DE1204540B - Vehicle suspension in which the load to be cushioned is borne simultaneously by two types of elastic cushioning members - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

~. rr

12-4 54 "

■ • 4 S i?

Int. α .:

B62d

German class: 63 c - 41

Number: 1204 540

"File number: T'1334" 011 / 6S c
ί.ι. ·· .- «.-, ν5ί (· η ν r; U,;>':! -., - Date of registration: June 11, 1957

November 4, 1965

The invention relates "to a vehicle suspension system in which the load to be cushioned is supported by two types of elastic suspension girders at the same time;"vöü'-whom? ^? da's "eiiid · äus '^ inerim'ech'ä-" fdsclien * Feilet b'estetitTwelclie ¹ fuVsiett ^ atfein'eine "with tler'load hneär-verääderh & ite -Mslink% ng ^: weögt S ¹ UBnS lii der-'Nföskhe' ett -'gewfsseTtt WöÄe'S'diese'f'-Ätrs · - leflküng has, Mhreüd'das 'change ak§ a = firing of pneumatic Äif'b'estehf. ^!! ""' »* · '""' * ■ Fa-M «-Ο- · - · *

In particular, the invention relates to vehicle suspension. This type of vehicle is used for vehicles whose load can fluctuate within wide limits. The invention is intended in particular to form such a cushion so as to better the various requirements of practice -. 'Corresponds than hitherto, and in particular'its' Isöchronisniüs despite the Belastungsänderungeii · "retains ^f."

Vehicle suspension systems in which a mechanical Feüet'mit! Emerpneumatisdien Fede ¥ -i £ oMiinierMst, sM-än: sich "befeannt." ^rj BeiMitesen "-ÄbfedeMafe 'h' but 'the Öasfflasse'-the ff% ⁿ pneÜMätisch ^ Edel nitiht kbüsta'nt''There^'isf" ^feriföt:?. one ⁱⁿ cushioning *% ekännt ?, ^in-4 the ""pnfcumati-'Feder'-only äls- ^s Stbßdäinp "fer'dient tiüd '" die ^ Aüslenkutfg k% ifesweg "-to a could'value', •• If -'diei'Graße vehicle suspension, in which the to be cushioned
Load is borne simultaneously by two types of elastic cushioning members "

* Aiomeidier "" "" '* ""

Maurice Francois Alexandre Julien;
Usines-Paulstr-a Societe 'anonyme, ^ Paris

Representative:

Dipl.-Tng. E. F. Eitner, patent attorney,

Mii'nchen: S ^ vErhaiafstr / S "^ '' ⁴ ^"""'' r

Named as Effindef: "" "

Maurice Frangois Alexandre Julien, Paris

"Requested priority *: ■ - ~ ·
ao iJfä'ökfeifcE'vbin '2'5IJUm 1956 (717 325)

• ■■ Υ * Λ ■; .r. . .ν. Vi ~. ~; i-Khrf ■ ί '· ή ü

exposed surface of the "deformable wall opposite HegenÜe'i'Mäcfter -λ« · «> - ικ« λ.- ' ^: «« μμ.' «.iaM-iusii

