DE1630058C

DE1630058C - Hydropneumatic suspension strut with internal level control device

Info

Publication number: DE1630058C
Authority: DE
Inventors: Hans-Jürgen Dr.-Ing. 5850 Hohenlimburg; Löhr Manfred 5868 Letmathe Hoffmann
Original assignee: Hoesch AG
Current assignee: Hoesch AG
Publication date: 1972-05-18

Description

Die Erfindung betrifft ein hydropneumatisches Federbein mit innerer Niveauregeleinrichtung zum Anschluß an eine außen liegende Druckmittelquelle, insbesondere für Kraftfahrzeuge, mit einem ölgefüllten Arbeitszylinder, der durch einen von einer hohlen Kolbenstange getragenen und mit Dämpfungsorganen versehenen Arbeitskolben in einen kolbenstirnseitigen und in einen kolbenstangenseitigen Arbeitsraum unterteilt wird, von denen der kolbenstirnseitige Arbeitsraum mit einem von einer Arbeitsgasfeder belasteten und von dieser durch eine Membran getrennten ölraum in Verbindung steht, mit Anschlüssen für eine von der Druckmittelquelle kommende Hochdruckleitung und für eine Rücklaufleitung, die in die Kolbenstangenbohrung bzw. in ein zentrisch ■ in der Kolbenstangenbohrung angeordnetes Rohr münden, und mit der Niveauregeleinrichtung, die aus einem Aufregelventil zur Verbindung des kolbenstirnseitigen Arbeitsraumes mit der Hochdruckleitung und einem Abregelventil zu dessen Verbindung mit der Rücklaufleitung besteht, welche als wegabhängig von der Stellung der Kolbenstange im Arbeitszylinder betätigte Hubventile ausgebildet, zentrisch in der hohlen Kolbenstange angeordnet sind und mit dieser und mit einem an einem Boden des Arbeitszylinders abgestützten Regelteil zusammenwirken. The invention relates to a hydropneumatic spring strut with an internal level control device for Connection to an external pressure medium source, in particular for motor vehicles, with an oil-filled one Working cylinder carried by a hollow piston rod and with damping elements provided working piston in a piston front side and in a piston rod side working space is divided, of which the piston front-side working space with one of a working gas spring loaded and separated from this oil space by a membrane is in communication, with connections for a high pressure line coming from the pressure medium source and for a return line which in the piston rod bore or in a tube arranged centrally ■ in the piston rod bore open, and with the level control device, which consists of a regulating valve for connecting the piston face Working space with the high pressure line and a regulating valve for its connection with the return line, which is dependent on the position of the piston rod in the Working cylinder actuated lift valves formed, are arranged centrally in the hollow piston rod and cooperate with this and with a control part supported on a base of the working cylinder.

