FR2776332A1 - Balanced pivot for vehicle hatchback door - Google Patents

Abstract

The vehicle door pivot has a balance (64) to compensate for the load moment when the door is opened and closed. The load moment exceeds the balance moment at the end of the closure travel. The balance has at least one spiral spring connected to the vehicle body, and to a rotary drive connected to the door. The axes (A1, A3) of the door pivot and drive are parallel.

Description

"Improved articulation device of a leaf pivotally mounted on the

  body of a motor vehicle "The present invention relates to a hinge device of an opening pivotally mounted on the structure of the body of a motor vehicle according to an angular pivoting stroke, in particular between an extreme open position and an extreme position closed, and of the type comprising means for balancing the opening which apply a balancing torque to it which compensates for the resistant torque due to the mass

0o of the opening.

  An example of such an articulation device is described and represented in French patent application n. 94 02817 of March 11, 1994, published under the number FR-A-2.717.143, in which the articulation device of the opening, in particular of a tailgate of a vehicle, is of the type comprising energy storage means constituted for example by a spiral spring, which store energy in the closed position and which restore it under the form of a balancing torque upon opening to compensate for the resisting torque due to the

0o tailgate mass.

  The balancing torque which compensates for the resisting torque therefore decreases progressively from a maximum value corresponding to the extreme closed position towards a minimum value corresponding to the extreme open position, this progressive decrease, linear or not, of the balancing torque being due progressive relaxation of the spiral spring. French patent application no. 95.11437, published under no. FRA-2739.349, proposes an articulation device of the type mentioned above, in which the balancing means substantially compensate for the whole of the resistive torque throughout its pivoting stroke, and in that the value of the balancing torque passes through a maximum in one

pivot point.

  Thanks to such a design, it is in particular possible to perfectly balance the different types of tailgate

vertical in closed position.

  According to other aspects of this design, the balancing means comprise at least one balancing spiral spring, one end of which is connected to the structure of the vehicle body and the other end of which is connected to a drive linked in rotation to the leaf which is pivotally mounted about an articulation axis carried by the body structure of the motor vehicle, the inner end of the spiral spring being linked in rotation to a drive axis carried to rotation by the structure of the vehicle body, and there are provided means for driving the drive shaft in rotation by the opening. The articulation and drive axes are parallel, and the rotational drive means comprise a first toothed sector linked in rotation to the drive axis and a second toothed sector linked in rotation to the leaf which cooperate by meshing to constitute a gear which ensures the driving in rotation of the drive axis on a first part of the pivoting stroke of the opening which extends from one of the two extreme positions to said intermediate point of so as to apply to the sash a balancing torque of increasing value along this first part, the teeth of each toothed sector preferably being arranged on a pitch profile with variable radius to constitute a gear with

  variable gear ratio.

  The drive means comprise a drive mechanism by cam and roller which ensures the drive in rotation of the drive axis on a second part of the pivoting stroke of the opening which extends from said intermediate point to the other of the two extreme positions so as to apply to the opening a balancing torque of decreasing value along this second part of the pivoting stroke of the opening. The roller is eccentric relative to the articulation axis and is linked in rotation to the opening, and o it cooperates with a cam profile formed on a lever.

  transmission linked in rotation to the drive axis.

  This design is satisfactory from the functional point of view, but it is structurally complex all the more since the roller is carried by a sector linked in rotation to I5 the opening and whose periphery is toothed to constitute the second toothed sector, and the transmission lever is linked in rotation to the first toothed sector by disengageable means of rotation connection, arranged between the transmission lever and the drive axis, which are disengaged along the

  first part of the sash pivoting stroke.

  The invention aims to propose an articulation device of the type described and shown in the document mentioned above for the articulation and balancing of an opening, in particular vertical, that is to say an opening which s '' extends substantially in a vertical plane in the closed position, the curve of the resisting torque to be balanced has very reduced values of the resisting torque in one of the extreme positions, and in particular in the closed position, this resisting torque in the extreme position can possibly be very weak, and aims to propose such a device, the structure of which is

  simplified compared to the state of the art.

