MXPA96005405A - Set to reduce noise and vibration of automobi - Google Patents

Abstract

The present invention relates to an assembly for use to reduce noise and vibration of automobiles, the assembly comprising: a spring seat retainer comprising (a) first and second surfaces directed in opposite manner, (b) a recessed area in the first surface, (c) an axially directed inner cavity, and a spring insulator having at least a portion of a surface coexisting with a portion of the second surface of the spring seat retainer, characterized in that it comprises a bumper of rattle having an outer surface, a portion of which is coexistent with a portion of the inner cavity of the spring seat retainer, and a coil spring having a lowermost section retained within the recessed area of the spring seat retainer, way that the coil spring surrounds the traquet bumper

Description

"A SET TO REDUCE THE NOISE AND VIBRATION OF AUTOMOBILES" 1. BACKGROUND OF THE INVENTION This invention relates to assemblies for use in vehicle suspension systems and, more particularly, assemblies for use in vehicle suspension systems that contain coil springs. Automobile vehicles are used in a variety of road surfaces and conditions. The crashes and sounds generated by the vehicle on these different surfaces contribute to the quality of the ride perceived by the driver and passengers. For a vehicle to project an image of value and reliability, it is necessary to minimize the negative sounds and responses of the vehicle. Accordingly, significant attention is paid to areas such as the interface between the coil springs and the spring seats of the vehicle with the aim of providing a firm, safe and silent operation of the vehicle suspension system. The points of contact between the suspension components of the vehicle experience a large amount of movement. At some points, work occurs during all types of vehicle operating conditions. A suspension system usually experiences service cycles comprising rattles and rebounds in response to the inlets from the road surface with which the vehicle's tires have interfacial contact. Therefore, the operation of the suspension has a direct impact on what the owner of a vehicle feels and hears and contributes significantly to one of the perceived running characteristics of the vehicle. Negative sounds or noises can often be generated by metal contact between the components of the system. This has frequently been found to be the case when helical springs are used in a suspension assembly. The ends of the coil springs frequently come into contact with the spring seats of the metal vehicle. The relative movement that occurs during vehicle operation between the dock and the coincident vehicle surfaces typically causes objectionable sounds. Although it has been conventional to use resilient insulators between the coil spring and its points of contact with the vehicle, it has been found that these systems have a tendency to degrade over time, particularly at the point of contact. This type of wear is sometimes referred to as charge degradation. US Pat. No. 5,421,565, attempts to solve this problem by providing a specific foam insulator placed between the coil spring and the spring seat. The configuration of the foam insulator is intended to eliminate the problem of the degradation of the concentrated load. However, these configurations are still subject to degradation over time. Also, the prior art systems are vulnerable to corrosion due to metal / metal interfaces. Finally, these systems, in general, require the assembly of multiple components at the point of use. Problems of exit or extrusion of the foam can also occur. Accordingly, it would be desirable to provide a set for use in suspension systems to reduce automobile noise and degradation that eliminates localized distribution and stress and metal-to-metal contacts. It would also be desirable that this assembly be capable of being supplied for the manufacture of automobiles as a single unit, without the need for bolts and other separate parts.

It would also be desirable for the assembly to exhibit optimum durability throughout the duration of the motor vehicle. Finally, the design of the assembly must finally provide cost reductions and improvements in efficiency.

COMPENDIUM OF THE INVENTION The present invention provides the desirable advantages mentioned above. These advantages are achieved by an assembly comprising a spring seat retainer having at least (a) first and second surfaces directed oppositely, (b) a recessed area in the first surface, and (c) a lower cavity axially directed . The assembly also has a spring insulator having at least a portion of a surface coexisting with a portion of a second surface of a spring seat retainer. A rattle bumper is placed so that a portion of its outer surface coexists with a portion of the inner cavity of the spring seat retainer. Finally, the assembly also has a coil spring having the lower section retained within the recessed area of the spring seat retainer in such a manner that the coil spring surrounds the rattle bumper. It will further be appreciated that the assembly of the invention actually consists of a series of sub-assemblies, the first sub-assembly (1) having a spring seat retainer having at least (a) first and second surfaces directed oppositely, (b) a recessed area on the first surface, and (c) an axial cavity directed axially; and (2) a spring insulator having at least a portion of a surface coexisting with a portion of the second surface of the spring seat retainer, such that the spring insulator is releasably connected to the spring seat. . A second sub-assembly comprises the first sub-assembly and a rattle bumper having an outer surface, a portion of which is coexistent with a portion of the inner cavity of the spring seat retainer of the first subassembly. A third sub-assembly comprises the second subassembly and a coil spring having a lower section retained within the recessed area of the spring seat retainer such that the coil spring surrounds the rattle bumper.

