Screwed assembly of a motor vehicle structure

Abstract

The present invention relates to a screwed assembly of a motor vehicle structure comprising: a first part (10) and a second part (24); a screwable clamping member (42) for forcibly holding the first (10) and second (24) parts together. The first part (10) has a V-shaped groove (12), while the second part (24) comprises a tab (30) having two opposite tab edges (32, 34) that are inclined towards one another. Moreover, the tab (30) is designed to be wedge-engaged in the V-shaped groove (12) so as to hold the parts (10, 24) in a fixed position relative to one another.

Description

[0001] Title of the invention: Screwed assembly of a motor vehicle structure

[0002] [The present invention relates to a screwed assembly of a motor vehicle structure.

[0003] It is known to join two parts together by drilling them and inserting a threaded rod through their holes to be able to press them against each other by means of nuts.

[0004] Thus, the two parts define an interface extending along two components and a coefficient of friction between the two parts. Therefore, the two parts are held in a fixed position relative to each other depending on the clamping force applied perpendicular to the interface.

[0005] More precisely, the force required for their relative movement along the plane defined by the two components is equal to the product of the coefficient of friction and the force applied perpendicular to these two components.

[0006] In order to maintain a clamping force and therefore an axial tension in the threaded rod above a certain threshold, to keep the two parts in a fixed position relative to each other over time, braking devices are usually used, for example elastic washers or toothed washers. Furthermore, there is a tendency to use relatively large clamping members to obtain a sufficiently high axial tension.

[0007] However, motor vehicles are by nature subject to vibratory movements, which tend to cause the loosening of screwed assemblies, despite braking devices.

[0008] Also, a problem which arises and which the present invention aims to solve is to provide a screwed assembly of a motor vehicle structure whose two parts applied against each other remain in a fixed position relative to each other, over time and despite vibratory movements.

[0009] For this purpose, and according to a first object, there is proposed a screwed assembly of a motor vehicle structure comprising: a first part and a second part; a screwable clamping member for forcibly holding said first and second parts against each other. Also, said first part has a V-shaped groove, while said second part comprises a tongue having two opposite tongue edges inclined towards each other; and said tongue is adapted to be engaged in a wedge in said V-shaped groove so as to hold said parts in a fixed position relative to each other.

[0010] Thus, a feature of the invention lies in the production of a V-shaped groove in the first part and in the implementation of a tongue on the second part. The tongue is a five-sided polyhedral element extending out of the second part, and it has two opposite faces forming edges. The two edges are then inclined towards each other so as to be able to cooperate with the V-shaped groove.

[0011] Indeed, when the tongue is engaged in the groove, the two opposite edges of the tongue come into contact respectively against the two opposite edges of the groove. And when the two parts are forced against each other using the screw-on clamping member, the tongue gets stuck in the groove as will be explained in more detail later in the description.

[0012] Thus, it is understood that the second part and the first part are held in a fixed position relative to each other in a direction perpendicular to the V-groove and the tongue. And furthermore, the two parts are held in a fixed position relative to each other in a perpendicular direction, that is, in the direction defined by the tongue and the V-groove, thanks to the crossing of the tongue inside the V-groove.

[0013] In this way, the intensity of the forces required to be exerted on the two parts to move them relative to each other is much greater than that required when the two parts have a flat interface. In other words, the risk of one of the parts slipping relative to the other is minimal.

[0014] Furthermore, such a connection can be ensured with less tension in the screw-on clamping member as will be explained below.

[0015] According to a particularly advantageous implementation characteristic of the invention, said first part has at least one first orifice opening into the bottom of said groove, while said second part has at least one second orifice opening into said tab, and said screwable clamping member comprises a threaded rod adapted to be engaged in the first and second orifices.

[0016] Therefore, according to a first variant embodiment, said first orifice is threaded, while said second orifice passes right through said second part, and said screwable clamping member comprises a head at one of the ends of said threaded rod to come into contact with said second part, while said threaded rod is engaged in said first threaded orifice.

[0017] Thus, after the two parts have been applied against each other, while the tongue is engaged inside the V-groove, and the first and second holes are opposite each other, the threaded rod is inserted through the second hole of the second part and then the threaded rod is screwed into the tapping until the head of the threaded rod is applied against the second part. By forcing the threaded rod, the tongue is also forced into the V-groove, which leads to the locking of the second part and the first part relative to each other.

