FR2863991A1 - Drive shaft mounting and guiding arrangement for windshield wiper mechanism of glass panel of motor vehicle, has drive shaft with bulge part that is received inside complementary housing of cylindrical barrel of plastic material - Google Patents

Abstract

The arrangement has a drive shaft (12) with a protrusion (24) that is received inside a complementary housing (26) of a cylindrical barrel (20) of plastic material. The protrusion is removed from the housing by elastic deformation of the protrusion and/or housing, due to an axial movement of the protrusion towards lower part of the shaft with respect to the barrel, when a windshield wiper mechanism is subject to a violent impact.

Description

"Arrangement for guiding a drive shaft of

  The invention provides an arrangement for pivotally guiding a wiper mechanism drive shaft, which allows the drive shaft to be erased in the event of an impact. deletion of the upper end of the shaft inside the engine compartment in case of impact.

  The invention more particularly proposes an arrangement for mounting and pivoting guidance about a generally vertical axis, with respect to a body structure element of a motor vehicle, a drive shaft of a wiper mechanism having an upper end attached to a wiper arm and whose lower end is attached to a crank of a transmission linkage of the type which includes a guide plate which is intended to be attached to the body structure element and which comprises a cylindrical shaft in which the shaft is pivotally guided.

  In the event of a vehicle collision with a pedestrian, the part of the windscreen wiper mechanism that protrudes outwardly from the vehicle is a blunt object that may cause injury.

  The existence of means allowing a downward clearance of the upper end of the drive shaft relative to the vehicle body is known, in particular in the document WO-A-99.38736 which describes means allowing the drive shaft to slide axially into the barrel in case of impact.

  The document DE-A-195.46.906 also describes such means for erasing the shaft by means of an elastic ring interposed between the shaft and its guide shaft.

  The ring is attached to the barrel and has several resilient fingers which are received in an annular groove of the shaft, and which are able to exit the groove in case of impact.

  Nevertheless, such an arrangement requires the use of an additional ring whose structure is relatively complex, which increases the cost of its manufacture.

  It is an object of the invention to provide an arrangement for guiding a drive shaft for which the shaft retaining means has a simplified structure.

  For this purpose, the invention proposes an arrangement of the type described above, characterized in that the shaft comprises a bulge which is received inside a housing complementary to the barrel, to achieve the blocking of the shaft by vertical movement relative to the barrel, and which is adapted to exit the housing by elastic deformation of the bulge and / or housing, by an axial displacement downwardly of the shaft relative to the barrel, when the wiper mechanism is subject to a violent impact is whose vertical component (F) is oriented downwards, the value of the component being greater than a determined threshold value.

  According to other features of the invention: the housing is made integrally with the barrel by molding an elastically deformable material; - The housing is made in a generally cylindrical ring coaxial with the shaft, which is made of an elastically deformable material, and which is received in a cavity of the barrel; - The cavity comprises a section of internal radial dimensions greater than the outer radial dimensions of the ring, to allow an increase in the outer diameter of the ring at the exit of the bulge out of the housing; the section of the cavity is of generally frustoconical shape; - the bulge is realized come from matter with the tree; bulge is an insert that is attached to the shaft; - The housing is arranged at the lower axial end of the barrel - the bulge and the housing are generally spherical shape; - The housing is extended downwards by a conical annular portion coaxial with the shaft, the inner diameter s increases downwardly forming a ramp; the upper end of the shaft is fixed to the wiper arm by means of a connecting ring which is able to disengage from the shaft or the arm during the impact; the barrel is extended axially upwards by an annular flange against which the arm is able to come into abutment upon impact, to cause the ring to become detached from the arm; the arrangement comprises an annular sealing gasket arranged between the bulge and the housing, at the lower end of the housing.

  Other features and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended figures, in which: FIG. 1 is a diagrammatic representation in perspective and cutaway of a arrangement for mounting a drive shaft having a bulge and a complementary housing according to the invention; - Figures 2A and 2B are sections along the axis A of the arrangement shown in Figure 1, showing the relative positions of the drive shaft and the shaft, before and after the impact; FIGS. 3A to 3C are enlarged details of various embodiments of the bulge; - Figures 4A and 4B are similar views to Figures 2A and 2B, showing another embodiment of the housing.