known Fahrzeugabfedefung'Mrf die'Druckltift for the 'pneumatic spring ^; 'äus "'ein" -Drücklüitsy ^! stem after Atttiet ■ D'ruciluftbrem'sänlizierto ^T vbB ¹ Bisäibaihn'-wagen-Oder-von ^^ menY ^ Eolbenkofflpressor ägelifcferl ·, dfe ^ dwdfr-'die - SchWingbewe'gtfngen "'der-"Fede'rh% e7-made5 -wkdr "Auc" h ^l -hiej is the ' ^x ' Aüslenßaig ^! 'not constant *' because ^{> 4} ! the - ■ E & iHtüng- ^ works with ^ eiaeM piston / which * chft a 'cylinder displacement came to allow air to be displaced. In this Bekännfön Äbffedefun'g'i ^ miubrigen-tiife pneumaiisehe ^ def only effective- when the "vehicle * belastetest; -währerid" They ^ iÄ "-leerein RECOGNIZED * ird" ^of: iFateeügs keihen part 'defr cushioned Eäst -tragt · ~ "- ■" ■ " ¹ ^""- ⁿ ' ^: ·''- ■ ¹ ^" - ". v ¹ ' ·· '''In contrast, the invention exists in the case of suspensions of the included'g'egehMeÄ&' Ärt däfinjidaß 'däsöelästisehe Abf eäerungsglietf'prieumätfecHör - -type of- eirier' Ga ¹ S ^ quantity -with 'constant -measures-' formed '-the ^ is'formed' in a 'dense;"atleast" partly düi? Ch-'^; a deformable, offering a 'negligent resistance' to the deformation ^^ Wandiing limited, aas-der'-peculiarities pheutoatisclen ¹ ! Feder '· uM'eiiiem with this Yerbundeuen "Bfehältfer" imposing receptacle system • is'' and -deafeai - VbrandeiHchir pressure is constantly balanced by the pressure of a liquid ^ m'enge is, '* welciter aüf-'die,'der'Vom · Gas FlussiiMeifäinenge ^: miÄe'ls ^l --fei) Eie &' ^! I ¥ etteüe # s ^: i ^v 'b'ewiSi wffd' ^ te ssSm-iiewelh'dMes «Gfrgän 'Öuiife ^ diö-iÄiji lenkdn ^ der ^ FgOeiiung- geStg & 6rt- ^: * 5 ¥ a, Äda
furthermore ^ def 'disgusting' - 'Criick' stäädig-nin «'ä
phöum'äfisohen FMe'r'äu ^! sgeübt "" wi (l ', welcTie between the -abgefe'dei * ¹ ten'MääSe ^i% fnä ^"i of - abgefe'äeitet ftichf mass mgesfchältät ^" is """^" ^ ¹ --1 -'"'- J-oaaie \« r: zvs > ^s I>ie'ErfifidMg'wiM on the basis of the drawing bi> il ^ Siflif "'''' « 'r ^ aRi

F i g. 1 shows a diagram which illustrates the operation of a vehicle suspension according to the invention, and "'·· \

F i g. 2 shows a practical embodiment of such a cushioning.

-. * It is first-to certain properties of the usual -mechanischen ^l and pneumatic -Abf ede "· stanchion .erinnert. A "mechanical" cushioning is understood here to mean cushioning, - which springs made of metal or any other fixed plant, such as -z. B. 'rubber, used, in which cfie · - · rigidity K' is constant or practically constant, at least in the vicinity of a certain static 'deflection' of the 'spring ^< Deflection 'ä ^{; a} f Miieären Fedör at "-einer ⁱ ' B ^f 6läs'türig ^I Mg 'det- ^! Distance between ^; ' dM iäittleretf positions Hes ^; frSien ^: Endes de

is unloaded'Zustand or under the load Mg and that its rigidity K is the ratio between this suspended load Mg and the corresponding

Deflection d , i.e. K = —r-) ·

If the original suspended mass is Af ₀ , the natural frequency (W _{0 of} the fixed suspension is in a first approximation equal to that of a simple pendulum, the length of which is equal to the deflection d ₀ corresponding to the load M _B g , namely

what can also be written:

adiabatic exchange, d. H. without heat exchange with the outside area) XUggt ..

When the suspended mass M ₁ = λ M ₀ , where e.g. B. λ is greater than one, compresses the above pressure control, which seeks to keep the deflection of the suspension constant, the invariable gas mass to a pressure P ₁ , which is greater than P ₀ by pushing it into a volume V ₁ , which is less than V ₀ . After equilibrium has been established, one has P ₁ S = Mjg = λM _o g = λP ₀ S, i.e. P ₁ = λ P ₀ , and one then obtains the natural angular frequency of the perpendicular oscillations of the mass M ₁ around its equilibrium position (which is the same as the previous one ):

CO _n =

CO ₁ =

with L = ---,

M ₀

. If the suspended mass M ₁ = λ M ₀ , ao results for the new natural angular frequency of the suspension:

^{0) 1} ~

The mechanical suspension, which is characterized by a deflection that changes with the load, is therefore not isochronous and its angular frequency changes with this deflection like the reciprocal of the square root of the load ratio.

