . A correct insertion position is depicted in FIG.  7 . The dish  56  comes into abutment against the rear face  50  of the support  22 , depicted in FIG. 1, and compresses the elastic washer  48 . A rotation of the body  16  makes it possible to bring it from its mounting position to its axial locking position, in which the front faces  35  of the brackets  34  are in abutment on the rear face of the transverse wall  20  of the support  22 , under the action of the return force exerted by the elastic washer  48  on the collar  44  of the body  16 , which is held by the dish  56 . 
     This configuration in axial locking is more particularly described with reference to FIG.  2 . FIG. 8 illustrates in detail the angular positioning of the brackets  34  of the body  16  on the rear transverse face of the wall  20 , between two cutouts  40  in the support  22 . 
     The axial holding of the cylinder  12  in the support  22  is provided as long as the brackets  34  occupy an appropriate angular position, each of them being positioned between two cutouts  40  in the support  22 . The determination of this position being particularly important, the arrangement  10  has for this purpose means of rotationally immobilising the body  16  with respect to the support  22 . 
     In accordance with a preferred embodiment of the invention, the dish  56  is rotationally fixed with respect to the body  16  of the cylinder  12 . As can be seen in FIGS. 1 and 4, an additional rectilinear ridge  64  connects two cutouts  60  in the dish  56 , substantially along a tangent to the circular orifice  57 . The body  16  has a flat  66  arranged between the two brackets  34  complementary to the relevant cutouts  60  in the dish  56 , so that, when the dish  56  is slipped axially onto the body  16 , the ridge  64  is in linear contact with the flat  66 . The dish  56  is thus rotationally connected to the body  16 . 
     Advantageously, the flat  66  on the body  16  is a shape resulting directly from the process of casting of the cylinder  12 . In addition, since producing the flat  66  in the body  16  corresponds to a reduction in the diameter of the cylindrical body  16  in the associated transverse plane, this arrangement makes it possible to refrain from producing similar rectilinear ridges in the elastic washer  48  and in the support  22 , which simplifies the shapes of the latter parts, and therefore reduces their manufacturing cost. 
     The dish  56  has, on its rear face  58 , an axial stud  68 , which is described with reference to FIGS. 1 and 4. The axial stud  68  extends towards the rear and is arranged on a radial edge  70  of a cutout  60 . The axial stud  68  is slightly offset angularly towards the inside of the relevant cutout  60 , so that it is able, when the body  16  provided with the washer  48  and the dish  56  is inserted into the support  22 , to pass through the orifice  18  in the support  22 . The axial stud  16  is arranged on an edge  70  of the cutout  60  which is chosen so as, between the mounting position and the locking position, to travel an entire width of a cutout  40  in the support  22  without encountering the wall  20  of the support  22 , so that it makes it possible to define an annular rotational travel of the cylinder  12  corresponding to an angular difference a between two edges of the same cutout  60 , the axial stud  68  coming into abutment against a radial edge the cutout  40  of the wall  20  of the support  22  at the end of angular travel of the cylinder  12 . This travel α is particularly depicted in FIG. 8, the direction of rotation of the cylinder  12  being illustrated by the arrow. 
     The cylinder  12  has additional means of immobilising with respect to rotation, which enable the body  16  to keep its angular abutment position against the support  22 . This is because, in the preferred embodiment of the invention, the dish  56  has teeth  72  carried by its rear face  58 . The teeth  72  are depicted in FIGS. 1 and 4. The teeth  72  extend axially towards the rear in order to bite into the front face  50  of the support  22  and prevent rotation of the cylinder  12  in the reverse direction to locking. Advantageously, in the preferred embodiment of the invention, the teeth  72  are produced by folding the metal sheet from which the dish  56  is produced, and for this reason are preferably arranged at the edge of one or more cutouts  60 . Advantageously the teeth  72  form an acute angle (not shown) with the rear face  58  of the dish  56 , the apex of this angle being turned in the direction of rotation of locking of the cylinder, in order to assist locking and prevent accidental unlocking. 
     In a variant (not shown) the teeth  72  can be carried in a similar fashion by the front faces  35  of the brackets  34  of the body  16 . In this case, the teeth  72  are made in one piece with the material of the cylinder  12 . 
     However, all these arrangements are not restrictive of the invention. 
