FR2898170A1 - Suspension support for strengthening a connection and filtering between body shell and the suspension of a vehicle, comprises a main framework and a secondary framework forming lid that surrounds an interior space of the frameworks - Google Patents

Abstract

The suspension support for strengthening a connection and filtering between body shell and the suspension of a vehicle, comprises a main framework (1) and a secondary framework (2) forming lid that surrounds an interior space of the frameworks. The suspension of the vehicle consists of a helicoid spring (4) and a shock absorber. The main framework has a plate shaped bottom pierced by an opening and a parallel peripheral edge. The helicoid spring is useful as a support against a first elastic body (7), which is positioned against an inner side of the peripheral edge. The suspension support for strengthening a connection and filtering between body shell and the suspension of a vehicle, comprises a main framework (1) and a secondary framework (2) forming lid that surrounds an interior space of the frameworks. The suspension of the vehicle consists of a helicoid spring (4) and a shock absorber. The main framework has a plate shaped bottom pierced by an opening and a parallel peripheral edge. The helicoid spring is useful as a support against a first elastic body (7), which is positioned against an inner side of the peripheral edge. A free end of a rod of the shock absorber is placed in an internal space through the opening in a base of the internal space. An axial and radial clearance of the rod is limited by a disc (6) against which the rod is based. The disc is sandwiched between a second and a third elastic ring shaped body, which are inserted into a fourth elastic ring shaped body. The second, third and fourth elastic bodies are made of cellular thermoplastic polyurethane of density (0.4-0.9). An additional elastic body is made of thermoplastic polyurethane of density higher than 1, and is interposed between the disc and the elastic bodies, which forms a U-shaped profile. The two wings of the profile extend respectively on both sides of upper and lower side of the disc. The second, third and fourth elastic ring shaped bodies have closed cells of an average diameter of 100 mu m, density of 107>/cm3> and hardness of 75-85 shore A. A peripheral edge of the disc is notched, and comprises a series of openings constituting anchoring channels of polyurethane constitutive of the additional elastic body with respect to the disc. The additional elastic body constitutes an overcasted element on the disc, and the elastic bodies constitute an overcasted element on the additional elastic body.

Description

The present invention relates to a suspension support ensuring the

  binding and filtering between the body and the suspension of a vehicle consisting of a coil spring and a damper. In the document FR-A-2,829,818 in the name of the present applicant, examples of such a support are described. In Figure 1 attached is shown in section, according to a longitudinal median plane, an embodiment of a support described in this document. This support essentially comprises a main reinforcement 1 and a secondary reinforcement forming a cover 2, both of which delimit an inner space E. They are for example both made of steel or aluminum. The frame 1 has the general shape of a plate, with a bottom 10 and a peripheral rim 12 generally parallel to each other, but perpendicular to the longitudinal median axis XX 'of the support. The bottom 10 is pierced with a circular opening 13, centered on the axis XX '. Against the free edge of this opening is crimped a thrust limiting cup 3, of axis XX ', which is directed opposite the rim 12. The latter and the bottom 10 are connected by an intermediate wall 11 which is slightly diverging in the direction of the flange 12. 20 The secondary armature 2 is supported on the flange 12. It is fixed at its periphery 22, for example by crimping. This cover also has a circular axial opening 23, whose diameter is greater than that of the opening 13. In regularly distributed zones, for example three in number, the two armatures receive, through appropriate orifices, F screw fixing to the body of a vehicle. A single screw is visible in Figure 1. This support comprises a coil spring of which a single turn 4 is shown in the figure. This spring is of axis XX '. It bears against a first elastic member 7 positioned against the underside of the peripheral rim 12 of the main frame. This member here consists of an "L" section ring, which bears not only against said flange 12, but also against the intermediate wall 11.

