Motor vehicle suspension stop

Abstract

The invention relates to a suspension bump stop for a motor vehicle, comprising an upper cup (2) and a lower cup (3) forming a relative rotation interface between them, said lower cup having a lower bearing wall (4) against which a suspension spring (1) is intended to bear, said bearing wall having an annular bearing surface (4a) extending along a radial dimension, the bearing wall (4) having a wall (6) which extends axially in projection from the radial bearing surface (4a) over a height H, said radial bearing surface having at least one set of three bosses (7a) distributed angularly and which extend in axial projection over a height h which is less than the height H. Figure 1

Description

Title of the invention: Motor vehicle suspension stop

[0001] The invention relates to a motor vehicle suspension stop, in particular intended to be integrated into a telescopic suspension leg of a steering wheel of a motor vehicle, as well as a motor vehicle suspension leg comprising such a stop.

[0002] The invention applies in particular to a suspension stop comprising a fixed upper cup intended to be associated with the vehicle body and a rotating lower cup having a support for the suspension spring, said cups forming with each other an interface of relative rotation around an axis.

[0003] In particular, the lower cup has a lower wall having an annular bearing surface which extends substantially radially, and on which the upper coil of the suspension spring is supported to drive the lower cup in rotation according to the driving conditions.

[0004] The problem that arises is that the support between the spring and the lower cup then depends on the geometry of the spring, and in particular on that of the free end of its upper coil which is difficult to control insofar as it is obtained by cutting.

[0005] In particular, in the case where the free end is arranged in a superior projection relative to the continuity of the upper coil, the support can be made essentially at a single point at the level of said free end, which leads to a poor balance of the support of the spring.

[0006] Such an imbalance of support causes in particular a misalignment of the cups, which can eventually lead to malfunctions (rotation, noise...), or even premature wear of the thrust bearing.

[0007] The invention aims to improve the prior art by proposing in particular a suspension stop in which the lower cup is arranged to improve the balance of the support of the suspension spring on it, in order to guarantee proper functioning of said stop.

[0008] To this end, according to a first aspect, the invention proposes a suspension bump stop for a motor vehicle, said bump stop comprising an upper cup and a lower cup forming between them an interface for the relative rotation of said cups around an axis, said lower cup having a lower bearing wall on which a suspension spring is intended to bear, said bearing wall having an annular span extending along a radial dimension, the bearing wall having a wall which extends axially in projection from the radial span over a height H, said radial span having at least a set of three bosses distributed angularly and extending axially over a height h which is less than the height H.

[0009] According to a second aspect, the invention proposes a motor vehicle suspension leg comprising such a suspension stop and a suspension spring having an upper coil with a free end, said coil being arranged in axial support on the bosses of a radial bearing space and the free end of the coil being in angular contact with the axial wall.

[0010] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying figures, in which:

[0011] [Fig-1] represents in perspective the upper end of a suspension leg according to the invention, showing a suspension spring arranged in support under the lower cup of a stop;

[0012] [Fig.2] represents in perspective view from below the lower cup of the stop suspension of the [Fig.l];

[0013] [Fig.3] represents in perspective, viewed from below, a suspension stop according to a another embodiment of the invention,

[0014] [Fig.3a] partially showing in cross-section a portion of the overmolding of the element filtration on the support wall of the lower cup of said stop, centered on a boss of said support wall;

[0015] [Fig.4a] and

[0016] [Fig.4b] each represent, in perspective seen from below and along different angular arrangements, the lower cup of a suspension stop according to another embodiment of the invention.

[0017] In relation to these figures, a suspension stop is described below, in particular intended to be integrated into a suspension leg of a motor vehicle, for example a telescopic leg of a steering wheel of said motor vehicle.

[0018] A suspension leg conventionally comprises a shock absorber, a suspension spring 1, and a suspension stop on which the spring 1 rests, a wheel of the motor vehicle being mounted on the chassis by means of such a leg which allows the suspension of the body relative to the ground.

[0019] The suspension stop comprises a fixed upper cup 2 intended to be associated with the vehicle body, in particular via a filter block, and a rotating lower cup 3, said cups forming with each other an interface of relative rotation around an axis A.

[0020] In this description, the terms for positioning in space are taken with reference to the axis A of rotation of the suspension stop (vertical in [Fig. 1]). In particular: - the terms "interior" and "exterior" are relative to a disposition respectively close to and at a distance from this axis A; - the terms "axial" and "radial" are relative to an arrangement respectively along this axis A and moving away from or towards it.

[0021] Furthermore, the terms "upper" or "above" and "lower" or "below" are relative to the arrangement of the stop as shown in [Fig. 1].

[0022] In a known manner, the rotation interface may include rolling bodies which are arranged between the cups 2, 3 in order to allow their relative rotation around the axis A. To do this, the upper cups 2 and lower cups 3 may each include a washer, in particular made of stamped sheet metal, forming between them the rotation interface, each of said washers being provided with a lower and upper raceway respectively between which the rolling bodies are arranged.

