DE102024117078A1 - Valve assembly and electro-hydraulic steering system - Google Patents

Abstract

The present invention relates to a valve assembly (100) comprising at least one housing body (110) having at least one main chamber (120) and at least one slide valve assembly (130). The slide valve assembly (130) is movably arranged within the main chamber (120) of the housing body (110), the slide valve assembly (130) dividing the main chamber (120) into a first section (122) and a second section (124). The at least one slide valve assembly (130) is designed as a pressure-balanced slide valve assembly (130) and is configured such that the fluid pressure within the main chamber (120) is at least substantially the same in the first section (122) and the second section (124). The invention further relates to an electro-hydraulic steering system (1000) and a vehicle.

Description

The present invention relates to a valve assembly and an electro-hydraulic steering system for a vehicle, in particular a commercial vehicle. Furthermore, the present invention relates to a vehicle, in particular a commercial vehicle, with such a valve assembly and/or such an electro-hydraulic steering system.

In principle, various types and designs of valve devices are known from the state of the art.

However, it has been shown that the pressure conditions within these valve devices only allow a limited range of use and result in increased leakage and increased wear of the valve device.

Known valve devices only allow adjustment or the setting of a new position in the sense of a valve switching process against an internal fluid pressure. Therefore, the actuation speed of the respective valve device is also limited.

During rapid steering maneuvers, such as quick evasive maneuvers, a vehicle equipped with such a valve in an associated electro-hydraulic steering system may experience a drop or decrease in operating pressure in the steering system's piston chamber, particularly at low temperatures. This behavior can slow down an electro-hydraulic steering system and/or impair steering response in general.

Therefore, under certain circumstances, a driver might not receive the necessary hydraulic power steering assistance from the steering system in time. Furthermore, this operating behavior could negatively affect a driver's steering feel.

The object of the present invention is to provide a valve device that is cost-effective, efficient, and requires little maintenance, occupies a small installation space, and can provide improved system dynamics and/or system response, and is flexibly designed. Furthermore, the invention aims to provide an electro-hydraulic steering system and a vehicle.

This problem is solved according to the invention by a valve device according to independent claim 1, with regard to the electro-hydraulic steering system by the subject matter according to claim 13 and with regard to the vehicle by the subject matter of claim 15.

According to the present invention, a valve assembly, particularly for an electro-hydraulic steering system of a vehicle, is provided with at least one housing body having at least one main chamber and at least one slide unit, wherein the slide unit is movably arranged within the main chamber of the housing body, preferably translationally displaceable. The slide unit divides the main chamber into a first section and a second section, wherein the at least one slide unit is designed as a pressure-balanced slide unit and is configured such that at least substantially the same fluid pressure is present in the first section and in the second section, in particular pressure equalization between the first section and the second section is provided via the at least one slide unit.

The present invention is based on the fundamental idea that pressure equalization within the main chamber, i.e. between the first section and the second section, results in a lower load on the valve element or valve unit, and thus reduces leakage and wear of the valve assembly.

Furthermore, a pressure-balanced design of the valve assembly allows for more dynamic and faster adjustment of the slide unit within the main chamber. The movable slide unit must, at least primarily, only be moved against mechanical resistances such as frictional forces to achieve a new position of the valve assembly.

Therefore, venting a (pressure) connection, for example into a hydraulic tank, or connecting or separating two (pressure) connections can be carried out advantageously.

For the purposes of the present invention, the translational displaceability or mobility of the slide unit is understood to mean, in particular, that the slide unit is displaceable within the housing body. In particular, the valve assembly or the housing body may have a longitudinal axis so that the slide unit is arranged to be displaceable or movable in the longitudinal direction.

The slide unit divides the main chamber into a first section and a second section. Section. The slide unit is therefore provided within the main chamber in such a way that the volumes of the first and second sections can be changed based on the mobility of the slide unit.

The slide valve unit or valve assembly can be designed as a unidirectional valve assembly or as a bidirectional valve assembly.

According to the present invention, the at least one slide unit is designed as a pressure-balanced slide unit. For this purpose, the slide unit is configured such that the fluid pressure in the first section and the second section is at least substantially the same. Preferably, pressure equalization between the first section and the second section can be provided via or by means of the at least one slide unit, in particular by means of the design of the at least one slide unit.

In the context of the present invention, the pressure-balanced design of the valve unit can preferably be understood to mean that a hydraulic short-circuit connection is provided between the first section and the second section of the main chamber via the valve unit. Accordingly, there is no hydraulic separation between the first and second sections by means of the valve unit.

Furthermore, the functionality of the valve assembly can be changed or determined based on the pressure-balanced slide unit or the positioning position of the pressure-balanced slide unit within the main chamber, among other things to bring about a hydraulic separation or connection between ports of the valve assembly.

The present invention provides a low-maintenance, efficient, and in particular efficiently adjustable, as well as dynamically adjustable valve device.

In a preferred embodiment, the slide unit, in particular a cover element of the slide unit, has at least one through-opening so that a fluid connection between the first section and the second section of the main chamber is provided or can be provided.

In particular, a hydraulic fluid, such as oil, can flow from the first or second section to the second or first section along a pressure differential across the passage opening of the valve unit. Preferably, pressure equalization of the oil or hydraulic fluid within the main chamber, i.e., between the first and second sections, can occur across the valve unit.

For the purposes of the present invention, a passage opening can be understood to be a bore, a fluid channel, or the like. Further elements such as throttling elements, filter elements, or the like can be provided within the passage opening.

The passage opening of the valve unit allows for the formation of a (temporary) fluid connection between the first and second sections of the main chamber, enabling pressure equalization or a pressure-balanced valve unit.

A displacement or change in the position of the slide unit should preferably only occur against mechanical resistance forces, such as internal frictional forces of the valve assembly, but in particular not against a pressure difference between the first and second section of the main chamber.

According to a further preferred embodiment, the valve device has at least one sleeve element which is arranged inside the housing body, in particular is arranged immovably, wherein an inner side of the sleeve element and an outer side of the movable slide unit are provided to interact, in particular to form a sealing or fluid-tight sliding connection section by section.

According to the present invention, a fluid-tight connection of different ports of the valve assembly can be achieved by means of the interaction of at least one section of the outer surface of the slide unit and at least one section of the inner surface of the sleeve element. In particular, ports can be separated from one another by means of the interacting surfaces, or a fluid connection can be provided between ports in the valve direction as required.

In a preferred embodiment, the housing body has at least one first connection, wherein the sleeve element has at least one first connection opening, the first connection opening being configured along the sleeve element corresponding to the first connection of the housing body, such that a fluid connection between the main chamber and the first connection of the housing body can be provided as required, in particular depending on the position of the movable slide unit relative to the sleeve element.

In a preferred embodiment, the housing body has at least one second connection, wherein the sleeve element has at least one second connection opening. The second connection opening is configured along the sleeve element corresponding to the second connection of the housing body, such that a fluid connection between the main chamber and the second connection of the housing body can be provided as needed, in particular depending on the position of the movable slide unit relative to the sleeve element.

According to a further embodiment, the housing body has at least one third connection, wherein the third connection is designed along the housing body in such a way that a fluid connection to the main chamber is provided regardless of the position of the movable slide unit.

• - eine Fluidverbindung zwischen dem ersten Anschluss und dem zweiten Anschluss des Gehäusekörpers bereitstellbar ist,
• - eine Fluidverbindung zwischen dem ersten Anschluss und dem dritten Anschluss des Gehäusekörpers bereitstellbar ist,
• - eine Fluidverbindung zwischen dem zweiten Anschluss und dem dritten Anschluss des Gehäusekörpers bereitstellbar ist und/oder
• - eine Fluidverbindung zwischen dem ersten, zweiten und/oder dritten Anschluss des Gehäusekörpers trennbar ist.

In a further preferred embodiment, the slide unit is designed and movable in such a way, in particular the outside of the slide unit is provided to interact section by section with the inside of the sleeve element, such that depending on a positioning position of the slide unit

• - a fluid connection can be provided between the first port and the second port of the housing body,
• - a fluid connection can be provided between the first port and the third port of the housing body,
• - a fluid connection between the second port and the third port of the housing body can be provided and/or
• - a fluid connection between the first, second and/or third connection of the housing body is separable.

In particular, it is provided that a fluid connection between the main chamber and at least one connection of the housing body can be provided via at least one connection opening of the sleeve element.

It is thus provided that a fluid connection to the main chamber, in particular for a first connection and a second connection, can be provided or disconnected via the movable slide unit.

If necessary, a single first connection or multiple first connections may be provided, which are connectable or disconnectable. Furthermore, if necessary, only a single second connection or multiple second connections may be provided, which are connectable or disconnectable.

Furthermore, a single third port or a plurality of third ports may be provided, which has/have a permanent fluid connection to the main chamber.

By having the outer surface of the slide unit and the inner surface of the sleeve element interact at least section by section, in particular by forming a fluid-tight sliding connection, a fluid connection between connections of the housing body via the main chamber can be provided by releasing or separating a connection opening of the sleeve element through such interaction.