  To this end, the invention provides a device of the type mentioned above, characterized in that, at the end of the closing stroke, the values of the resisting and balancing torques are non-zero with the value of the resisting torque greater than the value of balancing torque. According to other characteristics of the invention - the articulation and drive axes are parallel, and in that the rotation drive means comprise a first toothed sector linked in rotation to the drive axis and a second toothed sector linked in rotation to the opening which cooperate by meshing to constitute a gear which ensures the driving in rotation of the drive axis on a first part of the pivoting stroke of the opening which extends from one of the two is extreme positions to an intermediate point so as to apply to the opening a balancing torque of generally increasing value and greater than the resisting torque along this first part; - The drive means comprise a drive mechanism by cam and roller which ensures the rotational drive of the drive axis on a second part of the pivoting stroke of the opening which extends from said point intermediate to the other of two extreme positions so as to apply to the opening a balancing torque of decreasing value and less than the resistive torque along this second part of the pivoting stroke of the opening; - the roller is carried by the first toothed sector and is eccentric relative to the articulation axis of this toothed sector, and it cooperates with a cam profile formed on the second toothed sector - the roller cooperates with the cam profile after the last tooth of the second toothed sector has finished cooperating with a final tooth of the first toothed sector at the end of the first part of the pivoting stroke; - The cam profile comprises a substantially curvilinear section which extends from the last tooth of the second toothed sector in a direction of orientation which is generally tangential with respect to the drive axis; the cam profile is produced integrally with the second toothed sector; - The cam profile consists of a non-toothed section of the edge of the second toothed sector which extends in a plane offset axially relative to the plane in which the toothed section of said edge extends; - The roller extends in a plane offset axially relative to the plane of the toothed edge of the first toothed sector which cooperates with the toothed edge of the second toothed sector; The opening is articulated on the structure of the body of the motor vehicle by means of a mechanism with two parallel articulation axes connected by an articulation rod; - The second toothed sector is linked in rotation to one end of the connecting rod articulated on the structure of the vehicle body around one of the two articulation axes which is carried by the structure; - the opening is articulated on the structure of the vehicle body by means of an articulation mechanism carrying two parallel articulation connecting rods, and one end of each

  connecting rods is associated with a balancing spiral spring.

  - The opening is a tailgate which, in the closed position, extends in a substantially vertical plane and which, in the open position, extends in a substantially horizontal plane above the vehicle; - The tailgate is formed by a panel masking a recess in a frame of the structure delimited by an upper cross member, by two lateral uprights and by a lower cross member, among which each lateral upright carries an axis of articulation of said end of a tailgate hinge rod, the other end of which is articulated on a hinge pin carried by the tailgate; - a first end of the connecting rod is articulated on the structure of the vehicle body around a first axis of articulation, the second end is articulated on the opening around a second axis of articulation, parallel to the first axis articulation, and means are provided for controlling the pivoting movement of the opening, relative to the second end of the connecting rod, to the pivoting movement of the first end of the connecting rod, relative to the structure

from the vehicle body.

  Other characteristics 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 drawings in which: - Figure 1 is a side view, with partial cutaway, of the rear part of a motor vehicle whose rear tailgate is equipped with a conforming articulation device to the teachings of the invention and is illustrated in an extreme open position; - Figure 2 is a diagram which illustrates the resisting torque and the balancing torque as a function of the angular position 3o of the opening relative to the fixed structure of the vehicle body - Figure 3 is a detail view at larger scale of the balancing means belonging to the articulation device according to the teachings of the invention illustrated in Figure 1 and which are shown here for the extreme position of full closure of the tailgate; - Figure 4 is a simplified view on a large scale which illustrates the relative angular position of the two toothed sectors when the tailgate is in its fully open position illustrated in Figure 1; - Figure 5 is a view similar to that of Figure 4 which illustrates the relative angular position of the two toothed sectors when the tailgate is in its position close to the end of the first part of its angular pivoting stroke; - Figure 5A is an enlarged view of the detail D5 of Figure 5; - Figure 5B is a view similar to that of Figure A which illustrates the relative angular position of the two toothed sectors just before their mutual disengaging at the end of the first part of the pivoting stroke, and the start of their mutual drive by cam and roller; FIG. 5C is a view similar to that of FIG. B which illustrates the relative angular position of the two toothed sectors at the start of the second part of the pivoting stroke during which the balancing is ensured by means of the action of the roller on the cam, without cooperation of the toothed sectors - FIG. 5D is a view similar to that of FIG. C which illustrates the relative angular position of the two toothed sectors at the end of the second part of the pivoting stroke when the tailgate is in its position is in its fully closed position - Figure 6 is a view similar to that of Figures 4 and 5 and corresponding to the angular pivoting position illustrated in Figure 5D; - Figure 7 is a detail view in section passing through the geometric axes of the articulation and drive axes and which also illustrates in section a connecting rod

  articulation with its servo rack.

