DE20010214U1 - Spring element - Google Patents

Description

BASF Aktiengesellschaft _#: 2O0Q0418,··, ₍ .0.Z. 0050/51474 DE

Spring element

Description
5

The invention relates to a spring element based on a cylindrical body (i) with a diameter (1) of 36 mm and a height (2) of 32 mm, which has a conical indentation (ii) with a depth (3) of 26 mm, an upper diameter (4) of 16 mm and a lower diameter (5) of 9 mm, wherein a cylindrical molded part (iii) with a diameter (6) of 9 mm and a height (7) of 11.8 mm, a truncated cone (iv) with a height (8) of 6 mm, a (iii) facing diameter (9) of 12.6 mm and a lower diameter (10) of 4 mm and a further cylindrical molded part (v) with a height (11) of 26 mm and a diameter (12) of 4 mm are centered on the lower side of (i) facing away from the indentation (ii). The spring elements are preferably based on cellular polyurethane elastomers, which may optionally contain polyurea structures, particularly preferably based on cellular polyurethane elastomers with a density according to DIN 53420 of 200 to 1100, preferably 300 to 800 kg/m ³ , a tensile strength according to DIN 53571 of > 2, preferably 2 to 8 N/mm ² , an elongation according to DIN 53571 of > 300, preferably 300 to 700% and a tear resistance according to DIN 53515 of > 8, preferably 8 to 25 N/mm. The spring elements according to the invention are shown in detail in Figures 1 and 2. The spring elements according to the invention are preferably used in automobile construction, particularly preferably in trucks, in particular for suspension and vibration damping of the passenger cabin.

The suspension elements made from polyurethane elastomers are used in automobiles, for example within the chassis, for example on the basis of elastic plastics, for example rubber or elastomers based on polyisocyanate polyaddition products, for example polyurethanes and/or polyureas, and are generally known. They are used in particular in motor vehicles as additional springs, impact absorbers or end stops.

As spring elements in trucks, for example, for suspension and vibration damping of the passenger cabin. The cabin is usually elastically mounted on the vehicle frame at several points. The bearing points serve directly or indirectly as connection points between the frame and the cabin.

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The vibration damper can be used continuously or only partially, and the vibration damper can convert the vibration energy into heat continuously or partially during driving. This decouples the cabin from the vibrations that are transmitted via the chassis. This leads to a significant improvement in driving comfort.

The invention can combine other important functions: In heavy-duty vehicles, the passenger cabins can usually be tilted. The unlocked cabin is tilted as a whole in the direction of travel via an axis, usually rotating bearing points on the front vehicle frame.

If the cabin is returned to its original position, the vibration damper can dissipate the energy, or part of the accelerated cabin mass, by converting it into heat. This prevents damage to the cabin or frame.

Due to the very different characteristics and properties of individual car models, the spring elements must be individually adapted to the various car models in order to achieve an ideal match. For example, when developing the spring elements, the weight of the vehicle, the chassis of the specific model, the intended shock absorbers, the dimensions of the car and its engine power as well as the desired spring characteristics depending on the desired comfort during the journey can be taken into account. In addition, the design of the cars means that individual solutions tailored to the respective car design have to be invented due to the space available.

For the reasons mentioned above, the known solutions for the design of individual spring elements cannot generally be transferred to new automobile models. With each new development of an automobile model, a new form of spring element must be developed that meets the specific requirements of the model.

The object of the present invention was therefore to develop a new, space-saving and cost-effective vibration damper for an existing concept, which would meet the specific requirements of this model and ensure the best possible driving comfort with high damping properties.

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0050/51474 EN

The spatial design of the spring elements, i.e. their three-dimensional shape, has a decisive influence on their function in addition to their material. The shape of the spring elements not only ensures that they fit precisely into the automobile construction, but also controls the spring characteristics in a targeted manner. Not only the length and thickness of the spring element influence the function, but also other design features such as milled recesses, curves, cuts, knobs, connection elements or similar. This three-dimensional shape of the spring element must therefore be developed individually for each automobile model.