  Along the axis XX 'is engaged, through the opening 13, the cylindrical rod 50 of a damper 5. The free end of its rod, of reduced section, partially leaves the secondary armature 2 through the opening 23 This end is referenced 51 and designated by the reference 52 the peripheral shoulder which corresponds to the change of section of the rod 50. The end 51 is threaded so as to allow the establishment of a nut (not shown). ) on this one. Against the shoulder 52 is a disk 6 forming a central frame, which has a central opening 60 of diameter adapted to engage on the end 51 of the rod of the damper without significant play. This disc is held in place by the nut of which it has been mentioned above. As clearly shown in the figure, this disk 6 is sandwiched between a second and a third ring-shaped elastic members, which respectively bear the references 8 and 8 '.

  These rings are based on the flat areas of the bottom wall 10 of the main armature 1 and 20 of the secondary armature 2. The disk assembly 6 / elastic members 8 and 8 'is inserted inside of a fourth annular elastic member 8 "which occupies the exclusively peripheral zone of the space E.

  Thanks to these elastic elements, it is understood that, whatever the movement movement of the rod damper, they are partially compensated by at least one of these elastic members. In a particularly advantageous embodiment, the elastic members 8, 8 'and 8 "are formed of a single piece.

  Still according to an advantageous embodiment, these elastic members (or the single piece they constitute) are made of cellular thermoplastic polyurethane (hereinafter referred to as foamed TPU), this material having closed cells with an average diameter of about 100. m, a cell density of about 107 / cm3, a density of between 0.4 and 0.9 and a hardness between about 75 and 85 shore A. These bodies can be made using a device of injection molding, as described in WO-98/31521 in the name of the American company TREXEL INC. The foaming can be carried out for example by the process described in US-4,473,665 and US-5,160,674, known as "MUCELL".

  Such support generally provides satisfaction in terms of separate filtering of vibrations from the damper rod from those of the spring. In addition, the elastic members employed provide a good compromise between stiffening and damping, this at any level of density of material. However, in case of radial stresses, it is found that the aforementioned disc 6 uses the foamed TPU and degrades it. The present invention aims to solve this problem, while retaining the advantages listed above, relating to the carrier according to the state of the art. The present invention therefore relates to a suspension support ensuring the connection and the filtering between the body and the suspension of a vehicle composed of a helical spring and a damper, which comprises a main frame and a secondary frame forming a cover , which delimit between them an internal space, the main frame having the general shape of a plate with a bottom pierced with a substantially parallel opening and a peripheral rim, the spring bearing against a first elastic member positioned against the lower face of said peripheral flange, the free end of the damper rod being received in the internal space through the opening made in its bottom, the axial and radial displacements of said rod being limited by a disk against which it rests, housed in said internal space, this disc being sandwiched between a second and a third elastic members in The ring shape, the assembly being inserted into a fourth annular elastic member, these second, third and fourth elastic members being made of cellular thermoplastic polyurethane having a density of between 0.4 and 0.9. This support is characterized essentially by the fact that is inserted between said disk and said elastic members, an additional elastic member consisting of thermoplastic polyurethane density greater than 1, which affects, seen in cross section, a profile in the general shape of "U ", whose two wings extend respectively on either side of the two upper and lower faces of said disk. At this density level, the TPU is compact and non-cellular (not foamed). By the term "elastic member" is meant a member which elastically deforms under the effect of a bias and which returns to its original shape when the solicitation has ceased.