[0018] According to a second variant, the first orifice also passes right through the first part and the threaded rod is engaged through the two parts so as to be able to engage the other end of the threaded rod in a nut. The tightening of the two parts against each other is carried out between the nut and the head of the screwable clamping member.

[0019] Preferably, said second orifice is oblong. In this way, the second part can be pre-adjusted against the first part before the final tightening of the two parts against each other. The freedom of adjustment of the two parts relative to each other is exercised in a direction parallel to the groove and the tongue. Its amplitude is limited by the two opposite ends of the oblong orifice against which the threaded rod can come into abutment.

[0020] According to a particularly advantageous characteristic of the invention, said tongue has an isosceles trapezoidal cross-section.

[0021] Thus, as will be explained below, the tongue defines a median plane and its two opposite edges are inclined at the same angle relative to the median plane. This allows for identical support of the two edges of the tongue against the two opposite edges of the groove.

[0022] And according to a particularly advantageous embodiment, said tongue edges are inclined at an angle greater than 10° relative to the median plane defined by said tongue. The tongue edges are for example inclined at an angle of 15° relative to the median plane. In this way, perfect wedging of the tongue is obtained inside the V-groove. According to a preferred embodiment of the invention, said first part has two first orifices spaced from each other by a given distance and opening into the bottom of said groove, while said second part has two second orifices spaced from said given distance and opening into said tongue, and said screwable clamping member comprises two threaded rods adapted to be engaged respectively in the two first and two second orifices.

[0023] Thanks to this method of implementation, it is advantageous to increase the length of the V-groove and correspondingly the length of the tongue. Therefore, the tongue is jammed inside the V-groove over a greater distance and consequently, the intensity of the force to be exerted on the two parts to be able to drive them in movement relative to each other is greatly increased. In other words, and this is the aim of such a method of implementation, the two parts are immobile relative to each other despite the forces they undergo. Advantageously, the two second orifices are oblong; and the two first orifices are tapped.

[0024] Preferably, said V-groove has a flat bottom and two groove edges respectively inclined at an angle greater than 100° relative to said flat bottom. For example, the groove edges are inclined at an angle of 105° relative to the flat bottom. In this latter example, perfect cooperation with the tongue is obtained when the tongue edges are inclined at an angle of 15° relative to the median plane.

[0025] According to a particularly advantageous embodiment of the invention, said first part is a portion of a first axle arm, while said second part is a connecting flange for connecting said first axle arm to a second axle arm. In this way, a rigid connection is obtained between the two axle arms. According to another object, in accordance with the invention, there is provided a rear axle of a motor vehicle comprising: two longitudinal trailing arms symmetrical to each other with respect to a median plane P, each of the trailing arms having on the one hand a front end comprising a first articulation and a second articulation intended to be connected to the body of the vehicle by defining a substantially transverse articulation axis, and on the other hand a rear end opposite said front end and comprising a spindle support;the second articulations extending between the first articulations, and said articulation axes being able to intersect at a point of intersection belonging to said median plane P; a first flange extending forward and having a first first end capable of extending in said median plane P and a second first end secured to one of the arms pulled on the side of its second articulation; a second flange extending rearward and having a first second end capable of extending in said median plane P and a second second end secured to the other arm pulled on the side of its second articulation; a connecting element extending in a substantially longitudinal direction and respectively pivotally connecting said first first end and said first second end of said first and second flanges;and in that one or other of said arms has a groove, while one or other of said second ends comprises a tab to be able to form with said one or other of said arms a screwed assembly as described above.;

[0026] Other features and advantages of the invention will emerge from reading the description given below of particular embodiments of the invention, given for informational but non-limiting purposes, with reference to the appended drawings in which:

[0027] [Fig. 1] is a partial schematic cross-sectional view of an element of the invention;

[0028] [Fig. 2] is a partial schematic cross-sectional view of another element of the invention;

[0029] [Fig. 3] is a schematic cross-sectional view of the two elements illustrated in [Fig. 1] and [Fig. 2] cooperating with each other;

[0030] [Fig. 4] is a schematic longitudinal sectional view of the two elements illustrated in [Fig. 1] and [Fig. 2] cooperating with each other;

[0031] [Fig. 5] is a partial schematic top view of the section V - V illustrated in [Fig.4]; and,

[0032] [Fig. 6] is a schematic top view of a rear axle of a motor vehicle including a screwed assembly according to the invention.