  In the following description, identical, similar or similar elements will be designated by the same reference numerals.

  There is shown in Figure 1 a plate 10 for guiding a drive shaft 12, pivoting about a vertical axis A.

  The shaft 12 is an element of a wiper mechanism of a motor vehicle glazing panel (not shown), and is intended to be connected at its upper end 12s to a wiper blade 14 (shown in FIGS. 4A, 4B) and at its lower end 12i to a crank 16 of a motion transmission linkage.

  The plate 10 includes a sole 18 for attachment to a body structure element of the vehicle, and it comprises a cylindrical shaft 20 coaxial with the shaft 12 and the axis A. The shaft 20 allows for the guiding pivoting of the shaft 12. For this, its inner cylindrical wall 20i is complementary to the outer cylindrical wall 12e of the shaft 12.

  Finally, the barrel 20 comprises means 22 for locking the shaft 12 in axial movement downwards.

  These locking means 22 of the shaft 12 further enable the shaft 12 to move axially downwardly relative to the barrel 20 when the wiper mechanism is subjected to a violent impact whose vertical component, that the the figures are represented by the arrow F, is greater than a determined threshold value.

  According to the invention, these locking means 22 comprise a bulge 24 which is integral with the shaft 12, and which is received in a complementary housing 26 of the barrel 20.

  To allow the shaft 12 to pivot relative to the shaft 20, the bulge 24 and the housing 26 both have a symmetry of revolution about the vertical axis A, and according to a preferred embodiment, the bulge 24 and the housing 26 are of spherical shape.

  The bulge 24 is carried by the shaft 12 and is arranged between the lower end 12i and the upper end 12s of the shaft 12 This means that the housing 26 is traversed by the shaft 12 and therefore it is open at its upper and lower extremities.

  According to a preferred embodiment of the housing 26, the upper opening of the housing 26 is complementary to the shaft 12, that is to say that its diameter is equal to the diameter of the shaft 12, and the lower opening of the housing 26 is designed to achieve the axial locking of the shaft 12 when the wiper mechanism is in normal use, and to allow the release of the bulge 24 during impact.

  For this purpose, as can be seen in Figure 2A, the diameter of the lower opening is smaller than the largest diameter of the bulge 24, so as to achieve the axial blocking of the bulge. Also, the diameter of the lower opening is greater than the diameter of the shaft 12.

  To allow the downward axial movement of the shaft 12 relative to the shaft 20, and according to another aspect of the invention, the bulge 24 or the housing 26 is able to deform elastically during the impact.

  For this purpose, the bulge 24 or the housing 26, respectively, is made of an elastically deformable material whose elasticity characteristics are determined so that it deforms during impact, and the diameter of the lower opening of the housing 26 is determined, depending on the type of elastic material, and depending on the threshold value of the vertical component of the shock.

  According to a preferred embodiment of the invention, the housing 26 is deformed during the shock.

  FIGS. 1, 2A and 2B show a first embodiment of the invention according to which the housing 26 is made integral with the barrel 20.

  The barrel 20 is thus made of an elastic material capable of being molded, in particular of plastic material.

  According to another aspect of the invention, the housing 26 is made near the lower end 20i of the barrel 20.

  Thus, the outlet of the bulge 24 out of the housing 26 corresponds to a complete detachment of the bulge 24 relative to the barrel 20. As a result, the bulge 24 can no longer oppose the axial movement of the shaft 12 after the impact.

  Figures 2A and 2B shows the relative positions of the shaft 12 and the bulge 24 relative to the barrel 20 and the housing 26 respectively before and after the shock.

  As can be seen in FIG. 2A, when the bulge 24 is present inside the housing 26, that is to say before the shock, the lower portion of the housing 26 makes it possible to retain the bulge axially, preventing thus the shaft 12 to move axially downwards relative to the shaft 20.

  When the wiper mechanism is subjected to a violent impact, this results in a bearing force of the bulge 24 against the housing 26, the amplitude of which makes it possible to cause the elastic deformation of the housing 26, and more particularly of the lower part of the accommodation 26.