  There is shown in Figure 1 a side view of the rear part of a motor vehicle 10 whose body 12 is 1o open at the rear to allow access to the passenger compartment 14 of the

  vehicle and for example its load.

  To this end, the opening is delimited by a frame consisting essentially of two vertical lateral uprights, one of which 16 is shown in FIG. 1, the opposite lateral upright being arranged symmetrically with respect to the median longitudinal plane of symmetry, and by two upper 18 and lower 20 crossmembers which delimit a recess, the closure of which is ensured by an opening 22, also called tailgate, which is generally pivotally mounted relative to the structure of the body 12 of the vehicle,

around a horizontal axis.

  The tailgate 22 is illustrated in the extreme maximum open position in FIG. 1 and also in silhouette 22 ′ in the extreme closed position in which it extends in a plane.

substantially vertical.

  According to a known design, the opening 22 is pivotally mounted on the body 12 by a system with two geometric horizontal axes of articulation A1 and A2 by means of an articulation mechanism with two parallel connecting rods, one of which

24 is illustrated in FIG. 1.

  Referring to FIGS. 1 and 7, it can be seen that a first end 26 of each connecting rod 24 is mounted articulated on the structure of the vehicle body around the first articulation axis A1 and that the second opposite end is articulated on the opening 22 around the second articulation axis A2 parallel to the first articulation axis A1, these two axes extending in the general transverse direction of the vehicle. The first articulation axis A1 is located vertically 0o in the vicinity of the upper cross member 18 and in the extreme open position, the tailgate 22 extending in a plane

  substantially horizontal above the vehicle 10.

  According to a known technique, which is for example described and represented in the document FR-A-2,703.005 to the content of which reference may be made for more details, the pivoting movement of the opening 22 around the axis A2 relative to the second end of the connecting rod 24 is slaved to the pivoting movement of the first end 26 of the connecting rod 24 relative to the structure 12, 16 of the vehicle body by a servo mechanism comprising in particular a rack 30 which cooperates simultaneously with a toothed pinion (not shown) linked in rotation to the opening and, in the vicinity of its end 26 illustrated in FIG. 8, with a toothed pinion 32 which is rotationally integral with the housing 38 by welding 40 and which extended by a tubular sleeve 34 which is rotatably mounted in the hollow body of the connecting rod 24, one end of which in the form of a yoke is crossed by a bush 36, of geometric axis A1, which passes through the box ier 38 of a mechanism

  -30 balancing according to the teachings of the invention.

  The assembly is assembled axially by a pivot screw

  to which it is fixed, for example by welding 40.

  Thus, during the overall pivoting movement of the tailgate 22, the body of the connecting rod 24 pivots relative to the housing 38 about the axis A1. There is shown in Figure 2, in a torque-angle diagram, a first curve CR which corresponds to the value of the resistant torque due to the mass of the opening and which the user must overcome when handling the tailgate 22 from 0o its fully open position corresponding to an angle of 0 until it is fully closed, here corresponding to an angle of

 , and vice versa.

  As can be seen in FIG. 2, the value of the resistive torque CR is positive and low for the two extreme positions of opening and closing and it passes through a maximum M for an intermediate angular position of the opening corresponding to an angle "i" (of about 55), the different angles of rotation mentioned above being measured relative to the vehicle body around the axis A1. In accordance with the invention, the purpose of the balancing mechanism of the resisting torque is to apply to the sash a balancing torque represented by the curve CE in FIG. 2 which compensates for the resisting torque by being slightly greater than that ci along most of the angular travel

pivot.

  More specifically, for an angle of 0O (corresponding to the fully open position of the tailgate 22), the value of the balancing torque CE is slightly greater than the positive value of the resisting torque CR so as to guarantee the maintenance in the extreme position d opening of the tailgate 22 and, for an angle ll of 125 (corresponding to the extreme closing position of the tailgate 22), it is positive and slightly less than the positive value of the resisting torque CR so as to guarantee that the extreme position of closing the tailgate 22 so as to assist the user at the end of closing, in particular to facilitate locking interlocking of the tailgate in the closed position. As can be seen in FIG. 2, the value of the balancing torque CE becomes less than the value of the resisting torque CR for an angle "k", here equal to approximately 100, that is to say after passing through the maximum values of the couples CR and CE, the two torque curves intersecting at a point P2. From the point of view of balancing the tailgate 22, there is thus i5 a first part of its pivoting stroke comprised substantially between 0 and k, corresponding practically to three quarters of the stroke and which is called a part of "on -balancing ", and a second part

  between d and 125, called "under-balancing".

