Adjustment device for a steering system of a motor vehicle and steering system for a motor vehicle

Abstract

The present invention relates to an adjustment device (1, 110) for a steering system of a motor vehicle, comprising two adjustment components (51, 52, 61, 62, 31, 4) adjustable relative to each other along an adjustment direction, with sliding surfaces arranged to slide against each other, and comprising a lubrication device (7, 8, 9, 10) with a lubricant reservoir (74, 84, 94) in which a lubricant can be received and dispensed onto at least one sliding surface of at least one of the adjustment components (51, 52, 61, 62, 31, 4). To enable improved lubrication, the invention proposes that the lubrication device (7, 8, 9, 10) has a dispensing device (70, 80, 90) which interacts with one or both of the adjustment components (51, 52, 61, 62, 31, 4) for actuation.

Description

State of the art

[0001] The invention relates to an adjustment device for a steering system of a motor vehicle, comprising two adjustment components adjustable relative to each other along an adjustment direction with sliding surfaces arranged to slide against each other, and comprising a lubrication device with a lubricant reservoir in which a lubricant can be received and which can be applied to at least one sliding surface of at least one of the adjustment components.

[0002] The invention further relates to a steering system according to the preamble of claim 13 and a method for operating an adjusting device according to the preamble of claim 14.

[0003] A motor vehicle's steering system typically comprises several components that can be moved or adjusted relative to one another. Each pair of these adjustable components forms a generic adjustment device. A sliding guide or bearing with sliding surfaces in contact is located between the components, allowing them to be adjusted relative to each other along a specific direction. A viscous and / or fluid lubricant, such as grease or oil, introduced into the lubrication gap between the sliding surfaces reduces friction, enabling smooth and low-wear sliding movement and a high natural frequency for the adjustment device.

[0004] An adjusting device for a steering system of a motor vehicle can, for example, be a shell unit with a longitudinally linearly telescoping sleeve tube, or an axially adjustable spindle drive with sliding threaded surfaces, as described, for example, in EP 4 230 502 A1, or a steering gear and the like.

[0005] To ensure optimal operating characteristics, it is necessary that a sufficient quantity of lubricant is present as a continuous lubricating film on the sliding surfaces for as long as possible, preferably filling the lubrication gap between the sliding surfaces. For this purpose, EP 4 230 502 A1 proposes a lubrication device in which a lubricant reservoir is formed in a sliding surface, specifically in the thread of a spindle drive, which can be filled with lubricating grease. This forms a lubricant reservoir from which lubricant is released onto the sliding surfaces of the thread during operation. The stored lubricant supply, which is larger than the amount of lubricant in the lubrication gap between the sliding surfaces, enables consistently uniform and improved lubrication over the long term.However, over time, the lubricant reservoir in the lubricant holders can dry out, or, depending on operating or environmental conditions, lubricant release can become uneven. This can impair lubrication, potentially leading to undesirable increases in noise or a reduction in stiffness.

[0006] In view of the problems explained above, one object of the present invention is to enable improved lubrication. Description of the invention

[0007] This problem is solved according to the invention by the adjusting device with the features of claim 1, the steering system according to claim 13 and the method according to claim 14. Advantageous further developments are set out in the dependent claims.

[0008] In an adjusting device for a steering system of a motor vehicle, comprising two adjusting components adjustable relative to each other along an adjustment direction with sliding surfaces arranged to slide against each other, and comprising a lubrication device with a lubricant reservoir in which a lubricant can be received that can be dispensed onto at least one sliding surface of at least one of the adjusting components, the invention provides that the lubrication device has a dispenser device which interacts with one or both adjusting components for actuation.

[0009] The sliding surfaces in sliding contact form a sliding bearing in which the two adjustment components slide against each other, so that they can be moved relative to each other in and against their predetermined adjustment direction, i.e., forward and backward adjustment.

[0010] The dispenser device according to the invention is adapted for conveying or directing a free-flowing lubricant. Its inlet is connected to the lubricant reservoir, for example, a grease or oil supply, the volume of which preferably corresponds to a multiple of the lubricant applied as a lubricating film between the sliding surfaces. The outlet or dispensing point of the dispenser device, from which the lubricant is dispensed, is located in the region of a sliding surface. When actuated by the two adjusting components, the dispenser device conveys or directs lubricant from the lubricant reservoir onto the sliding surface, and thereby directly or indirectly into the lubrication gap.

