Steering acutating device

Abstract

The invention discloses a steering actuating device (1) for a vehicle, wherein the steering actuating device (1) comprises the following: - a hydraulic drive unit (2), - a conversion unit (3), - an output element (4) which is designed to impress an output torque or an output force onto a steering mechanism, wherein the hydraulic drive unit (2) is fluidically connected to the conversion unit (3) so that the hydraulic drive unit (2) can apply hydraulic pressure to the conversion unit (3), and wherein the conversion unit (3) has a piston (3.1) and a transmission unit (3.2), wherein the piston (3.1), when the hydraulic pressure is applied to it, introduces a piston force into the transmission unit (3.2), and the transmission unit (3.2) impresses the output torque or the output force onto the output element (4) in response to the piston force introduced. The invention also discloses a steering system and a vehicle.

Description

[0001] DESCRIPTION

[0002] Steering control device

[0003] The present invention relates to a steering actuating device, a steering system and a vehicle.

[0004] The increasing electrification of road vehicles, and especially commercial vehicles, is leading to a similar advance in the electrification of vehicle subsystems, such as steering systems with steered wheels, as greater electrical power is now available than in conventionally powered vehicles, which is also suitable for operating such subsystems. Further drivers for the electrification of subsystems are increasing legal requirements for CO2 reduction and the implementation of driver assistance functions. Therefore, especially in steering systems, there is a trend toward electromechanical steering systems. However, such electromechanical steering systems must be relatively large in order to apply the necessary output torque or force to a steering mechanism to operate the steering, which ultimately leads to a steering angle of the vehicle's steered wheels.Since mechanical connections are also required to transmit the necessary output torque or force to the steering mechanism, this creates difficulties in accommodating electromechanical steering systems within the vehicle's installation space. In addition to electromechanical steering systems, hydraulic steering systems are also known and are used in conventionally powered vehicles. In these systems, a pump connected to the combustion engine is continuously operated to generate the required hydraulic pressure. This impedes energy-efficient operation of the steering system because the pump is operated even when no output torque or force needs to be applied to the steering mechanism.

[0005] It is therefore an object of the present invention to provide a steering actuation device, a steering system, and a vehicle that allow at least one of the problems described above to be solved. This object is achieved by the subject matter of the independent claims.

[0006] Advantageous further training is the subject of the subclaims.

[0007] According to the invention, a steering actuating device for a vehicle is provided, the steering actuating device comprising:

[0008] - a hydraulic drive unit,

[0009] - an implementation unit,

[0010] - an output element which is designed to impart an output torque or an output force to a steering mechanism, wherein the hydraulic drive unit is fluidly connected to the conversion unit so that the hydraulic drive unit can hydraulically apply pressure to the conversion unit, and wherein the conversion unit has a piston and a transmission unit, wherein the piston, when subjected to the hydraulic pressure, introduces a piston force into the transmission unit, and the transmission unit impresses the output torque or the output force onto the output element in response to the introduced piston force.

[0011] The piston of the conversion unit is preferably designed to be pressurized from both sides by the hydraulic drive unit. This allows bidirectional pressure to be applied to the piston, and it is possible to apply the output torque or force to the output element in a first direction or, depending on the pressure, in a second direction. Thus, the output torque or force can be output with different signs.

[0012] The piston is preferably guided in a pressure chamber, whereby the piston can be pressurized by supplying working fluid to this pressure chamber. If the piston can be pressurized from both sides, a pressure chamber is advantageously provided on both sides of the piston in which the piston is guided. In this case, the movement of the piston changes the volume of both pressure chambers. If the piston moves in such a way that the first of the two pressure chambers increases, the second pressure chamber decreases simultaneously.

[0013] The working medium can be pumped by the hydraulic drive unit.

[0014] Alternatively, embodiments are also conceivable that have pistons that can be pressurized from one side, allowing the corresponding piston force to be introduced into the transmission unit. In this case, two pistons can be provided, with only one of the two pistons being selectively pressurized to generate the required output torque or output force.

[0015] The selective pressurization of individual pressure chambers of the steering actuation device, and in particular of the conversion unit, can be controlled by a valve that directs the working medium to the designated pressure chambers depending on the valve position. The valve can be part of the drive unit or the conversion unit, or it can be arranged in a fluid connection between the drive unit and the conversion unit.

