FR2885188A1 - Ball joint for steering column controlling system of motor vehicle, has blades either in contact with respect to each other by their lateral edges and sides or in contact with ball surface when blades are folded back on ball surface - Google Patents

Abstract

The ball joint has a sleeve (3) interposed between a cup and a ball when the ball is plugged in the cup for pivoting with respect to the cup. The sleeve is constituted of a set of blades (11, 12, 13) in which an interior surface of each of the blade comes in contact with a ball surface. Inter-blade spaces separate the blades from each other. The blades are either in contact with respect to each other by their lateral edges and sides or in contact with the ball surface when the blades are folded back on the ball surface.

Description

ROTULE CONSISTING OF TWO PARTS MALE AND FEMALE

  The present invention relates to ball joints consisting of a male part and a female part between which is interposed a sleeve to promote the rotation of one of the two parts relative to the other. , and more particularly the ball joints which find an advantageous application in the steering control systems of motor vehicles or the like.

  It is known that, in the field of motor vehicles, the steering column is connected, in particular to the front wheels, by means of gears, rods and ball joints which make it possible to orient the wheels whatever their position relative to to the chassis.

  It is therefore easy to imagine that, given the quantity of vehicles put on the market, these ball joints must be produced industrially in large series, without their cost reaching large sums.

  One of the embodiments of this type of patella currently used consists of a cup-shaped cup, a shirt of a substantially homothetic shape of the inner shape of the cup, and therefore also shaped bowl, and a sphere mounted at one end of a control rod and placed inside the shirt. The cup is crimped onto the sphere by folding the shirt over the surface of the sphere, while allowing the control rod to emerge so that the sphere can pivot in a determined solid angle.

  Gold finds that with this kind of patella structure, when the cup is crimped by folding its edges towards the sphere, the shirt deforms non-uniformly, making some sort of folds or waves, and comes into contact with the sphere only by the summits of these undulations. Therefore, the bearing surface of the sphere on the sleeve can be reduced to a minimum value and can even vary from one ball to another, depending on the intensity of the forces exerted for the crimping of the cup.

  With such a ball structure, the spheres do not rotate with the same degree of friction. For some ball joints, the spheres pivot easily, for others, they come almost to the limit of jamming. In all cases, a non-negligible mechanical clearance appears very rapidly in the rotation of the sphere relative to the jacket and the cup, which very quickly causes vibrations in the steering control systems of the vehicles.

  Also, the object of the present invention is to provide a ball joint which at least largely overcomes the aforementioned drawbacks of the ball joints of the prior art schematically described above.

  More specifically, the subject of the present invention is a ball joint characterized in that it comprises a cup, a sphere of radius R, said cup being arranged so that its inner wall is capable of containing a spherical volume of radius greater than R and being made of a material enabling it to be crimped, and a sleeve interposed between the cup and the sphere when the sphere is plugged into the cup so as to pivot relative to said cup in a determined solid angle after said cup has been crimped to enclosing said sphere in said jacket, said jacket consisting of: a plurality of lamellae, the inner face of each lamella adapted to come into contact with the surface of the sphere being of a shape substantially congruent with that of said surface; the sphere, * substantially flexible links connecting said slats to allow said slats to fall back on the surface of the sp re, and * inter-lamella spaces separating said lamellae from each other, said inter-lamella spaces being defined so that, when the lamellae are folded on the surface of the sphere, they are at most in contact with each other others by their lateral edges and that their inner face is in contact with the surface of the sphere without deformation.

  Other features and advantages of the invention will appear in the course of the following description given with reference to the accompanying drawings for illustrative but not limiting purposes, in which: FIG. 1 represents, in schematic and cutaway form, an embodiment of FIG. 2 and 3 show, in schematic form, another embodiment of the ball joint according to the invention, FIG. 2 being similar to a longitudinal sectional view and FIG. 3 a perspective view. FIGS. 4 and 5 show, in schematic form, another embodiment of the ball joint according to the invention, FIG. 4 being similar to a longitudinal sectional view. and FIG. 5 is a perspective view of the jacket forming part of the ball joint according to FIG. 4. FIGS. 6 and 7 show, in schematic form, another embodiment. embodiment of the ball joint according to the invention in accordance with Figure 4, Figure 6 being comparable to a longitudinal sectional view and Figure 7 a perspective view of the sleeve forming part of the ball joint according to Figure 6, FIGS. 8A and 8B show, respectively in perspective and in a side view, another embodiment of a jacket that can be used to produce a ball joint according to the invention, in a configuration before being mounted in cooperation with the sphere of this ball, and Figure 9 shows another embodiment of a sleeve that can be used to make a ball joint according to the invention, in a configuration before being mounted in cooperation with the sphere of this ball joint, for example as in the case of the embodiment according to FIG.