  To this end, and as can be seen in FIG. 2, the value of the balancing torque CE drops suddenly from a point P1 corresponding to an angle "j" between i

and k and which here is equal to 95.

  The balancing means according to the invention make it possible to obtain the profile of the curve of the balancing torque illustrated.

in Figure 2.

  The balancing means are illustrated in detail in FIGS. 3 to 7 and they comprise a hollow housing 38 which is fixed to

  the body 12 of the vehicle on the upright 16.

  The hollow housing 38 is crossed transversely by the pivot 36 determining the axis of articulation A1 and by a tubular pivot 50, for example made integrally with the housing 38, and which determines a geometric axis A3 parallel to

axis A1.

  The sleeve 36 of axis A1 serves as a guide in rotation to the sleeve 34 and it is linked in rotation, by welds 44 and 46, on the one hand to a wing 51 of the yoke 35, and, on the other hand, to

clevis 35.

  A toothed sector 52 produced, in the form of a plate in the form of an angular sector, is fixed by welding to the wing 51,

  under the latter, considering FIG. 7, of the yoke 35.

  It extends in a plane perpendicular to the axes A1 and A3 and its circular peripheral edge 54 has teeth 56 As can be seen in Figures 1 and 7, a toothed sector 58 is rotatably mounted around the pivot 50 and the axis A3 and it is produced in the form of a plate, which extends in the same plane as the toothed sector 52, substantially in the form of an angular sector and whose circular peripheral edge 60 comprises teeth 62 capable of meshing with teeth

56 of the toothed sector 52.

  A balancing spiral spring 64 is interposed between the toothed sector 58 and the housing 38. To this end, the internal strand 66 of the spiral spring 64 is linked in rotation, by two flats, to a sleeve 68 made integrally with the toothed sector 58 and which is pivotally mounted on the pivot 50, while its outer strand 70 is fixed to the housing 38 by a tab 72 which takes

  pressing against a rod 74 of the housing 38.

  There is shown in Figure 3 in broken lines, a line D1 which connects the geometric axes A1 and A2 of articulation of the connecting rod 24, the angular position of the line D1 relative to the axis A1 being used for the establishment curves

shown in Figure 2.

  In the vicinity of its circular peripheral edge 54, au-

  beyond the end of the toothed sector section 56, the sector 52 comprises a cam profile 78 which is made integrally with the sector 52 and which is constituted by a section 80 of the edge 54 which extends the toothed section 56 beyond of the last tooth 156 while extending in a plane which is offset axially relative to the main general plane of the sector 52. The cam profile 78 is designed to cooperate with the external surface 77 of a roller 76 which is mounted to rotate on the

  toothed sector 58, around an axis A4 parallel to the axis A3.

  As can be seen in different figures, the axis A4 is eccentrically radially with respect to the axis A3 so that the roller 76 extends above the teeth 62 belonging to the toothed sector 58 and so that its external cylindrical surface 77 can cooperate, as will be explained below, with the cam profile 78 at the end of the mutual engagement race of the toothed sectors 52 and 58, the axis A4 being thus arranged in the vicinity of the end of the toothed section 62

from sector 58.

  Considering FIG. 7, the roller 76 is located above the upper face of the toothed sector 58, that is to say that it extends in the same plane as that in which the cam profile extends. 78 so that the surface 77 cooperates with this cam profile 78 during certain operating phases. We will now describe the functioning of the mechanism

  balancing, in particular with reference to FIGS. 3 to 7.

  In the extreme open position illustrated in FIG. 4, the resistive torque CR is positive and weak and the spiral spring 64 which is slightly banded exerts a small positive balancing torque CE via the toothed sector 58, 62 at which it is linked in rotation and which meshes with the toothed sector 52, 56 linked in rotation to the sleeve 34 to which is

applied the balancing torque.

  Starting from this fully open position and progressively closing the tailgate 22, the orientation rod D1, and therefore the toothed sector 52-56, pivots clockwise, considering FIG. 4, until reaching the intermediate position illustrated in FIGS. 5 and 0o 5A corresponding to the angle j of rotation of the line D1 around

of axis A1.