With "pneumatic" cushioning with deflection compensated at least partially under load is a cushioning to understand which the elasticity a compressible gas, e.g. B. air is used and works with a certain mass of this gas, the pressure of which is regulated so that when there is a change the load on the suspension, this has a constant or practically constant deflection.

Such cushioning is particularly known under the name of hydropneumatic cushioning or .ole-pneumatic suspension known, depending on whether the pressure changes of the compressed gas by Pressurized water or pressurized oil can be controlled.

If) the original suspended mass is M ₀ and the unchangeable gas mass occupies a volume V ₀ under a pressure P ₀ , the natural angular frequency Cu _{0 of} the perpendicular oscillations of this mass around its position of equilibrium can be written:

CO _n =

where h _{0 is} the height of a fictitious cylinder, the volume of which is V ₀ , and which has the cross section S with which the compressed gas holds the mass M ₀

where g, α and S have the same values as before.

Since the equilibrium is set relatively slowly at the level corresponding to the constant selected deflection, the conversion takes place isothermally and one obtains in practice: P ₁ V ₁ = P ₀ F ₀ , ie P ₁ A ₁ = P ₀ Ii ₀ .

One therefore obtains

pi

and

CO ₁ =

= co _o

S =

M ₀ g

and Zz _n = ——

and where σ is a polytropic exponent (such that pV = constant) which in the case of diatomic gases, e.g. B. air, between 1 (with an isothermal exchange during the oscillation, i.e. when the entire generated heat is dissipated) and 1.41 (with a The pneumatic cushioning with deflection compensated under load is therefore not isochronous and its natural angular frequency changes like the square root The change in pressure P ₀ , which seeks to keep the deflection constant or to limit its changes with a variable load, causes an isochronism error, but in the opposite sense as with mechanical springs.

In summary it can be said that the "mechanical" suspension and the "pneumatic" suspension with deflection compensated for under load, both are not isochronous. Your circular frequencies Both change with the load, but in the opposite sense, namely in one proportional to the reciprocal of the square root of the load ratio and at the other pro proportional to this root.

In order to remedy the isochronism error of this cushioning, cushioning is used according to the invention the one above with a cushioning of the other above type combined in such a way that they work essentially in parallel, and that their At least partially compensate for changes, so that the resulting cushioning is practically in spite of the very significant load fluctuations is isochronous, d. H. has an angular frequency to which the load changes have practically no influence.

Such an arrangement is particularly useful for vehicles for transporting passengers, as it allows the comfort of the cushioning regardless of the number and weight of passengers close.

The calculation shows that the most favorable isochronism conditions are obtained when the two

5 6

Suspension (mechanical suspension and the two types of suspension (mechanical suspension

compensated pneumatic suspension), which prak or compensated pneumatic suspension)

work table in parallel, set as follows where the combined suspension exists,

are: would be 40%.

If P ₁ and P _{2 are} the practical limits of FIG. 5, it should be noted that the determination of the

are the load acting on the sprung part, initial conditions according to the above explanations

First of all, the overall arrangement for the beginning is in no way a limitation. The same

conditions set, which has a value P which applies to those used in the above calculation

Load correspond to which between the arith parameters. Rather, it is the combination that is essential

metic means A + Zl _and the geometric ^{10 em} ! f mechanical cushioning with a pneumatic

2 ⁶ muffle cushioning, especially for precise or

Mean 1 / P ₁ P ₂ is located. even approximate and even roughly

It is assumed that then e.g. B. the two approximated production of the isochronism conditions.

Cushions bear half the load. On F i g. 1 is the cushioning very schematically

An initial value is thus obtained for the setting 15 of any suitable control element

of the level Z of the sprung part with respect to the mass 1 shown on a part 2, which in turn

unsuspended part. Therefore, if the mechanical on the steering knuckle or the wheel axle of a wheel 3

Spring, as stated above, half of the load P rests, whereby the clearance consists of two springs,

is supposed to take up, this level is Z through the examinations which work in parallel and are constantly at the

steering ä = £ the —ta spring under the - ™ * ^^

_Concern t be 8tim n _t . The other part 1 of the

The load is represented by the pneumatic spring on a bellows 5 which is inflated under pressure take whose parameters, in particular that of this 25, which is very little in the transverse direction

" ,, P , 1. j α" .ι j 1 χ τ. j is stretchable but axially deformable.