[0033] [Fig. 1] partially shows, in cross-section, a first part 10 made of a metallic material, for example steel.

[0034] It has a V-shaped groove 12, made in an application face 13 of the part 10, and extending longitudinally along the y axis of the reference (x, y, z). The V-shaped groove 12 defines two opposite groove edges 14, 16 and a flat bottom 18. Its depth is for example between 20 mm and 30 mm, while its width is between 40 mm and 80 mm.

[0035] The groove edges 14, 16 define an angle of substantially 110° with the flat bottom 18.

[0036] In addition, the part 10 has two threads, a first 20 and a second 22, arranged at a distance from each other along the y axis, in the flat bottom 18 of the V-shaped groove 12 and substantially equidistant from the two opposite groove edges 14, 16.

[0037] The section plane of [Fig. 1] is made at the right of the first tapping 20.

[0038] [Fig. 2] illustrates in cross-section a second part 24 adapted to cooperate with the first part 10 to be integral with it, as will be explained in the remainder of the description.

[0039] The second part 24 has a first face 26 opposite a second face 28. And the second part 24 has a tongue 30 which extends projecting from the second face 28. The tongue 30 extends longitudinally in the direction y and it has two opposite tongue edges 32, 34 inclined towards each other.

[0040] It has a 36 front face and is of isosceles trapezoidal section.

[0041] Also, the two tongue edges 32, 34 form an angle, close to 250° relative to the front face 36.

[0042] The tab 30 has a thickness of between 20 mm and 30 mm and a width of between 40 mm and 80 mm.

[0043] Furthermore, the second part 24 has two orifices, a first orifice 38 and a second orifice 40, made at a distance from each other in the direction of the y axis. The two orifices 38, 40 are centered and they pass through the second part 24 from one side to the other at an equal distance from the two opposite tongue edges 32, 34, emerging from the front face 36 of the tongue 30 and, opposite, from the first face 26.

[0044] The two orifices 38, 40 are oblong and they extend in the direction of the y axis.

[0045] Also, the two oblong orifices 38, 40 are spaced from each other by a distance equal to the distance separating the two threads 20, 22 made in the first part 10.

[0046] Thus, the second part 24 is applied to the first part 10, so as to engage the tongue 30 inside the groove 12, the two oblong orifices 38, 40 coming respectively opposite the two threads 20, 22. Reference will be made to [Fig. 3] and [Fig. 4] showing, for the first in cross section, and for the second in longitudinal section, the two parts 10, 24 applied one on the other and, moreover, provided with two fixing screws 42, 44.

[0047] First of all, it will be observed precisely in [Fig. 3] that the tongue 30 of the second part 24 engages, forming a wedge, in the groove 12 of the first part 10.

[0048] In other words, the two opposite tongue edges 32, 34 inclined towards each other come to bear respectively against the two opposite groove edges 16, 14.

[0049] The two fixing screws 42, 44 each have a threaded rod 46 and a head 48 at the end of the threaded rod 46. Also, the two fixing screws 42, 44 are engaged through the two oblong orifices 38, 40 and screwed into the two threads 20, 22, while the head 48 of the fixing screws 42, 44 comes to bear against the first face 26 of the second part 24.

[0050] An advantage of the invention is to allow the relative translational movement of the second part 24 with respect to the first part 10 in the direction of the y axis, as long as the fixing screws 42, 44 are not tightened.

[0051] This possibility is offered thanks to the two oblong orifices 38, 40, which allow this relative movement of the second part 24 with respect to the first part 10.

[0052] As will be observed in [Fig. 4] and [Fig. 5], the length L of the oblong orifices 38, 40 is substantially greater than or equal to twice the diameter D of the threaded rods 46.

[0053] Therefore, it is understood that the amplitude of adjustment of the second part 24 relative to the first part 10, in the direction of the y axis, is substantially equal to the diameter of the threaded rod 46 of the fixing screws 42, 44.

[0054] Thus, this adjustment is possible before tightening the fixing screws 42, 44. Indeed, before tightening, the tongue 30 can be slid inside the V-groove 12.