It will be appreciated that the final subassembly and, therefore, the assembly of the invention may further contain a fastening means (d) for releasably connecting the assembly with an automotive spring seat or equivalent article. Those skilled in the art will appreciate that these automotive dock seats will, in general, be welded to the axle of an automotive vehicle. A particularity of the whole of the invention is that the supply of a single assembly provides improved efficiency and cost to the manufacturer of the end-use automobile. In addition, the use of a fastening means (d) provides the manner in which metal bolts and fasteners such as those previously used are no longer required. This reduces the possibility of joints susceptible to the action of various fluids and corrosion. Another advantage of the invention is the preferred use of microcellular polyurethane in the construction of the rattle bumper and the spring insulator. The microcellular polyurethane provides a progressive load deviation behavior and maximum durability. In addition, the design of the spring insulator as a separate unit allows the use of microcellular polyurethane with different operating characteristics compared to the rattle bumper. It has also been found that the specific construction of the assembly of the invention allows the design of high-functioning spring insulators at relatively low cost per unit. Finally, the fact that the individual component parts can be manufactured for use in assemblies intended for use in a variety of vehicles, reduces the cost per unit of the total assembly. Significant operational differences in the various assemblies are easily achieved, however, due to the use of custom-made components of the spring insulator and the rattle bumper made of microcellular polyurethane. Those skilled in the art will further appreciate that the reduction of metal-to-metal interactions and the elimination of areas vulnerable to concentrated loading improves the overall durability of the overall duration operation. 2. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 provides a lateral elevation in cross section of the assembly of the invention.

Figure 2 provides a lateral elevation in cross section of the assembly of the invention fixed to a seat and axle of the vehicle spring. Figure 3 provides a respective view of a spring isolator of the assembly of Figure 1. Figure 4 is a cross-sectional view in side elevation of an alternative embodiment of the assembly of the invention as it is attached to a seat and spring shaft vehicle. Figure 5 is a respective view of the spring insulator of the assembly of Figure 4. 3. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Referring generally to the drawings, the various preferred embodiments of the assembly of the invention are illustrated. A preferred embodiment is illustrated in Figures 1 and 2. Figure 1 provides a cross-sectional side view of the assembly 10 of the invention. Figure 2 provides a cross-sectional view of the assembly 10 attached to the seat 12 of the spring and the shaft 14. As shown in Figure 1, the assembly 10 comprises a spring seat retainer 16, a spring isolator 18, the 20 rattle bumper and coil spring 22. The retainer 16 of the spring seat is intended to function as the base or core component of the assembly 10 where the other components of the assembly are subsequently fixed. It will be appreciated by those skilled in the art that in this way, the use of bolts and other fasteners is not required reducing the potential for metal-to-metal interaction and subsequent noise and corrosion. The retainer 16 may have a variety of shapes and configurations as necessary to meet the engineering requirements. However, the following aspects will usually be present. For example, the first and second opposingly directed surfaces 24 and 26 are intended respectively to define the top or top surface of the retainer 16 and its bottom or bottom surface. Either or both of the upper surface 24 or the lower surface 26 may consist of a variety of surfaces that exist in parallel planes as illustrated in Figure 1. The retainer 16 of the spring seat will further contain an area 28 recessed at minus one of the planes of the first or top surface 24. The recessed area 28 may also be referred to as an inverted groove or shoulder. The internal surface 30 of the recessed area 28 has a concave shape relative to the first surface 24 or greater. The retainer 16 of the spring seat further comprises an axially directed interior cavity 32. The cavity 32 is limited by the interior surface 34. The inner surface 34 has an upper section 35 and a lower section 37. The upper section 35 is separated from the lower section 37 by a shelf 39 which extends radically inwards. In this embodiment, the interior cavity 32 is characterized by a sample 48 protruding from the plane of the upper section 35 of the surface 34 of the interior wall. The notch 48 functions to retain the rattle bumper 20 as will be discussed below. The design of the spring seat retainer provides a significantly large load bearing area for the spring insulator subjected to helical spring loads when compared to the conventional coil spring / spring insulator interfaces. As a result, the localized compression adjustment is minimized. Therefore, the retainer 16 of the spring seat provides maximum distribution of the loads of the coil spring in relation to the isolation of the spring.