Usually, vibration dampers of other types are screwed to the connection point. The screws can be foamed into the vibration damper by the cellular polyurethane elastomer, or can be subsequently inserted into the vibration damper.

The invention does not require any screw connections. The spring element according to the invention, which is shown in Figures 1 and 2, has a cylindrical body (i) with a diameter (1) of 36 mm and a height (2) of 32 mm, which has a conical indentation (ii) with a depth (3) of 26 mm, an upper diameter (4) of 16 mm and a lower diameter (5) of , wherein a cylindrical molded part (iii) with a diameter (6) of 9 mm and a height (7) of 11.8 mm, a truncated cone (iv) with a height (8) of 6 mm, a (iii) facing diameter (9) of 12.6 mm and a lower diameter (10) of 4 mm and a further cylindrical molded part (v) with a height (11) of 26 mm and a diameter (12) of 4 mm are centered on the lower side of (i) facing away from the indentation (ii). Components (i), (iii), (iv) and (v) can be produced in one step, for example in a single mold, or sequentially, for example by first producing (i) in a corresponding mold and then foaming (iii), (iv) and (v) onto the prefabricated part. Production-related deviations in dimensions of up to 2 mm are tolerable.

The first cylindrical body (i) can correspond in diameter and length to the hole on the frame of the attachment point and serves to fix the vibration damper. The truncated cone (iv), which is always larger in maximum diameter (9) than the first cylindrical body (iii), serves to secure the vibration damper against falling out and anchors it. The last cylindrical body (v) is an assembly aid with which the

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A truncated pyramid is pulled through the mounting hole and its dimensions can vary greatly.

The damping characteristics of this vibration damper must be specifically adapted to the vehicle. In particular, it is important to achieve the required force-displacement characteristic with the spring stiffnesses contained therein.

The following should be noted especially in this case:

- Low dynamic stiffening during vibration decoupling Maximum possible damping at high vibration energies

Limiting the travel of the suspension at high loads (tilting of the cabin)
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The force-displacement characteristic characterizes the above-mentioned properties and must be strictly observed.

These requirements are met by the spring elements presented at the beginning. This three-dimensional shape proved to be particularly suitable for meeting the specific requirements of the special automobile model, particularly with regard to the specific spatial requirements and the required spring characteristics.

By combining the damping characteristics in view of the spatial limitations, the development was the basis for this application, particularly because of the space-saving and cost-effective mounting.

The vibration dampers according to the invention are preferably based on elastomers based on polyisocyanate polyaddition products, for example polyurethanes and/or polyureas, for example polyurethane elastomers, which may optionally contain urea structures. The elastomers are preferably microcellular elastomers based on polyisocyanate polyaddition products, preferably with cells having a diameter of 0.01 mm to 0.5 mm, particularly preferably 0.01 to 0.15 mm. The elastomers particularly preferably have the physical properties described at the beginning. Elastomers based on polyisocyanate polyaddition products and their production are generally known and described in many ways, for example in EP-A 62 835, EP-A 36 994, EP-A 250 969, DE-A 195 48 770 and DE-A 195 48 771.

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The production is usually carried out by reacting isocyanates with compounds that are reactive towards isocyanates.

The elastomers based on cellular polyisocyanate polyaddition products are usually produced in a mold in which the reactive starting components are reacted with one another. Generally common molds can be used as molds, for example metal molds, which, due to their shape, ensure the three-dimensional shape of the spring element according to the invention.

The polyisocyanate polyaddition products can be prepared by well-known methods, for example by using the following starting materials in a one- or two-stage process:

(a) isocyanate,

(b) compounds reactive towards isocyanates,

(c) water and, where appropriate,

(d) catalysts,

(e) propellants and/or

(f) Auxiliaries and/or additives, for example polysiloxanes and/or fatty acid sulfonates.

The surface temperature of the inner mold wall is usually 40 to 95 ⁰ C, preferably 50 to 90 ⁰ C.

