FR3141973A1 - Screwed assembly of motor vehicle structure - Google Patents

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 forcefully holding said first (10) and second (24) parts against each other. Said first part (10) has a V-shaped groove (12), while said second part (24) includes a tongue (30) having two opposing tongue edges (32, 34) inclined towards each other. And said tongue (30) is adapted to be engaged at a corner in said V-shaped groove (12) so as to maintain said parts (10, 24) in fixed position relative to each other. Figure to be published with the abstract: Fig. 3

Description

Screwed assembly of motor vehicle structure

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

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 using nuts.

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.

More precisely, the effort necessary for their relative movement according to the plane defined by the two components is equal to the product of the friction coefficient and the force applied perpendicularly to these two components.

In order to maintain a clamping force and consequently an axial tension in the threaded rod greater than a certain threshold, to maintain the two parts in a fixed position relative to each other over time, we usually use devices braking, for example to spring washers or even toothed washers. Furthermore, we tend to use relatively large clamping members to be able to obtain a sufficiently large axial tension.

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

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

For this purpose, and according to a first object, a screwed assembly of a motor vehicle structure is proposed comprising: a first part and a second part; a screwable clamping member for forcefully 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 at a corner in said V-shaped groove so as to maintain said parts in a fixed position relative to each other.

Thus, a characteristic 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 polyhedral element with five faces extending projecting from 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.

Indeed, when the tongue is engaged in the groove, the two opposite edges of the tongue respectively come into contact with the two opposite edges of the groove. And when the two parts are forced against each other thanks to the screwable clamping member, the tongue gets stuck in the groove as will be explained in more detail later in the description.

Thus, we understand that the second part and the first part are held in fixed position relative to each other in a direction perpendicular to the V-shaped groove and the tongue. And what's more, the two parts are held in a fixed position relative to each other in a perpendicular direction, i.e. in the direction defined by the tongue and by the V-shaped groove, thanks to the crossing of the tongue at the inside the V-groove.

In this way, the intensity of the forces to be exerted on the two parts, to cause them to move relative to each other, is much greater than that of those which must be exerted when the two parts have an interface plane. In other words, the risk of one of the parts sliding relative to the other is slight.

In addition, such a connection can be ensured with less tension in the screwable clamping member as will be explained below.

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 tongue, and said member screwable clamp comprises a threaded rod adapted to be engaged in the first and second holes.

Therefore, according to a first variant of execution, said first orifice is tapped, while said second orifice passes through said second part right through, and said screwable clamping member comprises a head at one of the ends of said threaded rod for come into contact with said second part, while said threaded rod engages in said first threaded orifice.

Thus, after the two parts have been applied against each other, while the tongue is engaged inside the V-shaped groove, and the first and second orifices are facing one of the Otherwise, we engage the threaded rod through the second orifice of the second part then we screw the threaded rod into the thread until the head of the threaded rod is applied against the second part. By forcefully screwing the threaded rod, we force the tongue into the V-shaped groove, which leads to the blocking of the second part and the first part relative to each other.

According to a second variant, the first orifice also passes through the first part right through 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 two parts are tightened against each other between the nut and the head of the screwable tightening member.

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 abut.

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

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 identical support of the two edges of the tongue against the two opposite edges of the groove.

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, we obtain perfect wedging of the tongue inside the V-shaped 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 at 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.

Thanks to this mode of implementation, it is possible to advantageously increase the length of the V-shaped groove and correlatively the length of the tongue. Therefore, the wedging of the tongue inside the V-shaped groove takes place over a greater distance and consequently, the intensity of the effort to be exerted on the two parts to be able to cause them to move one by one. compared to the other, is greatly increased. In other words, and this is the aim of such a method of implementation, the two parts are stationary relative to each other despite the efforts they undergo.

Advantageously, the two second orifices are oblong; and the first two holes are tapped.

Preferably, said V-shaped 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° to the flat bottom. In this last example, perfect cooperation with the tongue is obtained when the tongue edges are inclined at an angle of 15° relative to the median plane.

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. This results in a rigid connection between the two axle arms.