[0016] The transmission unit is preferably arranged between the piston and the output element. It serves, in particular, to absorb the piston force and generate the output torque or force from it, which is then applied to the output element. Preferably, a part of the transmission unit can be formed integrally with the piston or connected to the piston to form a single unit.

[0017] The output element can be designed as a translationally displaceable element. However, it can also alternatively be designed as a rotatable shaft or have a rotatable shaft. The output element is preferably designed as a Pitman arm or has a Pitman arm. This can be connected to the shaft of the output element. The transmission unit can, in particular, have a gear with which the piston force is converted into a torque, which is then applied to the output element. For this purpose, the transmission unit, in particular the gear, can have a mechanism designed to convert a translational movement into a rotational movement.In particular, such a mechanism may comprise a combination of pinion and rack, a motion thread and / or a ball screw, wherein the translationally moved side of the respective mechanism is preferably in contact with the piston directly or via intermediate elements and the rotationally moved side is preferably in contact with the output element directly or via intermediate elements.

[0018] Preferably, a part of the transmission unit's gearing can be formed integrally with the piston or connected to the piston to form a single unit. In particular, the translationally movable part of the mechanism can be connected to the piston or formed integrally with it. For example, the rack is connected to the piston or formed as part of the piston, with corresponding teeth being formed on the piston that engage with the corresponding pinion.

[0019] The steering actuating device preferably has a module which is formed by the drive unit. For this purpose, all elements of the drive unit are particularly preferably provided on a common carrier element and / or in a common housing of the drive unit. The common carrier element can be a base plate to which all elements of the drive unit are connected. Alternatively, however, it can also be provided that one of the elements of the drive unit functions as a common carrier element on which at least one further element is mounted or provided. In addition, it can be provided that at least one of the elements of the drive unit is mounted or provided on a further element of the drive unit, and this in turn is provided on the common carrier element.Such a drive unit can advantageously be designed as a separate component and independently of the steering actuation device disclosed here and below, as well as the steering system and the vehicle described below.

[0020] By designing the drive unit as a module, a separate component is available, which particularly facilitates assembly and disassembly of the steering actuator or the drive unit within the steering actuator. Maintenance is also advantageous, as a drive unit requiring maintenance can be removed and serviced as a complete component, while a second drive unit can be inserted, allowing the steering actuator to continue operating.

[0021] The drive unit preferably has a pump as an element for pressurizing the conversion unit. The pump is preferably designed as a bidirectional pump. In particular, it can have or be designed as an internal gear pump or a sickle pump. With a bidirectional design, depending on the pump's conveying direction, it is possible to convey working medium to different pressure chambers in order to pressurize the piston of the conversion unit from different sides. If the pump is a unidirectional pump, a valve can be provided which is designed to supply working medium to one or the other pressure chamber depending on the valve position. Such a valve can also be provided if at least two pistons are provided and the conveyance of working medium is to take place selectively in the respective pressure chambers of the pistons.Such a pump is preferably in contact with a reservoir for the working fluid. The reservoir can be part of the steering actuation device.

[0022] Preferably, the pump of the drive unit is provided so as to be drivable by an electric machine, wherein the electric machine is provided as an element of the drive unit. Such an electric machine advantageously allows the steering actuation device to be operated on demand. This means that, unlike in conventionally powered vehicles, in which the pump is not driven by an electric machine but permanently by the combustion engine, on-demand operation of the pump is possible here, in that it is only activated when pressure is required on the conversion unit or piston. In this way, it is possible to achieve significantly more energy-efficient operation compared to conventionally powered vehicles.

[0023] The drive unit preferably has a control device as an element, which is designed to control the drive unit, in particular the electric motor and / or the pump, to generate pressure. If the drive unit is designed as a module, the control device can also be connected to the support element or be provided in the housing of the drive unit.

[0024] In addition to this design, the control device can also be provided separately as part of the steering actuator. This allows for more flexible positioning of the control device. Furthermore, it allows for a smaller drive unit.

[0025] In general, the control device can be designed as an electrical or electronic control device, which in particular outputs a control signal for controlling the drive unit or the pump of the drive unit. The control signal can correspond to the input signal mentioned below.