  By the term "disc" is meant both an object of circular shape (or forming a circle) and generally flat, pierced at its center, an object of the same type provided with an annular flange bordering its opening . Thanks to the invention, the cellular thermoplastic polyurethane does not degrade, since it is no longer in direct contact with the disc. This considerably increases its service life. In addition, because of its compactness, the thermoplastic polyurethane which is the additional elastic member does not degrade or virtually no. Moreover, according to other advantageous and non-limiting characteristics of this support: the second, third and fourth elastic members consist of a polyurethane having the following characteristics: closed cells with an average diameter of about 100 m cell density of about 10 '/ cm3, and hardness between about 75 and 85 shore A; the second, third and fourth members constitute one and the same elastic piece which also affects, in cross-section, a generally U-shaped profile, the two wings of which extend respectively on either side of the two upper and lower faces of said disk; the peripheral rim of said disk is crenellated; the periphery of said disk comprises a series of openings which constitute anchoring channels of the polyurethane constituting said additional elastic member, relative to this disk; said additional elastic member constitutes an element overmolded on said disk; said elastic piece constitutes an element overmolded on said additional elastic member. Other characteristics and advantages of the invention will appear on reading the following detailed description of some embodiments. This description, given in a non-limiting manner, will be made with reference to the appended figures in which: - Figure 2 is a top view of a central frame disk, capable of being integrated into a frame according to the present invention; FIG. 3 is a view similar to the preceding one, the disc having its periphery partially provided with said additional elastic member; - Figure 3bis is a partial view of the disk of Figure 2, according to the sectional plane A-A; FIG. 4 is a view, along a vertical and median sectional plane of the disk of the preceding figures, in which the said additional elastic member 5 is "sandwiched" by a single piece of cellular TPU; - Figure 5 is a sectional view of a support according to the invention, the latter being said "monobloc"; - Figure 6 is a sectional view, along a longitudinal median plane, of an embodiment of a support according to the invention, said multi-piece; FIG. 7 is a partial view, in section and along a median plane of a disc coated with an additional elastic member of a shape different from that which has been presented above. The disk or central frame 6 shown in Figure 2 is for example made of steel. Its central opening 60 allows it to be attached to the rod of a damper, as has already been described with reference to FIG. 1. Its periphery has a thickness slightly less than its central portion, this difference in thickness thus constituting a The periphery of this disc is crenellated, which means that it presents alternately, radially directed, recessed and protruding portions with respect to one another. The parts in "hollow" (that is to say recessed) are referenced 61, while the protrusions are referenced 62. The interest of such a characteristic will be explained later in the description. Of course, in an embodiment not shown, this disc may have a strictly circular contour. Note that the periphery of said disc has, in the projecting portions 62 above, a series of openings 63 which open on the two large opposite faces of the disc. The interest of such a feature will also be explained later. As indicated above, the support according to the invention is essentially characterized by the fact that is interposed between the disc 6 and said elastic members (or the single piece that they together), an additional elastic member consisting of thermoplastic polyurethane of density equal to about 1.2, which affects, seen in cross section, a profile in the general shape of "U", whose two wings extend respectively on either side of the two upper and lower faces of said disk. For reasons of simplification, the material that constitutes this body will be called a "compact TPU".

  In Figure 2 is only shown this disc, partially coated with said additional elastic member, which here is the reference 9. Preferably, the member 9 is overmolded on the disc 6, according to a standard thermoplastic injection technique. The member 9 extends in the direction of the center of the disk, up to the "march" of which it has been mentioned above. The serrated periphery of the disc prevents the TPU from rotating with respect to the disc. In addition, the openings 63 in the disk 6 constitute as many channels for anchoring the TPU on the disk. In other words, the bond between these two elements is improved. Referring now to FIG. 4, it can be seen that the member 9 is covered with a single elastic piece 80 made of foamed TPU, with a density of between 0.4 and 0.9 and preferably having the additional characteristics listed. upper. In an embodiment not shown, this part 80 could consist of several distinct elements, in the manner of what has been shown in FIG. 1. The part 80 is preferably overmolded on the disk assembly 6 / member 9 The polyurethane used for the piece 80 and the member 9 is of the same type, which leads to a perfect compatibility of the connection between these two elements, when overmolded. Bonding takes place when the foamed TPU, still molten, comes into contact with the compact TPU. More specifically, during this contact, the compact TPU 30 melts on the surface and the two materials are soldered to each other. The pressure in the mold, due to the physical "foaming" phenomenon of the foamed TPU, exerts and maintains a stress on the connection during the cooling time of the TPU. Both materials can be injected according to two different processes. Thus, either the moldings are made on different presses, or the molding takes place on a "bi-injection" press, so that the two materials are injected simultaneously. In Figure 5, the assembly of Figure 4 is shown mounted within a qualified monobloc support.