Depending on the design of the housing component of the valve assembly with first, second and/or third ports, a multitude of fluid connections between the first, second and/or third ports of the housing component can be provided by means of the pressure-balanced slide unit in operative connection with the sleeve elements via/along the main chamber in order to ensure appropriate interconnection or use of the valve assembly.

According to a further preferred embodiment of the present invention, the slide unit has at least one sealing section along the outside for interaction with the inside of the sleeve element, in particular for interaction with a counter section of the inside of the sleeve element, so that a fluid connection between the first port, the second port and/or the third port can be disconnected as required.

In particular, sections may be provided along the outside of the slide unit and along the inside of the sleeve element which are designed and intended to interact with each other, in particular so that a sealing effect can be provided as required.

Within the valve assembly, fluid connections between various ports of the housing components can be established or disconnected depending on the position of the pressure-balanced slide unit.

According to another embodiment, the sealing section of the slide unit is designed to interact with the opposing section of the sleeve. senelements, provided in such a way, in particular with an effective surface designed in such a way in combination with the opposite section of the sleeve element, such that the at least one sealing section with the at least one opposite section forms a stop for the movable slide unit.

Accordingly, a sealing section of the slide unit can have a specific geometric design, so that a fluid-sealing end stop can be provided for the pressure-balanced slide unit.

In a preferred embodiment, the valve assembly has a drive unit, preferably an electromagnet, for moving the slide unit, preferably for translational movement in a longitudinal direction of the valve assembly.

The drive unit ensures targeted and efficient positioning and movement of the pressure-balanced slide unit within the main chamber.

According to a further embodiment, the valve assembly has at least one preloading element, in particular a spring element, for preloading the slide unit in a direction of movement of the slide unit.

• - an der Antriebseinheit oder
• - innerhalb der Hauptkammer im Bereich eines längsseitigen Endes der Ventileinrichtung, in mittelbarem oder unmittelbarem Kontakt mit der Schiebereinheit.

According to another preferred embodiment, a preloading element is arranged in the slide unit.

• - on the drive unit or
• - within the main chamber in the area of a longitudinal end of the valve assembly, in indirect or direct contact with the slide unit.

The pre-tensioning element can be used in particular to provide pre-conditioning of the pressure-balanced slide unit.

This allows the slide unit to be moved to a specific position in the unloaded, uncontrolled, or unpowered state of the valve assembly, in order to ensure a targeted initial state of the valve assembly.

According to a secondary aspect of the invention, an electro-hydraulic steering system for a vehicle, in particular a commercial vehicle, is provided with a valve device according to the invention.

• - wenigstens ein Lenkgetriebe, insbesondere Spindellenkgetriebe;
• - wenigstens eine erste Leitung, durch die das Lenkgetriebe mit Hydraulikfluid versorgbar und/oder steuerbar ist;
• - wenigstens eine zweite Leitung, durch die das Lenkgetriebe mit Hydraulikfluid versorgbar und/oder steuerbar ist; und
• - wenigstens eine mit der ersten Leitung und/oder der zweiten Leitung verbundene oder verbindbare Ventileinrichtung nach einem der vorhergehenden Ansprüche zum Druckabbau in der ersten Leitung und/oder der zweiten Leitung,

wobei die Ventileinrichtung bedarfsweise betätigbar ist, insbesondere elektromagnetisch betätigbar ist.According to a preferred embodiment, the steering system further comprises:

• - at least one steering gear, in particular a screw steering gear;
• - at least one first line through which the steering gear can be supplied with hydraulic fluid and/or controlled;
• - at least one second line through which the steering gear can be supplied with hydraulic fluid and/or controlled; and
• - at least one valve device connected or connectable to the first line and/or the second line according to one of the preceding claims for pressure reduction in the first line and/or the second line,

wherein the valve device can be actuated as required, in particular electromagnetically actuated.

The design of the valve assembly with a pressure-balanced slide unit ensures a targeted, efficient and dynamic supply of changing or alternating fluid connections along first, second and/or third ports.

According to the present invention, for example, an advantageous pressure reduction within the electro-hydraulic steering system can be ensured by means of the valve device in order to guarantee a suitable and safe functioning of the steering system.

In a further subordinate aspect, a vehicle, in particular a commercial vehicle, is provided with an electro-hydraulic steering system according to the present invention and/or a valve device according to the invention.

All structural and functional features related to the valve device described above and the possible embodiments can also be provided, alone or in combination, in the steering system and/or the vehicle according to the invention, and the associated advantages can be achieved accordingly.

Further details and advantages of the invention will now be explained in more detail with reference to the exemplary embodiments shown in the schematic drawings.

• 1 eine Schnittdarstellung eines Ausführungsbeispiels einer Ventileinrichtung in verschiedenen Schaltzuständen;
• 2 eine Schnittdarstellung eines weiteren Ausführungsbeispiels einer Ventileinrichtung;
• 3 eine Schnittdarstellung eines weiteren Ausführungsbeispiels einer Ventileinrichtung;
• 4 eine Darstellung verschiedener Konfigurationen für eine Ventileinrichtung, insbesondere gemäß einem der Ausführungsbeispiele nach den 1 bis 3;
• 5 eine Schnittdarstellung eines weiteren Ausführungsbeispiels einer Ventileinrichtung;
• 6 eine Schnittdarstellung eines weiteren Ausführungsbeispiels einer Ventileinrichtung;
• 7 eine Darstellung einer Schaltungsanordnung eines Ausführungsbeispiels eines Lenksystems;
• 8 eine Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 9 eine Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 10 eine Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 11 eine schematische Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 12 eine schematische Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 13 eine schematische Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems;
• 14 eine schematische Darstellung einer Schaltungsanordnung eines weiteren Ausführungsbeispiels eines Lenksystems; und
• 15 eine Schnittdarstellung eines weiteren Ausführungsbeispiels einer Ventileinrichtung.

They show:

• 1 a sectional view of an exemplary embodiment of a valve device in various switching states;
• 2 a sectional view of another embodiment of a valve device;
• 3 a sectional view of another embodiment of a valve device;
• 4 a representation of various configurations for a valve assembly, in particular according to one of the embodiments according to the 1 to 3 ;
• 5 a sectional view of another embodiment of a valve device;
• 6 a sectional view of another embodiment of a valve device;
• 7 a representation of a circuit arrangement of an embodiment of a steering system;
• 8 a representation of a circuit arrangement of a further embodiment of a steering system;
• 9 a representation of a circuit arrangement of a further embodiment of a steering system;
• 10 a representation of a circuit arrangement of a further embodiment of a steering system;
• 11 a schematic representation of a circuit arrangement of a further embodiment of a steering system;
• 12 a schematic representation of a circuit arrangement of a further embodiment of a steering system;
• 13 a schematic representation of a circuit arrangement of a further embodiment of a steering system;
• 14 a schematic representation of a circuit arrangement of a further embodiment of a steering system; and
• 15 a sectional view of another embodiment of a valve device.

1 shows a sectional view of an embodiment of a valve device 100 in various switching states.

The valve assembly 100 is according to 1 provided with a housing body 110 in which a main chamber 120 is formed, with a slide unit 130, a sleeve element 140 and a drive unit 150.

In particular, the valve assembly is in accordance with 1 designed as a normally open 3/3 valve.

The housing body 110 can be designed as a single piece or in multiple parts. According to 1 A multi-part design is provided, wherein the housing body 110 can be provided with a separately designed upper part to close off the main chamber 120.

The housing body 110 can be arranged according to 1 extend along a longitudinal axis X.

Furthermore, according to 1 It is evident that the drive unit 150 is attached to a longitudinal end of the housing body 110. The slide unit 130 is movable within the main chamber 120 by means of the drive unit 150, in particular translationally displaceable in the direction of the longitudinal axis X.

The housing body 110 and the components arranged therein can be designed symmetrically, in particular rotationally symmetrically, with respect to the longitudinal axis X.

A piston rod 152 extends from the drive unit 150 into the main chamber 120 and into the slide unit 130. The slide unit 130 is coupled to the drive unit 150 via the piston rod 152.

After 1 It may also be provided that the housing body is designed with at least one first (hydraulic) connection 111, at least one second (hydraulic) connection 112 and at least one third (hydraulic) connection 113.

The first and second ports 111 and 112 can, for example, serve as hydraulic connections for hydraulic lines, preferably for a bidirectional steering gear. The third port 113 can, for example, serve as a connection for a supply line to a hydraulic tank.

According to 1 It is intended that the first and third connections 111; 113 are to be designated as pressure connections (designation according to 1 : P1, P2) are used, with the second port 112 being a port for a hydraulic tank (designation according to 1 : T) is provided.

The slide unit 130 and the sleeve element 140 are arranged within the housing body 110. The sleeve element 140 is fixedly arranged within the housing body 110. The slide unit 130 is movable within the main chamber 120, in particular translationally displaceable.

The slide unit 130 can be understood as being arranged in the main chamber 120. In this sense, the sleeve element can be understood as being arranged within the housing body 110, wherein the main chamber 120 is determined or defined by the sleeve element 140 in conjunction with the housing body 110.