[0011] The dispensing device is designed to convey or direct a free-flowing lubricant, such as grease or the like, from the lubricant reservoir to the dispensing point on the thread. It can be externally actuated to release a specific quantity of lubricant, for example, as a discrete, measured, or unmeasured portion. Preferably, the dispensing device can be adapted to the fluid properties of the lubricant, such as viscosity, wettability, etc., and to the required operating characteristics, for example, with regard to dosing the optimal amount of lubricant for operation.

[0012] According to the invention, the dispenser device is designed to interact with the two adjustment components, which are adjustable relative to each other, in a drive-like manner. It is coupled to the two adjustment components accordingly, preferably by a direct or indirect, preferably mechanical, connection. In this way, the relative movement of the adjustment components that occurs during adjustment can be actively used to drive the dispenser device in order to pump the lubricant from the lubricant reservoir and apply it to the at least one sliding surface.

[0013] The dispenser device according to the invention provides active or forced lubrication of the sliding guide between the adjustment components, whereby the lubricant is not only passively carried along by the sliding surfaces as in the prior art, but can be actively conveyed or supplied and introduced into the lubrication gap. This has the advantage that a continuously continuous lubricating film can be maintained even under adverse operating conditions. This prevents the sliding guide from running dry even with frequent adjustments at high speeds, unfavorable environmental and operating conditions, long adjustment ranges, and the like, and ensures smooth adjustment and low-wear operation throughout the entire service life of the steering system.

[0014] A significant advantage is that the dispenser device according to the invention is driven and / or actuated solely by the relative movement of the adjusting components that occurs during operation, without requiring an external energy supply. In particular, no additional external drive devices are required, such as motor-driven external lubrication systems or the like, thus enabling reliable operation and a compact, simple design.

[0015] It is preferred that the dispensing device includes a pump. The pump is designed to deliver a free-flowing lubricant such as grease or the like. It can be driven by an external actuator for active delivery of the lubricant. Preferably, it can be adapted to the viscosity and other flow properties of the lubricant and the required operating characteristics, for example, with regard to dosing the optimal amount of lubricant for operation. Preferably, the pump can be connected on the inlet side to a storage chamber that provides a supply of lubricant. From this, it can draw lubricant and dispense it in a metered manner at a dispensing point, e.g., a sliding surface. For this purpose, the pump can preferably be connected on the outlet side to an applicator device.

[0016] The pumping device advantageously allows for an actively metered and demand-based dispensing of lubricant, adapted to the specific operating conditions.

[0017] Alternatively, the dispensing device can be configured to passively deliver the fluid, free-flowing lubricant from the lubricant reservoir to the dispensing point without active pumping. If the lubricant's fluid properties allow it to flow independently from the reservoir to the dispensing point, driven by pressure, capillary action, cohesion, or other forces, a particularly simple dispensing device design can be advantageously achieved. For this purpose, the dispensing device can be provided with a guide for directing a self-flowing lubricant fluid from the lubricant reservoir to the thread. Actuation of the dispensing device in this case can consist, for example, of opening a closure device such as an outlet valve or a pinch seal, etc., or simply of receiving, for example, a small amount of lubricant.Lubricant droplet escaping from a pipe or lubricant-soaked body by touching or wiping.

[0018] It is possible for the adjustment direction to be linear along an axis. This creates a linear bearing or guide, which enables a straight, axial adjustment of the adjustment components along the axis, also known as the adjustment axis. In a steering system, linear adjustment can be used to adjust the position of a steering column, to adjust the position of a steering actuator to generate a steering angle for the wheels, and so on.

[0019] Alternatively, the adjustment direction can follow a path that is at least partially curved. This path can, for example, include arcs and determines the relative movement of the sliding surfaces during non-linear adjustment of the components, such as a pivoting motion. In other words, the vector of the adjustment direction follows the path tangentially. This path can, for example, be circular arcs around a pivot or rotation axis during relative pivoting of the components. Other path configurations, deviating from a linear guide, can be achieved using, for example, hinges, cams, or other guides.

[0020] One possible design for the sliding surfaces is a helical shape, formed by the sliding threads of the lead screw and the lead screw nut of an adjusting device designed as a spindle drive. The lead screw and the lead screw nut are the two axially adjustable components relative to each other.