According to another object, in accordance with the invention, there is proposed a rear axle of a motor vehicle comprising: two longitudinal drawn arms symmetrical to each other relative to a median plane P, each of the drawn arms having a on the other 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 rocket support ; the second joints extending between the first joints, and said articulation axes being able to intersect at an intersection point 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 drawn from the side of its second articulation; a second flange extending towards the rear and having a first second end capable of extending in said median plane P and a second second end secured to the other arm drawn from the side of its second articulation; a connecting element extending in a substantially longitudinal direction and pivotally connecting said first first end and said first second end of said first and second flanges respectively; and in that one or the other of said arms has a groove, while one or the other of said second ends comprises a tongue to be able to form with said one or the other of said arms a screwed assembly as described above.

Other particularities and advantages of the invention will emerge on reading the description given below of particular embodiments of the invention, given for information but not limitation, with reference to the appended drawings in which:

is a partial schematic cross-sectional view of an element of the invention;

is a partial schematic cross-sectional view of another element of the invention;

is a schematic cross-sectional view of the two elements illustrated on the And cooperating with each other;

is a schematic view in longitudinal section of the two elements illustrated on the And cooperating with each other;

is a partial schematic top view of the V – V section shown on the ; And,

is a schematic top view of a rear axle of a motor vehicle including a screwed assembly according to the invention.

There partially shows, in straight transverse section, a first part 10 made of a metallic material, for example steel.

It has a V-shaped groove 12, made in a facing face 13 of the part 10, and extending longitudinally along the y axis of the mark (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.

The groove edges 14, 16 define an angle of approximately 110° with the flat bottom 18.

In addition, the part 10 has two threads, a first 20 and a second 22, provided 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.

The cutting plan of the is operated to the right of the first tapping 20.

There illustrates in straight transverse 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.

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.

It has a front face 36 and it is of isosceles trapezoidal section.

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

The tongue 30 has a thickness of between 20 mm and 30 mm and a width of between 40 mm and 80 mm.

Furthermore, the second part 24 has two orifices, a first orifice 38 and a second orifice 40, made at a distance from one another in the direction of the y axis. The two orifices 38, 40 are centered and they pass through the second part 24 right through, equidistant from the two opposite tongue edges 32, 34, emerging from the front face 36 of the tongue 30 and, on the opposite side, from the first side 26.

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

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.

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.

We will refer to the And showing, for the first in cross section, and for the second in longitudinal section, the two parts 10, 24 applied one on top of the other and, moreover, provided with two fixing screws 42, 44.

First of all, we will observe precisely on the that the tongue 30 of the second part 24 engages forming a corner in the groove 12 of the first part 10.

In other words, the two opposite tongue edges 32, 34 inclined towards each other are applied respectively against the two opposite groove edges 16, 14.

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 bears against the first face 26 of the second part 24.

An advantage of the invention is to authorize the relative movement in translation of the second part 24 relative to the first part 10 in the direction of the y axis, as long as the fixing screws 42, 44 are not tightened.

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

As we will observe on the And , 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.

Therefore, we understand 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 .

Thus, this adjustment is possible before tightening the fixing screws 42, 44. Indeed, before tightening, the tongue 30 can be driven to slide inside the V-shaped groove 12.

This possibility of sliding 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 relative to the median plane is greater than 10°

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. In this way, the screw heads 48 come to bear against the second part 24 , while the screw rods 46 penetrate further into the threads 20, 22.

Consequently, the tongue 30 is forcefully driven inside the groove 12 in the direction of the z axis. Thus, the two opposite tongue edges 32, 34 are first driven in friction against the two opposite groove edges 16, 14 respectively, then become blocked by jamming.

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

And such blocking 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, can not necessarily be high to obtain the required blocking of the two parts 10, 24 relative to each other.

Such a screwed assembly is advantageously used 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 link connecting the two flanges. One of the flanges, for example, has an end on which a tongue is machined, as described above, while a V-shaped groove is provided on the corresponding axle arm.