  Indeed, the complementary spherical shapes of the bulge 24 and the lower portion of the housing 26 are in the form of ramps vis-à-vis, so that a bearing force oriented axially downwards of the bulge 24 on the housing 26 generates at all points of the lower part of the housing 26 an outward radial force.

  Thus, the housing 26 widens so that the diameter of its lower opening becomes equal to the largest diameter of the bulge 24, to allow the bulge 24 to pass through this opening and to disengage from the barrel 12.

  After the bulge 24 has come out of the housing 26, as shown in FIG. 2B, the housing 26 and the barrel 20 spring back to their original shape, for which the diameter of the lower opening is smaller than the largest bulge diameter 24.

  The use of an elastic material is advantageous for the realization of the housing 26.

  However, since the housing 26 is made integral with the barrel 20, this means that the plate 10 is also made of the same elastic material.

  However, the plate 10 is subjected to many variable mechanical stresses. Thus, the fact that the plate 10 is made of an elastic material, implies that the plate 10 can be deformed in a random manner, and therefore involves a bad scan of the arm relative to the area to be wiped.

  Therefore, according to another embodiment of the invention shown in Figures 4A and 4B, the barrel 20 is made of a rigid material, for example aluminum, and the housing 26 is formed in a piece 28 to the barrel 20 which is made of an elastically deformable material.

  This insert here consists of a ring 28 generally cylindrical and coaxial with the axis A of the shaft 12. It is fixed to the lower end 20i of the barrel 20 by any known means, including by embedding.

  The ring 28 comprises a cylindrical body 32 of revolution in which the housing 26 is formed, and a radial flange 34 which extends the lower end 32i body 32 radially outwardly.

  To receive the ring 28, the lower end 20i of the shaft 25 has a cavity 30 coaxial with the axis A of the shaft 12 and which is open downwards.

  The cavity 30 comprises an upper section 36 and a lower section 38 which respectively receive the body 32 and the flange 34 of the ring 28.

  The flange 34 is received in the lower section 38 so as to achieve the axial positioning and the fixing of the ring 28 in the cavity 30. For this, and by way of non-limiting example, the collar 34 is recessed inside. of the lower section 38.

  When the bulge 24 comes out of the housing 26 in the event of an impact, the housing 26 is deformed, that is to say that the body 32 of the ring 28 is deformed.

  This deformation of the body 32 mainly consists of an increase in its outer diameter. Thus, to allow deformation of the body 32, certain dimensions of the upper section 36, in particular its internal diameter, are greater than those of the body 32.

  According to a preferred embodiment of the cavity 30 shown in the figures, the upper section 36 is of frustoconical shape, whose diameter at its lower end is greater than the diameter at its upper end.

  In addition, the diameter of the upper section, at its upper end is generally equal to the outer diameter of the body 32 of the ring 28, to prevent radial movement of the ring 28 in the cavity 30.

  The bulge 24 is introduced into the housing 26 by elastic interlocking, according to an upward axial movement of the bulge 24 relative to the housing 26.

  To promote the elastic deformation of the lower opening of the housing 26, the housing 26 is extended axially downwards by a conical annular portion 40 forming a ramp coaxial with the vertical axis A, on which the bulge 24 is supported when introductory movement in housing 26.

  As can be seen in the figures, this conical annular portion 40 which extends the housing 26 is used when the housing 26 is made integral with the barrel 20, as shown in FIGS. 1, 2A, and 2B, but also when the housing 26 is formed in the insert ring 28, as shown in Figures 4A and 4B.

  FIGS. 3A to 3C show different embodiments of the bulge 24, which may be used in combination with any of the embodiments of the housing 26 described above.

  According to a first embodiment shown in FIG. 3A, the bulge 24 is formed integrally with the shaft 12, by machining or any other known embodiment.

  This makes it possible to have an arrangement for mounting the shaft 12 whose structure is relatively simple, especially when the housing 26 is made integrally with the barrel 20.

  According to another embodiment shown in FIG. 3B, the bulge 24 is part of a tip 42 which extends the lower end 12i of the shaft 12 to the crank 16.