[0055] This sliding possibility is easier if the angle formed by the groove edges 16, 14 with the flat bottom 48 is greater than 100°, while the angle formed by the tongue edges 32, 34 with respect to the median plane is greater than 10°.

[0056] When the relative adjustment of the second part 24 with respect to the first part 10 is achieved, the fixing screws 42, 44 are tightened. As a result, the screw heads 48 come to bear against the second part 24, while the screw rods 46 penetrate further into the threads 20, 22.

[0057] As a result, the tongue 30 is forcibly driven into the groove 12 in the direction of the z-axis. Thus, the two opposite tongue edges 32, 34 are first frictionally driven against the two opposite groove edges 16, 14 respectively, and then lock by wedging.

[0058] In this way, the two parts 10, 24 are locked relative to each other in translation along the direction of the y axis. They are obviously also locked in translation along the other two directions x and z.

[0059] And such locking can be obtained without it being necessary to apply significant tightening to the two fixing screws 42, 44. In other words, the axial tension in the fixing screws 42, 44, i.e. in the z direction, may not necessarily be high to obtain the required locking of the two parts 10, 24 relative to each other.

[0060] Such a screwed assembly is advantageously implemented to connect together two opposite axle arms of a rear axle of a motor vehicle. The two axle arms are then connected together mechanically by means of two flanges and a connecting rod connecting the two flanges. One of the flanges, for example, has one end on which a tongue is machined, as described above, while a V-groove is provided on the corresponding axle arm.

[0061] Two threads are then made in the bottom of the V-groove, while two oblong holes are provided at the end of the flange. The end of the flange is applied to the axle arm, while two fixing screws are engaged through the oblong holes and screwed into the two threads respectively.

[0062] This results in a bolted assembly in which the flange and the axle arm remain in a fixed position relative to each other throughout the life of the motor vehicle, despite the significant forces they can withstand.

[0063] Reference will be made to [Fig. 6] illustrating the implementation of a screwed assembly in accordance with the invention on a rear axle of a motor vehicle 50.

[0064] The rear axle 50 thus comprises two trailing arms, a left arm 52 and a right arm 54. They extend longitudinally along the axis X and symmetrically to each other with respect to a median plane P when they are at rest. The trailing arms 52, 54 have two front ends, a left front end 56 and a right front end 58, respectively opposite two rear ends, a left rear end 60 and a right rear end 62. The rear ends 60, 62 comprise spindle supports receiving the wheels.

[0065] Also, the left arm 52 comprises a first left articulation 64 located towards the outside of the rear axle and a second left articulation 66 located towards the inside, while the right arm 54 comprises a first right articulation 68 located towards the outside of the rear axle and a second right articulation 70 located towards the inside. The second articulations 66, 70 are secured respectively to two oblique arms, a left oblique arm 67 and a right oblique arm 71, extending obliquely from the arms 52, 54 towards the median plane P.

[0066] The first left articulation 64 and the second left articulation 66 are mounted articulated on the body of the motor vehicle by defining an articulation axis A1 extending substantially transversely.

[0067] Furthermore, the first right articulation 68 and the second right articulation 70 are also mounted articulated on the body of the vehicle by defining a substantially transverse articulation axis A2 as well.

[0068] The second joints, left 66, right 70, extend between the first joints, left 64 and right 68. Furthermore, and at rest, the articulation axes A1 and A2 intersect at a point of intersection belonging to the median plane P.

[0069] Furthermore, the rear axle 50 comprises, on the left, a first flange 72 extending forward and having a first first end 74 extending in said median plane P and, on the opposite side, a second first end 75 secured to the left arm 52 and more precisely to the oblique arm 67.

[0070] The rear axle 50 comprises, on the right, a second flange 76 extending towards the rear and having a first second end 78 extending in the median plane P. On the opposite side, it comprises a second second end 79 secured to the right arm 54 and precisely to the oblique arm 71, in accordance with the invention.

[0071] The first first end 74 and the first second end 78 of the first 72 and second 76 flanges are then connected by a connecting element 80 extending substantially in the longitudinal direction X in the median plane P. The connecting element is mounted at each of its ends to pivot on the first ends 74, 78. And according to a particular embodiment, the right arm 54 and the second flange 76 are connected together in an adjustable manner by means of a screwed assembly, the subject of the invention.