[0026] Preferably, the drive unit is directly connected to the conversion unit. In this case, the drive unit and the conversion unit together form a single component. This can be achieved, in particular, by providing both in a common housing, or by connecting the drive unit and the conversion unit to one another. This connection can be achieved, for example, by connecting elements such as screws. In particular, it can be provided that both the drive unit and the conversion unit have separate housings, with both housings being connected to one another to form the separate component. Both the drive unit and the conversion unit have connections that are in contact with one another and via which the working medium can be conveyed to apply hydraulic pressure to the conversion unit or the piston.In this way, the drive unit and the conversion unit form a common component or module that can be assembled or disassembled as a whole.

[0027] By designing the drive unit and the transfer unit as a single component or module, assembly and disassembly of the steering actuation device is simplified. Maintenance is also advantageous, as a combination of drive unit and transfer unit requiring maintenance can be removed and serviced as a complete component, while a second combination can be inserted, allowing the steering actuation device to continue operating.

[0028] Alternatively, the drive unit is provided separately from the conversion unit, with a line connection between the drive unit and the conversion unit being provided to apply hydraulic pressure to the conversion unit. This allows for relatively free positioning of the drive unit. It does not necessarily have to be connected to the conversion unit or be located near it. In contrast, the conversion unit is less freely positionable due to its mechanical connection to the output element or, via the output element, to the steering mechanism.The separate design of the drive unit and the conversion unit enables better utilization of the installation space by the steering actuation device, as the drive unit does not have to be positioned in a location predetermined by the conversion unit, compared to designs in which the drive unit and conversion unit are connected to each other. The cable connection between the drive unit and conversion unit can be routed relatively freely.

[0029] Preferably, the drive unit, and in particular the electric machine and / or the pump of the drive unit, is designed to apply hydraulic pressure to the conversion unit in response to an input signal. Such an input signal can be provided, for example, by the control device of the drive unit for the pump or for the electric machine. The input signal itself can be generated from a steering command that is transmitted to the drive unit or the steering actuation device. Preferably, the steering actuation device has a detection unit that is designed to detect a steering command. The detection unit can detect the steering command, which is transmitted, in particular, externally to the steering actuation device. The steering command itself can originate from different sources, as explained below.

[0030] The steering actuation device preferably has a driver interface for receiving a driver's steering command (driver steering command), wherein the detection unit is configured to translate the driver steering command into the steering command and / or detect it as an input signal. The driver interface preferably has a steering wheel via which a driver can generate the corresponding driver steering command by turning the steering wheel or applying a corresponding torque to the steering wheel.

[0031] The detection unit preferably has a torque sensor and / or a rotation angle sensor to detect the steering command. This is particularly advantageous when the driver specifies a steering command (driver steering command) using the steering wheel. The driver steering command can then be detected by detecting the torque applied by the driver to the steering wheel or the rotation angle set there. However, it is also possible for the torque directly applied by the driver or the set rotation angle not to be detected. For example, a transmission ratio can be provided so that the torque or rotation angle is detected after the transmission ratio.

[0032] Alternatively or additionally, the detection unit has a data interface for detecting the steering command. A data interface can, in particular, be connected to a control system of the vehicle that is designed to control and steer the vehicle partially or fully automatically. These can primarily be control systems that are referred to in technical circles as ADAS or HAD systems. Such systems can transmit steering commands directly to the steering actuation device via the data interface of the detection unit. Such a steering command can correspond to a torque or an angle of rotation on a steering wheel, or it can be completely different from this. For example, the use of the steering actuation device is also conceivable in fully autonomous vehicles that do not have a steering wheel or a comparable driver interface.Therefore, a steering command can also be recorded via the data interface, which does not correspond to a torque or a rotation angle on a steering wheel.

[0033] The detected steering command or driver steering command can generally be used as an input signal, in particular for activating the electric machine and / or the pump, or it can be provided that a corresponding input signal is generated therefrom by the detection unit or by the control device in order to activate the electric machine and / or the pump.

[0034] The steering actuating device preferably has a mechanical connection from the driver interface to the conversion unit, in particular to the transmission unit, via which the steering command of a driver can be mechanically impressed on the conversion unit. This can be realized, for example, by a direct mechanical through-drive leading from the driver interface, for example from the steering wheel, to the steering actuating device. This can be a direct shaft connection or a shaft connection with an intermediate gear. Alternatively or additionally, it can also be provided that the connection has deflections, in particular in the form of U-joints and / or bevel boxes. In this way, a driver can introduce a torque directly into the steering actuating device or into the conversion unit by mechanical means.The conversion unit is preferably designed to impart an output torque or an output force to the output element in response to the introduced torque.