     The dish  56  can be produced from plastics material, and in this configuration all the functional forms of the dish  56  are obtained by moulding. FIG. 13 illustrates a dish  56  produced by moulding according to a second embodiment of the invention. In a similar manner to the previous embodiment, the dish  56  carries the teeth, stud and cutouts (not shown) on its rear face  58 , and the protrusion  61  allowing on mounting, as depicted in FIG. 14, its axial immobilisation with respect to the collar  44  on the body  16  of the cylinder  12 . The teeth  72  are, according to this second embodiment of the invention, produced in one piece with the plastics material of the dish  56 , and disposed for example on the rear face  58  of the dish  56  between two cutouts  60  or, in a variant (not shown), on the periphery of the rear face  58 . 
     FIGS. 13 and 14 also illustrate an embodiment as a variant of the rotational fixing of the dish  56  to the body  16 . This is because, in this case, the dish  56  does not have a ridge  64 , the body  16  does not have a flat  66 , and the rotational fixing of the body  16  and dish  56  is advantageously effected by means of an axial catch  65  which is arranged radially inside the wall  59  of the dish  56  and is intended to cooperate with a complementary scallop  67 , arranged radially on the collar  44  of the body  16 . 
     This connection is depicted in FIG.  14 . The catch  65  is produced in one piece with the plastics material of the dish  56 . The dish  56  is elastically returned by a suitable washer  48 , which has a recess  63  allowing the passage of the catch  65  through the washer  48 . Such a washer is depicted more particularly in FIG.  9 . 
     The design of the catch  65  is not limitative of the invention, and such a rotational fixing could, non-limitatively of the invention, be associated with the first embodiment of the dish  56 , the catch then being formed by an axial fold (not shown) in the metal sheet of the front face  58  of the dish  56 . 
     Moreover, as illustrated by FIG. 14, the plastic dish  56  is advantageously slightly deformable and, on mounting, deforms axially in abutment against the support  22  so that the periphery of its rear face  58  is in contact with the support  22  and thus provides a seal between the areas A and B of the vehicle delimited by the body structure element  14  of the vehicle, that is to say here the support  22 . In addition, the protrusion  61  is radially elastic, so that, when the dish  56  is in abutment through its rear face  58  on the support  22 , the elastic mounting of the protrusion  61  on the collar  44  also participates in the seal between the areas A and B of the vehicle. 
     FIGS. 9 to  12  illustrate various variants of washers  48  for producing axial elastic means according to the invention. 
     FIG. 9 illustrates a corrugated washer  48 , also referred to as an “Onduflex” washer. The washer  48  depicted is associated with a second method of rotational fixing of the dish  56  to the body  16 , since it includes the recess  63  intended to allow passage of the catch  65  described above with reference to FIGS. 13 and 14. However, non-limitatively of the invention, such a washer  48  could be associated with the first method of rotationally fixing the dish  56  to the body  16 . In this case (not shown), it would not have a recess  63 , but only cutouts  52  similar to those described with reference to FIG.  1 . Axial corrugations  69  in the washer  48  would give it its axial elasticity. 
     FIG. 10 depicts an elastic washer made of arched and split wire for the first embodiment of rotational fixing of the dish  56  to the body  16 . The washer  48  is similar to a turn on a helical spring, and is mounted on the body  16  of the cylinder  12  depicted in FIG. 1, by separating its arms  71 . Advantageously, such a washer could also be used for the second embodiment of rotational connection of the dish  56  to the body  16 . 
     FIG. 11 depicts an elastic washer made from an elastomer material for the first embodiment of rotational fixing of the dish  56  to the body  16 . The washer  48  is produced from an elastomer material and is mounted on the body  16  whilst deforming radially. Advantageously, a washer of this type could also be used for the second embodiment of rotational fixing of the dish  56  to the body  16 . In this case it would have a recess similar to the recess  63  in the washer described in FIG.  9 . 
     FIG. 12 illustrates a split elastic washer for the first embodiment of rotational fixing of the dish  56  to the body  16 . The washer  48  is mounted on the body  16  of the cylinder  12  depicted in FIG. 1, by separation of its arms  73 . Advantageously, a washer  48  of this type could also be used for the second embodiment of rotational fixing of the dish  56  to the body  16 . In this case, it would have a recess similar to the recess  63  in the washer described in FIG.  9 . 
     Advantageously, the arrangement  10  makes it possible to obtain a rapid fixing of a hydraulic cylinder  12  in the bulkhead of a vehicle. This arrangement  10  is all the more advantageous since it does not require any particular tool, unlike fixings with conventional screws, and is easily demountable. This is because it suffices to exert a high torque in the opposite direction to the locking on the cylinder  12  in order to overcome the opposing reaction force of the teeth  72  and allow easy demounting of the cylinder  12 .