Hydropneumatische Federbeine dieser Gattung sind bekannt, beispielsweise aus der französischen Patentschrift 1 224 488. Bei diesem Federbein bestehen die Dämpfungsorgane im Arbeitskolben nur aus einer Drosselöffnung. Das hat den Nachteil, daß die Dämpfung in der Zugstufe und die Dämpfung in der Druckstufe nicht getrennt eingestellt werden können. Ein weiterer Nachteil dieser Ausführung wird darin gesehen, daß das am Boden des Arbeitszylinders abgestützte Regelteil ein feststehender Taststift ist. Somit ist für den Taststift eine Länge erforderlich, die größer sein muß, als der gesamte Hub. Hierdurch wird der Taststift jedoch sehr stark knickgefährdet. Bei diesem bekannten Federbein liegen mit dem Aufregelventil eine Drosselbohrung und ein Rückschlagventil und mit dem Abregelventil ebenfalls eine Drosselbohrung in Reihe. Aus der USA.-Patentschrift 2 976 032 ist ein ähnliches Federbein bekannt, das keinen mit Dämpfungsorganen versehnen Kolben hat, sondern eine hohle Stange wirkt als Plunger. Die Dämpfungsorgane werden durch für Zug- und Druckstufe getrennte Bodenventile gebildet. Damit ist der Nachteil verbunden, daß die Zugstufe für die Dämpfung vom Druck der Arbeitsgasfeder begrenzt wird. Da in der Zugstufe im allgemeinen aber der Hauptanteil der Dämpfungskraft liegt, ist es zweckmäßig, die Dämpfungskraft durch einen mit Dämpfungsventilen versehenen Kolben aufzubringen. Hydropneumatic struts of this type are known, for example from the French Patent specification 1 224 488. In this strut, the damping elements in the working piston only exist from a throttle opening. This has the disadvantage that the damping in the rebound stage and the damping cannot be set separately in the pressure stage. Another disadvantage of this design is seen in the fact that the control part supported on the bottom of the working cylinder is a fixed stylus is. Thus, a length is required for the stylus which must be greater than the entire stroke. As a result, however, the stylus is very much at risk of kinking. Are in this known strut with the regulating valve a throttle bore and a check valve and likewise with the regulating valve a throttle bore in series. A similar strut is disclosed in US Pat. No. 2,976,032 known that has no piston lined with damping organs, but acts as a hollow rod as a plunger. The damping elements are formed by separate bottom valves for rebound and compression. This has the disadvantage that the rebound stage for the damping from the pressure of the working gas spring is limited. Since the main part of the damping force is generally in the rebound stage, it is advisable to apply the damping force by means of a piston provided with damping valves.

Ein Federbein mit innerer Niveauregelung, bei dem die Dämpfungskraft durch einen mit Dämpfungsventilen versehenen Kolben aufgebracht wird, ist zwar aus der französischen Patentschrift 1 477 042 bekannt, doch steuert bei diesem bekannten Federbein die innere Niveauregeleinrichtung die Förderrichtung einer ständig angetriebenen außen liegenden Pumpe. Das hat den großen Nachteil, daß für jedes Federbein eine eigene fremdangetriebene Pumpe erforderlich ist.A suspension strut with internal level control, in which the damping force is controlled by a damping valve provided piston is applied, is from French patent 1,477,042 known, but in this known strut the inner level control device controls the conveying direction a constantly driven external pump. That has the big disadvantage that for everyone Suspension strut requires its own externally driven pump is.

Ein anderes bekanntes Federbein mit innerer Niveauregeleinrichtung nach der deutschen Auslegeschrift 1 128 309 hat als Regelorgan Radialbohrungen vorgesehen, die dadurch abgedichtet werden, daß sie von der Innenwand der hohlen Kolbenstange überdeckt werden. Durch diese gleitende Abdichtung ist die Gefahr eines vorzeitigen großen Verschleißes und damit die eines Undichtwerdens gegeben.Another known strut with an internal level control device according to the German interpretation 1 128 309 has provided radial bores as a control element, which are sealed by the fact that they be covered by the inner wall of the hollow piston rod. Through this sliding seal is there is a risk of premature wear and tear and thus of a leak.

Der Erfindung liegt die Aufgabe zugrunde, ein hydropneumatisches Federbein mit innerer Niveauregeleinrichtung zu schaffen, bei dem ein am BodenThe invention is based on the object of a hydropneumatic spring strut with an internal level control device to create one at the bottom

ίο des Arbeitszylinders abgestütztes, mit den Regelventilen zusammenwirkendes Regelteil von der Kolbenstange mitnehmbar angeordnet ist und bei dem die das Auf- und Abregein steuernden Ventile als Hubventile ausgebildet sind, wodurch eine baulich einfachere, weniger beanspruchte und nicht verschleißanfällige Niveauregeleinrichtung erzielt wird. Diese Aufgabe wird erfindungsgemäß bei einem Federbein der eingangs genannten Gattung dadurch gelöst, daß ein das genannte Regelteil bildendesίο the working cylinder supported with the control valves cooperating control part is arranged to be carried along by the piston rod and in which the valves controlling the up and down are designed as lift valves, creating a structurally simpler, less stressed and not susceptible to wear level control device is achieved. According to the invention, this object is achieved in a strut of the type mentioned at the beginning solved that a said control part forming