  This nozzle 42 here comprises an upper orifice 44 open upwards and which receives a knurled portion 46 complementary to the lower end 12i of the shaft 12, and the tip 42 has at its lower end 42i a knurled portion 48 which is received in a complementary orifice 50 of an end 16a of the crank 16.

  These knurled portions 46, 48 and the complementary orifices 44, 50 allow the end piece 42 to transmit the driving torque of the shaft 12 pivotally about the axis A coming from the crank 16.

  There is shown in Figure 3C a third embodiment of the bulge 24 which is a portion of a cylindrical sleeve 52 which is traversed by the knurled portion 46 extending the shaft 12 downwards.

  Here, the lower end of the knurled portion 46 is received directly in the complementary orifice 50 of the crank 16, so that the sleeve 52 does not have to transmit the drive force of the shaft 12, it can therefore consist of a piece of revolution about the vertical axis A of the shaft 12.

  Finally, according to yet another embodiment (not shown) of the bulge 24, it consists of an annular element, or rod, which is attached to the outer cylindrical wall 12e of the lower end 12i of the shaft 12.

  For this, the bulge is received in a complementary annular groove, made in the outer cylindrical wall 12 of the shaft 12.

  According to a preferred embodiment of this rod, its section is circular, so that the portion of the rod which projects relative to the outer cylindrical wall 12e of the shaft 12 has a generally convex shape.

  In addition, the ring is made of a relatively rigid material, for example an iron alloy, so that it is the housing 26 which deforms effectively during the shock.

  FIG. 3A shows another aspect of the invention making it possible to prevent the bulge 24 from coming out of the housing 26 during handling of the plate 10 before it is mounted on the vehicle body structure element.

  In this aspect, the outer cylindrical wall 20e of the lower end 20i of the barrel 20 carries an annular ring 54.

  This annular ring is positioned axially on the barrel 20 at the lower opening of the housing 26, and is made of a rigid material.

  Thus, it prevents the lower end of the barrel 20 from deforming radially to allow the bulge to pass.

  The positioning of the annular ring 54 on the barrel 20 is achieved by means of an annular rib 66 which extends radially outwardly from the outer cylindrical wall 20e of the barrel 20 and which is received in a complementary annular groove 68 of the ring 54.

  FIG. 3A shows another aspect of the invention according to which sealing means, which here consist of an annular lip seal 56, are arranged at the level of the lower opening of the housing 26.

  Here, the seal 56 is received in the space between the conical portion 40 and the lower end of the shaft 12, thus preventing any impurity from entering between the bulge 24 and the housing 26.

  When the bulge 24 is out of the housing 26, the shaft 12 can then move axially downwardly relative to the barrel 20, so that it no longer forms an element likely to injure someone.

  However, the upper end 12s of the shaft 12 is connected to the wiper arm 14, and therefore, during the displacement of the shaft 12 relative to the shaft 20, the arm being secured to the shaft 12 abuts against the upper end of the barrel 20, preventing any further movement of the shaft 12.

  As can be seen in Figures 4A and 4B, and according to an alternative embodiment of the arrangement for mounting the shaft 12, the arm 14 is connected to the upper end 12s of the shaft 12 removably.

  Thus, when the arm 14 abuts against the upper end of the barrel 20, it disengages the arm 12 which can then continue its movement. The arm 14 is then no longer connected to the plate 10, it is completely detached from the vehicle and is no longer an element likely to injure someone.

  Here, the arm 14 is connected to the shaft 12 by means of a connecting ring 58 which is fixed to the upper end 12s of the shaft 12 by means of complementary conical surfaces 60 and by a nut Clamping 62.

  The connecting ring 58 is connected to the arm 14 via complementary cylindrical surfaces 58a, 14a, which are in contact with each other so as to generate friction forces opposing a movement of the connecting ring 58 relative to the arm 14 before the shock.

  The connecting ring 58 to transmit to the arm 14 the driving torque in rotation about the axis A, the cylindrical surfaces 58a and 14a are, according to a preferred embodiment of the invention, of non-circular radial section, for example they have a square section.

  The radial dimensions of the connecting ring 58 are greater than the diameter of the shaft 12. Thus, after its separation from the arm 14, the connecting ring 58 comes into axial abutment against the upper end 20s of the barrel 20, preventing and any displacement of the shaft 12 10 beyond this axial position.

