Patent Application
20080012188
Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, an insulator is shown generally at 20, 120, 220. In a first embodiment shown in
Although the invention is illustrated in different configurations in the first, second, and third embodiments, the insulators 20, 120, 220 in each of the embodiments include common features. The features common to each of the embodiments will be discussed prior to the discussion of each embodiment. To enhance consistency, the reference numerals of the common features of the insulator 20, 120220 in the first embodiment have been increased by 100 in the second embodiment, and increased by 200 in the third embodiment.
As shown in
Preferably, the first density of the first portion 28, 128, 228 is greater than the second density of the second portion 32, 132, 232 such that the compressibility of the second portion 32, 132, 232 is greater than the compressibility of the first portion 28, 128, 228. In other words, second portion 32, 132, 232 deforms more than the first portion 28, 128, 228 when subject to a load. Preferably the first density of the first portion 28, 128, 228 is further defined as being between 450 Kg/m3 and 1050 Kg/m3. Preferably, the second density of the second portion 32, 132, 232 is further defined as being between 300 Kg/m3 and 700 Kg/m3.
The first portion 28, 128, 228, the second portion 32, 132, 232, and the intermediate portion 30, 130, 230 are integrally formed of a common homogeneous microcellular polyurethane (MCU) material for defining a one-piece insulator 20 having different densities. In other words, the insulator 20, 120, 220 is a continuous unitary insulator 20, 120, 220 formed of MCU and having varying density within the insulator 20, 120, 220. For example, the MCU is of the type manufactured by BASF Corporation under the tradename Cellasto®. The MCU is a thermosetting material. In other words, once the MCU is formed and cured, the MCU is not meltable without permanently altering the chemical bonds and the physical properties of the MCU. Specifically, thermosetting material is defined by molecules that chemically bond with each other when heated. Thermosetting materials cannot melt without degrading because the melt temperature is higher than the chemical degradation temperature. More specifically, molecules of the thermosetting material cross-link with each other to create a permanent three-dimensional molecular network.
The MCU is formed from a two-step process. In the first step of the process, an isocyanate prepolymer is formed by reacting a polyol and an isocyanate. The polyol is polyester, and alternatively is polyether. The isocyanate is monomeric methyldiphenyl diisocyanate, and alternatively is naphthalene diisocyanate. In the second step of the process, the isocyanate prepolymer reacts with water to generate carbon dioxide and the carbon dioxide forms the cells of the MCU.
For example, polyester polyols are produced from the reaction of a dicarboxylic acid and a glycol having at least one primary hydroxyl group. For example, dicarboxylic acids that are suitable for producing the polyester polyols are selected from the group of, but are not limited to, adipic acid, methyl adipic acid, succinic acid, suberic acid, sebacic acid, oxalic acid, glutaric acid, pimelic acid, azelaic acid, phthalic acid, terephthalic acid, isophthalic acid, and combinations thereof. For example, glycols that are suitable for producing the polyester polyols are selected from the group of, but are not limited to, ethylene glycol, butylene glycol, hexanediol, bis(hydroxymethylcyclohexane), 1,4-butanediol, diethylene glycol, 2,2-dimethyl propylene glycol, 1,3-propylene glycol, and combinations thereof. The polyester polyol has a hydroxyl number of from 30 to 130, a nominal functionality of from 1.9 to 2.3, and a nominal molecular weight of from 1000 to 3000. Specific examples of polyester polyols suitable for the subject invention include Pluracol® Series commercially available from BASF Corporation of Florham Park, N.J.
For example, polyether polyols are produced from the cyclic ether propylene oxide, and alternatively ethylene oxide or tetrahydrofuran. Propylene oxide is added to an initiator in the presence of a catalyst to produce the polyester polyol. Polyether polyols are selected from the group of, but are not limited to, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, and combinations thereof. The polyether polyol has a hydroxyl number of from 30 to 130, a nominal functionality of from 1.8 to 2.3, and a nominal molecular weight of from 1000 to 5000. Specific examples of polyether polyols suitable for the subject invention include Pluracol® 858, Pluracol® 538, Pluracol® 220, Pluracol® TP Series, Pluracol® GP Series, and Pluracol® P Series commercially available from BASF Corporation of Florham Park, N.J.
For example, diisocyanates are selected from the group of, but are not limited to, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, ethylene diisocyanate, ethylidene diisocyanate, propylene diisocyanate, butylene diisocyanate, cyclopentylene-1,3-diisocyanate, cyclohexylene-1,4-diisocyanate, cyclohexylene-1,2-diisocyanate, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate, 1,4-naphthylene diisocyanate, 1,5-naphthylene diisocyanate, diphenyl-4,4′-diisocyanate, azobenzene-4,4′-diisocyanate, diphenylsulfone-4,4′-diisocyanate, dichlorohexamethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate, and combinations thereof. Specific examples of diisocyanates suitable for the subject invention include Lupranate® 5143, Lupranate® MM103, and Lupranate® R2500U commercially available from BASF Corporation of Florham Park, N.J.