  It is first of all specified that, in the figures, the same references designate the same elements, whatever the figure on which they appear and whatever the form of representation of these elements. Similarly, if elements are not specifically referenced in one of the figures, their references can be easily found by referring to another figure.

  It is also stated that the figures represent several embodiments of the object according to the invention, but that there may be other embodiments that meet the definition of this invention.

  It is further specified that, when, according to the definition of the invention, the object of the invention comprises "at least one" element having a given function, the embodiment described may comprise several of these elements. Conversely, if the embodiment of the object according to the invention as illustrated has several elements of identical function and if, in the description, it is not specified that the object according to this invention must obligatorily comprise a number particular of these elements, the object of the invention may be defined as comprising "at least one" of these elements.

  Lastly, it is specified that when, in the present description, an expression alone defines, without specific specific reference to it, a set of structural characteristics, [for example E = 1 (p, t, c, ...)] , these characteristics can be taken, for the definition of the object of the protection requested, when technically possible, either separately, [for example c, and / or t, and / or p, ...], or total and / or partial combination, [eg 1 (c, t, p), and / or E (t), and / or 1 (t, p), and / or E (c, p)].

  With reference to the figures, and more particularly to FIG. 1, the ball joint according to the invention comprises a cup 1 made of a material which allows it to be crimped, a sphere 2 of radius R, the cup 1 being arranged so that its inner wall 4 is able to contain a spherical volume of radius greater than R. The ball joint further comprises a jacket 3 which is interposed between the cup 1 and the sphere 2 when the sphere is plugged into the cup so as to pivot relative to the cup in a determined solid angle [3, after the cup has been crimped as will be explained below, to trap the sphere 2 in the sleeve 3, the latter being contained in the cup. Such a ball joint is well known in itself and makes it possible to ensure a rotational movement, in the solid angle [3, of a part shown diagrammatically at P1 with respect to another piece shown schematically in P2, FIG. 1. Such ball joints are found for example in motor vehicles or the like, between a wheel of the front axle and the steering column.

  According to an important characteristic of the invention, the liner 3 is constituted, FIGS. 1 to 9, of a plurality of lamellae 11, 12, 13, ..., the inner face 21, 22, 23, ... of each lamella adapted to come into contact with the surface 30 of the sphere 2 being of a shape substantially congruent with that of the surface of the sphere, that is to say, spherical of the same radius R as that of the sphere 2.

  The liner 3 further comprises relatively flexible links 16, 17, ... connecting the slats to enable them to fall back on the surface 30 of the sphere 2, and inter-slats spaces 111, 112, 113, ... separating these slats from each other.

  The inter-blade spaces are defined so that, when the slats 11, 12, 13, ... are folded over the surface 30 of the sphere 2, they are at most in contact with each other by their lateral edges being face and delimiting the interslice spaces separating them, and that their inner face 21, 22, 23, ... is in contact with the surface of the sphere without undergoing deformation.

  In other words, these inter-lamella spaces are defined so that two consecutive lamellae can come into contact with each other only by their lateral edges facing each other and bordering the interlamellar space separating them, but that , despite the pressure forces exerted for the crimping of the cup towards the sphere by imprisoning the jacket, the lamellae retain their original shape and do not undergo any deformations such as corrugations or the like, thus avoiding the disadvantages presented by the patellaes of the prior art recalled in the preamble of the present description.

  The jacket 3 may have different structures, depending on the needs and applications of the ball joint according to the invention.

  FIGS. 8A and 8B show an embodiment of a ball liner according to the invention, in its configuration before being mounted in cooperation with a sphere 2, FIG. 8A being a perspective view and FIG. 8B a side view. .

  According to this embodiment, the jacket 3 consists of two half-cups 40, 41, for example in the form of a bottomless bowl, and hinge means 43 connecting these two half-shells so that they are able to pivot one by report to the other to form the shirt 3 surrounding the sphere 2.