Value —- corresponding inflation pressure p, corresponding to - ^ ™., -,. ,. , ■, - ■,

2 i r -Q ₆₁ rj -, ^ 2 can _essentially only a vertical

are to be determined. Perform translational movement, d. i.e., its

The cushioning formed in this way, namely the strikes, is transmitted to each of the two springs 4 and 5 with substantially the same deflections, the mechanical cushioning and the pneumatic cushioning 3 °. On suspension, swing functional with the same period Fig. 1 is in fact believed that the part 2 to at launch of the load P that is to say, the static Wirkungs- two supported by a mass of 1 vertical rods 6 height A which ^derive in the formula for the angular frequency S *>. ^d ? ^ch If ^you can also use any other means for

ο ^ be intended for the same purpose,

of the vibrations of the pneumatic spring is received, 35 For the spring 4, a spring is selected whose

must expediently be equal to the deflection J = *, mechanical stiffness around the one defined below

2fc mean static deflection under load around

which in the same way in the formula for the circular constant or practically constant, thus the above

frequency of the vibrations of the fixed spring is received. to calculate the angular frequency of the fixed distance

This would also remain valid if the suspension adjustments made are applied.

mechanical spring yield is variable, the can.

instead of being constant. Namely, it is only the value that the bellows 5 forming the pneumatic spring forms

its rigidity around the deflection of the active part of a hydropneumatic or

Meaning, which corresponds to level Z , on oleopneumatic cushioning, which is preferable

which the pneumatic spring always carries the suspension 45 from the sprung part of the vehicle

seeks to be traced back. and as will be completed below.

The above initial conditions seem to correspond to a pipeline 7 connecting the bellows 5 with a best isochronism of cushioning around its equilibrium chamber or an equilibrium weight position. If thereupon the container 8, in which a deformable dense bellows changes the load from the value P, causes the 5 ° or a bubble 9 to be arranged. The bladder 9 contains change in pressure ρ in the pneumatic member an incompressible pressure medium, e.g. B. oil, and the correction of the level Z. is fed through a pipe 10, which with

The individual vibrations of the two springs are then connected to the intermediate chamber 11 of a slide no longer isochronous because, as stated above, it is. This chamber 11 is z. B. in a cylinder 12 Radial frequency of the vibrations at the one with the 55 delimited by two pistons 13 and 14, which by Load increases while they are rigidly connected to each other at the other a rod 15, and decreases with increasing load. Thanks to the openings in the position shown inventive combination of these two opposite feed line 16 or a discharge line 17 run Dependencies are what ultimately close one.

⁶ ° in the position shown is the

practically isochronous with the mass cushioned by the load P at the level Z above the

corresponding vibrations. Part 2 in a static equilibrium what a

The calculation shows that with the above precisely determined total deflection of the total

conditions corresponds to a doubling of the spring-loaded suspension. Due to the large deformation

Mass in the case of the subject of the invention 65 availability of the bladder 9 is located in this bladder

composite cushioning only one change contained incompressible pressure medium in the

the angular frequency of 4% would result, while pressure equilibrium with the gas, which in the

.this change of the order of magnitude for each of the internal volumes V of the equilibrium container 8, the

instructs

T6e $ nmic £ ien ^ ases iAaagUS6?. ^ FfoÄftmg ^ 0 ΐΰκϊ Her ZwiicHenkamnierll ^ aes; | Qhiet) ers.- "": * * "JThis inflation pressure ^ of the bellows S is maintained by '' that ⁴ " at the beginning of ^{': s} -the G16ichgewiBhts

■ e.Hes' ^ enfüs iremgefuhff becomes; "^" "Üiese'Ga-smksse we'd preferably chosen so that m'defftargBtefc

unff ^: die * pneumMsQhV'feaer'5je ^il äie'Oalft? e des' ^ re ¹ - "

_r %, if S is the contact cross-section of the bellows 5

at the crowd l'ist) / * ""

⁴ "Furthermore" Mt die-.between the smallest load P ₁ '- ■ untaergrMtetfBeiästunt ^ VefcM ^ eÄdSfuSg jpe

V ^ fSts ^ esti & niteiiWertBlimited? "K-TFACH def 'VersieTlunfUei ^ pistons 13 and 14 of the slider up or down is entwödBr ate tpeMeifeng'jj'p'-th" the "$ Abjfahri5 tungl7 * with the ZwiscleMkriiiafefXi '" desSchlebefs iii Ve'rbiidüng gläefzti ^ ä ^ kne ^ eranffe ^
mens'uTder bladder ^{1 9;} 'mlr' thus '* a ^l "' ÄJidertfiig '-"' diiS pressure 'of the "uHverärSlefffohSn gas flow vessels''m' äenfoOeh defined" volume F "and ¹ a deformation · - of the bellows 5 result.

