US3593978A - Hydro-pneumatic spring system, especially for motor vehicles - Google Patents

Hydro-pneumatic spring system, especially for motor vehicles Download PDF

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Publication number
US3593978A
US3593978A US816344A US3593978DA US3593978A US 3593978 A US3593978 A US 3593978A US 816344 A US816344 A US 816344A US 3593978D A US3593978D A US 3593978DA US 3593978 A US3593978 A US 3593978A
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United States
Prior art keywords
pump
hollow
spring system
piston
valve body
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Expired - Lifetime
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US816344A
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English (en)
Inventor
Manfred Lohr
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Fried Krupp AG Hoesch Krupp
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Hoesch AG
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
    • B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
    • B60G17/044—Self-pumping fluid springs

Definitions

  • a valve body is slidably guided with respect to the pump rod and has an abutment engageable upon the pump U-S- piston.
  • Ah insert member has a surface liftable with respect to Ink a valve seat provided by the valve body and a throttle-forming 501 Field ofSearch..................w.r
  • bore means makes possible passage of hydraulic medium from 8 the high-pressure storage into the operating chamber.
  • a preloaded tension spring means presses upon a surface of the in- [56] References Cited UNITED STATES PATENTS 11/1967 Axthammeretal.........
  • the present invention relates to a hydropneumatic spring system with hydraulic damping effect or if desired without a damping effect, and with automatic level control, which spring system will be able to control or stabilize the loads during a standstill and the relief during the drive, especially for motor vehicles, said spring system comprising two separate preloaded gas cushions operable to act upon a hydraulic medium which, by means ofa pumping or control mechanism arranged in a hollow piston rod, is controlled in conformity with the load.
  • Hydropneumatic spring systems or elements are known by means of which the nominal level of the vehicle is obtained under load only after the vehicle has driven a certain distance, and by means of which when relieved of load the'standing vehicle is brought back to its nominal level.
  • Spring elements or systems of this type have the drawback that when installed on the rear axle, after the vehicle has been loaded, the position of the bright lights will not be correct as long as the vehicle is below the nominal level whereby during night driving the driver of the oncoming vehicle will be blinded.
  • the residual travel stroke of the spring is relatively short.
  • an object of the present invention to provide a hydropneumatic spring system which will make it possible that when the standing vehicle is under load the desired level will be reached immediately and when the vehicle is relieved after having driven over a certain distance, the desired level will be reached.
  • FIG. 1 shows a hydropneumatic spring system according to the invention in the pumping range.
  • FIG. 2 shows the hydropneumatic spring system according to the invention in its normal range.
  • FIG. 3 illustrates the hydropneumatic spring system according to the invention in its upward-leveled range.
  • FIG. 4 represents a hydropneumatic spring element according to the invention with a high pressure accumulator above the upper suspension.
  • FIG. 5 is a hydropneumatic spring system without damping in its normal range.
  • the hydropneumatic springsystem according to the present invention is characterized primarily in that in the interior ofa hollow piston rod there is axially movably arranged a hollow pump rod the nonclamped-in end of which is provided with a pump piston having axially movably and slidably mounted thereon a valve bodywhich in its upward leveling or upward regulating range hasiits abutment engage the pump piston whereby the valve seat of said valve body is lifted off from a surface of an insert member and through the intervention of a throttle bore, the passage of hydraulic "fluid from a high-pressure accumulator to a working chamber is made possible.
  • the valve body is adapted by means of the pressure in the high-pressure accumulator which pressure acts through bores and an annular passage of the pump piston, a longitudinal groove of the valve body and the bores of the abutment upon the valve seat, is pressed upon the surface of the insert member in a sealing manner whereby the pumping effect will be interrupted whereas within the pumping range the valve body operates as suction valve and in cooperation with the check valve in the pump piston makes possible a pumping effect.
  • damping piston By means of a damping piston, a damping effect will be realized which is independent of the respective load or working position of the spring system. This damping effect will in the pulling direction be buffered between fixed walls, whereasthe pressure direction is determined by the pressure of the working chamber and is by means of a valve arranged in the guiding means for the rod limited in such a way that below the damping piston no low pressure will occur.
  • a particularly advantageous design of the hydropneumatic spring system according to the invention is realized by arranging the high-pressure accumulator for instance in the trunk of the vehicle, said highpressure accumulator being screwed onto an upper suspension system formed by a pin suspension.
  • the spring element or spring system and the high-pressure accumulator can be filled separately and can be subjected to a corresponding pressure.
  • a pipe of synthetic material e.g. polyvinylchloride, which pipe may have its upper end designed for instance as a sealing ring, gas and hydraulic liquid are separated from each other in the spring system.
  • a very simple hydropneumatic spring system without damping is obtained when during the compression of the spring (Einfedem) hydraulic liquid is, by a check valve in the piston, drawn into the space between the piston and the piston rod, which liquid when the piston and piston rod move outwardly is, by lifting off the valve body, pumped into the high-pressure accumulator until the piston ring of the piston moves over a longitudinal groove in the cylinder and thus ends the pumping effect.
  • An outer mantle 3 which at one endis closed by a bottom 4 encloses the hydropneumatic spring system.