zo Regelrohr, dessen Innenraum über das in der Kolbenstangenbohrung angeordnete Rohr mit der Rücklaufleitung verbunden ist, sich an einem Ende mit einem das Abregelventil bildenden durchbohrten Stopfen an dem Boden des Arbeitszylinders abstützt, gegen den es durch eine Ventilfeder gedrückt wird, mit seinem anderen Ende in der Kolbenstangenbohrung verschiebbar gelagert ist und einen Anschlag aufweist, durch den es im Abregeibereich von einer Schulter der hohlen Kolbenstange mitgenommen wird, so daß das Abregelventil von seinem Sitz am Boden abgehoben wird, und mit dem es im Aufregelbereich das mit seinem Ventilkörper abgedichtet auf dem Reßelrohr verschiebbar gelagerte Aufregelventil von seinem Ventilsitz in der mit der Hochdruckleitung verbundenen Kolbenstangenbohrung abhebt. Das Regelrohr weist an seinem in die Kolbenstangenbohrung hineinragenden Ende einen innen mit einer Dichtung versehenen Führungskopf auf, mit dem es auf dem mit der Rücklaufleitung verbundenen Rohr verschiebbar gelagert ist. An dem Führungskopf des Regelrohrs stützt sich eine Ventilfeder des Aufregelventils ab.zo control tube, the interior of which is about that in the piston rod bore arranged pipe is connected to the return line, pierced at one end with a regulating valve forming The plug is supported on the bottom of the working cylinder, against which it is pressed by a valve spring, is slidably mounted with its other end in the piston rod bore and a stop by means of which it is carried along by a shoulder of the hollow piston rod in the de-energizing area, so that the regulating valve is lifted from its seat on the floor, and with which it is in the regulating range which is sealed with its valve body on the Reßelrohr displaceably mounted on regulating valve of his The valve seat lifts off in the piston rod bore connected to the high pressure line. The control tube has at its end protruding into the piston rod bore an inside with a seal provided guide head with which it is slidable on the pipe connected to the return line is stored. A valve spring of the regulating valve is supported on the guide head of the regulating tube away.

In weiterer Ausgestaltung des Federbeins, bei dem mit dem Aufregelventil eine Drosselbohrung und ein in Richtung zum kolbenstirnseitigen Arbeitsraum hin öffnendes Rückschlagventil in Reihe liegen, geht die Kolbenstangenbohrung im Bereich des Arbeitskolbens in die mit dem Aufregelventil in Reihe liegende Drosselbohrung über, die in eine Ausnehmung mündet, in der das mit dem Aufregelventil in Reihe liegende Rückschlagventil angeordnet ist.In a further embodiment of the strut, in which the control valve has a throttle bore and a in the direction of the piston front-side working chamber opening check valve are in series, the Piston rod bore in the area of the working piston in the one in series with the regulating valve Throttle hole over that opens into a recess in which the with the regulating valve in series horizontal check valve is arranged.

Bei einer weiteren Ausführungsform des Federbeins, bei der mit dem Abregelventil eine Drosselbohrung in Reihe liegt, ist der Innenraum des Regelrohres durch die mit dem Abregelventil in Reihe liegende Drosselbohrung mit der zu dieser koaxialen Bohrung des das Abregelventil bildenden Stopfens verbunden.In a further embodiment of the suspension strut, in which the regulating valve has a throttle bore is in series, the interior of the control tube is in series with the regulating valve lying throttle bore with the coaxial bore of the stopper forming the regulating valve connected.

Ein Ausführungsbeispiel der Erfindung wird an Hand von Abbildungen erläutert, von denen
F i g. 1 ein Federbein im Normalbereich,
F i g. 2 im Aufregel- und
F i g. 3 im Abregeibereich
wiedergibt.An embodiment of the invention is explained with reference to figures, of which
F i g. 1 a shock absorber in the normal range,
F i g. 2 in up-regulation and
F i g. 3 in the de-registration area
reproduces.