  In this position, the toothed sector 56 meshes with its last tooth 156 with a final tooth 162 for meshing the toothed sector 58. The clockwise rotation of the toothed sector 52 caused the rotation of the toothed sector counterclockwise 58 thus increasing, by winding effect, the bandage of the spiral spring 64 and therefore the value of the balancing torque applied by the latter to the leaf 22 so as to compensate for the significant resistant torque due to the mass of the leaf which , in the absence of the balancing mechanism, would tend to violently close the tailgate forcing the user to retain this downward movement, and this up to the angle i of rotation, the value of the resisting torque then decreasing gradually until at angle "j" due to the evolutionary profile

  teeth of the two toothed sectors.

  As can be seen in FIG. 5A, the teeth of the two toothed sectors approach the moment from which they will stop cooperating, that is to say that only the

  last tooth 156 still meshes with the last tooth 162.

  This balancing "relay" phenomenon is illustrated in the consecutive figures 5A to 5C in which it can be seen that, in FIG. 5B, the outer cylindrical profile 77 of the roller 76 comes for the first time into contact with the first section 80 of the profile cam 78 at a PC contact point when the

  teeth 156 and 162 have ceased their mutual engagement, i.e.

  say at the time when the point of contact S illustrated in FIG. 5B constitutes the last point of contact between the profiles in

  involute of circle of these teeth 156 and 162.

  In this relay point position illustrated in FIG. 5B, the teeth 156 and 162 have a point of contact, of

  same as the surface 77 of the roller 76 with the start of the profile 80.

  This means that the two contacts are made with orientations of the contact efforts which are different and which

  give the same balancing effort.

  The distances between the different centers are constant and identical so that the torque

  balancing at the relay point (Figure 5B) is the same,

  that is, there is no discontinuity in the value of

this couple.

  Beyond, as can be seen in FIG. 5C, there is no longer any meshing contact between the teeth 156 and 162 but it is only the roller 76 by its surface 62 which cooperates with the cam profile 78 to drive the A3 axis. From FIG. 5C, the relative rotational movement, that is to say the pivoting curve of the connecting rod will continue with rolling of the roller 76 on the cam profile 78 in order to allow the use of the end of the linear curve of the spiral spring 64 to obtain the under-balancing illustrated in FIG. 3 from point P2, the value of the balancing torque

  -30 CE being almost linear between 95 and 125.

  Cam profile 78 determines the value of the sub-

  balancing and the determination of this profile makes it possible to obtain a very high precision on the value of the balancing torque in order in particular to obtain the assistance desired for the user during the final phase of closing the rag with a view to the engagement of the locking mechanism thereof. During the reverse pivoting movement of the leaf 22 from its extreme closed position 22 'to its extreme open position illustrated in FIG. 1, the relative movements of the various components are carried out in the reverse order to those which come from 'be described previously.

Claims (18)