The retainer 16 of the spring seat can comprise any suitable rigid material such as plastic or metal. However, plastic is especially preferred since the use of these materials minimizes metal-to-metal interactions and aids in the reduction of noise transmitted from the road and the rear axial towards the coil spring. Correspondingly, the squeaks and other noises perceived negatively are reduced. The appropriate plastic includes nylon, isoprene and polypropylene. A particularly preferred plastic is nylon when the performance characteristics are of predominant importance. A particularly preferred and commercially available material is Ultramid (R) 1 nylon which can be obtained from BASF Corporation of Wyandotte, Michigan. Alternatively, expensive materials such as polypropylene may be preferred in some designs. 1 Ultramid is a registered trademark of BASF Aktiengesellschaft and is used under license granted by BASF Corporation. A component integrated in the assembly 10 in the reduction of noise and vibration of automobiles is the insulator 18 of the spring. The insulator 18 functions to dampen vibrations and reduce the noise transmitted from the road / rear axle to the coil spring. The insulator 18 will generally comprise an elastomeric material. These materials may be foamed or not foamed. Suitable materials include polyurethane and rubber, both natural and butyl. Polyurethane, especially foamed or microcellular polyurethane, is preferred. An especially preferred material can be obtained commercially from BASF Corporation of Wyandotte, Michigan as the microcellular polyurethane Elastocell ™. The Elastocell ™ microcellular polyurethane usually has a density of 0.20 gram per cubic centimeter to 0.80 gram per cubic centimeter. Densities of .30 to .65 gram per cubic centimeter are preferred, with densities of .35 to .60 gram per cubic centimeter being especially preferred. 2 Elastocell ™ is a trademark of Elastogran GmbH and is used under license granted by BASF Corporation. The illustrative materials will usually have compression adjustments (D 3574, TEST D from the American Society for Testing Materials) of no more than 20 percent. Compression settings of no more than 10 percent are preferred, with compression adjustments of no more than 6 percent being especially preferred. In addition, these materials, in general, will have resistance to breakage (Method D 624 of the American Society for the Testing of Materials) of at least 8 KN / mm. Breaking strengths of at least 12 KN / mm are preferred with breaking strengths of at least 20 KN / mm or more being especially preferred. Finally, the illustrative materials will be characterized by exceptional durability. Those skilled in the art will appreciate that durability depends on the design and configuration of the part. More commonly, durability will be evaluated in terms of the number of cycles achieved before the failure of the part under a certain load. The use of microcellular polyurethane is particularly advantageous since a wide range of performance characteristics such as damping of specific frequency scales can be achieved in addition to the handling of the polyurethane composition and / or the symmetry of the part. The shape and configuration of the spring insulator 18 provides additional advantages to the assembly 10. Generally, the insulator 18 will have a thickness or height 36 of between 1 to 100 millimeters with thicknesses 36 of 5 to 55 millimeters being preferred. The thickness of 10 to 30 millimeters are especially preferred. In general, the insulator 18 will have a wafer-like configuration such as that illustrated in Figure 3. The asylator 18 will generally have a top surface 38 and an opposing bottom surface 40. The spring isolator 18 will generally be attached to the retainer 16 of the spring seat such that at least a portion of the upper surface 38 of the insulator 18 is consistent with at least a portion of the lower surface 26 or second of the retainer 16 of the dock seat. The insulator 18 can be fixed or attached to the retainer 16 of the spring seat by compression adjustment or mechanical means. Even when it is not essential, the insulator 18 of the spring, will generally have an interior portion 42 open. It will be appreciated by those skilled in the art that the spring insulator 18 need not be restricted to a cylindrical disk shape which is illustrated in Figure 3. Instead, the bushing 18 may have a square shape or a similar shape, as necessary to achieve coexistence between the upper surface 38 of the insulator 18 and the second or lower surface 26 of the retainer 16 of the spring seat. The configuration of the insulator 18 allows the use of what would otherwise be prohibitively expensive materials in the construction of the insulator 18. The wafer-like configuration, disc or slab of the insulator 18 allows the use of insulator manufacturing techniques wherein a Single large unit is molded or configured. Individual insulators can then be molded by cutting into strips or cutting a single large unit. This manufacturing technique results in a considerably lower cost per unit in relation to the insulator 18. It will be appreciated by those skilled in the art that these advantages could not be achieved with the constructions of the prior art assembly. Attachment of the insulator 18 to the retainer 16 of the spring seat results in a formation of the first sub-assembly 44. Placed within the axially directed interior cavity 32 of the