The sleeve element 140 can be configured with at least one first connection opening 141 and at least one second connection opening 142. According to 1 Preferably at least two first and second connection openings 141; 142 are provided.

The first connection opening 141 is designed along the sleeve element 140 such that it is essentially aligned with or oriented towards the first connection 111 of the housing body 110. The second connection opening 142 is designed along the sleeve element 140 such that it is essentially aligned with or oriented towards the second connection 112 of the housing body 110.

Furthermore, the sleeve element 140 is designed along one outer surface such that a flow path from the first and second connection openings 141 and 142 to the first and second connections 111 and 112, respectively, is ensured. Here, the sleeve element 140 has a flow path groove 148 along its outer surface for the first and second connection openings 141 and 142.

In particular, the flow path grooves 148 can each be circumferential flow path grooves 148, so that a fluid connection is provided between several first or second connection openings 141; 142 arranged distributed along a circumference of the sleeve element 140 and to the first or second connection 111; 112 of the housing body 110.

Adjacently arranged flow path grooves 148 can be hydraulically separated from each other by means of sealing elements on the sleeve element 140 and/or on the housing body 110.

Furthermore, the sleeve element 140 has an inner surface 144. The inner surface 144 is designed to interact or interact, particularly sectionally, with the slide unit 130, and in particular with an outer surface 136 of the slide unit 130.

The slide unit 130 can be designed as a single piece or in multiple pieces. According to 1 The sliding unit 130 has a separately designed cover element 132 provided, in conjunction with a jacket section or jacket element.

The slide unit 130 can essentially be designed in a pot shape.

Within the main chamber 120, the slide unit is provided to be movable, in particular to be displaceable along the longitudinal axis X of the valve assembly 100.

The valve unit 130 divides the main chamber 120 into a first section 122 and a second section 124. The volumes of the two sections 122 and 124 can complement each other depending on the position of the valve unit 130 within the main chamber 120, forming the main chamber 120 as a whole.

In particular, the main chamber 120 can be understood as being limited or formed by an inner side of the housing body 110 and an inner side 144 of the sleeve element 140.

The slide unit 130 has at least one through-opening 134, so that a fluid connection between the first section 122 and the second section 124 of the main chamber 120 can be provided.

According to 1 Two or more passage openings 134, symmetrically designed with respect to the longitudinal axis X, may be provided.

Preferably, the at least one through-opening 134 can be configured as a fluid connection, a fluid channel, or the like, in the sense of a short circuit. Alternatively, filter elements, throttling elements, or the like can be provided in the at least one through-opening 134.

Pressure equalization between the first and second sections 122; 124 of the main chamber 120 is possible via the passage openings of the valve unit 134.

The adjustment or movement of the slide element 130 within the main chamber 120 shall occur, at least substantially, independently of or without the influence of a fluid pressure difference between the first and second sections 122; 124. The slide unit 130 is designed as a pressure-balanced slide unit, at least substantially.

Furthermore, the sliding unit 130 has an outer surface 136.

The outer surface 136 of the slide unit 130 is provided, at least in sections, for interaction with the inner surface 144 of the sleeve element, in particular for joint formation dung of a fluid-tight sliding connection along which the slide unit 130 is movable within the main chamber 120.

According to 1 The outer surface 136 can have a U-shaped basic form.

In particular, the gate unit 130 can be designed with a flow path groove 137 along the outside 136.

Preferably, the at least one flow path groove 137 along the outer side 136 of the slide element 130 is designed such that a fluid connection between the at least one first and second connection opening 142 of the sleeve element 140 can be provided as required by means of the flow path groove 137 of the slide unit 130, in particular depending on the positioning position of the slide unit 130 within the main chamber 120.

Furthermore, a fluid connection between the at least one first and second connection opening 142 of the sleeve element 140 can be separated as required by means of the fluid-tightly interacting outer surface 136 and inner surface 144, in particular if the slide unit 136 assumes a different or different position within the main chamber 120.

After 1 The housing body 110 has a third connection 113; in particular, the third connection 113 can be formed at a longitudinal end, preferably opposite the drive unit 150.

The third connection 113 can be provided in such a way that a continuous fluid connection to the main chamber 120, in particular to the second section 124, is present, regardless of the position of the slide unit 130.

According to the exemplary embodiment 1 Based on the movable, pressure-balanced slide unit, 130 different fluid connections can be provided and separated within the valve assembly 100, as shown in 1 illustrated by the different switching states.

On the one hand, a fluid connection between the first port 111 and the third port 113 can be provided via the main chamber 120 or the second section 124, the first port opening 141 and the associated flow path groove 148 of the sleeve element (see 1 , left illustration). For this purpose, the slide unit 130 can assume a position by means of which the second connection opening 142 of the sleeve element 140 can be covered fluid-tight by means of the outer surface 136 of the slide unit 130, in conjunction with the inner surface 144.

In another position of the slide unit 130, a fluid connection between the first port 111 and the second port 112 can be provided via the first and second port openings 141; 142 and the respective associated flow path grooves 148 of the sleeve element 140 (see 1 (centered representation). The specific position of the valve unit 130 can align the flow path groove 137 with respect to the first and second connection openings 141; 142 in such a way that a fluid-tight fluid connection is provided within the main chamber 120, in particular fluid-tightly separated from the first and second sections 122; 124. The flow path groove 137 of the valve unit 130 can be understood as a kind of short circuit. In particular, the valve unit 130 with the flow path groove 137 provides a direct and isolated fluid connection between the first and second connection openings 141; 142 or the first and second connections 111; 112.

Furthermore, a fluid connection between the second and third ports 112; 113 can be provided by means of a further positioning position of the slide unit 130 (see 1 (right illustration). For this purpose, the slide unit 130 can be positioned such that the first connection opening 141 is fluid-tightly separated by the outer surface 136 of the slide unit 130, in particular from the main chamber 120. Preferably, the flow path groove 137 of the slide unit 130 can completely overlap and encompass the first connection opening 141. The fluid connection can extend from the first connection 112, via the flow path groove 148 and the second connection opening 142 of the sleeve element 140, into the main chamber 120 and thus provide access to the third connection 113. In particular, the fluid connection can extend within the main chamber 120 from the first section 122, via the at least one through-opening 134 of the slide unit 130, into the second section 122, with which the third connection 113 is connected. 1 is directly connected.

For example, a valve device 100, as in a first embodiment according to 1 It has been shown that the implementation of various functionalities in an electro-hydraulic steering gear is conceivable.

• - eine Niederdruck-Funktion zur Verbesserung der Dynamik des (elektro-)hydraulischen (Lenk-)Systems;
• - eine Leckage-Funktion zur Erleichterung einer Pumpenfunktion, zur (Druck-/Volumenstrom-)Schwankungsminimierung bei niedrigen Drehzahlen und/oder zur Erhöhung des Wirkungsgrades der Pumpenfunktion, insbesondere indem ein kritischer Betriebsbereich der Pumpe (aufgrund von Misch-Reibungsverhalten) übersprungen bzw. ausgespart und ein optimaler Betriebsbereich sichergestellt werden kann;
• - eine Heizungsfunktion zum Aufwärmen des Hydraulikfluids, der Hydraulikpumpe 1114 und/oder des Lenkgetriebes 1102, während des Betriebs (d.h. anhand einer Verbindung zwischen einem der Druckanschlüsse P1 oder P2 mit dem Hydrauliktank T) oder des Leerlaufs der Hydraulikpumpe (d.h. hydraulischer Kurzschluss innerhalb der Ventileinrichtung 100 zwischen den Druckanschlüssen P1 und P2), wobei ein Erwärmen bzw. Aufheizen in lediglich unidirektionale (Förder-)Richtung oder in bidirektionale (Förder-)Richtung der Hydraulikpumpe 1114 vorstellbar ist;
• - eine Dämpfungsfunktion anhand einer (gezielten) Leckage zwischen der Druckseite und dem Tank;
• - eine Funktion zur Wiederbefüllung des Tanks mit Hydraulikfluid und/oder
• - eine Back-up-Funktion für ein elektrohydraulisches Lenksystem umgesetzt werden (vgl. 1, mittige und rechte Darstellung).

Based on a fluid connection or hydraulic connection between one of the pressure ports P1 or P2 (in 1 : first connection 111 or third connection 113), and a hydraulic tank T (in 1 : second connection 112) can, in Dependence on the pressure conditions at the first or second (pressure) port 111; 112

• - a low-pressure function to improve the dynamics of the (electro-)hydraulic (steering) system;
• - a leakage function to facilitate pump operation, to minimize (pressure/volume flow) fluctuations at low speeds and/or to increase the efficiency of the pump function, in particular by skipping or omitting a critical operating range of the pump (due to mixed friction behavior) and ensuring an optimal operating range;
• - a heating function for warming the hydraulic fluid, the hydraulic pump 1114 and/or the steering gear 1102, during operation (i.e. by means of a connection between one of the pressure ports P1 or P2 with the hydraulic tank T) or when the hydraulic pump is idling (i.e. hydraulic short circuit within the valve assembly 100 between the pressure ports P1 and P2), wherein heating in a unidirectional (delivery) direction only or in a bidirectional (delivery) direction of the hydraulic pump 1114 is conceivable;
• - a damping function based on a (targeted) leakage between the pressure side and the tank;
• - a function for refilling the tank with hydraulic fluid and/or
• - a backup function for an electro-hydraulic steering system is implemented (see 1 , center and right representation).