  1. Device (38) for articulating an opening (22) pivotally mounted on the structure of the body of a motor vehicle according to an angular pivoting stroke, in particular between a first extreme open position and a second extreme closed position, and of the type comprising means (64) for balancing the opening which apply to it a balancing torque (CE) which compensates for the resistant torque (CR) due to the mass of the opening, and which substantially compensate for the entire torque throughout its pivoting stroke, the value of the balancing torque passing through a maximum at a point (i) of the pivoting stroke, characterized in that, at the end of the closing stroke, the values of resistant (CR) and balancing (CE) torques are non-zero with the value of the resistant torque (CR) greater than the value of the torque balancing (CE).   2. Articulation device according to claim 1, characterized in that the balancing means comprise at least one balancing spiral spring (64), one end (72) of which is connected to the structure of the vehicle body (16 , 38) and the other end (66) of which is connected to a member   drive (52) linked in rotation to the opening.   3. A hinge device according to claim 2, characterized in that the opening (22) is pivotally mounted about a hinge pin (A1) carried by the structure of the body of the motor vehicle, in that the internal end (66) of the spiral spring is linked in rotation to a drive axis (68, 52, A3) carried in rotation by the structure of the body of the vehicle, and in that means are provided (56, 62) driving in rotation of the drive axis by the opening (22).   4. Articulation device according to claim 3,   characterized in that the axes of articulation (A1) and of driving   ment (A3) are parallel, and in that the rotary drive means comprise a first toothed sector (58, 62) linked in rotation to the drive axis (A3, 68) and a second toothed sector (52 , 56) linked in rotation to the opening which cooperate by meshing to form a gear which 1o ensures the driving in rotation of the drive axis on a first part of the pivoting stroke of the opening (22) which extends from one of the two extreme positions to an intermediate point (j) so as to apply to the opening a balancing torque (22) (CE) of generally increasing i5 value and greater than the resisting torque the along this first part.   5. A hinge device according to claim 4, characterized in that the teeth (56, 62) of each toothed sector (52, 58) are arranged on a primitive profile with variable radius to form a gear with variable gear ratio.   6. Articulation device according to one of claims   4 or 5, characterized in that the drive means comprise a drive mechanism by cam (78) and roller (76) which ensures the rotary drive of the drive axis over a second part of the stroke pivoting of the opening which extends from said intermediate point (j) to the other of the two extreme positions so as to apply to the opening a balancing torque (CE) -30o of decreasing and lower value to the resistive torque (CR) along this second part of the pivoting stroke of the opening (22).   7. Articulation device according to claim 6, characterized in that the roller (76) is carried by the first toothed sector (58, 62) and is eccentric relative to the articulation axis (A3) of this sector toothed, and in that it cooperates with a cam profile (78) formed on the second toothed sector (52, 56).   8. An articulation device according to claim 7, to characterized in that the roller (76) cooperates with the cam profile (78) after the last tooth (156) of the second toothed sector (52, 56) has finished cooperate with a final tooth (162) of the first toothed sector (58, 62) at the end of the first part of the pivoting stroke.   9. Articulation device according to one of claims   7 or 8, characterized in that the cam profile (78) comprises a substantially curvilinear section which extends from the last tooth (156) of the second toothed sector (52, 56) in a direction of generally tangential orientation compared to the drive axis.   10. Articulation device according to any one of   Claims 7 to 9, characterized in that the cam profile   (78) is made integrally with the second toothed sector (52, 56).   11. An articulation device according to claim 10, characterized in that the cam profile (78) is constituted by a non-toothed section of the edge (54) of the second toothed sector (52, 56) which extends in a plane axially offset from the plane in which the toothed section of said extends edge.   12. Articulation device according to claim 11, characterized in that the roller (76) extends in a plane offset axially relative to the plane of the toothed edge (60) of the first toothed sector (58, 62) which cooperates with the toothed edge of the second toothed sector (52, 56). 13. Articulation device according to any one of   previous claims, characterized in that the opening   (22) is articulated on the structure of the body of the motor vehicle by means of a mechanism with two parallel axes o of articulation (A1, A2) connected by a connecting rod articulation (24).   14. The articulation device according to claim 13 taken in combination with any one of   Claims 4 to 12, characterized in that the second sector   toothed (52, 56) is linked in rotation to one end (26) of the connecting rod (24) articulated on the structure of the vehicle body around one (A1) of the two axes of articulation which is carried by structure.   15. An articulation device according to claim 14, characterized in that the opening (22) is articulated on the structure of the vehicle body by means of an articulation mechanism comprising two parallel articulation connecting rods (24) , and in that one end of each of the connecting rods is   associated with a balancing spiral spring (64).   16. Articulation device according to any one of   previous claims, characterized in that the opening   (22) is a tailgate which, in the closed position (22 '), extends in a substantially vertical plane and which, in the open position, extends in a substantially horizontal plane above the vehicle.   17. A hinge device according to claim 16, cara; terized in that the tailgate (22) is formed by a panel masking a recess of a frame of the structure delimited by an upper crosspiece (18), by two lateral uprights (16) and by a lower crossmember (20), among which each lateral upright carries a hinge pin (A1) of said end (26) of a connecting rod (24) of the tailgate hinge (22), the other end is articulated on a hinge pin (A2) carried by the tailgate.   18. Hinge device according to one of the claims   cations 14 or 15, characterized in that a first end (26) of the connecting rod is articulated on the structure of the vehicle body around a first articulation axis (A1), in that the second end is articulated on the opening (22) around a second axis of articulation (A2), parallel to the first axis of articulation (A1), and in that there are provided means (30, 32) for controlling the pivoting movement of the opening (22), relative to the second end of the connecting rod, to the pivoting movement of the first end of the connecting rod (24), relative to the structure of the vehicle body (12, 16 ).