The production of the molded parts is advantageously carried out at an NCO/OH ratio of 0.85 to 1.20, wherein the heated starting components are mixed and introduced into a heated, preferably tightly closing mold in an amount corresponding to the desired molded part density.

The molded parts are cured after 5 to 60 minutes and can therefore be demolded.
35

The amount of reaction mixture introduced into the mold is usually such that the molded bodies obtained have the density already shown.

The starting components are usually introduced into the mold at a temperature of 15 to 120 ⁰ C, preferably 30 to 110 ⁰ C. The degrees of compaction for producing the molded bodies are between 1.1 and 8, preferably between 2 and 6.

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The cellular polyisocyanate polyaddition products are advantageously produced by the one-shot process using low-pressure technology or, in particular, reaction injection molding (RIM) in open or preferably closed molds. The reaction is carried out in particular with compression in a closed mold. The reaction injection molding technique is described, for example, by H. Piechota and H. Röhr in "Integralschaumstoffe", Carl Hanser-Verlag, Munich, Vienna 1975; D.J. Prepelka and J.L. Wharton in Journal of Cellular Plastics, March/April 1975, pages 87 to 98 and U. Knipp in Journal of Cellular Plastics, March/April 1973, pages 76-84.

When using a mixing chamber with several inlet nozzles, the starting components can be fed in individually and mixed intensively in the mixing chamber. It has proven advantageous to work according to the two-component process.

According to a particularly advantageous embodiment, a prepolymer containing NCO groups is first prepared in a two-stage process. For this purpose, component (b) is reacted with (a) in excess, usually at temperatures of 80 ⁰ C to 160 ⁰ C, preferably 110 ⁰ C to 150 ⁰ C. The reaction time is calculated to achieve the theoretical NCO content.

Accordingly, the production of the moldings according to the invention is preferably carried out in a two-stage process in which, in the first stage, a prepolymer containing isocyanate groups is prepared by reacting (a) with (b) and, in the second stage, this prepolymer is reacted in a mold with a crosslinking component optionally containing the other components described at the outset.

In order to improve the demolding of the vibration dampers, it has proven advantageous to coat the inner surfaces of the mold, at least at the beginning of a production series, with conventional external mold release agents, for example wax- or silicone-based ones or, in particular, with aqueous soap solutions.

Depending on the size and geometry of the molded part, the mold life is on average 5 to 60 minutes.

After the molded parts have been produced in the mold, the molded parts can preferably be tempered for a period of 1 to 48 hours at temperatures typically ranging from 70 to 120 ^° C.

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The following can be stated regarding the starting components for the production of polyisocyanate polyaddition products:

Generally known (cyclo)aliphatic and/or aromatic polyisocyanates can be used as isocyanates (a). Aromatic diisocyanates are particularly suitable for producing the composite elements according to the invention, preferably 2.2 ^l -, 2.4 ^l - and/or 4,4 *-diphenylmethane diisocyanate (MDI), 1, 5-naphthylene diisocyanate (NDI), 2,4- and/or 2,6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate (TODI), 1,2-diphenylethane diisocyanate, phenylene diisocyanate and/or aliphatic isocyanates such as 1,12-dodecane, 2-ethyl-1,4-butane, 2-methyl-1,5-pentane-1,4-butane diisocyanate and preferably 1,6-hexamethylene diisocyanate and/or cycloaliphatic diisocyanates e.g. cyclohexane-1,3- and 1,4-diisocyanate, 2,4- and 2,6-hexahydrotoluene diisocyanate, 4,4'-, 2,4'- and 2,2'-dicyclohexylmethane diisocyanate, preferably l-isocyanato-3,3,5-trimethyl-S-isocyanatomethylcyclohexane and/or polyisocyanates such as polyphenylpolymethylene polyisocyanates. The isocyanates can be used in the form of the pure compound, in mixtures and/or in modified form, for example in the form of uretdiones, isocyanurates, allophanates or biurets, preferably in the form of reaction products containing urethane and isocyanate groups, so-called isocyanate prepolymers. Preference is given to using optionally modified ^2,2V- , 2,4*- and/or 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 3,3'-dimethyldiphenyl diisocyanate (TODI), 2,4- and/or 2,6-tolylene diisocyanate (TDI) and/or mixtures of these isocyanates.