  To allow the shaft 12 to have an amplitude of axial movement sufficient for the bulge 24 to emerge from the housing 26 and that its upper end 12s can be sufficiently concealed after the impact, the upper end 20s of the barrel 20 is extended axially upwards by a cylindrical flange 64.

  The inner radius of the cylindrical flange 64 is greater than the largest radial dimension of the connecting ring 58, and the axial length of the cylindrical flange 64 is determined so as to allow sufficient axial travel of the connecting ring 58. and donating the shaft 12, for the outlet of the bulge 24 out of the housing 26.

  Finally, the flange is shaped so that the arm 14 extends near the upper end annular edge 64s of the flange before impact.

  Thus, when the impact on the shaft 12, the arm 14 abuts against the upper edge 64 of the flange 64, then the shaft 12 continues its axial displacement downwardly relative to the barrel 20, so that the bulge 24 so the housing 26. Also, the connecting ring 58 moves in the flange 64 to abut against the upper end 20s of the barrel 20.

Claims (13)

  1. Arrangement for mounting and guiding pivotally about a generally vertical axis (A), with respect to a body structure element of a motor vehicle, a drive shaft (12) of a wiper mechanism having an upper end (12s) attached to a wiper arm (14) and whose lower end (12i) is attached to a crank (16) of a transmission linkage of the type which comprises a guide plate (10) which is intended to be fixed to the body structure element and which comprises a cylindrical shaft (20) in which the shaft (12) is pivotally guided, characterized in that the shaft (12) comprises a bulge (24) which is received inside a housing (26) complementary to the shaft (20), for locking the shaft (12) in vertical movement with respect to the shaft ( 20), and which is adapted to exit the housing (26) by elastic deformation of the bulge (24) and / or the housing (26), by a displacement axially downwardly of the shaft (12) relative to the shaft (20), when the wiper mechanism is subjected to an impact whose vertical component (F) is oriented downwards, the value of the component being greater than a determined threshold value.   2. Arrangement according to the preceding claim, characterized in that the housing (26) is made integrally with the shaft (20) by molding an elastically deformable material.   3. Arrangement according to claim 1, characterized in that the housing (26) is formed in a generally cylindrical ring (28) coaxial with the shaft (12), which is made of an elastically deformable material, and which is received in a cavity (30) of the barrel (20).   4. Arrangement according to the preceding claim, characterized in that the cavity (30) comprises an upper section (36) which receives a body (32) of the ring (30) and which is of internal radial dimensions greater than the external radial dimensions of the body (32) of the ring (28), to allow an increase in the outer diameter of the body (32) of the ring (28) at the outlet of the bulge (24) out of the housing (26).   5. Arrangement according to the preceding claim, characterized in that the upper portion (36) of the cavity (30) is of generally frustoconical shape.   6. Arrangement according to any one of the preceding claims, characterized in that the bulge (24) is made integrally with the shaft (12).   Arrangement according to one of claims 1 to 5, characterized in that the bulge (24) is a part of an insert (42) which is mounted on the shaft (12).   8. Arrangement according to any one of the preceding claims, characterized in that the housing (26) is arranged at the lower axial end (20i) of the shaft (20).   9. Arrangement according to any one of the preceding claims, characterized in that the bulge (24) and the housing (26) are of generally spherical shape.   10. Arrangement according to any one of the preceding claims, characterized in that the housing (26) is extended downwards by a conical annular portion (40) coaxial with the shaft (12), whose inner diameter increases towards the bottom forming ramp.   11. Arrangement according to any one of the preceding claims, characterized in that the upper end (12s) of the shaft (12) is connected to the wiper arm (14) by means of a connecting ring. (58) which is able to disengage from the shaft (12) or arm (14) during impact.   12. Arrangement according to the preceding claim, characterized in that the shaft (20) is extended axially upwards by a cylindrical collar (64) against which the arm (14) is adapted to come into abutment upon impact, to cause the detaching the connecting ring (58) from the arm (14).   13. Arrangement according to any one of the preceding claims, characterized in that it comprises an annular sealing gasket (56) arranged between the bulge (24) and the housing (26) at the annular portion (40). conical.