  For the sake of simplicity, the spring and the damper rod which are normally part of the support have not been represented. In this one-piece support, the main frame and the abutment limit cup, generally shaped as two separate pieces, constitute here a single piece referenced 1.

  Note that the secondary armature 2 is shaped according to the profile of the workpiece 80. In FIG. 6, we are dealing with a more conventional structure support, called "multi-piece", shaped in the same way as that of FIG. 1. This section clearly shows the implantation within the disk 6 / member 9 / part 80 assembly. In the case of radial stress, it is easy to understand that the part 80 is not directly stressed, which increases its life time. Finally, in Figure 7 is shown the disc 6 coated with a member 9 having an intermediate region forming extra thickness. Such an allowance and more generally any variation in thickness or diameter of the member 9 can adjust the stiffness of the support according to the (or) direction (s) desired (s). Moreover, the increase of the surface of the member 9 makes it possible to reinforce the connection with the part 80. The support according to the invention also has the following advantages: the use of overmouldings of two materials of the same nature makes it possible to dispense with the use of adhesives, that is to say products based on solvents; disk 6 can have a simple and inexpensive geometry, with overmoulding of complexly shaped foamed TPU; the fatigue resistance of the foamed TPU is improved because there is no longer any abrasion phenomenon between the disc 6 and this TPU.

Claims (7)

  1. Suspension support providing the connection and the filtering between the body and the suspension of a vehicle composed of a helical spring (4) and a shock absorber (5), which comprises a main frame (1) and a frame secondary cover (2) defining between them an internal space (E), the main frame (1) having the general shape of a plate with a bottom (10) pierced with an opening (13) and a rim peripheral (12) substantially parallel, the spring (4) bearing against a first elastic member (7) positioned against the underside of said peripheral flange (12), the free end (51) of the rod (50) of the damper (5) being received in the internal space (E) through the opening (13) formed in its bottom, the axial and radial displacements of said rod (50) being limited by a disk (6) against which it is supported, housed in said internal space (E), this disc being sandwiched between a second (8) and a third (8 ') ring-shaped elastic members, the assembly being inserted into a fourth annular elastic member (8 "), these second, third and fourth resilient members (8, 8', 8") being made of cellular thermoplastic polyurethane having a density of between 0.4 and 0.9, characterized in that between said disk (6) and said elastic members (8, 8 ', 8 ") is interposed an additional elastic member (9) composed of thermoplastic polyurethane of density greater than 1, which affects, seen in cross-section, a generally U-shaped profile, the two wings of which respectively extend on either side of the two upper and lower faces of said disk (6).   2. Support according to claim 1, characterized in that the second (8), third (8 ') and fourth (8 ") elastic members are made of a polyurethane having the following characteristics: closed cells of a diameter average of about 100 m, cell density of about 107 / cm3, and hardness between about 75 and 85 shore A.   3. Support according to claim 2, characterized in that the second (8), third (8 ') and fourth members (8 ") constitute one and the same elastic piece (80) which also affects, seen in cross-section, a profile in the general shape of "U", whose two wings extend respectively on either side of the two upper and lower faces of said disk (6).   4. Support according to one of the preceding claims, characterized in that the peripheral rim of said disk (6) is crenellated.   5. Support according to one of the preceding claims, characterized in that the periphery of said disk (6) comprises a series of openings (63) which constitute anchoring channels of the polyurethane constituent of said additional elastic member (9), relative to this disc (6).   6. Support according to one of the preceding claims, characterized in that said additional elastic member (9) constitutes a molded element on said disk (6).   7. Support according to claim 3 or according to one of claims 4 to 6 in combination with claim 3, characterized in that said elastic piece (80) constitutes a molded element on said additional elastic member (9).