Generally known polyhydroxyl compounds can be used as compounds (b) which are reactive towards isocyanates, preferably those having a functionality of 2 to 3 and preferably a molecular weight of 60 to 6000, particularly preferably 500 to 6000, in particular 800 to 5000. Polyether polyols, polyester polyalcohols and/or hydroxyl-containing polycarbonates are preferably used as (b).

Suitable polyether polyols can be prepared by known processes, for example by anionic polymerization with alkali hydroxides, such as sodium or potassium hydroxide, or alkali alcoholates, such as sodium methylate, sodium and potassium ethylate or potassium isopropylate, as catalysts and with the addition of at least one starter molecule which contains 2 or 3, preferably 2 reactive hydrogen atoms bound, or by cationic polymerization with Lewis acids, such as antimony pentachloride, boron fluoride etherate, etc. or bleaching earth.

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as catalysts consisting of one or more alkylene oxides with 2 to 4 carbon atoms in the alkylene radical.

Suitable alkylene oxides are, for example, 1,3-propylene-5 oxide, 1,2- or 1,3-butylene oxide, preferably ethylene oxide, 1,2-propylene oxide and tetrahydrofuran. The alkylene oxides can be used individually, alternately one after the other or as a mixture. Examples of starter molecules that can be considered are: water, organic dicarboxylic acids such as succinic acid, adipic acid, phthalic acid and terephthalic acid, aliphatic and aromatic, N-mono- and N,N'-dialkyl-substituted diamines with 1 to 4 carbon atoms in the alkyl radical, such as mono- and dialkyl-substituted ethylenediamine, 1,3-propylenediamine, 1,3- or 1,4-butylenediamine, 1,2-, 1,3-, 1,4-, 1,5- and 1,6-hexamethylenediamine, alkanolamines such as ethanolamine, N-methyl- and N-ethylethanolamine, dialkanolamines such as diethanolamine, N-methyl- and N-ethyldiethanolamine, and trialkanolaitiines such as triethanolamine, and ammonia. Preferably used are di- and/or trihydric alcohols, e.g. alkanediols with 2 to 12 C atoms, preferably 2 to 4 C atoms, such as e.g. ethanediol, propanediol-1,2 and -1,3, butanediol-1,4, pentanediol-1,5, hexanediol-1,6, glycerol, trimethylolpropane, and dialkylene glycols, such as diethylene glycol and dipropylene glycol.

Polyester polyalcohols, also referred to below as polyester polyols, are preferably used as (b). Suitable polyester polyols can be prepared, for example, from dicarboxylic acids with 2 to 12 carbon atoms and dihydric alcohols. Examples of dicarboxylic acids that can be considered are:

aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid and sebacic acid and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. The dicarboxylic acids can be used individually or as mixtures. To produce the polyester polyols, it may be advantageous to use the corresponding carboxylic acid derivatives, such as carboxylic acid esters with 1 to 4 carbon atoms in the alcohol residue, carboxylic acid anhydrides or carboxylic acid chlorides, instead of the carboxylic acid. Examples of dihydric alcohols are glycols having 2 to 16 carbon atoms, preferably 2 to 6 carbon atoms, such as ethylene glycol, diethylene glycol, butanediol-1,4, pentanediol-1,5, hexanediol-1,6, decanediol-1,10, 2-methylpropane-1,3-diol, 2,2-dimethylpropanediol-1,3, propanediol-1,3 and dipropylene glycol. Depending on the desired properties, the dihydric alcohols can be used alone or, if appropriate, in mixtures with one another.