[0035] To enable this, the transmission unit provided in the conversion unit is preferably designed to combine or superimpose the hydraulically applied piston force and the torque applied by the driver. This can be achieved, for example, by means of a superimposed gear. In particular, it can be provided that the piston is connected to the shaft of the mechanical connection via a motion thread, a ball screw, a combination of pinion and rack, and / or similar.

[0036] The mechanical connection from the driver interface to the conversion unit advantageously enables the realization of a mechanical fallback level, so that even if pressure application by the drive unit is no longer possible, for example because the pump, the electric machine, the control device or the drive unit as a whole is defective, a steering command can still be mechanically introduced into the conversion unit.

[0037] The drive unit can also be used to support a torque generated by the driver via the driver interface and applied to the conversion unit via the mechanical connection. In this case, the driver is assisted by applying pressure to the piston.

[0038] Preferably, the driver's steering command is or includes a driver steering torque, wherein the mechanical connection has a freewheel that allows mechanical transmission of the driver steering torque to the conversion unit when the output force or torque of the output element is insufficient to match the driver's steering command. In this way, the torque provided by the driver via the driver interface can be used as support for the steering actuation device.

[0039] According to an advantageous embodiment of the invention, the driver interface is implemented without a mechanical connection to the conversion unit. In this embodiment, the driver interface is preferably used as a data source, via which, for example, a steering command such as a steering angle or a steering torque can be transmitted to the detection unit. In such a case, the steering actuation device is less complex, since a mechanical superposition of a torque applied by the driver to the steering wheel with the piston force is no longer necessary. According to the invention, a steering system for a vehicle, in particular for a commercial vehicle, is provided, comprising the following:

[0040] - at least one axle with wheels steerable via a steering mechanism, and

[0041] - a steering actuating device as described above, wherein the steering mechanism is connected to the output element of the steering actuating device.

[0042] In this way, the vehicle's steerable wheels can be steered by operating the steering actuator. The output torque or force can be applied to the steering mechanism via the output element of the steering actuator.

[0043] According to the invention, a vehicle, in particular a commercial vehicle, is provided with a steering system as described above.

[0044] The vehicle itself is preferably designed as a conventional vehicle, i.e., one powered by an internal combustion engine, electric, or hybrid. In particular, it can be provided that the vehicle can drive in partially or fully automated mode. In such a case, a control system of the vehicle, which controls the partially or fully automated operation of the vehicle, is preferably connected to the detection unit in order to send corresponding steering commands to the steering actuation device.

[0045] The invention is described below using preferred embodiments with reference to the accompanying drawings.

[0046] They show:

[0047] Fig. 1 shows a first embodiment of the invention,

[0048] Fig. 2 shows a second embodiment of the invention,

[0049] Fig. 3 shows a third embodiment of the invention and Fig. 4 shows a fourth embodiment of the invention.

[0050] Fig. 1 shows a first embodiment of the invention.

[0051] A steering actuation device 1 is shown, which has a hydraulic drive unit 2 and a conversion unit 3. Furthermore, the steering actuation device 1 has an output element 4, which is provided here as a rotatable element and can be designed, in particular, as a Pitman arm to support an output torque on a steering mechanism (not shown). The output element 4 is provided so as to be rotatable in the plane of the drawing about an axis oriented perpendicular to the plane of the drawing.

[0052] The hydraulic drive unit 2 here has a housing 2.1 that contains the elements of the hydraulic drive unit 2. The drive unit 2 has the following elements, although this list is not intended to be exhaustive: a pump 2.2, an electric machine 2.3, and a control device 2.4. The electric machine 2.3 is designed to drive the pump 2.2 in response to an input signal provided by the control device 2.4, so that the pump can deliver a hydraulic working medium to the conversion unit 3. The drive unit 2 itself is designed as a module by its housing 2.1. It is thus formed as a separate component. This particularly facilitates the assembly and disassembly as well as the maintenance of the drive unit 2. The control device 2.4 itself can be designed as an electrical or electronic control device.