Ein Federbein 11 ist mit einer oberen AufhängungA strut 11 is provided with an upper suspension

12 an einem Aufbau, mit einer unteren Aufhängung12 on a structure with a lower suspension

13 an einer Radachse eines Fahrzeuges befestigt. Die untere Aufhängung 13 ist mit einem Boden 14 eines13 attached to a wheel axle of a vehicle. The lower suspension 13 is one with a floor 14

Claims

3 43 4

Outer tube 15 connected, while the other, the space 26 in connection, in the piston front-open side of the outer tube 15 with a, a side working chamber 26. By the throttle bore piston rod seal 16 receiving cover 17 311 is delayed, so that is closed at. In a brief opening of the opening valve 43, for example tube 15, in the bottom of the outside and held by the cover 17, when driving through potholes or with the working cylinder 18, cornering with damping elements, no immediate adjustment takes place. equipped working piston 19 out. The upward regulation process is ended when the compression organs are spring-loaded damping valves 20 and the rod 30 extends so far that the upward regulation and 21 of the known design are provided, which again lies on the valve seat 301 with the throttle valve 43. The self-bores 22 and 23 in the working piston 19 together with the non-return valve 46 and a function parallel to this. A sealing piston ring 24 seals 47 are required in the event that the interior of the working cylinder 18 is divided into a working chamber 25 on the piston rod side by repeated up and down in the state and into a pressure equalization between the working gas spring 27 and the working chamber 26 on the piston end. One of the high pressure accumulators 39 occurs. In the case of pressure release working gas spring 27, the piston rod 30, which is the same and retracted from the outer tube 15, would accommodate the annular space vehicle formed by the working cylinder 18 on the gas cushion of these two spaces, in which a membrane 28 holds the working springs, the spring characteristic being very flat The gas spring 27 is separated from an oil chamber 29. One would leak. Through the check valve 46 and recess 181 in the working cylinder 18, a seal 47 is achieved that the vehicle, in connection between the working gas spring 27 chamber 26 and the oil chamber 29 on the piston front side, creates this state only. springs.

The working piston 19 sits on a hollow piston. When the vehicle is unloaded, the piston rod 30 extends the cover 17 as a piston rod rod 30, the control tube 35 is used via its guide and its piston rod bore 31 strikes 351 from a shoulder 302 of the piston rod one side is taken along by the upper suspension 12 25 30, and the control is closed as a result. In this piston rod bore 31 valve 41 protruded from the bottom 14 of the outer tube 15 a coaxially extending with her, lifted in the upper, so that the liquid from the piston front suspension 12 attached tube 32, which has a side working space 26 through the bore 411, a Return line 33 is connected to a low-pressure supply throttle bore 48 in the interior 40 of the control chamber 34 (FIG. 3). The free other 30 tube 35 and from there via the tube 32 and the end of this tube 32 dips into a piston rod bore 31 partially received by the return line 33 to the low pressure reservoir 34, and drains away.

slidable regulating tube 35. A seal 36 in the regulating process is complete when the pistons have a on the pipe 32 displaceable guide rod 30 is retracted so far that the control head 37 of the regulating tube 35 seals the valve 41 from the 35 again on the bottom 14 of the outer tube . Piston rod bore 31 formed space which 15 rests.