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Preferably used polyester polyols are ethanediol polyadipate, 1,4-butanediol polyadipate, ethanediol butanediol polyadipate, 1,6-hexanediol neopentyl glycol polyadipate, 1,6-hexanediol 1,4-butanediol polyadipate, 2-methyl-1,3-propanediol-1,4-butanediol polyadipate and/or polycaprolactones.

Suitable polyoxyalkylene glycols containing ester groups, essentially polyoxytetramethylene glycols, are polycondensates of organic, preferably aliphatic dicarboxylic acids, in particular adipic acid with polyoxymethylene glycols having a number-average molecular weight of 162 to 600 and optionally aliphatic diols, in particular butanediol-1,4. Also suitable polyoxytetramethylene glycols containing ester groups are those polycondensates formed from polycondensation with e-caprolactone.

Suitable polyoxyalkylene glycols containing carbonate groups, essentially polyoxytetramethylene glycols, are polycondensates of these with alkyl or aryl carbonates or phosgene. 20

Examples of components (b) are given in DE-A 195 48 771, page 6, lines 26 to 59.

In addition to the components already described which are reactive towards isocyanates, it is also possible to use low molecular weight chain extenders and/or crosslinking agents (bl) having a molecular weight of less than 500, preferably 60 to 499, for example selected from the group of di- and/or trifunctional alcohols, di- to tetrafunctional polyoxyalkylene polyols and alkyl-substituted aromatic diamines or mixtures of at least two of the chain extenders and/or crosslinking agents mentioned.

As (bl), for example, alkanediols having 2 to 12, preferably 2, 4 or 6 carbon atoms can be used, e.g. ethane-, 1,3-propane-, 1,5-pentane-, 1,6-hexane-, 1,7-heptane-, 1,8-octane-, 1,9-nonane-, 1,10-decanediol and preferably 1,4-butanediol, dialkylene glycols having 4 to 8 carbon atoms, such as diethylene glycol and dipropylene glycol and/or di- to tetrafunctional polyoxyalkylene polyols.

However, branched-chain and/or unsaturated alkanediols with usually no more than 12 carbon atoms are also suitable, such as 1,2-propanediol, 2-methyl-, 2,2-dimethyl-propanediol-1,3, 2-butyl-2-ethylpropanediol-1,3, butene-2-diol-1,4 and butyne-2-diol-1,4, diesters of terephthalic acid with glycols with 2 to 4 carbon atoms, such as terephthalic acid-bis-ethylene glycol-

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or -butanediol-1,4, hydroxyalkylene ethers of hydroquinone or resorcinol, such as 1,4-di-(b-hydroxyethyl)-hydroquinone or 1,3-di(b-hydroxyethyl)-resorcinol, alkanolamines with 2 to 12 carbon atoms, such as ethanolamine, 2-aminopropanol and 3-amino-2,2-dimethylpropanol, N-alkyldialkanolamines, such as N-methyl- and N-ethyl-diethanolamine.

Examples of higher-functional crosslinking agents (bl) include tri- and higher-functional alcohols, such as glycerin, trimethylolpropane, pentaerythritol and trihydroxycyclohexanes, as well as trialkanolamines, such as triethanolamine.

The following can be used as chain extenders: alkyl-substituted aromatic polyamines with molecular weights preferably from 122 to 400, in particular primary aromatic diamines which have at least one alkyl substituent in the ortho position to the amino groups, which reduces the reactivity of the amino group by steric hindrance, which are liquid at room temperature and at least partially, but preferably completely, miscible with the higher molecular weight, preferably at least difunctional compounds (b) under the processing conditions.

To produce the moldings according to the invention, the technically readily accessible 1,3,5-triethyl-2,4-phenylenediamine, l-methyl-3,5-diethyl-2,4-phenylenediamine, mixtures of 1-methyl-3,5-diethyl-2,4- and -2,6-phenylenediamines, so-called DETDA, isomer mixtures of 3,3'-di- or 3,3',5,5'-tetraalkyl-substituted 4,4'-diaminodiphenylmethanes with 1 to 4 C atoms in the alkyl radical, in particular 3,3',5,5'-tetraalkyl-substituted 4,4'-diaminodiphenylmethanes containing methyl, ethyl and isopropyl radicals, and mixtures of the aforementioned tetraalkyl-substituted 4,4'-diaminodiphenylmethanes and DETDA can be used.