The monomeric methyldiphenyl diisocyanate is selected from the group of 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, and combinations thereof. Specific examples of monomeric methyldiphenyl diisocyanates suitable for the subject invention include Lupranate® M and Lupranate® MS commercially available from BASF Corporation of Florham Park, N.J. The monomeric methyldiphenyl diisocyante may also be modified with carbonimide. Specific examples of carbonimide-modified monomeric methyldiphenyl diisocyante include Lupranate® 5143 and Lupranate® MM103 commercially available from BASF Corporation of Florham Park, N.J.
Preferably, the insulator 20, 120, 220 presents a skin of increased density 34, 134, 234 continuous with and surrounding the first portion 28, 128, 228, the intermediate portion 30, 130, 230, and the second portion 32, 132, 232. Specifically, when the insulator 20, 120, 220 is formed from MCU, the skin of increased density 34, 134, 234 results from the forming process. Because the insulator 20, 120, 220 has the skin of increased density 34, 134, 234, the insulator 20, 120, 220 is more resistant to slicing, abrasion, and wear.
In the first embodiment, as shown in
The shoulder portion 36 defines the first density and the projection portion 38 defines the second density different from the first density. The intermediate portion 30 has a transitional density transitioning between the first density of the shoulder portion 36 and the second density of the projection portion 38.
Preferably, the first density of the shoulder portion 36 is greater than the second density of the projection portion 38 such that the compressibility of the projection portion 38 is greater than the compressibility of the shoulder portion 36. In other words, the projection portion 38 deforms more than the shoulder portion 36 when subject to a load. Preferably, the first density of the shoulder portion 36 is further defined as being between 450 Kg/m3 and 1050 Kg/m3. Preferably, the second density of the projection portion 38 is further defined as being between 300 Kg/m3 and 700 Kg/M3.
More specifically, the shoulder portion 36, the intermediate portion 30, and the projection portion 38 are integrally formed of common homogeneous MCU material for defining a one-piece jounce bumper 22 having different densities. In other words, the jounce bumper 22 is a continuous unitary jounce bumper 22 formed of MCU and having varying density within the jounce bumper 22.
Preferably, the jounce bumper 22 includes the skin of increased density 34 continuous with and surrounding the shoulder portion 36, the intermediate portion 30, and the projection portion 38. The skin of increased density 34 increases resistance to slicing, abrasion, and wear.
As shown in
As shown in
As shown in
The first wheel suspension system 48 includes a suspension support structure 50 for mounting the first wheel suspension system 48 to the vehicle, a piston rod 56, a shock tube 54, and the jounce bumper 22. The piston rod 56 extends from the suspension support structure 50 along the axis A. A shock tube 54 is disposed about the piston rod 56 and is moveable toward and away from the suspension support structure 50 along the axis A. In other words, the piston rod 56 is telescopically received in the shock tube 54 and is telescopically slideable such that the piston rod 56 and the shock tube 54 are extendable and retractable relative to one another.
The jounce bumper 22 is mounted to the suspension support structure 50 about the piston rod 56 for isolating impacts between the shock tube 54 and the suspension support structure 50. Specifically, the bore 40 of the jounce bumper 22 receives the piston rod 56 and the jounce bumper 22 is disposed along the piston rod 56 adjacent to the suspension support structure 50. As the piston rod 56 retracts into the shock tube 54, the shock tube 54 approaches the suspension support structure 50 and applies a load to and compresses the jounce bumper 22.
As the load increases and the projection portion 38 is further compressed, the load is transmitted through the projection portion 38 to the shoulder portion 36. Because the shoulder portion 36 is less compressible than the projection portion 38, when a load is applied to the projection portion 38, the projection portion 38 compresses more than the shoulder portion 36 compresses.
As shown in
Accordingly, the jounce bumper 22 of the present invention has advantageous impact isolating characteristics. Specifically, because the projection portion 38 is more compressible than the shoulder portion 36, the projection portion 38 absorbs loads exerted by the shock tube 54. Because the shoulder portion 36 is less compressible than the projection portion 38, the shoulder portion 36 provides an increased block height. The block height is the height of the jounce bumper 22 when the jounce bumper 22 is fully compressed, i.e. when the jounce bumper 22 can not be compressed further. In other words, due to the varying density of the jounce bumper 22, the jounce bumper 22 has the combination of favorable characteristics, specifically the ability to isolate impacts as well as having an increased block height. The jounce bumper 22 may be optimized for specific applications by varying the height of the jounce bumper 22, the first density of the shoulder portion 36, and the second density of the projection portion 38 such that the jounce bumper 22 has favorable impact isolation and block height characteristics.