  To mount this sleeve in cooperation with the sphere, it is sufficient to pass the control rod 9 secured to the sphere (Figure 1) by the bottom of one of the two half-shells, the latter being in the open position as shown in Figure 8, then close the two half-shafts on each other by imprisoning the sphere.

  To obtain the patella, the "sphere-shirt" assembly is inserted into a cup 1, then the cup is crimped towards the sphere.

  The ball joint according to the invention may have other shapes, such as those which are more particularly illustrated in FIGS. 3, 5, 7 and 9.

  According to the embodiments illustrated in FIGS. 3, 5 and 7, the jacket 3 consists of two half-shells 40, 41 linked by one of their bases along a connecting ring 44. In these embodiments, the half-shells are of general shape, either substantially frustoconical or cylindrical, and the inter-lamella spaces are, preferably, made in planes substantially perpendicular to the plane of the ring 44.

  To obtain a ball joint according to the invention comprising a jacket as described above, it is sufficient to forcefully insert the sphere into the jacket by spreading the lamellae, then to introduce this assembly into the cup, and to crimp the cup to imprisoning said assembly, until the slats are perfectly folded on the surface 30 of the sphere 2.

  FIG. 9 represents another possible form for the jacket 3, in which the retaining ring 44 is not situated between two half-shells but integral with only one of the two half-shells, the lamellae of this half-shell being held in the extension of the slats of the other half-shell to form a unitary liner which has the advantage of allowing the introduction of spheres of large diameter, the deflection of the slats can be, in this embodiment, more important than in the other embodiments.

  According to a possible embodiment for certain applications, the ball joint according to the invention further comprises, FIG. 4, means 50, such as a helical spring or the like, for applying an elastic force between the jacket 3 and the cup 1 so as to be well plated. the shirt 3 on the surface 30 of the sphere 2.

  In an advantageous embodiment, when the cup 1 consists of a sleeve open at both ends, it comprises, at one end of the mancon, a cover 60 constituting its bottom 61, and means for securing the cover 60 with the end of the sleeve.

  Advantageously, the means 50 for applying an elastic force between the cup 1 and the liner 3 then cooperate between the cover 60 and the liner, the two ends of the spring coming respectively to bear against this cover 60 and the tops 62 of the sipes which are advantageously shaped as illustrated in Figures 4 and 5 to at least partially embed an end of the spring and maintain at least laterally.

  According to a preferred and advantageous embodiment for industrial manufacture, when the jacket 3 is made of a molded plastic material, the means 50 for applying an elastic force between the cup 1 and the jacket 3 are constituted, FIGS. 6 and 7, by at least one stud 51, 52, ... made on the top 62 of a lamella 11, 12, 13, ..., and advantageously a stud made on the top 62 of each lamella turned towards the bottom 61 of the cup 1, this pad being made of an elastomeric thermoplastic material overmolded on the top 62 of the strip.

  To promote the rotation of the sphere 2 relative to the cup 1, at least one of the inner faces 21, 22, 23, ... slats 11, 12, 13, ... adapted to come into contact with the surface 30 of the sphere 2, and advantageously all these inner faces, comprises a self-lubricating layer.

  When the liner 3 is made of a molded plastic material as mentioned above, this self-lubricating layer is obtained by overmolding a layer of a thermoplastic material.

  It has been defined above a cup 1 arranged so that its inner wall 4 is adapted to contain a spherical volume radius greater than R, to allow the interposition of the shirt 3. It is however specified that, although it may have different shapes, the inner wall 4 of the cup preferably has a shape of revolution relative to a point or a straight line, for example one of the following forms: frustoconical revolution (Figure 4); cylindrical of revolution (Figure 1); a cylindrical part of revolution contiguous to a frustoconical part of revolution; spherical; two frustoconical parts of revolution contiguous with their large bases (figures 2 and 6).

  As mentioned above, the cup is made of a material allowing its crimping. This material can be of any type, but the most commonly used is steel or the like.

  As for all the constituent elements of the jacket 3, namely the strips 11, 12, 13, ..., the flexible links 16, 17, the hinge means 43 and the ring 44, it is made of a only piece generally by molding.