Provided that the pressure ports P1 and P2 (in 1 : first and third connections 111; 113) are hydraulically connected to each other and the (hydraulic) tank (in 1 : second connection 112) is hydraulically separated by means of the sliding element 130 or the flow path groove 137, a parking heater function can be implemented during idling (see 1 , left illustration).

Based on the specific design of the sleeve element 140, a normally open 3/3-way valve can be implemented by means of various positioning positions of the pressure-balanced slide unit 130 within the main chamber 120.

The normally open position of the valve device 100 is according to 1 as a fluid connection of the pressure ports according to the first with the third port 111; 113 (in 1 : P1 and P2).

The valve unit 100 represents a cost-effective solution that also takes up little installation space and allows for efficient and dynamic control.

2 Figure 1 shows a sectional view of another embodiment of a valve device 100. The differences compared to the embodiments described above will be discussed in detail below.

In 2 Valve assembly 100 is shown as a normally closed 3/3-way valve. According to 2 It is provided that the valve unit 130 is designed along its outer side in such a way that, in the de-energized state, the first connection 111 is hydraulically separated (cf. 2 : left illustration).

In particular, the river channel groove 137 can be so smaller compared to the embodiment shown in the following example. 1 be designed such that a larger interaction area is present along the outside 136 of the slide unit 136.

Preferably, the (interacting) surface of the outer surface 136 of the sliding unit 130, which is intended to interact with the inner surface 146 of the sleeve element 140, can be designed to be so large that the first and/or the second connection opening 141; 142 of the sleeve element can be completely covered or separated.

According to 2 The at least one first connection opening 141 is covered and hydraulically separated by means of the outer surface 136 of the slide unit 130.

Furthermore, according to 2 the second connection opening is hydraulically separated by the gate unit 130, in particular by means of an overlap of the flow path groove 137 of the gate unit 130.

So is after 2 It is provided that the first port 111, the second port 112 and the third port 113 can be hydraulically separated from each other.

In particular, the outer surface 136 of the slide element 130 is designed such that the first connection 111, the second connection 112 and the third connection 113 can be separated (hydraulically) from each other.

Furthermore, according to 2 , compared to the embodiment according to 1 , the arrangement of a prestressing element 160 is provided.

In particular, it is provided that the pretensioning element 160 pretensions the slide unit 130 in one direction of movement.

The prestressing element 160 is according to 2 arranged within the main chamber 120, for pre-tensioning the slide unit 130 in the direction of the longitudinal axis X.

The preloading element 160 can be located at one end of the main chamber 120 opposite the drive unit and in direct contact with the slide unit 130. Alternatively, the preloading element 160 can be arranged in indirect contact with the slide unit 130.

According to 2 The preload element 160 is designed as a spring, in particular as a compression spring.

• - Niederdruck-Funktion zur Verbesserung der Dynamik des (elektro-)hydraulischen (Lenk-)Systems;
• - eine Leckage-Funktion zur Erleichterung einer Pumpenfunktion, zur (Druck-/Volumenstrom-)Schwankungsminimierung bei niedrigen Drehzahlen und/oder zur Erhöhung des Wirkungsgrades der Pumpenfunktion, insbesondere indem ein kritischer Betriebsbereich der Pumpe (aufgrund von Misch-Reibungsverhalten) übersprungen bzw. ausgespart und ein optimaler Betriebsbereich sichergestellt werden kann;
• - eine Heizungsfunktion zum Aufwärmen des Hydraulikfluids, der Hydraulikpumpe 1114 und/oder des Lenkgetriebes 1102, während des Betriebs (d.h. anhand einer Verbindung zwischen einem der Druckanschlüsse P1 oder P2 mit dem Hydrauliktank T), wobei ein Erwärmen bzw. Aufheizen in lediglich unidirektionale (Förder-)Richtung oder in bidirektionale (Förder-)Richtung der Hydraulikpumpe 1114 vorstellbar ist;
• - eine Dämpfungsfunktion anhand einer (gezielten) Leckage zwischen der Druckseite P1; P2 und dem Tank T (in 2: erster oder dritter Anschluss 111; 113 in Verbindung mit dem zweiten Anschluss 112);
• - eine Funktion zur Wiederbefüllung des Tanks mit Hydraulikfluid.

For example, using the embodiment according to 2 The implementation of various functionalities in an electro-hydraulic steering gear is conceivable, starting from the functions as in the exemplary embodiment according to 1 described:

• - Low-pressure function to improve the dynamics of the (electro-)hydraulic (steering) system;
• - a leakage function to facilitate pump operation, to minimize (pressure/volume flow) fluctuations at low speeds and/or to increase the efficiency of the pump function, in particular by skipping or omitting a critical operating range of the pump (due to mixed friction behavior) and ensuring an optimal operating range;
• - a heating function for warming the hydraulic fluid, the hydraulic pump 1114 and/or the steering gear 1102 during operation (i.e. by means of a connection between one of the pressure ports P1 or P2 with the hydraulic tank T), wherein heating in only unidirectional (delivery) direction or in bidirectional (delivery) direction of the hydraulic pump 1114 is conceivable;
• - a damping function based on a (targeted) leakage between the pressure side P1; P2 and the tank T (in 2 : first or third connection 111; 113 in conjunction with the second connection 112);
• - a function for refilling the tank with hydraulic fluid.

Based on the design of the valve assembly with the preloading element 160, according to 2 A normally closed 3/3-way valve is feasible.

3 Figure 1 shows a sectional view of another embodiment of a valve assembly. The differences compared to the embodiments described above will be discussed in detail below.

According to 3 is, compared to the embodiment according 2 , provided that the preloading element 160 can be arranged in direct or indirect contact with the drive unit 150.

In particular, the preloading element 160 can be arranged in a recess of the housing body 110 on the drive unit 150, preferably arranged concentrically to the piston rod 152.

4 shows a representation of various configurations for a valve assembly 100, in particular according to one of the embodiments according to the 1 to 3 In particular, in 4 an outside of the sleeve element 140 in expanded form.

According to 4 It can be provided that three first and three second connection openings 141; 142 are arranged distributed along the sleeve element 140.

In particular, the connection openings 141; 142 are arranged distributed along the respective associated river channel grooves 148.

Furthermore, the first and second connection openings 141; 142 can be used according to 4 exhibit different geometries or be designed with different geometries.

It is conceivable that the first and second connection openings 141, 142 have a circular shape, a square or rectangular shape, a triangular shape, a rhombus shape, an elliptical shape or the like.

The geometry of the connection openings 141; 142 along the sleeve element 140 can be used to influence, in particular, the control behavior in operative connection with the slide unit 130, especially the outside 136 of the slide unit 130, and/or the flow behavior during the presence of a (partial) fluid connection.

5 Figure 1 shows a sectional view of another embodiment of a valve device 100. The differences compared to the embodiments described above will be discussed in detail below.

The exemplary embodiment according to 5 This can be used as a switching or proportional valve, according to the in 5 The representation shown depicts a proportional valve, which acts or is used.

After 5 The first connection 111 can be intended for connection to a (hydraulic) tank, the second connection 112 as a pressure connection for connection to a second pressure line (in 5 : P2) and the third connection 113 as a pressure connection for connection to a second pressure line (in 5 : P1). Alternatively, different configurations or assignments of terminals 111; 112; 113 are conceivable, as also shown, among other things, in accordance with 1 shown.

According to 5 It is further provided that the valve unit 130 has at least one additionally formed sealing section 138 along the alternating or cooperating outer surface 136.

The sleeve element 140 can be configured to correspond with at least one counter-section 146.

According to 5 The slide unit 130 has a projection along its outer surface 136, which is formed with two inclined or chamfered sealing sections or sealing surfaces 138. The sealing sections or sealing surfaces are designed for fluid-tight engagement or contact with corresponding counter sections 146 of the sleeve element 140.

In particular, the sleeve element 140 can be used according to 5 to be understood as being designed in multiple parts and/or supplemented by the design of the housing body 110, which preferably form or limit the main chamber 120.

The inner surface 144 is appropriately designed to form the corresponding counter-sections 146.

According to 5 The inner surface 144 can have a recess or indentation in the area of the first outlet opening 141, which allows at least partial engagement of the projection of the outer surface 136 with the sealing sections 137. The projection with the sealing sections 137 can move along the recess on the inner surface 144 according to the mobility of the slide unit 130, with the opposing sections 146 forming a stop in each case.

When a sealing section 138 is brought into suitable contact with a counter section 146 according to a corresponding positioning position of the slide unit 130, a fluid-tight connection is preferably formed along this contact.

• - zwischen dem ersten Anschluss 111 (gemäß 5: Hydrauliktank T) und dem dritten Anschluss 113 (gemäß 5: Druckanschluss P1) oder
• - zwischen dem zweiten Anschluss 112 (gemäß 5: Druckanschluss P2) und dem ersten Anschluss 111 (gemäß 5: Hydrauliktank T).