[0053] The conversion unit 3 has a piston 3.1, which in the drawing is designed to be displaceable from top to bottom and vice versa. The piston 3.1 is provided within a cylinder that guides the piston 3.1 during its displacement. Within the cylinder, the piston 3.1 separates a first pressure chamber 3.3 from a second pressure chamber 3.4. By displacing the piston 3.1 downwards, the volume of the first pressure chamber 3.3 is increased, while simultaneously the volume of the second pressure chamber 3.4 is reduced. By displacing the piston 3.1 upwards, the volume of the first pressure chamber 3.3 is reduced, while simultaneously the volume of the second pressure chamber 3.4 is increased.

[0054] The piston 3.1 is further connected to a transmission unit 3.2. The transmission unit 3.2 is designed to convert a piston force, which is generated by pressurizing the piston 3.1 in one of the pressure chambers 3.3, 3.4, into an output torque that is impressed on the output element 4. For this purpose, the transmission unit 3.2 has a combination of pinion and rack, wherein the rack is connected to the piston 3.1 and engages with the pinion, which is connected to the output element 4. A piston force is thereby transmitted via the rack to the transmission unit 3.2 and then to the pinion, so that an output torque can be impressed on the output element 4.

[0055] The conversion unit 3 further comprises a housing 3.5, in which the piston 3.1, the pressure chambers 3.3 and 3.4, and the transmission unit 3.2 are located. The conversion unit 3 itself is designed as a module through its housing 3.5. It is thus formed as a separate component. This facilitates, in particular, the assembly and disassembly of the conversion unit 3, as well as its maintenance.

[0056] In the embodiment shown, the hydraulic drive unit 2 and the conversion unit 3 are connected to one another in that their housings 2.1, 3.5 are in direct contact with one another. The drive unit 2 and the conversion unit 3 thus form a module or a single component. The respective connections for transmitting hydraulic working medium from the pump 2.2 to the pressure chamber 3.3 or to the pressure chamber 3.4 are directly fluidically connected to one another through the contact of the two housings 2.1, 3.5. The pump 2.2 can thus directly pump working medium to the pressure chambers 3.3 and 3.4. The pump paths of the hydraulic working medium are represented by the two arrows leading from the pump 2.2 to the pressure chambers 3.3 and 3.4.

[0057] In addition to the drive unit 2 and the conversion unit 3, the

[0058] Steering actuation device 1 has a detection unit 5. This is designed to detect a steering command. The steering command can, as shown in the drawing, originate from a driver interface 6, which is shown here as a steering wheel. To detect the steering command, the detection unit 5 can have a torque sensor and / or a rotation angle sensor. The steering command can then be detected by detecting the torque applied by the driver to the steering wheel or the rotation angle set there. However, it is also possible that the torque applied directly by the driver or the set rotation angle is not detected. For example, a transmission ratio can be provided so that the torque or rotation angle is detected after the transmission ratio.

[0059] Alternatively or additionally, the detection unit 5 has a data interface for detecting the steering command. A data interface can in particular be connected to a control system of the vehicle that is designed to control the vehicle partially or fully automatically. Such systems can transmit steering commands directly to the steering actuating device via the data interface of the detection unit. Such a steering command can correspond to a torque or an angle of rotation on a steering wheel, or it can be completely different from this. For example, the use of the steering actuating device is also conceivable in fully autonomous vehicles that do not have a steering wheel or a comparable driver interface 6. Therefore, a steering command that does not correspond to a torque or an angle of rotation on a steering wheel can also be detected via the data interface.

[0060] The detection unit 5 is designed to forward the detected steering command to the drive unit 2, wherein the control device 2.4 is designed to translate the steering command into a corresponding input signal for the electric machine 2.3.

[0061] The operation of the steering control device 1 is as follows:

[0062] Resulting from the steering command, which is sent via the driver interface 6 to the

[0063] If the detection unit 5 indicates that no steering is necessary, the

[0064] Activation of the electric motor 2.3 by the input signal from the control device 2.4. As a result, the pump 2.2 does not deliver any working fluid to the conversion unit 3 or to one of the pressure chambers 3.3, 3.4 therein, resulting in the piston 3.1 not being pressurized from the upper or lower side in the drawing. Thus, no output torque is applied to the output element 4 via the transmission unit 3.2.