[0023] Alternatively, the cups 2, 3 can be mounted in relative rotation in a smooth manner, with or without the interposition of a friction washer in the rotation interface.

[0024] The lower cup 3 has a lower support wall 4, against which the suspension spring 1 is intended to bear. In particular, as shown in [Fig. 1], the spring 1 comprises an upper coil la which bears axially against the lower wall 4.

[0025] Thus, when the spring 1 is subjected to compression and expansion, the winding of the coils of the latter is modified, which causes the rotation of the lower cup 3. In addition, the steering of the wheels also induces a rotation of the lower cup 3.

[0026] The cups 2, 3 allow, in particular, for the absorption of the forces from the spring 1 and possibly those from the shock absorber. For this purpose, the cups 2, 3 are made of a sufficiently rigid material, in particular a thermoplastic material, for example of the polyamide type, preferably polyamide 6.6, possibly reinforced with glass fibers.

[0027] Advantageously, the cups 2, 3 can be made by molding, in particular in thermoplastic material as described above, in order to facilitate their manufacture, and thus reduce the overall production costs of the suspension stop.

[0028] In relation to the figures, the lower cup 3 has an axial sleeve 5 around which the upper coil la of the spring 1 is wound, the support wall 4 having an annular bearing surface 4a which extends externally in a radial direction, and against the axial face of which said upper coil comes to rest.

[0029] In particular, the support wall 4 has an internal curved span 4b connecting the sleeve 5 to the external radial span 4a, said internal span preferably having a radius of curvature substantially equal to the radius of curvature of the upper loop la, in order to allow said loop to conform to said inner span when winding around the sleeve 5.

[0030] To ensure optimal support of the upper coil on it, the support wall 4 has a wall 6 which extends axially in projection from the radial span 4a over a height H, and on which a free end 1b of said coil comes to angular stop when the spring 1 is mounted under the lower cup 3.

[0031] This arrangement allows the upper coil to be secured against the support wall 4, limiting the risk of unintentional movement of its free end 1b. Thus, the risk of damage to the support wall 4 by the free end 1b of the spring 1 during the relative movements of the cups 2, 3 is avoided.

[0032] In particular, the wall 6 can have any geometric shape that can accommodate the end 1b of the spring 1, with sufficient dimensioning to support the maximum forces expected in operation.

[0033] The radial span 4a further presents at least one set of three bosses 7a, 7b which are distributed angularly on said radial span, extending axially over a height h which is less than the height H of the wall 6.

[0034] These bosses 7a, 7b form three points of contact on each of which the upper coil of a spring 1 is intended to come into axial contact when the said spring is mounted under the lower cup 3, which guarantees a good balance of said support, and thus a good alignment of the cups 2, 3 to ensure optimal operation of the stop.

[0035] Advantageously, the bosses 7a, 7b are arranged, both by their geometry, their arrangement and / or their angular distribution on the radial span 4a, so that the free end 1b of the coil la is not in support on said radial span, in order to avoid the dependence of the support of the spring on the geometry of said free end.

[0036] To achieve this, in the embodiments shown, each set includes in particular a boss 7a', 7b' which is disposed at an angular distance from the wall 6 which is less than 10°, and in particular less than 5°, so that the upper spiral comes to bear axially on said boss near its free end 1b which is angularly abutted against said wall.

[0037] Each set of bosses 7a, 7b extends over the radial span 4a over a sufficiently large angular range to ensure a balanced distribution of the axial supports of the spiral la, said angular range being in particular between 200° and 260°. For the same reasons, the bosses 7a, 7b are equally distributed angularly over the radial span 4a.

[0038] In Figures 2 and 3, the radial span 4a comprises a single set of three bosses 7a which extend over said radial span along an angular range on the order of 240°, the median zones of two adjacent bosses 7a being separated by an angular distance of the order of 100°.

[0039] In figures 4a and 4b, the radial span 4a has two sets of three bosses 7a, 7b which extend angularly respectively on either side of the axial wall 6, each following an angular range of the order of 225°, the median areas of two adjacent bosses 7a, 7b of the same set being spaced by an angular distance of the order of 72.5°.

[0040] The arrangement of figures 4a and 4b provides a lower cup 3 which is adapted for mounting springs 1 having different winding directions of their coils la. Thus, depending on the laterality of the winding of a spring 1 (left or right), the upper coil la of said spring will be positioned to bear against one or the other of the sets of bosses 7a, 7b.

[0041] In particular, the bosses 7a, 7b of the two sets are distributed symmetrically on either side of the axial wall 6, and each of said sets includes a boss 7a”, 7b” diametrically opposite said wall.

[0042] To improve the axial support of the spiral on them, each boss 7a, 7b extends angularly along a length L of significant dimension, in particular greater than its height h, in particular at least 5 times greater.