These movements of the piston of the slide are _{sa ia} ^ er tafc 'the V ^ n ^ e ^^ äu-aer Abfedefuug- ¹ wleiier ^ tellSn' ^: '(Which ^ ^s in ^!!! natufiiöief ^J way ^ Ä dhn € - ± Önipens-ä'tiöX ^l d'e'ir öb! | En

Cushion
iiöief

ieXMrknlfterbe ^ fifnÄfwuidSHX'iiiafe'm

MäikcrpdegBaWgSwältwir ^ zwec ^ ert, which is between the arithmetic

the values of the limit loads P ₁ and P ₂ . ^ '^ ScnlieMcJtt pchtefman * es * zWecTknuU $ ^ "so" einVäaß aie "' Ä ^ genb ^ c ^ säusien £ ungelfi 'eggs * feathers 4""ünd ~ S iim äas'Mveäu'Zter'MäVseU.nerum'fur' denJ? ert ^e P ^v

are the same (by making -r- = -gj- ,

one achieves the equality of the individual circle sequences UeFFeyäefn'ft and ^ S ^ uf ^ don ^ err ^ äSF ^ ßelaMÜni).

.Under recombining the omgen Aiisfüiirurigen ^ wjfra '"also * ate ¹ 'determination" dfer 'VefscKfeäenen-Iaräm'etef ^? cjer Ärifehefu'ng'zlif.iHCTsMun ^ aer preferred, supplementslur aas work, which "aen'gunstigMen ^ isochronism ^ inYe'r oscillations around ^ their ^ same ^ EissteEuiag ^ ferum" guarantee, Iqlgenä like made: * "" ^{8 JC5ie limit values} "?! 'uHa'ϊ * ^ who ^ en' accepted. Au's * 4iesen '" one runs "onei ^^ is ^ hen- ^ jlen ^ ben äefimerten' ^ Mittelweifte fiegenaen '^ erif von Püüä .des · vehiclei' gegedüber-ihTetti urspiüngMchen ^value -genommen ⁸ ode? has decreased. ^JTC 3And ^4l Ö.'erartigo ^{a> 's} Komßensation ^f -from cabin applicable to AugenblicksschVngungen mitigating be independent iKufe-isrffle * ^{Stange53? t} BeMigung of-'Scffieöer's with aem' nichV aBgefeäertbn ΐέΐί Tmcht'sfärf'verfeüt- ^ s'endem ** & * & ■ ei & r-delayed-Steüeittng, which eg under the exit of the "Part 2 a

i uf 'alibiHh

gg

Contains rod 24, which, with hoofs 'von nagg feathers 25 ", has an aÄ - ^' Gäätaz $ mtf 'ük ' Ge ff Af ^

springs 25 an aÄ ^ Gäätaz $ mtf ük Ge rod ff formed AidfanuBt ^ b ^ atigT :, whichWefsMs'mit aer ^ rodW'zur ^ inexpensive ^ sffitebers ver "bunäeh" isf ^ and''eieren · movement ^ urch- a leeigae -feii the damper 28-sterM is braked. "- *** Under these conditions, the vibrations o'er '" Abfeäerung "were included, ¹ * without the" bends of the "SbhieiSers" Mmi ^ eeiMÜssenf' ^ hreüd a "significant permanent change der gepfeetertentaslrWQlcTfe'd ^ eAWeaerung ziTentlästen o3er zamenuaruck ^ n iucbt, '''* efne "Terstellung ^ iles

which ζ. B. depending on the rigidity !: aei mecfianisclieil-ffed'eY'HMrmmtWd;wdäurc'n^{; 1} d% ⁵ # ^£ ^ f'f yr ^^ Afa "