To achieve special mechanical properties, it may also be expedient to use the alkyl-substituted aromatic polyamines in a mixture with the aforementioned low molecular weight polyhydric alcohols, preferably di- and/or trihydric alcohols or dialkylene glycols.

However, aromatic diamines are preferably not used. The products according to the invention are therefore preferably prepared in the absence of aromatic diamines.

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The preparation of the cellular polyisocyanate polyaddition products can preferably be carried out in the presence of water (c). The water acts both as a crosslinker to form urea groups and as a blowing agent due to the reaction with isocyanate groups to form carbon dioxide. Due to this dual function, it is listed separately from (e) and (b) in this document. By definition, components (b) and (e) therefore do not contain any water, which by definition is listed exclusively as (e).

The amounts of water which can be used are conveniently from 0.01 to 5% by weight, preferably from 0.3 to 3.0% by weight, based on the weight of component (b). The water can be used completely or partly in the form of the aqueous solutions of the sulfonated fatty acids.

To accelerate the reaction, generally known catalysts (d) can be added to the reaction mixture both during the preparation of a prepolymer and optionally during the reaction of a prepolymer with a crosslinking component. The catalysts (d) can be added individually or in admixture with one another. These are preferably organometallic compounds, such as tin(II) salts of organic carboxylic acids, e.g. tin(II) dioctoate, tin(II) dilaurate, dibutyltin diacetate and dibutyltin dilaurate and tertiary amines such as tetramethylethylenediamine, N-methylmorpholine, diethylbenzylamine, triethylamine, dimethylcyclohexylamine, diazabicyclooctane, N,N'-dimethylpiperazine, N-methyl,N'-(4-N-dimethylamino)butylpiperazine, &Ngr;,&Ngr;,&Ngr;',N",N"-pentamethyldiethylenediamine or similar.

Other suitable catalysts are: amidines, such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tris-(dialkylaminoalkyl)-s-hexahydrotriazines, in particular tris-(ν,ν-dimethylaminopropyl)-s-hexahydrotriazine, tetraalkylammonium hydroxides, such as e.g.

Tetramethylammonium hydroxide, alkali hydroxides, such as sodium hydroxide, and alkali alcoholates, such as sodium methylate and potassium isopropylate, as well as alkali salts of long-chain fatty acids with 10 to 20 C atoms and optionally pendant OH groups.

Depending on the reactivity to be set, the catalysts (d) are used in amounts of 0.001 to 0.5 wt.%, based on the prepolymer.

If necessary, blowing agents (e) commonly used in polyurethane production can be used. Suitable examples are low-boiling liquids which, under the influence of

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exothermic polyaddition reaction. Suitable liquids are those that are inert towards the organic polyisocyanate and have boiling points below 100 ^° C. Examples of such liquids that are preferably used are halogenated, preferably fluorinated hydrocarbons, such as methylene chloride and dichloromonofluoromethane, per- or partially fluorinated hydrocarbons, such as trifluoromethane, difluoromethane, difluoroethane, tetrafluoroethane and heptafluoropropane, hydrocarbons, such as n- and iso-butane, n- and iso-pentane and the technical mixtures of these hydrocarbons, propane, propylene, hexane, heptane, cyclobutane, cyclopentane and cyclohexane, dialkyl ethers, such as dimethyl ether, diethyl ether and furan, carboxylic acid esters, such as methyl and ethyl formate, ketones, such as acetone, and/or fluorinated and/or perfluorinated, tertiary alkylamines, such as perfluorodimethylisopropylamine. Mixtures of these low-boiling liquids with one another and/or with other substituted or unsubstituted hydrocarbons can also be used.