Thus, according to 5 A fluid connection is provided using the opposing sections 146 as (end) stops for a positioning position of the slide unit 130.

• - between the first connection 111 (according to 5 : hydraulic tank T) and the third connection 113 (according to 5 : Pressure port P1) or
• - between the second connection 112 (according to 5 : pressure port P2) and the first port 111 (according to 5 : Hydraulic tank T).

A hydraulic/fluid connection between the second port 112 (according to 5 : pressure port P2) and the third port 113 (according to 5 : Pressure connection P1) is according to 5 not planned.

The implementable functionalities in the case of the exemplary embodiment according to 5 are comparable to those in the exemplary embodiment according to 2 described functionalities.

In particular, the valve assembly 100 is designed according to 5 A normally open 3/2-way valve can be implemented.

In 6 A sectional view of a further embodiment of a valve assembly 100 is shown. The differences compared to the embodiments described above will be discussed in detail below.

Opposite the 5 is in 6 Another variant of a valve device 100 with at least one sealing section 137 and at least one counter section 146 is shown.

The exemplary embodiment according to 6 It can preferably act or be used as a proportional valve.

After 6 The housing body only has the first port 111 and the third port 113. The first port 111 and the second port 112 can be used as pressure ports (according to...). 6 : P1; P2). Alternatively, for example, a wiring configuration is possible. One of the first and third connections 111; 113 could be conceivable with a (hydraulic) tank.

Corresponding to the design of the housing body 110 with only one first and one third connection 111; 113, the sleeve element 140 is designed with at least one first outlet opening 141 and an associated flow path groove 148.

Thus, the sleeve element 140 exhibits according to 6 in particular no second connection opening 142.

Furthermore, according to 6 provided that the outer surface 136 of the valve unit 130 does not have a flow path groove 137.

The outer side 136 of the slide unit 130 is according to 6 designed to interact or interact with the inner surface 144 of the sleeve element 140 in such a way that a counter section 146 forms a single stop for the sealing section 138 of the outer surface 136.

According to 6 The sealing section 138 at a longitudinal end of the slide unit 130 can be designed as a single-stage or multi-stage chamfer of the outer surface 136 such that the slide unit 130 can come into contact with the opposite section 146 in a corresponding positioning position, in order to form a fluid-tight (contact) connection.

In particular, the sealing section 138 can be formed along the outside 136 at one end of the slide unit 130 facing the drive unit or the third connection 113.

Thus, according to 6 It is provided that, in the case of fluid-tight contact between the sealing section 138 and the counter section 146, as well as in further fluid-tight interaction of the remaining outer surface 136 with the inner surface 144, a hydraulic separation of the first connection 111 from the third connection 113 can take place.

If the slide unit 130 is moved to a further positioning position, the fluid-sealing contact between the counter section 146 and the sealing section 138 is released, and a fluid connection can be established from the first port 111 via the flow path groove 148, which provides at least one first connection opening 141 into the first section 122 of the main chamber 120. From the first section 122 of the main chamber 120, the fluid connection can be continued via the at least one through-opening 134 of the pressure-balanced slide unit 130 into the second section 124 and up to the third port 113 of the housing body 110.

Furthermore, it is from 6 , especially in relation to 5 , recognizable that the sealing section 138 can be designed in multiple stages.

The sealing section 138 is in 6 The sealing section 138 is illustrated as a two-stage design, wherein the sealing section 138 has two differently designed areas, in particular two areas with different chamfers. Preferably, the two or more areas of the sealing section 138 can be separated from each other in fluid-tight contact with the sleeve element by the opposing section 146.

By designing the sealing section 138 as a multi-stage sealing section 138, a changing behavior of the slide unit 130 during pressure build-up before, during and after the occurrence or dissolution of a (fluid-)sealing contact between the slide unit 130 and the sleeve element 140 can be provided.

Furthermore, according to 6 the preload element 160, preferably in the form of a (compression) spring, is provided within the main chamber 120, in particular the second section 124, and in direct contact with the slide unit 130.

The preloading element 160 can be used to preload the slide unit 130 in the direction of or against the opposite section 146 as a stop.

• - eine Leckage-Funktion zur Erleichterung einer Pumpenfunktion, zur (Druck-Nolumenstrom-)Schwankungsminimierung bei niedrigen Drehzahlen und/oder zur Erhöhung des Wirkungsgrades der Pumpenfunktion, insbesondere indem ein kritischer Betriebsbereich der Pumpe (aufgrund von Misch-Reibungsverhalten) übersprungen bzw. ausgespart und ein optimaler Betriebsbereich sichergestellt werden kann;eine Heizungsfunktion zum Aufwärmen des Hydraulikfluids, der Hydraulikpumpe 1114 und/oder des Lenkgetriebes 1102, während des Leerlaufs der Hydraulikpumpe (d.h. hydraulischer Kurzschluss innerhalb der Ventileinrichtung 100 zwischen den Druckanschlüssen P1 und P2), wobei ein Erwärmen bzw. Aufheizen in lediglich unidirektionale (Förder-)Richtung oder in bidirektionale (Förder-)Richtung der Hydraulikpumpe 1114 vorstellbar ist;
• - eine Dämpfungsfunktion anhand einer (gezielten) Leckage zwischen der Druckseite P1; P2 und dem Tank T (in 2: erster oder dritter Anschluss 111; 113 in Verbindung mit dem zweiten Anschluss 112);
• - eine Back-up-Funktion für ein elektrohydraulisches Lenksystem.

For example, using the embodiment according to 6 The implementation of various functionalities in an electro-hydraulic steering gear is conceivable, starting from functions such as... 1 described:

• - a leakage function to facilitate pump operation, to minimize (pressure-flow rate) fluctuations at low speeds and/or to increase the efficiency of the pump operation, in particular by allowing a critical operating range of the pump (due to mixed friction behavior) to be skipped or omitted and an optimal operating range to be ensured; a heating function to warm the hydraulic fluid, the hydraulic pump 1114 and/or the steering gear 1102, during the idling of the hydraulic pump (i.e., hydraulic short circuit within the valve assembly 100 between the pressure ports P1 and P2), wherein heating is only in a unidirectional (delivery) direction. or is conceivable in a bidirectional (conveying) direction of the hydraulic pump 1114;
• - a damping function based on a (targeted) leakage between the pressure side P1; P2 and the tank T (in 2 : first or third connection 111; 113 in conjunction with the second connection 112);
• - a backup function for an electro-hydraulic steering system.

Based on the design of the valve device according to 6 A normally closed 2/2-way valve or 2/2-proportional valve can be implemented.

In general, all embodiments of a valve device 100 shown within the scope of this invention can be designed as a directional control valve, a spool valve, or an on/off valve, or as a proportional valve with appropriately designed, in particular single-stage or multi-stage beveled, sealing sections 138 along the outside 136 of the spool unit 130.

Furthermore, in accordance with the present invention, it is conceivable that the design as a proportional valve can be provided by a targeted structuring or surface (size) modification of the outside 136 of the slide unit 130, for example in the form of grooves or the like.

7 Figure 1 shows a circuit arrangement of an embodiment of a steering system 1000. In particular, the electro-hydraulic steering system 1000 can include a valve assembly 100 according to one of the embodiments described above. 1 to 6 exhibit.

The electro-hydraulic steering system 1000 for a commercial vehicle has a steering gear 1102 in the form of a spindle steering gear.

The screw steering gear 1102 can be designed as a ball screw steering gear, although other types of gears are also conceivable.

The electro-hydraulic steering system 1000 further includes a first line 1104 through which the steering gear 1102 can be supplied with hydraulic fluid and controlled.

Accordingly, the electro-hydraulic steering system 1000 has a second line 1106 through which the steering gear 1102 can also be supplied with hydraulic fluid and controlled.

Furthermore, the steering system 1000 has a valve assembly 100, preferably a valve assembly 100 according to one of the embodiments according to 1 to 6 .

The valve assembly 100 can, for example, be designed as a 3/3-way valve assembly, an on/off valve assembly, or a low-pressure valve assembly.

The valve assembly 100 is connected on the input side to the first line 1104 and also on the input side to the second line 1106.

The valve assembly 100 is according to 7 On the output side, it is also connected or connectable to a hydraulic tank 1110 via a return line 1112 of the steering system 1000.

Therefore, a hydraulic fluid can be transferred or forwarded to the hydraulic tank 1110 via the valve device 100.

Furthermore, the valve device 100 can, for example, be used for pressure reduction in the first line 1104 and/or the second line 1106.

The valve assembly 100 can be actuated or controlled on demand, preferably electromagnetically, by means of a control unit that is assigned to or associated with the steering system 1000 and is not shown in the figures.

Furthermore, the pump unit 1114 is connected to the first and second lines 1104, 1106.

The pump unit 1114 can be designed as a double-acting hydraulic pump, so that depending on the direction of rotation either the first line 1104 or the second line 1106 can be printed.