retainer 16 of the spring seat, there is a ratcheting bumper 20. The ratcheting bumper 20 is positioned within the cavity 32 in such a manner that at least a portion of the external surface 46 of the ratcheting bumper 20 coexists with the interior surface 34 of the cavity 32 of the retainer 16. In particular, the lower part 47 of the ratcheting bumper 20 rests on the shelf 39 of the retainer 16 of the spring seat. The ratcheting bumper 20 can be securely positioned within the interior cavity 32 of the retainer 16 by means of a matrix clamping construction as illustrated in Figure 1 or through mechanical interference. As illustrated in Figure 1, the inner wall or surface 34 of the spring seat retainer is configured in such a manner that the protruding notch 48 is configured to coincide with a recessed or grooved section 50 of the outer surface 46 of the bumper 20 of rattle. The ratcheting bumper 20 may further have a cavity 52 of the internal core axially directed by the inner walls 54. Those skilled in the art will appreciate that the construction of the interior cavity 52 is such that the use of struts is possible, but is not required. Therefore, the cavity 52 is optional. In fact, it is an advantage of the assembly of the invention that the use of struts is not necessary and that it is not preferred. The ratcheting bumper 20 will generally comprise an elastomeric material, such as polyurethane or a natural or synthetic rubber, as described above with respect to the insulator 18. Microcellular polyurethane such as that discussed above is preferred. above with respect to the insulator 18 of the spring. However, it will be appreciated that the construction of the assembly 10 is such that the microcellular polyurethane and particularly, the Elastocell ™ microcellular polyurethane of varying density and performance characteristics can be used in order to obtain the different assemblies having performance characteristics addressed with particularity The addition of the ratcheting bumper 22 to the first assembly 44 comprising the spring seat retainer 16 and the spring isolator 18 results in the formation of a second sub-assembly 56. To the second sub-assembly 56 is further attached a spring 22 helical. The coil spring 22 will generally consist of metal and will have a construction such as those traditionally known in the art. The pier 22 helical will generally have an upper portion 58 and a lower portion 60. The lower portion 60 of the coil spring 22 is releasably attached to the spring seat retainer 16 by means of the lower positioning portion within the recessed area 28 of the first upper surface 24 of the spring seat retainer 16. It will be appreciated that the coil spring 22 surrounds the ratcheting bumper 20 and that the ratcheting bumper 20 extends upwardly through the helidoidal spring 22. Attaching the coil spring 22 to the second sub-assembly 56 results in the formation of a third sub-assembly 62, which can also be called a complete set. As illustrated in Figure 1, assembly 10 is a single unit that has no loose parts and is capable of being immediately fixed to a spring seat. The fixing of the assembly 10 will generally be carried out by means of a fixing means 64 and of the retainer 16 of the spring seat. The fixing means 64 generally comprises an extended arm 66 and a fixing hook 68, generally, there will be at least two extension arms 66 and are obviously opposite to create a distance D] _ between them. The extension arm 66 can be configured in such a way that the distance D ^ in the rest position is greater than the distance D? _ When the extension arms 66 are placed inside the opening 70 of the spring seat 12. The restricting edge 72 and the fixing hook 68 ensure that the assembly 10 fits securely within the seat 12 of the spring. Those skilled in the art will appreciate that the spring seat 12 will preferably consist of a steel die and can be welded on an axle 14 or otherwise mounted on the remainder of a car. The latter will be the case when it comes to higher assemblies. The design of the spring seat is intended to provide a means for positioning and fixing the insulator and providing a site in which the entire assembly 10 can be held in place. Turning now to an alternative embodiment of the assembly 10, Figure 4 illustrates an assembly 10a comprising a retainer 16a of the spring seat, a spring isolator 18a, a ratcheting bumper 20a and the coil spring 22a. It will be appreciated that, in general, the configuration of this embodiment corresponds to the discussion with respect to the embodiment of Figures 1 and 2. However, the fixing means 64 extends through the insulator 18a of the spring through a cavity 72 of the insulator 18a which is illustrated in Figure 5. The extension arm 66a extends through the cavity or hole 72 in the insulator 18a such that the outer surface 74 of the extension arm 66 coexists with the surface 76 or the inter-hole or cavity 42a of the insulator 18a. In this case, the insulator 18a is placed securely between the retainer 16a of the spring seat and the seat 12a of the spring. It should be understood that while the invention shown and described herein constitutes the preferred embodiments of the invention, it is not intended to illustrate all possible forms. A variety of constructions of set of variable configurations can be created by a person skilled in the art without deviating from the spirit and scope of the invention that is disclosed and claimed herein.