aei mecfianisclieilfedeYHMrmmtWd; wdäurcnd% value ⁵ '#es "- ^£ ^ iveausZf'auf weloyr ^ ie ^ Abfeaerung constantly zuiucklefuhfl ^ wffa's'as well as ^ äef -" yrert -ä & sprung Änofanung "wunscnteü ^l 'Sinn ^ ur'FÖlg ^u " ^! In Tigl-rW-'eme Vörtelmf te 'Äu & fürttünisform defErnnaung ^; darpsteHt, · ΐ »εϊwhich * difeicKechäfflsbh'e Feaer4 and the iailSk

is'!

practically the 'value of a circle freshness Mr "overall .biederung is.' ^λ · * '"■' * ■ "" · ■■> ·· "- '"»'» tn

Ji ^ & ii

what of course

sWg ^ utm ^ feaendfetismerGUedVnl _s ' _Äec Hä% isc'he'Glie'a un ^'aä'äpneuniä'tisclife ^ Giiecl,

Claims (4)

Patent claims: 55 tat ^ by deryeran
Way 'controlled'wM A mechanism of this kind includes a supply at 5.altef.i9 '- for ^ ias ^' unassociated pressure- " niltterpSfy, .in 'which each A"b'fuhrleitungl7 mun] iet (wefch'e originally ^^ through' äeri "unteien'.Kölb^; en \ l ^ äes * slide closed) 7and'vön'weic'heM the always g ^! efyllte Leftung'20 '^;for.feeding'emefiP'uinpe*' !!, e.g. ^ E.g.- one 'Gear pump,''äb'geEtj' which "feeds the" for- "spiritedEcli ofiiem'uper" piston 13 of the.Scliie'bBrs verscBlbsseheJ Leftimg 1 $ , 'wblcne "' öme * sctieniä- ^ AbfedMönngfenken 'getfägen ein'Ms einf'-m'echaÖsbTiBif Fedgrbestüt '/' welcte ψ jföb'äirö fiit * a &Mäsrffiig-Enear'vef- i i * 'h g ^; G, "While 'das * arYdere' consists of" a _# pedening of a pneiimatic kind ^; * d ä ' ^: d UrVh ^ gWk eh ή- ¹ ^ YHhi% that the elastic cushioning member h' ^c! Gi | ⁱ⁵ I % g pneumätischef> type '^; from '' ^ä a ^c - ^! Gaiöiäfi | e ^{; i} It 'konakiiter ^ mass' gfebpdef ^ wirdj ^i: the- ^! M ¹ a "dichten / inmdesfens ^ e'iiweise 'diirch a deformbareno', 'άέϊ ¹ " deformation · a ""vdrn'schlgb'aren 10 Resistance offering limited wall, is contained from the actual pneumatic spring (S) and a container (8) connected to this receiving system, and the variable pressure is constantly balanced by the pressure of a liquid amount, which is applied to the gas-acted area of the deformable Wall (9) opposite surface of the same acts, and that the change in this pressure is caused by changing the amount of liquid by means of a distributor (11 to 15), the movable member is controlled by the deflections of the suspension, and that the variable pressure is constantly in the pneumatic spring (S) is exerted, which is connected between the sprung mass (1) and the unsprung mass (2). 2. Vehicle suspension according to claim 1, characterized in that the slide of the distributor (13 to 15) with an unsprung part (2) of the vehicle in a manner known per se Is connected via a damping transmission, which in particular resilient springs (25) and includes a damper (28). 3. Vehicle suspension according to claim 1 or 2, characterized in that the mechanical The cushioning element consists of a helical compression spring (4). 4. Vehicle suspension according to one of claims 1 to 3, characterized in that the mechanical cushioning member and the pneumatic cushioning member arranged coaxially are. Considered publications: German Patent Nos. 459 576, 828 701; German patent application D 11011 11/63 c (published on July 22, 1954); French Patent No. 733,664; U.S. Patent No. 1029,462; Magazine: »Das Auto, Motor und Sport«, October 29th. 1955, pp. 10 to 12. 1 sheet of drawings 509 720/265 10.65 © Bundesdruckerei Berlin