Alternatively, it may also be conceivable that only a single-acting hydraulic pump is provided and is connected to the first and second lines 1104; 1106 via a corresponding switching valve (not shown in the figures), which connects the hydraulic pump to the first or the second line 1104; 1106 depending on the switching logic.

Alternatively, it may also be conceivable that two pump units 1114 could be provided, with one pump unit 1114 being assigned to or connected with the first or the second line 1104, 1106.

The pump unit 1114 in 7 It can be connected to the steering gear 1102 via the first line 1104 and, alternatively, via the second line 1106. so that the actual connection depends on a direction of rotation control of the pump unit 1114.

Such control can be effected by a control unit that is assigned to or associated with the steering system 1000 and is not shown in the figures.

As in 7 As can be seen, the hydraulic tank 1110 is symbolically shown outside a module 1126 of the pump unit 1114. Alternatively, the hydraulic tank 1110 or an additional hydraulic tank can also be provided inside the module 1126 of the pump unit 1114 (see the following embodiments according to...). 11 to 13 ).

According to 7 The first line 1104 and the second line 1106 are connected to the hydraulic tank 1110 via the check valves 1118; 1120 (in 7 (not explicitly illustrated) connected.

The two check valves 1118; 1120 can be arranged in such a way that hydraulic fluid can be supplied from the hydraulic tank 1110 to the pump 1114 via the check valves 1118; 1120, while preventing backflow towards the hydraulic tank 1110.

The first check valve 1118 and the second check valve 1120 can also serve and/or function as suction valves in this case.

Advantageously, a pressure build-up, in particular a pressure build-up controllable or controlled via a control unit assignable or associated to the steering system 1000, for example the already named, can thus take place under the influence, preferably support, of the suction valves.

In other words, the first and second check valves 1118; 1120 can assist the pump 1114 in building up pressure, especially along the first and second lines respectively up to the steering gear 1102.

As in 7 As can be seen, the pump unit 1114 or the construction module 1126 can also be assigned a temperature sensor 1122 and a pressure sensor 1124, which are provided, for example, along the at least one suction line 1116.

It is understood that the temperature sensor 1122 and the pressure sensor 1124 can be connected or linked to the control unit of the pump unit 1114 and/or a control unit that can be assigned or associated with the steering system 1000, for example the one already mentioned above, for controlling an operation and/or partial operation of the steering system 1000 via signal technology.

Furthermore, according to 7 An additional backup valve 1160 may be provided on the steering gear 1102. Alternatively, such a backup valve 1160 may, for example, be integrated into the valve assembly 100.

As in 7 As shown, the backup valve 1160 can be connected, at least indirectly, to the first line 1104 via the pressure chamber of the steering gear 1102 assigned to the first line 1104.

On the other hand, the backup valve 1160 can be indirectly connected to the second line 1106 via the respective pressure chamber of the steering gear 1102 assigned to the second line 1106.

The respective pressure chambers of the steering gear 102 can be connected and preferably short-circuited by means of the backup valve 1160, especially in an emergency situation or in the event of a fault.

This allows the safety and/or reliability of the steering system 1000 to be further improved, as the pressure chambers of the steering gear 1102 can be connected in an emergency situation, thereby ensuring a corresponding pressure reduction or pressure equalization and thus a steering function in terms of the mobility of the (hydraulic) piston in the steering gear at all times.

In a sense, the backup valve 1160 can thus form and/or enable a fault circuit that is not specifically indicated in the figures and/or function as such.

In an emergency, the backup valve 1160 can switch from its closed position to a through position in order to provide a fluid short circuit between the two pressure chambers of the steering gear 1102.

Furthermore, the backup device or the backup valve device, in particular the backup valve 1160, can be controlled or controlled via a control unit that can be assigned to or associated with the steering system 1000.

• Sobald die Pumpe 1114 von der Antriebseinheit bzw. dem Elektromotor (z.B. entgegen dem Uhrzeigersinn) angetrieben wird, kann sie den Abschnitt der ersten Leitung 1104, der sich bis zu dem Lenkgetriebe 1102 sowie zu einem ersten Anschluss 1128 der Ventileinrichtung 100 erstreckt, mit einem Hydraulikfluid-Druck beaufschlagen.

The function of the steering system 1000 according to the embodiment shown below 6 can be described as follows:

• As soon as the pump 1114 is disconnected from the drive unit or the electric motor (e.g., counterclockwise) (clockwise) it can apply hydraulic fluid pressure to the section of the first line 1104, which extends to the steering gear 1102 and to a first connection 1128 of the valve assembly 100.

With regard to the short-term and/or long-term temperature control of the hydraulic fluid during commissioning or continuous operation of the electro-hydraulic steering system 1000, the hydraulic fluid can be circulated by means of the pump unit 1114 and via the valve device 100 along the return line 1112.

In particular, the pump 1114 can pump the hydraulic fluid via the first or second pump fluid port along the first or second line 1104; 1106 to the valve assembly 100 with the inlet ports 1128; 1130.

Using the valve device 100, the hydraulic fluid can be returned directly to the hydraulic tank 1110 via the return line 1112.

• Bei dem Druckaufbau zur Ausübung einer Lenkunterstützung kann die (Hydraulik-)Pumpe 1114 durch das als Nachsaugventil fungierende zweite Rückschlagventil 1120 unterstützt werden, insbesondere wenn durch die Pumpe 1114 entlang der zweiten Leitung 1106 ein hinreichender Unterdruck erzeugt wird, der zu einem Öffnen des zweiten Rückschlagventils 1120 führt.

Furthermore, the pressure build-up for the application of steering assistance can be carried out using the present steering system 1000 as described below:

• During pressure build-up to provide steering assistance, the (hydraulic) pump 1114 can be supported by the second check valve 1120, which acts as a suction valve, especially when the pump 1114 generates a sufficient vacuum along the second line 1106, which leads to the opening of the second check valve 1120.

Consequently, the pump 1114 and the steering gear 1102 are connected to each other via the first line 1104 and the connection of the steering gear 1102 connected to the first line 1104 is printed.

Subsequently, the pressure in the assigned first pressure chamber of the steering gear 1102 increases, and the piston is forced into a displacement movement because the pressure in the opposite, second pressure chamber is lower, thus achieving the steering assistance. In this sense, the second pressure chamber can be understood as a low-pressure chamber.

The pressure in the opposite second pressure chamber is therefore lower because the connection of the steering gear 1102 is connected to the return line 1112 via the section of the second line 1106 and via the valve assembly 100.

In this case, the hydraulic fluid is displaced from the opposite, second pressure chamber and via the valve assembly 100 into the return line 1112 and then fed back to the hydraulic tank 1110 via the return line 1112.

A rapid return of the hydraulic fluid can be initiated, for example, if the operating pressure in the first line 1104 is higher compared to the operating pressure in the second line 1106 and the second line 1106 is connected to the return line 1112 by means of the at least partially controllable valve device 100.

Thus, the second line 1106 can be connected to the return line 1112 depending on the pressure difference between the first line 1104 and the second line 1106 and the actuable valve device 100.

This enables a rapid pressure relief phase in the pressure chamber of the steering gear 1102 connected to the second line 1106, and thus the response behavior of the steering system 1000 can be improved, preferably enabling a faster system response and a better steering feel.

It should be taken into account that the pump 1114 can preferably only be driven in one direction of rotation and therefore only the first or the second line 1104, 1106 can be printed on at any given time.

In the case described above, the first line 1104 is therefore printed by the (hydraulic) pump 1114, whereas the second line 1106 is not printed, at least in the section between pump 1114 and steering gear 1102 and/or valve assembly 100.

• Sobald die Pumpe 1114 von der Antriebseinheit bzw. dem Elektromotor (nun im Uhrzeigersinn) angetrieben wird bedruckt sie den Abschnitt der zweiten Leitung 1106, der sich bis zu dem Lenkgetriebe 1102 sowie zu einem zweiten Anschluss 1130 der Ventileinrichtung 100 erstreckt.

If the direction of rotation of pump 120 is reversed, the previously described relationship or case occurs in exactly the opposite way, as described below:

• As soon as the pump 1114 is driven by the drive unit or the electric motor (now clockwise), it prints the section of the second line 1106, which extends to the steering gear 1102 and to a second connection 1130 of the valve assembly 100.

During pressure build-up, the pump 1114 is supported by the first check valve 1118, which acts as a suction valve.

Consequently, the pump 1114 and the steering gear 1102 are now connected to each other via the second line 1106 and the connection of the steering gear 1102 connected to the second line 1106 is printed.

As a result, the pressure in the associated second pressure chamber of the steering gear 1102 increases, and the piston is forced into a displacement movement because the pressure in the opposite first pressure chamber is now lower, thus achieving steering assistance. In this case, the first pressure chamber of the steering gear 1102 can be considered a low-pressure chamber.

The pressure in the opposite first pressure chamber is therefore lower because the connection of the steering gear 1102 is connected to the return line 1112 via the section of the first line and via the valve assembly 100.

In this case, the hydraulic fluid is displaced from the opposite, first pressure chamber and directed via the valve assembly 100 into the return line 1112 and then fed back to the hydraulic tank 1110 via the return line 1112.