The most suitable amount of low-boiling liquid for producing such cell-containing elastic moldings from elastomers containing bonded urea groups depends on the density that is to be achieved and on the amount of water that is preferably used. In general, amounts of 1 to 15% by weight, preferably 2 to 11% by weight, based on the weight of component (b), give satisfactory results. It is particularly preferred to use only water (c) as a blowing agent.

In the production of the molded parts according to the invention, auxiliary substances and additives (f) can be used. These include, for example, generally known surface-active substances, hydrolysis inhibitors, fillers, antioxidants, cell regulators, flame retardants and dyes. Suitable surface-active substances are compounds which serve to support the homogenization of the starting materials and are optionally also suitable for regulating the cell structure. Examples of emulsifiers according to the invention include additional compounds with an emulsifying effect, such as the salts of fatty acids with amines, e.g. diethyl oleate, diethanolamine stearic acid, diethanolamine ricinoleic acid, salts of sulfonic acids, e.g. alkali or ammonium salts of dodecylbenzene or dinaphthylmethanedisulfonic acid. Other possible foam stabilizers are e.g. ethoxylated alkylphenols, ethoxylated fatty alcohols, paraffin oils, castor oil or ricinoleic acid esters, Turkey red oil and peanut oil and cell regulators such as paraffins and fatty alcohols. In addition, polysiloxanes and/or fatty

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acid sulfonates can be used. Generally known compounds can be used as polysiloxanes, for example polymethylsiloxanes, polydimethylsiloxanes and/or polyoxyalkylene silicone copolymers. The polysiloxanes preferably have a viscosity at 25°C of 20 to 2000 MPas.

Generally known sulfonated fatty acids, which are also commercially available, can be used as fatty acid sulfonates. Sulfonated castor oil is preferably used as the fatty acid sulfonate.

The surface-active substances are usually used in amounts of 0.01 to 5 parts by weight, based on 100 parts by weight of components (b). 15

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Spring element

Summary 5 The invention relates to a spring element based on a cylindrical body (i) with a diameter (1) of 36 mm and a height (2) of 32 mm, which has a conical indentation (ii) with a depth (3) of 26 mm, an upper diameter (4) of 16 mm and a lower diameter (5) of 9 mm, wherein a cylindrical molded part (iii) with a diameter (6) of 9 mm and a height (7) of 11.8 mm, a truncated cone (iv) with a height (8) of 6 mm, a (iii) facing diameter (9) of 12.6 mm and a lower diameter (10) of 4 mm and a further cylindrical molded part (v) with a height (11) of 26 mm and a diameter (12) of 4 mm are centered on the lower side of (i) facing away from the indentation (ii).

Claims (5)

1. Spring element based on a cylindrical body (i) with a diameter ( 1 ) of 36 mm and a height ( 2 ) of 32 mm, which has a conical indentation (ii) with a depth ( 3 ) of 26 mm, an upper diameter ( 4 ) of 16 mm and a lower diameter ( 5 ) of 9 mm, wherein a cylindrical molded part (iii) with a diameter ( 6 ) of 9 mm and a height ( 7 ) of 11.8 mm, a truncated cone (iv) with a height ( 8 ) of 6 mm, a (iii) facing diameter ( 9 ) of 12.6 mm and a lower diameter ( 10 ) of 4 mm and a further cylindrical molded part (v) with a height ( 11 ) of 26 mm and a diameter ( 12 ) of 4 mm. 2. Spring element according to claim 1 based on cellular polyurethane elastomers. 3. Spring element according to claim 1 based on cellular polyurethane elastomers with a density according to DIN 53420 of 200 to 1100, a tensile strength according to DIN 53571 of 2, an elongation according to DIN 53571 of ≥ 300 and a tear resistance according to DIN 53515 of ≥ 8 N/mm. 4. Automobiles containing spring elements according to one of claims 1 to 3. 5. Truck comprising spring elements according to one of claims 1 to 3.