[0072] Thus, the right arm 54, and more precisely the right oblique arm 71, has a longitudinal V-shaped groove, masked by the second second end 79. Two threads spaced from each other are made in the bottom of the groove. In addition, the second second end 79 of the second flange 76 comprises a tongue according to the invention and adapted to be engaged in a wedge in the V-shaped groove in order to be able to hold the second flange 76 in a fixed position on the right oblique arm 71 thanks to the two screwable clamping members 42', 44'.

[0073] The advantage of such an assembly lies in the possibility of adjusting the relative position of the second flange 76 and the right oblique arm 71 prior to their immobilization in a fixed position.

Claims

CLAIMS

1. [Bolt assembly of motor vehicle structure comprising: - a first part (10) and a second part (24); - a screwable clamping member (42, 44) for forcibly holding said first (10) and second (24) parts against each other; characterized in that said first part (10) has a V-shaped groove (12), while said second part (24) comprises a tongue (30) having two opposite tongue edges (32, 34) inclined towards each other; and in that said tongue (30) is adapted to be engaged in a wedge in said V-shaped groove (12) so as to hold said parts (10, 24) in a fixed position relative to each other.

2. Screwed assembly according to claim 1, characterized in that said first part (10) has at least one first orifice (20, 22) opening into the bottom (18) of said groove, while said second part (24) has at least one second orifice (38, 40) opening into said tongue (30), and in that said screwable clamping member (42, 44) comprises a threaded rod (46) adapted to be engaged in the first (20) and second (38) orifices.

3. A screwed assembly according to claim 2, characterized in that said first orifice (20, 22) is threaded, while said second orifice (38, 40) passes right through said second part (24), and in that said screwable clamping member (42, 44) comprises a head (48) at one end of said threaded rod (46) to come into contact with said second part (24), while said threaded rod (46) is engaged in said first threaded orifice (20, 22).

4. Screwed assembly according to claim 2 or 3, characterized in that said second orifice (38, 40) is oblong.

5. Screwed assembly according to any one of claims 1 to 4, characterized in that said tongue (30) has an isosceles trapezoidal cross section.

6. Screwed assembly according to claim 5, characterized in that said tongue edges (32, 34) are inclined at an angle greater than 10° relative to the median plane defined by said tongue (30).

7. Screwed assembly according to any one of claims 1 to 6, characterized in that said first part (10) has two first orifices (20, 22) spaced from each other by a given distance and opening into the bottom of said groove (18), while said second part (24) has two second orifices (38, 40) spaced by said given distance and opening into said tongue (30), and in that said screwable clamping member (42, 44) comprises two threaded rods (46) adapted to be engaged respectively in the two first and two second orifices.

8. Screwed assembly according to any one of claims 1 to 7, characterized in that said V-shaped groove (12) has a flat bottom (18) and two groove edges respectively inclined at an angle greater than 100° relative to said flat bottom (18).

9. A screwed assembly according to any one of claims 1 to 8, characterized in that said first part (10) is a portion of a first axle arm, while said second part (24) is a connecting flange for connecting said first axle arm to a second axle arm.

10. Rear axle (50) of a motor vehicle comprising: - two longitudinal trailing arms (52, 54) symmetrical to each other with respect to a median plane P, each of the trailing arms (52, 54) having on the one hand a front end (56, 58) comprising a first articulation (64; 68) and a second articulation (66, 70) intended to be connected to the body of the vehicle by defining a substantially transverse articulation axis (A1, A2), and on the other hand a rear end opposite (60, 62) to said front end and comprising a spindle support; the second articulations (66, 70) extending between the first articulations (64, 68), and said articulation axes (A1, A2) being able to intersect at a point of intersection belonging to said median plane P; - a first flange (72) extending forward and having a first first end (74) capable of extending in said median plane P and a second first end (75) integral with one of the pulled arms (52) on the side of its second articulation (66); - a second flange (76) extending rearwardly and having a first second end (78) capable of extending in said median plane P and a second second end (79) integral with the other (54) arm pulled on the side of its second articulation (70); - a connecting element (80) extending in a substantially longitudinal direction and respectively pivotally connecting said first first end (74) and said first second end (78) of said first (72) and second (76) flanges; and in that one (52) or the other (54) of said arms has a groove, while one (75) or the other (79) of said second ends comprises a tab to be able to form with said one or the other of said arms a screwed assembly according to any one of claims 1 to 9.

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