In this case, a rapid return of the hydraulic fluid can be initiated if the operating pressure in the second line 1106 is higher compared to the operating pressure in the first line 1104 and the first line 1104 is connected to the return line 1112 by means of the at least partially controllable valve device 100.

Thus, the first line 1104 can be connected to the return line 1112 depending on the pressure difference between the first line 1104 and the second line 1106 by means of the actuable valve device 100, preferably by means of the actively controllable valve device 100.

This enables a rapid pressure relief phase in the pressure chamber of the steering gear 1102 connected to the first line 1104, and thus the response behavior of the steering system 1000 can be improved, preferably enabling a faster system response and a better steering feel.

The pump 120 can preferably only be driven in one direction of rotation, and therefore only the first or the second line 1104; 1106 can be printed on at any given time.

In the second case described above, the second line 1106 is therefore printed by the (hydraulic) pump 120, whereas the first line 1104 is not printed, at least in the section between pump 1114 and steering gear 1102 and/or valve assembly 100.

In summary, it should also be noted that, depending on the direction of rotation of the pump, either the first or the second line 1104; 1106 is printed, so that the steering gear 1102 is preferably always printed by only one of the lines 1104; 1106 and thus the other line 1104, 1106 (which is not printed) can be connected or is connected to the return line 1112 via the valve device 100.

Since the piston displacement direction of the piston in the steering gear 1102 also changes depending on the steering direction, the control/pressure of the steering gear 1102 via the first line 1104 or the second line 1106 also changes accordingly. By enabling a rapid pressure reduction using the valve assembly 100, the piston displacement direction can also be quickly changed, thus enabling a fast and dynamic change of steering direction.

8 Figure 1 shows a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

In the sense of 8 can be considered a possible alternative to the embodiment according to 7 , an additional or supplementary hydraulic tank 1210, may be provided within the construction module 1126. In particular, the additional or supplementary hydraulic tank 1210 may be provided as an integral component of the construction module 1126, for example the hydraulic pump 1114, in parallel to the hydraulic tank 1110 connected to or flanged to the construction module 1126.

Furthermore, according to 8 , and opposite 7 , it is provided that a return line check valve 1202 is provided along the return line 1112 between the (hydraulic) tank 1210 and the valve assembly 100.

In particular, the return line check valve 1202 can be arranged along the return line 1112 in such a way that an oil flow or oil leakage from the valve assembly 100 via return line 1112 into the hydraulic tank 1210 is provided or enabled and an opposite backflow, i.e. from the hydraulic tank 1210 via the return line 1112 to the valve assembly 100, can be prevented.

9 Figure 1 shows a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

The exemplary embodiment according to 9 differs from the embodiment according to 7 especially in the design of the hydraulic pump 1114 and the connection of the hydraulic tank 1110.

According to 9 It is intended that the hydraulic pump 1114 is connected to the hydraulic tank 1110 only via the leakage line 1115.

The hydraulic tank 1110 has a fluid connection to the steering gear 1102 and the hydraulic pump 1114 via the return line 1112 with the valve assembly 100.

Therefore, the suction of hydraulic fluid from the (hydraulic) tank 1110 by the pump 1114 can only take place, or at least primarily, via the valve assembly 100 and the return line 1112.

10 Figure 1 shows a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

According to 10 is in comparison to the embodiment example according to 9 In particular, it is provided that the steering system 1000 is designed without a separate backup valve 1160.

In particular, the backup valve 1160 can be integrated into the valve assembly 100. Alternatively, the steering system 1000 can be configured without a backup valve 1160.

11 Figure 1 shows a schematic representation of a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

In the sense of 11 , compared to the embodiment according to 7 and according to the exemplary embodiment 8 , as a possible alternative, an additional or supplementary hydraulic tank 1210, in addition to and preferably in connection with the hydraulic tank 1110, can be provided within the construction module 1126.

The valve assembly 100 is designed according to 11 On the output side, the pump unit 1114, in particular the construction module 1126 of the pump unit 1114, and the associated hydraulic tank 1210 are connected or connectable via the return line 1112.

Along the return line 1112, according to 11 Furthermore, a filter unit 1208 may be provided. In particular, the filter unit can be arranged between the additional hydraulic tank 1210 and the return line check valve 1202.

The filter unit can be arranged according to the illustration in 11 The filter unit 1208 may be designed as part of the construction module 1126 or attached to or flanged to the construction module 1126. Alternatively, the filter unit 1208 may be provided independently of the construction module 1126 along the return line 1112.

The valve device 100 can therefore transfer or forward a hydraulic fluid to the construction module 1126 of the hydraulic pump 1114 and into the hydraulic tank 12120, for example for efficient temperature control of the hydraulic fluid, for example during the initial commissioning of the electro-hydraulic steering system 1000.

As in 11 As can be seen, the hydraulic tank 1210, as part and/or supplement to the hydraulic tank 1110, is symbolically represented within the construction module 1126, in the sense of integrated design.

Using the valve assembly 100, the hydraulic fluid can be returned directly to the hydraulic pump module 1114 via the return line 1112 in order to return to the hydraulic tanks 1110; 1210.

The valve assembly 100 preferably enables a short-circuit circulation of the hydraulic fluid via the hydraulic tanks 1110 and 1210 of the hydraulic pump 1114. This allows for the short-term adjustment of the hydraulic fluid's operating temperature and/or temperature control of the pump unit 1114 and other components of the steering system 1000.

In particular, efficiency can be increased and the operating temperature of the pump unit 1114 can be appropriately set by circulating only the smallest possible volume of hydraulic fluid via the short-circuited fluid connection along the valve assembly 100 and by increasing or adjusting the fluid temperature primarily within the construction module 1126 of the pump unit 1114.

Furthermore, according to 11 , and opposite 7 , it is provided that a return line check valve 1202 and a filter device 1208 are provided along the return line 1112 between the pump unit 1114 and the valve assembly 100.

This arrangement has the advantage that the filter or filter assembly 1208 does not need to be located on the high-pressure side, but rather on the low-pressure side in the return line 1112. Consequently, the filter assembly 1208 can be mechanically less robust and structurally simpler, as it is not subjected to such high pressures. As a result, cost advantages can also be realized through this type of filter design.

Preferably the return line check valve 1202 is in accordance with 9 provided between the filter unit 1208 and the valve unit 100.

In particular, the return line check valve 1202 can be arranged along the return line 1112 in such a way that an oil flow or oil leakage from the valve assembly 100 via the filter assembly 1208 and a hydraulic fluid connection into the hydraulic tank 1210 is provided or enabled, and an opposite backflow, i.e. from the hydraulic tank 1210 via the filter assembly 1208 to the valve assembly 100, can be prevented.

12 Figure 1 shows a schematic representation of a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

In particular, according to 12 compared to the embodiment according to 11 It is provided that the filter unit 1208, in particular exclusively the filter unit 1208, is arranged along the return line.

Accordingly, the exemplary embodiment of a steering system can be 1000 according to 12 along the return line 1208 without a check valve 1202.

Furthermore, a third check valve 1152 can be arranged in the first line 1104 and a fourth check valve 1154 in the second line 1106, in particular between the valve assembly 100 or the steering gear 102 and the hydraulic pump 1114, so that backflow to the hydraulic pump 1114 or the baud module 1126 and the suction of hydraulic fluid from the steering gear 1102 by the pump 1114 can be prevented.

In the first and second lines 1104; 1106, two check valves 1118; 1120; 1152; 1154 can each be arranged, so that, depending on a direction of rotation or delivery of the pump 120, a targeted suction of hydraulic fluid from the hydraulic tank 1110 is made possible.

The check valves 1118; 1120; 1152; 1154 prevent or stop the (hydraulic) pump 120 from drawing hydraulic fluid from the steering gear 1102 or the valve device 1108 along the first or second line 1104; 1106.

13 Figure 1 shows a schematic representation of a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

In particular, 13 an embodiment in the sense of a combination of the embodiments according to the 11 and 12 dar.

According to 13 Along the return line 1112, next to the filter unit 1208, the return line check valve 1202 is also provided to prevent hydraulic backflow from the hydraulic tank 1210 to the valve assembly 100.

In addition, the third and fourth check valves 1204 and 1206 are arranged along the first and second lines 1104 and 1106 to prevent hydraulic flow from the steering gear 1102 towards the hydraulic pump 1114.

14 Figure 1 shows a schematic representation of a circuit arrangement of a further embodiment of a steering system 1000. The differences compared to the embodiments described above are discussed in detail below.

After 14 is in contrast to the embodiment according to 7 The valve assembly 100 is designed without a return line 1112.

In particular, the valve assembly 100 does not have a return line 1112 to the hydraulic tank 1110.

The valve assembly 100 is exclusively connected to the first line 1104 and the second line 1106 connected via the first or second connection 1128; 1130.

The valve assembly 100 according to 14 can be, for example, a valve device 100 according to the embodiment shown in the following 6 , in the sense of a 2/2-way valve.

15 Figure 1 shows a sectional view of another embodiment of a valve device 100. The differences compared to the embodiments described above will be discussed in detail below.