  • the bottom 4 is provided with a piston rod seal 5 while a further seal 6 is interposed between the bottom 4 and the outer mantle or jacket 3.
  • a hollow piston rod 7 is adapted to slide in guiding means 8 and is provided with an insert member 9 carrying a damping piston 10 movable in a cylinder 11.
  • An annular chamber I6 is formed by a supporting pipe 12 with openings 13 at the lower end thereof, and by the cylinder 11 with openings 14 at the upper end of said cylinder Ill, said.
  • a working chamber 17 between an intermediate member 18 and the bottom 4 is subdivided into a working gas chamber 17I and a working fluid chamber 172.
  • the said intermediate member 18 separates the working chamber 17 from a high pressure accumulator 19 which in its turn is subdivided by an elastic separating member 20 into a high-pressure gas chamber 191 and a high-pressure fluid chamber 192.
  • the supporting body is provided with passages 21 and furthermore comprises a pump limiting valve 22 and an elastic suspension 23 of a hollow pump rod 24 the hollow end of which carries a pump piston 25.
  • Piston 25 is provided with piston rings 26 and 27 which are so arranged that an annular passage 28 is formed thcrebetween which passage through bores 29 communicates with an inner bore 30 of the hollow pump rod 24 and also comprises a check valve 31.
  • the pump piston 25 is slidably guided in a valve body 32 which in its upper end has a valve seat 33 a throttling bore 34 while its lower end is provided with a longitudinal groove 35, an abutment 36, and a closure member 37.
  • the valve body 32 is pressed by a preloaded tension spring 38 against a surface 40 of the insert member 9.
  • the spring 38 is connected for instance to the closure member 37 and is furthermore for instance by a ring 39 connected to the hollow piston rod 7.
  • valve body 32 When the piston rod 7 moves inwardly, the valve body 32 will, by means of the valve seat 33, sealingly engage the surface 40 of the insert member 9, and the hydraulic liquid drawn in during the pulling stage is, by opening the check valve 31, pressed from the chamber 46 through the inner bore 30 of the hollow pump rod 24 and the passages 21 into the high-pressure liquid chamber 192. Simultaneously,hydraulic fluid flows from chamber 41 through a pressure stage damping valve 49 into the chamber 47 thereby realizing the pressure stage damping. in view of this pumping operation, the pressure effective for the supporting force of the spring system is reduced in the working chamber 17 whereby the hollow piston rod 7 moves inwardly until the level of the vehicle has been reached.
  • the pump-limiting valve 22 is arranged in the supporting body 15. This valve 22 will prevent the pres sure in the high-pressure accumulator from increasing unduly to a nonpermissible extent, especially when'thc spring system is rigidly clamped in, for instance, for testing purposes.
  • the chamber 46 will be under the pressure of the high-pressure accumulator 19 through the passages 21, the inner bore 30 of the hollow piston, rod 20, the bores 29, annular passage 28, longitudinal groove 35, and openings 50 in the abutments 36. [n this way, the valve seat 33 of the valve body 32 is pressed sealingly against the surface 40 whereby the pump effect is interrupted.
  • hydraulic fluid is, in conformity with the cross section 'of the hollow pump rod 24, movedback and forth between the chamber 46 and the high pressure fluid chamber 192.
  • a pressure stage limiting valve 51 is provided which opens when a and connecting bores 53.
  • the insert member 9 is provided with a seal 54 which prevents the escape of hydraulic fluid from the high-pressure liquid chamber 192 through chamber 46 into chamber 41 and back to the working fluid chamber 172.
  • the abutment 36 will,
  • Figure 4 represents a modification of the spring system according to the invention according to which a high-pressure accumulator 55 is arranged above an upper'suspension 56.
  • the outer diameter of the spring element or spring system is with this design considerably reduced when lack of installation space exists.
  • the upper suspension 56 forms a so-called pin suspension into which is built in a check valve 57. After screwing on the high-pressure accumulator 55 and sealing the same toward the outside by a seal 58, first the check valve 57 and after further tightening a check valve 59 of the high-pressure accumulator 55 is opened, and the connection between the high-pressure liquid pressure 552 and a chamber 60 is freed.
  • a working chamber 61 is in this instance advantageously by means of a pipe 62 of synthetic material having its upper end forming a sealing ring 63 and having its lower end immersed in the slight liquid level of the working chamber 61, subdivided into a working gas chamber 611 and a working fluid chamber 612. This is effected in such a way that when the hollow piston rod 7 is in motion, only hydraulic fluid can pass from the working fluid chamber 612 through an annular chamber 64 and via openings 14 into the chamber 41.
  • FIG. 5 A hydropneumatic spring element or spring system without damping is illustrated in FIG. 5.
  • a check valve 66 is lifted off by a piston 67 and fills a'chamber 68 below the piston 67 with hydraulic fluid from a chamber 69 above the piston 67, which chamber 69 communicates through openings 17, annular chamber 71 and openings 72 with the working fluid chamber 732.
  • a highpressure accumulator 82 acts through bores 80, 79, 78 onto the valve seat 86 of the valve body 74 and presses the same together by means of the preload of a pull spring 87 in a sealing manner against the surface 75 of piston 77.
  • an abutment 88 of the valve body 74' engages the bores 79 of a closure member 89 whereby the valve seat 86 with the valve body 74 is lifted off the surface 75 and hydraulic liquid is passed from the high-pressure liquid 822 through a bore 80, and a throttling bore 90 into the chamber 77 and from there passes through passage 76 into the chamber 68 and through groove 84 into the chamber 69.
  • ll Ahydropneumatic spring system having automatic level control both for regulation of loads during standstill and relief thereof controlled during running operation, especially for motor vehicles with two separate preloaded gaseous cushions operable toact upon a hydraulic medium which is controlled according to loadby a purhp and control mechanism, which compr ses: a cylinder, a hollow piston rod rcciprocably arranged in said cylinder, a high pressure fluid storage container, operating chamber means associate with said cylinder, a hollow pump rod having an axial bore and being axially movable in said hollow piston rod, a pump piston carried by a free end of said hollow pump rod, at valve body slidablyguided with respect to said hollow pump rod and having an abuttneht operable in upward leveling position to test against said pump piston, said valve body includihg valve seat means, an insert member having a seat surface adapted to be engaged and disengaged by said valve seat means, and throttle means associated with said valve body and operable in response to said valve seat means disengaging said seat surface to est