Claims (20)

R E I V I N D I C A C I O N E S;

1. A set for use to reduce the noise and vibration of automobiles, the assembly comprises: a spring seat retainer comprising (a) first and second surfaces directed oppositely, (b) a recessed area in the first surface, (c) an axially directed interior cavity; a spring insulator having at least a portion of a surface coexisting with a portion of the second surface of the spring seat retainer; a rattle bumper having an outer surface, a surface of which is coexistent with a portion of the inner cavity of the spring seat retainer; and a coil spring having a recessed lower section within the recessed area of the spring seat retainer such that the coil spring surrounds the rattle bumper.

The assembly according to claim 1, wherein the spring seat retainer further comprises (d) a fastening means for releasably connecting the assembly with an automotive spring seat.

3. The assembly according to claim 1, wherein the spring seat retainer comprises a polymer.

The assembly according to claim 3, wherein the spring seat retainer comprises a polymer that is selected from the group consisting of nylon and polypropylene.

The assembly according to claim 1, wherein the spring insulator comprises a microcellular polyurethane.

The assembly according to claim 5, wherein the spring insulator comprises a microcellular polyurethane having a density of .20 to .80 gram per cubic centimeter.

The assembly according to claim 1, wherein the rattle bumper comprises a microcellular polyurethane.

8. The assembly according to claim 6, wherein the microcellular polyurethane has a compression solidification not greater than 10 percent.

9. A set to be used to reduce the noise and vibration of automobiles, the assembly comprises: a spring seat retainer comprising (a) first and second surfaces directed in opposition, (b) a recessed area in the first surface, (c) an axial cavity directed axially; and a spring insulator having at least one paortion of a surface coexisting with a portion of the second surface of the spring seat retainer such that the spring insulator is releasably connected to the spring seat.

The assembly according to claim 9, further comprising a rattle bumper having an outer surface, a surface of which is coexistent with a portion of the inner cavity of the spring seat retainer.

The assembly according to claim 10, further comprising a coil spring having a recessed lower section within the recessed area of the spring seat retainer such that the coil spring surrounds the rattle bumper.

The assembly according to claim 9, wherein the spring seat retainer further comprises (d) a fastening means for releasably connecting the assembly with an automotive spring seat.

The assembly according to claim 9, wherein the spring seat retainer comprises a polymer.

The assembly according to claim 9, wherein the spring seat retainer comprises a polymer that is selected from the group consisting of nylon and polypropylene.

15. The assembly according to claim 9, wherein the spring insulator comprises a microcellular polyurethane.

16. The assembly according to claim 15, wherein the spring insulator comprises a microcellular polyurethane having a density of at least 20 grams per cubic centimeter and a compression solidification of at least 15 percent.

17. The assembly according to claim 9, wherein the rattle bumper comprises a microcellular polyurethane.

18. The assembly according to claim 15, wherein the microcellular polyurethane has a compressive setting or solidification not greater than 10 percent.

19. The assembly according to claim 18, wherein the spring insulator is a slice cut from a single molded unit and has a thickness of 5 millimeters to 55 millimeters.

20. A method for producing an assembly for use to reduce noise and vibration of automobiles, the method comprising: providing a spring seat retainer comprising (a) first and second opposingly directed surfaces, (b) a recessed area on the first surface and (c) an axially directed interior cavity; fixing a spring isolator on the spring seat retainer in such a manner so that at least the portion of an insulator surface is co-existing with a portion of the second surface of the spring seat retainer; releasably connecting the ratcheting bumper to the spring seat retainer in such a manner that a portion of an exterior surface of the ratcheting bumper is co-existent with a portion of the inner cavity of the spring seat retainer; and placing a lower portion of a coil spring within the recessed area of a spring seat retainer such that the coil spring surrounds the rattle bumper. SUMMARY OF THE INVENTION The invention provides an assembly for use to reduce the noise and vibration of automobiles transmitted from a road surface through the rim and axle system of the vehicle. The assembly of the invention comprises a spring seat retainer comprising (a) first and second opposingly directed surfaces, (b) a recessed area in the first surface and (c) an axially directed interior cavity. A spring isolator having at least a portion of a surface coexisting with a portion of the second surface of the spring seat retainer is affixed to the spring seat retainer. A rattle bumper having an outer surface is placed within the interior cavity of the spring seat retainer such that a portion of the outer surface of the rattle bumper coexists with the inner surface of the inner cavity of the seat retainer of dock. A coil spring is releasably connected to the spring seat retainer through an inner section retained within a recessed area of the spring seat retainer. The coil spring surrounds the rattle bumper. The invention provides advantages in cost and efficiencies as well as increased long-term durability and performance due to the elimination of the interactions of the vulnerable components with the degradation of the concentrated charge.