In particular, the valve assembly 100 is designed according to 15 provided as a proportional valve, wherein the slide unit 130 has at least one sealing section 138.

After 15 is in contrast to the embodiment according to 6 It is particularly provided that the sealing section 138 at a longitudinal end of the slide unit 130 is designed as a single-stage sealing section 138, preferably designed as a continuously uniformly chamfered surface. In particular, the design according to 15 to be understood as providing a single-stage proportional behavior, the design of which is based on 6 a multi-stage proportional behavior is allowed.

Furthermore, according to 15 It is provided that the one-piece or multi-piece sleeve element 140 does not have a specifically designed counter-section 146 along its inner side 144 for interaction with the sealing section 138. According to 15 To provide a (fluid-)sealing connection, an interaction between the outer surface 136 of the slide unit 130 and the inner surface 144 of the sleeve element 140 may be provided.

In the sense of the exemplary embodiment according to 15 The proportional behavior, in particular exclusively the proportional behavior, of the valve device 100 or the slide unit 130 is determined by means of the sealing section 138 of the slide unit 130.

The implementable functionalities in the case of the exemplary embodiment according to 15 are, in particular the design of the pressure connections P1; P2 as first connection 111 and third connection 113, comparable to those in the embodiment according to 6 described functionalities.

Based on the design of the valve assembly 100 according to 15 A normally closed 2/2-way valve or 2/2-proportional valve can be implemented.

Furthermore, another alternative in the sense of the exemplary embodiment according to 15 conceivable that a prestressing element 160 (in 15 (not shown) according to the 3 may be provided, preferably in a recess of the housing body 110 on the drive unit 150 and preferably arranged concentrically to the piston rod 152.

In summary, the present invention advantageously provides a valve device 100 with a pressure-balanced slide unit 130, which advantageously allows efficient control of hydraulic connections in, for example, an electro-hydraulic steering system 1000.

In particular, the valve device 100 enables the system dynamics or system response of the steering system 1000 to be reliably increased or accelerated during operation, especially during fast steering maneuvers.

In the case of an electro-hydraulic steering system 1000, optimized hydraulic steering assistance as well as improved steering feel for the driver of a vehicle can be ensured, among other things, by means of the valve device 100 according to the invention.

In particular, an actively, preferably electromagnetically, controllable design of the valve unit 100 can ensure a cost-effective, low-maintenance and simple implementation for reliable and rapid pressure control, e.g. in the sense of pressure reduction in a (low) pressure chamber of the steering gear.

Furthermore, the electromagnetically controllable and/or adjustable valve unit 100 allows for an advantageous design with regard to the installation space, the cost and the weight of a steering system in accordance with the present invention.

REFERENCE MARK LIST

100

Valve assembly

110

Housing body

111

first connection

112

second connection

113

third connection

120

Main chamber

122

first section

124

second section

130

Slide unit

132

Cover element

134

Passage opening

136

Outside

137

River channel groove (of the valve unit)

138

Sealing section

140

Sleeve element

141

first connection opening

142

second connection opening

144

inside

146

Opposite section

148

Flow path groove (of the sleeve element)

150

drive unit

152

piston rod

160

Preloading element

1000

Steering system

1102

steering gear

1104

first line

1106

second line

1110

hydraulic tank

1112

Return line

1114

hydraulic pump

1115

Leakage pipe

1116

Intake manifold

1118

first check valve

1120

second check valve

1122

temperature sensor

1124

Pressure sensor

1126

Building module

1128

first connection

1130

second connection

1160

Backup valve

1202

Return line check valve

1204

third check valve

1206

fourth check valve

1208

Filter unit

1210

integrated hydraulic tank

X

Longitudinal axis

Claims (15)

Valve assembly (100), in particular for an electro-hydraulic steering system of a vehicle, comprising at least one housing body (110) having at least one main chamber (120) and at least one slide unit (130), wherein the slide unit (130) is arranged to be movably, preferably translationally displaceable, within the main chamber (120) of the housing body (110), whereby the slide unit (130) divides the main chamber (120) into a first section (122) and a second section (124), whereby the at least one slide unit (130) is provided as a pressure-balanced slide unit (130) and is designed such that at least substantially the same fluid pressure is present in the first section (122) and in the second section (124), in particular pressure equalization between the first section (122) and the second section (124) is provided via the at least one slide unit (130). Valve assembly (100) according to Claim 1 , characterized in that the slide unit (130), in particular a cover element (132) of the slide unit (130), has at least one through-opening (134) so that a fluid connection between the first section (122) and the second section (124) of the main chamber (120) is provided or can be provided. Valve assembly (100) according to one of the preceding claims, characterized in that the valve assembly (100) has at least one sleeve element (140) which is arranged inside the housing body (110), in particular is arranged immovably, wherein an inner side (144) of the sleeve element (140) and an outer side (136) of the movable slide unit (130) are provided to interact, in particular to form a sealing sliding connection section by section. Valve assembly (100) according to one of the preceding claims, characterized in that the housing body (110) has at least one first connection (111), wherein the sleeve element (140) has at least one first connection opening (141), wherein the first connection opening (141) is formed along the sleeve element (140) in such a way as to correspond to the first connection (111) of the housing body (110), so that a fluid connection between the main chamber (120) and the first connection (111) of the housing body (110) can be provided as required, in particular depending on a positioning position of the movable slide unit (130) relative to the sleeve element (140). Valve assembly (100) according to one of the preceding claims, characterized in that the housing body (110) has at least one second connection (113), wherein the sleeve element (140) has at least one second connection opening (142), wherein the second connection opening (142) is formed along the sleeve element (140) in such a way as to correspond to the second connection (112) of the housing body (110), so that a fluid connection between the main chamber (120) and the second connection (112) of the housing body (110) can be provided as required, in particular depending on a positioning position of the movable slide unit (130) relative to the sleeve element (140). Valve assembly (100) according to one of the preceding claims, characterized in that the housing body (110) has at least one third connection (113), wherein the third connection is formed along the housing body (110) in such a way that a fluid connection to the main chamber (120) is provided regardless of the positioning position of the movable slide unit (130). Valve assembly (100) according to one of the preceding claims, in particular according to one of the Claims 4 until 6 , characterized in that the slide unit (130) is designed and movable in such a way, in particular the outer side (136) of the slide unit (130) is provided to interact section by section with the inner side (144) of the sleeve element (140) such that, depending on a positioning position of the slide unit (130), - a fluid connection between the first port (111) and the second port (112) of the housing body (110) can be provided, - a fluid connection between the first port (111) and the third port (113) of the housing body (110) can be provided, - a fluid connection between the second port (112) and the third port (113) of the housing body (110) can be provided and/or - a fluid connection between the first, second and/or third port (111; 112; 113) of the housing body (110) can be disconnected. Valve assembly (100) according to one of the preceding claims, characterized in that the slide unit (130) has at least one sealing section (138) along the outside (136) for interacting with the inside of the sleeve element (140), in particular for interacting with a counter section (146) of the inside (144) of the sleeve element (140), so that a fluid connection between the first port (111), the second port (112) and/or the third port (113) can be disconnected as required. Valve assembly (100) according to Claim 8 , characterized in that the sealing section (138) of the slide unit (130), designed to interact with the counter section (146) of the sleeve element (140), is provided in such a way, in particular with an effective surface designed in such a way in combination with the counter section (146) of the sleeve element (140), that the at least one sealing section (138) with the at least one counter section (146) forms a stop for the movable slide unit (130). Valve assembly (100) according to one of the preceding claims, characterized in that the valve assembly (100) has a drive unit (150), preferably an electromagnet, for moving the slide unit (130), preferably for translational movement in a longitudinal direction of the valve assembly (100). Valve assembly (100) according to one of the preceding claims, characterized in that the valve assembly (100) has at least one preloading element (160), in particular a spring element, for preloading the slide unit (130) in a direction of movement of the slide unit. Valve assembly (100) according to Claim 10 and/or 11, characterized in that a preloading element (160) of the slide unit (130) is arranged - on the drive unit (150) or - within the main chamber (120) in the area of a longitudinal end of the valve assembly (100), in indirect or direct contact with the slide unit (130). Electro-hydraulic steering system (1000) for a vehicle, in particular a commercial vehicle, with a valve device (100) according to one of the preceding claims. Electro-hydraulic steering system (1000) according to Claim 13 , characterized in that the steering system (1000) further comprises: - at least one steering gear (1102), in particular a screw steering gear; - at least one first line (1104) through which the steering gear (1102) can be supplied with hydraulic fluid and/or controlled; - at least one second line (1106) through which the steering gear (1102) can be supplied with hydraulic fluid and/or controlled; and - at least one connected to the first line (1104) and/or the second line (1106). or connectable valve device (100) according to one of the preceding claims for pressure reduction in the first line (1104) and/or the second line (1106), wherein the valve device (100) is actuated as required, in particular electromagnetically actuated. Vehicle, in particular commercial vehicle, with an electro-hydraulic steering system (1000) and/or a valve device (100) according to one of the preceding claims.