  • a hydropneumatic spring system which include des a check valve arranged in said pump piston, and in which in upward leveling position said abutment is operable to cover said check valve so as to rearwardly seal and close thc same,
  • a hydropneumatic spring system having automatic level control for regulation of loads during standstill and relief thereof during running operation, especially for inotorvchicles with two separate preloaded gaseous cushions operable to act upon a hydraulic medium which is controlled accbrding'to load by a pump and control mechanism, which comprises: a cyliilder, a hollow piston rod reciproeably arranged in said cylinder, a high-pressure fluid storage container, operating chamber means associated with said cylinder, a hollow pump rod having an axial bore and being axially movable in said hol low piston rod, a pump piston carried bya free end of said hollow ptlnip rod, a valve body slidably guided with respect to said hollow purnp rod and having an abutment operable in upward leveling position to rest against said ump piston, said valve body including valve seat means, an insert member having a seat surface adapted to be engaged and disengaged by said valve seat means, throttle means associated with said valve body and operable in response to said
  • a hydropneumatic spring system in which in pumping range said valve body with the valve seat operating as the inlet valve arid making possible pump operation with said check valve iri said pump piston.
  • a hydropneumatic spring system ih which a damping piston is so provided inside said spring system that the suction stepwise damping is buffered between rigid walls and the pressure stepwise damping is effected by means ofthe pressure in the operating chamber.
  • a hydropneumatic spring system which includes guiding means for said piston rod and also includes a pressure stepwise limiting vaIli/e associated with said guiding means for opcratively limiting the pressure stepwise damping.
  • a hydropneumatic spring system in which an overpressure valve means is provided in a supporting body.
  • a hydropneumatlc spring system which includes an upper suspension for said spring system and also includes high-pressure storage means arranged above said upper suspension.
  • a hydropneumatic spring system in which a separating clement formed at its upper end as a sealing ring is immersed in the slight liquid level of the operating chamber.
  • a hydropjncumatilc spring system having automatic level control for regulation of loads during standstill and relief thereof during running operation, especially for motor vchicles with two separate preloaded gaseous cushions operable to act upon a hydraulic medium whichis controlled according to load by a pump and control mechanism, which comprises: a cylinder, a hollow piston rod reciprocably arranged in said cylinder, at high-pressure fluid storage container, operating chamber means associated with said cylinder, a hollow pump rod having an axial bore and beihg axially movable in said hollow piston rod, :1 pump piston carried by a free end of said hollow pump rod, a valve body slldably guided with ,respcctto said hollow pump rod and having an abutment operable in upward leveling position to rest against said pump piston, said valve body including valve seat meahs, an insert member having a seat surface adapted to be engaged and disengaged by said valve seat means, throttle means associated with said valve body and operable in response to said valve seat means discngaging said seat surface
  • a hydropheumatic spring system according to claim 10 in which during installation of the high-pressure storage the'rb is an outward sealing with respect thereto, a check valve being provided in said upper suspension of 'the spring system and upon further tightened installation there is opening of tho high-pressure storage by check valve means.
  • a hydropneumatic spring system having automatic level control for regulation of loads during standstill and relief thereof during running operation, especially for motor vehicles with two separatcpreloaded gaseous cushions operable to act upon a hydraulic medium which is controlled according to load by a pump and control mechanism, which comprises: a cylinder, a hollow piston rod reciprobably arranged in said cylinder, a high-pressure fluid storage container, operating chamber means associated with said cylinder, a hollow pump rod having an axial bore and being axially movable in said hollow piston rod, a pump piston carried by a free end of said hollow pump rod, a valve body slidably guided with respect tb said hollow pump rod and having an abutment operable in upward leveling position to test against said pump piston, said valve body including valve seat means, an insert member having a seat surface adapted to be engaged and disengaged by said valve seat ,mcans, throttle means associated with said valve body and operable in response to said valve seat means disengaging said seat surface to establish fluid communication between said high pressure flu d storage container and
  • a hydropneumatic spring system in which a piston ring in a groove in normal range controls upwardly in said operating cylinder and thereby stops pump operation, while the pressure of the high-pressure storage through bores is operative upon a valve seat of a valve body and presses the same upon the surface of said piston and avoids a further upward regulation.
  • a hydropneumatic spring system in which in pumping range the piston is located below the groove in said operating cylinder, said check valve serving as a suction vent and said valve body with the pressure seat serving as a pressure vent whereby the pump operation is attained.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Damping Devices (AREA)
  • Vehicle Body Suspensions (AREA)
US816344A 1968-04-17 1969-04-15 Hydro-pneumatic spring system, especially for motor vehicles Expired - Lifetime US3593978A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681755237 DE1755237B1 (de) 1968-04-17 1968-04-17 Selbstpumpendes hydropneumatisches Federbein mit innerer Niveauregelung fuer Fahrzeuge