[0065] If the steering command, which is detected by the detection unit 5 from the driver interface 6, indicates that the vehicle's wheels should be steered, the control device 2.4 generates a corresponding input signal from the steering command forwarded by the detection unit 5 to the drive unit 2. This activates the electric motor 2.3, which then drives the pump 2.2. Depending on the steering command, the pump 2.2 then pumps working fluid into the upper pressure chamber 3.3 or the lower pressure chamber 3.4 in order to apply pressure to the piston 3.1 accordingly. A corresponding piston force acts on the piston 3.1, which is then supported in the transmission unit 3.2. The transmission unit 3.2 converts the piston force through the combination of pinion and rack into a corresponding output torque, which is impressed on the output element 4 and which can then be supported in a steering mechanism of the vehicle (not shown), ultimately causing the wheels of the vehicle to be steered.

[0066] Fig. 2 shows a second embodiment of the invention.

[0067] This essentially corresponds to the embodiment shown in Fig. 1. Therefore, reference is made to the description of Fig. 1. The following merely discusses the differences between the two embodiments.

[0068] In contrast to the embodiment of Fig. 1, here the drive unit 2 and the conversion unit 3 are not connected to one another. Both housings 2.1 and 3.5 are provided separately from one another, with a line connection 7 being provided between the two housings 2.1 and 3.5, so that the pump 2.2 can convey working medium to the pressure chamber 3.3 or to the pressure chamber 3.4 via the line connection 7. The functionality of this embodiment essentially corresponds to that of Fig. 1. Advantages here arise primarily from the more flexible arrangement options for the drive unit 2 and conversion unit 3, since the line connection 7 can run relatively freely in the vehicle. The drive unit 2 and the conversion unit 3 can therefore be placed at advantageous locations in the vehicle.

[0069] Fig. 3 shows a third embodiment of the invention.

[0070] This essentially corresponds to the embodiment in Fig. 1. Therefore, reference is made to the description of Fig. 1.

[0071] In addition to the embodiment shown in Fig. 1, the steering actuating device 1 has a mechanical connection 8 to the driver interface 6. Via the driver interface 6, a torque can thus be impressed on the connection 8, which can be introduced into the conversion unit 3. The mechanical connection 8 is designed here as a shaft that is connected to the piston 3.1. Between the piston 3.1 and the shaft, a gear (not shown) is provided, which is designed to convert the torque impressed on the shaft by the driver interface 6 into a force that acts on the piston 3.1. This force also acts like a piston force, which is generated by pressurizing the piston 3.1, in the drawing parallel to a vertical line that runs from top to bottom.To convert the torque applied to the shaft by the driver interface 6, the gearbox may have a ball screw, a motion thread, or similar.

[0072] The mechanical connection 8 from the driver interface 6 to the conversion unit 3 thus enables the realization of a mechanical fallback level, so that even if pressurization of the piston 3.1 by the drive unit 2 is no longer possible, for example because the pump 2.2 or the drive unit 2 as a whole is defective, a force can still be mechanically applied to the piston 3.1. In this embodiment, however, it is also possible for the torque mechanically introduced via the shaft of the mechanical connection 8 or the resulting force on the piston 3.1 to achieve a supporting effect through the additional hydraulic pressurization of the piston 3.1 by the pump 2.2, so that a driver needs to apply less force to the driver interface 6 to steer the vehicle.

[0073] Fig. 4 shows a fourth embodiment of the invention.

[0074] This embodiment essentially corresponds to a further development of the embodiment shown in Fig. 2, since here the drive unit 2 and the conversion unit 3 are designed separately from one another and fluidly connected to one another via a line connection 7. In addition, the mechanical connection 8 shown in Fig. 3 is also provided here, connecting the driver interface 6 to the conversion unit 3. Since the mechanical connection 8 corresponds in design and function to that shown in Fig. 3, reference is made to the corresponding description of Fig. 3.

[0075] In the drawings described above, a driver interface 6 in the form of a steering wheel is always shown. However, this will no longer be necessary in future vehicles if they are operated autonomously. In this case, the detection unit 5 receives a steering command exclusively from other control systems.

[0076] In a further embodiment not shown, which may be based in particular on one of the drawings in Figures 1 to 4, the piston 3.1 is formed integrally with the rack of the transmission unit 3.2. The teeth of the rack may be formed on the surface of the piston 3.1.

[0077] The invention ultimately provides an electrohydraulic steering actuation device 1 that, on the one hand, has the advantages of energy-efficient operation, in that the pressure is applied to the conversion unit 3 or the piston 3.1 only when necessary, i.e., the pump 2.2 of the drive unit 2 only needs to be operated when pressure is required. Furthermore, the use of hydraulic components allows for a relatively high transmission of forces and torques while simultaneously achieving a space-saving design and flexible arrangement options for the components of the steering actuation device 1 compared to an electromechanical solution.