Via a high pressure line 38 with a high pressure accumulator 39 (Fig. 3) is connected to the oil from the low pressure reservoir 34 ν to pump back the high pressure accumulator 39, a pump 49 is present in a known manner opposite an interior 40 of the control tube 35, which from which is under low pressure via the pipe 32. 40 oil via a suction valve 50 into a pump chamber 491. The lower end of the regulating tube 35 sucks in and, via a pressure valve 51, enters the stopper, which works as a regulating valve 41 and which presses the pressure accumulator 39. A pressure relief valve 52, in an axially extending bore 411, and a branch line 381 of the high pressure line 38 is closed by this, when the plug is installed, prevents a predetermined maximum from resting on the bottom 14 of the outer tube 15. A 45 pressure is exceeded. The pump 49 can be driven by a preloaded valve spring 42, which is at the bottom 14 and a continuously running motor; acts on the stopper of the regulating valve 41 and it can also be operated by an electric motor. and is switched off, in the normal range and in the upregulation range (Fig. 1 Another possibility is that the pressure and 2). A regulating valve 43 slides with a seal generating system attached to the structure, a pump vent 44 on the jacket of the regulating tube 35 and piston 492 of the pump 49 via a connecting rod with which the wheel axle is in the normal range and in the de-energizing range is connected so that the relative movement (F 1 and 3) on a valve seat 301 provided on a shoulder of the joints between the wheel axle and the structure for the actuating rod bore 31 of the pump 49, and is supported by a valve spring 45 and the

Pressure in the space of the piston rod bore 31 in claims: kept this situation.

If the vehicle is loaded so that the piston 60 1. Hydropneumatic strut with inner

rod 30 according to FIG. 2 retracts, then the level control device for connection to a

control valve 43 from a stop 351 on the control tube external pressure medium source, in particular

35 lifted from the valve seat 301 , and oil for motor vehicles flows, with an oil-filled type

from the high-pressure accumulator 39 (FIG. 3) via the high-working cylinder, which is passed through one of a hollow pressure line 38, the space of the piston rod drilling 65 piston rod borne and with damping

tion 31, a throttle bore 311 and a working piston provided with back organs into a piston

impact valve 46, which is located in a recess 312 on the lower front side and in a piston rod side

is brought, which is divided with the piston front-side work gen work space, of which the

Working space on the piston front side with one loaded by a working gas spring and by this separated by a membrane oil chamber is in communication, with connections for one of the Pressure medium source coming high pressure line and for a return line, which in the piston rod bore or open into a tube arranged centrally in the piston rod bore, and with the level control device that consists of a regulating valve for connecting the working chamber on the piston front side with the high pressure line and a regulating valve for its connection to the return line, which as stroke valves actuated as a function of the position of the piston rod in the working cylinder formed, are arranged centrally in the hollow piston rod and with this and with a interacting with a base of the working cylinder supported control part, characterized in that that a regulating tube (35) forming said regulating part, the interior (40) of which Via the pipe (32) arranged in the piston rod bore (31) with the return line (33) is connected, at one end with a stop valve (41) forming the pierced plug on. the base (14) of the working cylinder (18), against which it is supported by a valve spring (42) is pressed, mounted displaceably with its other end in the piston rod bore (31) is and has a stop (351) through which it is in the Abregeibbereich from a shoulder (302) the hollow piston rod (30) is taken so that the cut-off valve (41) of his Seat on the floor (14) is lifted off, and with which it is in the upregulation area with its valve body sealed on the control tube (35) slidably mounted open control valve (43) of his Valve seat (301) in the piston rod bore connected to the high pressure line (38) (31) takes off.

2. Strut according to claim 1, characterized in that the control tube (35) at his one end protruding into the piston rod bore (31) with a seal (36) on the inside provided guide head (37) with which it is connected to the return line (33) Tube (32) is slidably mounted.

3. Strut according to Claims 1 and 2, characterized in that there is a valve spring (45) of the regulating valve (43) is supported on the guide head (37) of the regulating tube (35).

4. Suspension strut according to Claims 1 to 3, in which a throttle bore and a check valve opening in the direction of the working chamber on the piston front side lie in series with the regulating valve, characterized in that the piston rod bore (31) in the region of the working piston, piston (19 transitions) in the (horizontal 43) '(series throttle bore (311) with the Aufregelventil which opens into a recess (312) in which the lying with the Aufregelventil in series check valve (46) is arranged.

5. Suspension strut according to Claims 1 to 4, in which the control valve has a throttle bore is in series, characterized in that the interior (40) of the control tube (35) through the throttle bore (48) lying in series with the regulating valve (41) with the one coaxial with it Bore (411) of the stop valve (41) forming the stopper is connected.

1 sheet of drawings