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US816344A Expired - Lifetime US3593978A (en) 1968-04-17 1969-04-15 Hydro-pneumatic spring system, especially for motor vehicles

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US (1) US3593978A (de)
DE (1) DE1755237B1 (de)
FR (1) FR1600135A (de)
GB (1) GB1261555A (de)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3752498A (en) * 1971-10-07 1973-08-14 Gen Motors Corp Oleo-pneumatic suspension assembly
US3836132A (en) * 1971-07-19 1974-09-17 Maremont Corp Self-leveling combined shock absorber and fluid spring assist unit
US3887224A (en) * 1974-04-01 1975-06-03 Gen Motors Corp Impact energy absorber with radially adjustable flow metering
US3904183A (en) * 1973-07-26 1975-09-09 Allinquant F M Suspension strut
US4045009A (en) * 1975-11-17 1977-08-30 General Motors Corporation Energy absorbing unit with improved control valve
US4135372A (en) * 1977-05-04 1979-01-23 The Torrington Company Universal joint
US5062616A (en) * 1989-04-29 1991-11-05 Boge Ag Self-pumping hydropneumatic shock absorbing strut
US5826863A (en) * 1995-12-20 1998-10-27 Fichtel & Sachs Ag Self-pumping hydropneumatic shock absorbing strut with internal level regulation
US5826862A (en) * 1995-12-07 1998-10-27 Fichtel & Sachs Ag Self-pumping hydropneumatic shock absorbing strut with internal level regulation
US5988655A (en) * 1996-11-08 1999-11-23 Kayaba Kogyo Kabushiki Kaisha Vehicular height adjusting device
US20070221457A1 (en) * 2006-03-22 2007-09-27 Zf Friedrichshafen Ag Self-pumping hydropneumatic shock absorber
US20070261931A1 (en) * 2006-05-11 2007-11-15 Zf Friedrichshafen Ag Self-pumping hydropneumatic spring strut unit with internal level control
US20080185244A1 (en) * 2007-02-07 2008-08-07 Atsushi Maeda Hydraulic shock absorber