[0043] In particular, in figures 4a and 4b, the bosses 7a”, 7b” diametrically opposed to the wall 6 are joined angularly to form a common boss 8 which extends angularly along a length L doubled with respect to the length L of the individual bosses 7a, 7b.

[0044] Advantageously, the individual bosses 7a, 7b each extend angularly along a length L of the order of 25°, the common boss 8 extending along a length L of the order of 50°.

[0045] Furthermore, each boss 7a, 7b, 8 has a lower surface 9 on which the upper coil la of the spring 1 is intended to come directly to rest, said lower surface being flat and extending radially.

[0046] In figures 3 and 3a, the support wall 4 is covered with a filtering element 10 which is made of a material more flexible than the material forming said wall, in particular an elastomer material of the TPU or TPE type, in order to filter the forces induced by the axial support of the spring 1.

[0047] In particular, the filtering element 10 comprises a crown 10a which is arranged on the radial bearing surface 4a to cover the bosses 7a, 7b, said crown having a thickness which is variable so as to present a flat lower surface 11 which extends radially.

[0048] In relation to [Fig.3a], the thickness e of the crown 10a on the bosses 7a, 7b is between 40% and 60% of the thickness E of said crown between said bosses.

[0049] This arrangement allows for less deformability at the level of the bosses, in order to concentrate the axial forces exerted by the support of the spring 1 at the level of said bosses.

[0050] The filtering element 10 further includes an axial skirt 10b intended to externally cover the sleeve 5 of the lower cup 3, as well as an intermediate ring 10c for connecting said axial skirt to the ring 10a for covering the bosses 7a, 7b, said intermediate ring having a curved geometry arranged to fit the span 4b for connecting the sleeve 5 to the bearing span 4a.

[0051] Advantageously, the filter element 10 is obtained by overmolding onto the lower cup 3, which makes it easier to manufacture.

Claims

Demands

1. Motor vehicle suspension stop, said stop comprising an upper cup (2) and a lower cup (3) forming between them an interface for relative rotation of said cups about an axis (A), said lower cup having a lower bearing wall (4) on which a suspension spring (1) is intended to bear, said bearing wall having an annular span (4a) extending along a radial dimension, said stop being characterized in that the bearing wall (4) has a wall (6) which extends axially in projection from the radial span (4a) over a height H, said radial span having at least one set of three bosses (7a, 7b) distributed angularly and which extend in axial projection over a height h which is less than the height H.

2. Suspension stop according to claim 1, characterized in that the set of bosses (7a, 7b) extends over the radial span (4a) over an angular range between 200° and 260°.

3. Suspension stop according to one of claims 1 or 2, characterized in that the bosses (7a, 7b) of a set are angularly equidistributed over the radial span (4a).

4. Suspension stop according to any one of claims 1 to 3, characterized in that each of the bosses (7a, 7b) extends angularly over a length L which is greater than its height h.

5. Suspension stop according to any one of claims 1 to 4, characterized in that each of the bosses (7a, 7b) has a flat lower surface (9) which extends radially.

6. Suspension stop according to any one of claims 1 to 5, characterized in that a boss (7a', 7b') is disposed at an angular distance D from the wall (6) which is less than 10°, in particular less than S°

7. d J. Suspension stop according to any one of claims 1 to 6, characterized in that the support wall (4) is covered with a filtering element (10) which is made from a material more flexible than the material forming said wall.

8. Suspension stop according to claim 7, characterized in that the filtering element (10) has a crown (10a) covering the bosses (7a, 7b), said crown having a variable thickness to present a flat lower surface (11) which extends radially.

9. Suspension stop according to any one of claims 7 or 8, characterized in that the filtering element (10) is made from an elastomeric material for example of the TPU or TPE type, the lower cup (3) being made from a thermoplastic material for example of the polyamide type, optionally filled with glass fibers.

10. Suspension stop according to any one of claims 7 to 9, characterized in that the lower cup (3) is obtained by molding, the filtering element (10) being overmolded onto said cup.

11. Suspension stop according to any one of claims 1 to 10, characterized in that the radial span (4a) has two sets of three bosses (7a, 7b) extending angularly respectively on either side of the axial wall (6).

12. Suspension stop according to claim 11, characterized in that the bosses (7a, 7b) are distributed symmetrically on either side of the axial wall (6).

13. Suspension stop according to any one of claims 11 or 12, characterized in that each of the sets comprises a boss (7a”, 7b”) diametrically opposite the wall (6), said bosses being joined to form a common boss (8) of doubled length L.

14. Motor vehicle suspension leg comprising a suspension stop according to any one of claims 1 to 13 and a suspension spring (1) having an upper coil (la) having a free end (1b), said coil being arranged in axial support on the bosses (7a, 7b) of a radial bearing clearance (4a) and the free end (1b) of the coil (la) being in angular abutment on the axial wall (6).

15. Suspension leg according to claim 14, characterized in that the bosses (7a, 7b) are arranged so that the free end (1b) of the spiral (la) is not in contact with the radial bearing (4a).

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