In the second embodiment, as shown in
Specifically, the bottom portion 58 extends along the axis A, the top portion 60 extends along the axis A, and the intermediate portion 130 is disposed between the bottom portion 58 and the top portion 60 along the axis A,
The bottom portion 58 portion defines the first density and the top portion 60 defines the second density different from the first density. The intermediate portion 130 has the transitional density transitioning between the first density of the bottom portion 58 and the second density of the top portion 60.
Preferably, the first density of the bottom portion 58 is greater than the second density of the top portion 60 such that the compressibility of the top portion 60 is greater than the compressibility of the bottom portion 58. In other words, the top portion 60 deforms more than the bottom portion 58 when subject to a load. Preferably, the first density of the bottom portion 58 is further defined as being between 450 Kg/m3 and 1050 Kg/m3. Preferably, the second density of the top portion 60 is further defined as being between 300 Kg/m3 and 700 Kg/m3.
Preferably, the body insulator 24 includes the skin of increased density 134 continuous with and surrounding the bottom portion 58, the intermediate portion 130, and the top portion 60. The skin of increased density 134 increases resistance to slicing, abrasion, and wear.
More specifically, the bottom portion 58, the intermediate portion 130, and the top portion 60 are integrally formed of common homogeneous MCU material for defining a one-piece body insulator 24 having different densities. In other words, the body insulator 24 is a continuous unitary body insulator 24 formed of MCU and having varying density within the body insulator 24.
Preferably, the body insulator 24 is generally cylindrical and defines an orifice 62 extending along the axis A through the body insulator 24.
As shown in
Because the bottom portion 58 is less compressible than the top portion 60. The top portion 60 absorbs and is compressed by loads exerted on the body insulator 24 by the vehicle body 68. As the load increases and the top portion 60 is further compressed, the load is transmitted through the top portion 60 to the bottom portion 58. Because the bottom portion 58 is less compressible than the top portion 60, when a load is applied to the top portion 60, the top portion 60 compresses more than the bottom portion 58 compresses.
The body insulator 24 of the present invention has advantageous impact isolating characteristics. Specifically, because the top portion 60 defines the second density lower than the first density of the bottom portion 58, the top portion 60 absorbs loads and dampens vibrations exerted by the vehicle body 68. Because the bottom portion 58 is less compressible than the top portion 60, the bottom portion 58 provides an increased block height. The block height is the height of the body insulator 24 when the body insulator 24 is fully compressed, i.e. when the body insulator 24 can not be compressed further. In other words, due to the varying density of the body insulator 24, the body insulator 24 has the combination of favorable characteristics, specifically the ability to isolate impacts as well as having an increased block height.
In the third embodiment, the first portion 228 is a lip 76 and the second portion 232 is a rim 78 such that the insulator 220 defines the coil spring isolator 26. The intermediate portion 230 extends between the lip 76 and the rim 78.
Specifically, the lip 76 defines the first density and the rim 78 defines the second density. The intermediate portion 230 has the transitional density transitioning between the first density of the lip 76 and the second density of the rim 78.
Preferably, the first density of the lip 76 is greater than the second density of the rim 78 such that the compressibility of the rim 78 is greater than the compressibility of the lip 76. In other words, the rim 78 deforms more than the lip 76 when subject to a load.
More specifically, the lip 76, the intermediate portion 230, and the rim 78 are integrally formed of common homogenous MCU material for defining a one-piece coil spring isolator 26 having different densities. In other words, the coil spring isolator 26 is a continuous unitary coil spring isolator 26 formed of MCU and having varying density within the coil spring isolator 26.
Preferably, the coil spring isolator 26 includes the skin of increased density 234 continuous with and surrounding the lip 76, the intermediate portion 230, and the rim 78. The skin of increased density 234 increases resistance to slicing, abrasion, and wear.
Preferably, the coil spring isolator 26 is generally cylindrical and the lip 76 defines a lip diameter LD and the rim 78 defines a rim diameter RD larger than the lip 76 diameter
In the third embodiment, as shown in
The coil spring isolator 26 absorbs loads and dampens vibrations from the coil spring 90. Specifically, because the rim 78 is more compressible than the lip 76, the rim 78 absorbs loads and dampens vibrations from the coil spring 90. Because the lip 76 is less compressible than the rim 78, the lip 76 has sufficient rigidity to maintain the coil spring 90 in position relative to the coil spring isolator 26. Specifically, the lip 76 has sufficient rigidity to prevent the coil spring 90 from moving in a plane generally perpendicular to the axis A of the coil spring isolator 26.
The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the present invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described.