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0059621A3 (de) * 1981-02-27 1983-07-06 Armstrong Patents Co. Limited Hydropneumatische Aufhängungseinheiten
EP0060098A3 (de) * 1981-03-09 1983-07-06 Armstrong Patents Co. Limited Hydropneumatische Aufhängevorrichtungen
FR2679306B1 (fr) * 1991-07-15 1994-03-04 Peugeot Motocycles Sa Element de suspension hydropneumatique telescopique notamment pour vehicule automobile.

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3353816A (en) * 1964-12-07 1967-11-21 Fichtel & Sachs Ag Self-leveling hydropneumatic suspension unit
US3497199A (en) * 1966-06-10 1970-02-24 Boge Gmbh Hydropneumatic,self-pumping,telescopic shock absorber,particularly for motor vehicles

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1117412B (de) * 1959-02-27 1961-11-16 Fichtel & Sachs Ag Hydropneumatische Abfederung, insbesondere fuer Kraftfahrzeuge
DE1254031B (de) * 1963-03-16 1967-11-09 Boge Gmbh Hydro-pneumatisches, selbstpumpendes Teleskopfederbein, insbesondere fuer Kraftfahrzeuge
DE1680679A1 (de) * 1965-12-17 1970-03-12 Fichtel & Sachs Ag Hydropneumatische Federung

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3353816A (en) * 1964-12-07 1967-11-21 Fichtel & Sachs Ag Self-leveling hydropneumatic suspension unit
US3497199A (en) * 1966-06-10 1970-02-24 Boge Gmbh Hydropneumatic,self-pumping,telescopic shock absorber,particularly for motor vehicles

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3836132A (en) * 1971-07-19 1974-09-17 Maremont Corp Self-leveling combined shock absorber and fluid spring assist unit
US3752498A (en) * 1971-10-07 1973-08-14 Gen Motors Corp Oleo-pneumatic suspension assembly
US3904183A (en) * 1973-07-26 1975-09-09 Allinquant F M Suspension strut
US3887224A (en) * 1974-04-01 1975-06-03 Gen Motors Corp Impact energy absorber with radially adjustable flow metering
US4045009A (en) * 1975-11-17 1977-08-30 General Motors Corporation Energy absorbing unit with improved control valve
US4135372A (en) * 1977-05-04 1979-01-23 The Torrington Company Universal joint
US5062616A (en) * 1989-04-29 1991-11-05 Boge Ag Self-pumping hydropneumatic shock absorbing strut
US5826862A (en) * 1995-12-07 1998-10-27 Fichtel & Sachs Ag Self-pumping hydropneumatic shock absorbing strut with internal level regulation
US5826863A (en) * 1995-12-20 1998-10-27 Fichtel & Sachs Ag Self-pumping hydropneumatic shock absorbing strut with internal level regulation
US5988655A (en) * 1996-11-08 1999-11-23 Kayaba Kogyo Kabushiki Kaisha Vehicular height adjusting device
US20070221457A1 (en) * 2006-03-22 2007-09-27 Zf Friedrichshafen Ag Self-pumping hydropneumatic shock absorber
US8042791B2 (en) * 2006-03-22 2011-10-25 Zf Friedrichshafen Ag Self-pumping hydropneumatic shock absorber
US20070261931A1 (en) * 2006-05-11 2007-11-15 Zf Friedrichshafen Ag Self-pumping hydropneumatic spring strut unit with internal level control
US20080185244A1 (en) * 2007-02-07 2008-08-07 Atsushi Maeda Hydraulic shock absorber
US8556048B2 (en) * 2007-02-07 2013-10-15 Hitachi, Ltd. Hydraulic shock absorber

Also Published As

Publication number Publication date
GB1261555A (en) 1972-01-26
DE1755237B1 (de) 1971-10-07
FR1600135A (de) 1970-07-20

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