[0078] LIST OF REFERENCE SYMBOLS

[0079] 1 steering control device

[0080] 2 hydraulic drive units

[0081] 2.1 Housing

[0082] 2.2 Pump

[0083] 2.3 electric machine

[0084] 2.4 Control device

[0085] 3 Implementation unit

[0086] 3.1 Piston

[0087] 3.2 Transmission unit

[0088] 3.3 Pressure chamber

[0089] 3.4 Pressure chamber

[0090] 3.5 Housing

[0091] 4 Output element

[0092] 5 Recording unit

[0093] 6 Driver interface

[0094] 7 Line connection

[0095] 8 mechanical connection

Claims

PATENT CLAIMS 1 . Steering control device (1 ) for a vehicle, comprising: - a hydraulic drive unit (2), - an implementation unit (3), - an output element (4) which is designed to impart an output torque or an output force to a steering mechanism, wherein the hydraulic drive unit (2) is fluidically connected to the conversion unit (3) so that the hydraulic drive unit (2) can hydraulically apply pressure to the conversion unit (3), and wherein the conversion unit (3) has a piston (3.1) and a transmission unit (3.2), wherein the piston (3.1), when subjected to the hydraulic pressure, introduces a piston force into the transmission unit (3.2), and the transmission unit (3.2) impresses the output torque or the output force onto the output element (4) in response to the introduced piston force.

2. Steering actuation device (1) according to claim 1, wherein the steering actuation device (1) comprises a module formed by the drive unit (2), and all elements of the drive unit (2) are provided on a common carrier element and / or in a common housing (2.1) of the drive unit (2).

3. Steering actuating device (1) according to claim 1 or 2, wherein the drive unit (2) has as an element a pump (2.2) for pressurizing the conversion unit (3).

4. Steering actuation device (1) according to claim 3, wherein the pump (2.2) is provided so as to be drivable by an electric machine (2.3), wherein the electric machine (2.3) is provided as an element of the drive unit (2), and / or wherein the drive unit (2) has as an element a control device (2.4) which is designed to control the drive unit (2) for pressure generation.

5. Steering actuating device (1) according to one of the preceding claims, wherein the drive unit (2) is directly connected to the conversion unit (3).

6. Steering actuating device (1) according to one of claims 1 to 4, wherein the drive unit (2) is provided separately from the conversion unit (3), wherein a line connection (7) is provided between the drive unit (2) and the conversion unit (3) for applying hydraulic pressure to the conversion unit (3).

7. Steering actuating device (1) according to one of the preceding claims, wherein the drive unit (2) is designed to apply the hydraulic pressure to the conversion unit (3) in response to an input signal.

8. Steering actuating device (1) according to claim 7, comprising a detection unit (5) which is designed to detect a steering command.

9. Steering actuating device (1) according to claim 8, comprising a driver interface (6) for receiving the steering command of a driver, wherein the detection unit (5) is designed to translate the driver's steering command into the steering command and / or to detect it as a steering command.

10. Steering actuating device (1) according to claim 8 or 9, wherein the detection unit (5) comprises a torque sensor, a rotation angle sensor and / or a data interface to detect the steering command.

11. Steering actuation device (1) according to one of claims 9 or 10, comprising a mechanical connection (8) from the driver interface (6) to the Implementation unit (3), in particular to the transmission unit (3.2), via which the steering command of a driver can be mechanically impressed on the implementation unit (3).

12. Steering actuation device (1) according to claim 11, wherein the steering command of a driver is or comprises a driver steering torque and the mechanical connection (8) has a freewheel which allows a mechanical transmission of the driver steering torque to the conversion unit (3) when the output force or the output torque of the output element (4) is insufficient to correspond to the driver steering command.

13. Steering actuation device (1) according to claim 9 or 10, wherein the driver interface (6) is realized without a mechanical connection to the conversion unit (3).

14. Steering system for a vehicle, in particular for a commercial vehicle, comprising - at least one axle with wheels steerable via a steering mechanism, and - a steering actuating device (1) according to one of claims 1 to 13, wherein the steering mechanism is connected to the output element (4) of the steering actuating device (1).

15. Vehicle, in particular a commercial vehicle, with a steering system according to claim 14.

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