Two threads are then made in the bottom of the V-shaped 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 elongated holes and screwed into the two threads respectively.

We thus obtain a screwed 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 efforts that they can bear it.

We will refer to the illustrating the implementation of a screwed assembly according to the invention on a rear axle of a motor vehicle 50.

The rear axle 50 thus comprises two drawn arms, a left arm 52 and a right arm 54. They extend longitudinally along the axis at rest.

The drawn 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 rocket supports accommodating the wheels.

Also, the left arm 52 comprises a first left joint 64 located towards the outside of the rear axle and a second left joint 66 located towards the inside, while the right arm 54 comprises a first right joint 68 located towards the outside of the rear axle. rear axle and a second right joint 70 located towards the inside. The second joints 66, 70 are respectively secured 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.

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

In addition, the first straight joint 68 and the second right joint 70 are also mounted articulated on the body of the vehicle by defining a joint axis A2 which is also substantially transverse.

The second joints, left 66, right 70, extending between the first joints, left 64 and right 68. In addition, and at rest, the hinge axes A1 and A2 intersect at an intersection point belonging to the plane median P.

In addition, the rear axle 50 comprises, on the left, a first flange 72 extended towards the front and having a first first end 74 extending in said median plane P and, on the opposite side, a second first end 75 integral with it. of the left arm 52 and more precisely of the oblique arm 67.

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. Oppositely, it comprises a second second end 79 integral with it. of the right arm 54 and precisely of the oblique arm 71, in accordance with the invention.

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 each of its ends pivoting on the first ends 74, 78.

And according to a particular mode of implementation, the right arm 54 and the second flange 76 are connected together in an adjustable manner thanks to a screwed assembly, object of the invention.

Thus, the straight 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 one another are made in the bottom of the groove. Furthermore, the second second end 79 of the second flange 76 comprises a tongue according to the invention and adapted to be engaged at a corner in the V-shaped groove to be able to hold the second flange 76 in a fixed position on the right oblique arm 71 thanks to to the two screwable clamping members 42', 44'.

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 (10)

Screwed assembly of motor vehicle structure comprising:
- a first part (10) and a second part (24);
- a screwable clamping member (42, 44) to forcefully hold 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. 'other ;
and in that said tongue (30) is adapted to be engaged at a corner in said V-shaped groove (12) so as to maintain said parts (10, 24) in fixed position relative to each other. 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 a 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) holes. Screwed assembly according to claim 2, characterized in that said first orifice (20, 22) is tapped, while said second orifice (38, 40) passes through said second part (24) right through, and in that said member screwable clamp (42, 44) comprises a head (48) at one of the ends 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 hole (20, 22). Screwed assembly according to claim 2 or 3, characterized in that said second orifice (38, 40) is oblong. Screwed assembly according to any one of claims 1 to 4, characterized in that said tongue (30) has an isosceles trapezoidal cross section. 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). 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 at 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. 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 inclined respectively at an angle greater than 100° relative to said bottom flat (18). 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 has a second axle arm. Rear axle (50) of a motor vehicle comprising:
- two longitudinal drawn arms (52, 54) symmetrical to each other with respect to a median plane P, each of the drawn 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 vehicle body by defining a substantially transverse articulation axis (A1, A2), and on the other hand an opposite rear end ( 60, 62) at said front end and comprising a rocket support; the second joints (66, 70) extending between the first joints (64, 68), and said articulation axes (A1, A2) being able to intersect at an intersection point belonging to said median plane P;
- a first flange (72) extending towards the front and having a first first end (74) capable of extending in said median plane P and a second first end (75) secured to one of the drawn arms ( 52) on the side of its second articulation (66);
- a second flange (76) extending towards the rear and having a first second end (78) capable of extending in said median plane P and a second second end (79) secured to the other (54) arm pulled from the side of its second joint (70);
- a connecting element (80) extending in a substantially longitudinal direction and pivotally connecting said first first end (74) and said first second end (78) of said first (72) and second (76) flanges respectively;
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 tongue to be able to form with said a or the other of said arms a screwed assembly according to any one of claims 1 to 9.