  The mounting of a ball joint according to the invention is carried out as follows: First, the sphere 2 is introduced into the jacket 3 by spacing the strips as described above. Then, this assembly is introduced into the cup 1 which is then crimped in a known manner to trap the sphere with the sleeve interposed between this sphere and the inner wall 4 of the cup.

  Referring to the accompanying figures, Figures 1 and 6 show, in solid lines, the shape of the cup 1 before crimping and, in broken lines, its shape after crimping. Figure 2, it shows, in solid lines, the shape of the cup 1 after crimping and, in broken lines, its shape before crimping.

  With the structure of the ball joint according to the invention, the lamellae of the jacket are more or less folded depending on the intensity of the forces exerted on the cup for its crimping, of course within certain limits, and the deformations of the jacket are essentially absorbed by the inter-lamella spaces 111, 112, 113 as explained above. In this way, the contact surface between the sphere and the liner is maximum and substantially continuous, resulting in a less rapid friction wear of the ball with respect to the ball joints of the prior art defined in the preamble of the present description.

  In addition, this ball structure allows to realize industrially a large number of such ball joints in which the male parts all have substantially the same qualities of rotation in the female parts, without risk of jamming.

Claims (9)

REVENDI CATIONS   1. Ball joint characterized in that it comprises a cup (1), a sphere (2) of radius R, said cup (1) being arranged so that its inner wall (4) is adapted to contain a spherical volume of radius greater than R and being made of a material allowing it to be crimped, and a jacket (3) interposed between the cup (1) and the sphere (2) when the sphere is plugged into the cup so as to pivot relative to said cup in a determined solid angle ((3) after said cup has been crimped to trap said sphere in said liner (3), said liner (3) consisting of: * a plurality of sipes (11, 12, 13,. ..), the inner face (21, 22, 23, ...) of each lamella (11, 12, 13, ...) adapted to come into contact with the surface (30) of the sphere (2) being a shape substantially congruent with that of said surface of the sphere, * substantially flexible links (16, 17, ...) connecting said slats to allow e said lamellas to fall back on the surface (30) of the sphere (2), and * inter-lamella spaces (111, 112, 113, ...) separating said lamellae from each other, these so-called spaces interlamelles being defined so that, when the slats (11, 12, 13, ...) are folded on the surface (30) of the sphere (2), they are at most in contact with each other by their side edges and that their inner face (21, 22, 23, ...) is in contact with the surface (30) of the sphere without deformation.   2. Ball joint according to claim 1, characterized in that said sleeve (3) consists of two half-shells (40, 41) and hinge means (43) connecting the two half-shells so that they are able to pivot relative to each other to form said jacket (3) surrounding the sphere (2).   3. Ball joint according to claim 1, characterized in that said sleeve consists of two half-shells (40, 41) connected by one of their bases along a connecting ring (44).   4. Ball joint according to one of claims 1 to 3, characterized in that it comprises means (50) for applying an elastic force between the cup (1) and the jacket (3) so as to press said jacket ( 3) on the surface (30) of the sphere (2).   5. Ball joint according to claim 4, characterized in that, when said cup consists of a sleeve open at both ends, it comprises a cover (60) and means for securing said cover (60) at one end of sleeve, said means (50) for applying an elastic force between the cup (1) and the liner (3) cooperating between said cover (60) and said liner (3).   6. Ball joint according to one of claims 4 and 5, characterized in that, the sleeve (3) being made of a molded plastic material, said means (50) for applying an elastic force between the cup (1) and said liner (3) are constituted by at least one stud (51, 52, ...) made on the top of a lamella (11, 12, 13, ...), said stud being made of a thermoplastic elastomer material overmolded on said vertex.   7. Ball joint according to one of claims 1 to 6, characterized in that at least one of the faces (21, 22, 23, ...) of the slats (11, 12, 13, ...). adapted to come into contact with the surface (30) of the sphere (2) comprises a self-lubricating layer.   8. Ball joint according to claim 7, characterized in that, said jacket (3) being made of a molded plastic material, said self-lubricating layer is obtained by overmolding a layer of a thermoplastic material.   9. Ball joint according to one of claims 1 to 8, characterized in that the inner wall (4) of said cup (1) is of revolution form with respect to one of the following: a point and a straight line , and has substantially one of the following forms: truncated cone of revolution; cylinder of revolution; a cylindrical part of revolution contiguous to a frustoconical part of revolution two frustoconical parts of revolution contiguous to their great bases; sphere.