[0021] It is preferred that the lubrication device includes a storage chamber. The storage chamber serves as a lubricant reservoir, containing a supply of lubricant, for example, a volume of grease or oil. The dispenser is connected to the lubricant reservoir via its inlet. The lubricant can be drawn from the storage chamber by the dispenser as needed and applied to the sliding surface. Preferably, the volume of the storage chamber can be dimensioned such that it can hold a sufficient supply of lubricant for lubrication over the entire service life of the adjusting device or steering system. Preferably, the lubricant supply is a multiple of the amount of lubricant that fills the lubrication gap between the sliding surfaces during operation.

[0022] In an advantageous further development, the storage chamber can be designed to be sealed to the outside except for the connection to the dispensing device. The storage chamber can, for example, be designed to be collapsible, such as a flexible pouch or piston cartridge whose internal volume, filled with lubricant, shrinks as lubricant is dispensed. This virtually eliminates potentially harmful external influences.

[0023] A further advantageous development can provide that the storage chamber incorporates pressure-building means to create overpressure within the chamber. This overpressure can, for example, be permanently present in the storage chamber, thereby supporting and / or enhancing the independent (passive) flow of the lubricant (without active pumping) from the storage chamber to the discharge point on the thread. For instance, a wall of a collapsible storage chamber designed as an expandable membrane, which expands when the chamber is filled and is thereby placed under mechanical tension, can constitute such a pressure-building means, since the mechanical tension of the membrane pressurizes the lubricant stored within it (relative to the outside of the storage chamber wall).

[0024] The lubrication system may include an applicator. The applicator is connected to the outlet of the dispenser and is designed to apply the lubricant, either actively pumped by the dispenser or flowing independently, in a controlled manner to a sliding surface, for example, as a continuous lubricating film. It thus forms the point of delivery of the lubricant to the thread. This allows for optimal lubrication with efficient lubricant use. Specifically, the applicator may include dispensing and application devices for the lubricant, such as nozzles, wipers, metering devices, or similar components.

[0025] Preferably, the lubrication device can be connected to one adjusting component and interact with an actuating element connected to the other adjusting component. For this purpose, the lubrication device and / or the dispensing device can be mechanically connected to the two adjusting components directly or indirectly in such a way that it can be actuated by their relative movement during adjustment. For example, the dispensing device can be integrated directly or indirectly between the adjusting components or components connected to them. The opposing relative movements during adjustment, for example in linearly opposite directions, can directly or indirectly drive, for example, a pump mechanism of an intermittently driven conveying device, actuate a closure device such as a shut-off valve, or, for example, actuate a [missing information].Lubricant droplets escaping from a pipe or a lubricant-soaked body are wiped off or absorbed.

[0026] In the aforementioned embodiment, the actuating element can be designed as a stop element. This embodiment can be achieved by fixing the dispenser to one adjustment component and cooperating with an actuating element that is fixed directly or indirectly to the other adjustment component. This actuating element can be designed as a stop element that strikes the dispenser at the end of its adjustment range, thereby mechanically actuating it.

[0027] Alternatively, the actuating element can be designed as a receiving element. The aforementioned design can also be implemented by fixing the dispenser to one adjustment component and cooperating with an actuating element fixed directly or indirectly to the other adjustment component. This actuating element can then be designed as a receiving element which, at the end of its adjustment path, contacts, receives, or wipes off a lubricant droplet—for example, one emerging from a pipe or a lubricant-impregnated body, or adhering there due to capillary or cohesive forces—and thus mechanically actuates the dispenser.

[0028] In operation, the two adjustment components move relative to each other in or against the direction of adjustment, i.e., towards or away from each other. This relative movement can be easily implemented, for example, as an actuating stroke for an intermittently driven pumping device. A linear adjustment movement can directly generate a stroke movement of a piston. For practical implementation, the pumping device can be moved along with one of the adjustment components and mechanically actuated and driven by the actuating element, which moves relative to the first adjustment component along with the other adjustment component during the adjustment process.

[0029] An advantageous embodiment can be achieved by having the dispenser incorporate a piston pump comprising a piston axially displaceable within a cylinder. The relative movement of the two adjustment components can be easily converted into an actuating stroke of a piston pump. For practical implementation, the dispenser can be moved along with one adjustment component, and the actuating element, which moves relative to the first adjustment component along with the other adjustment component during adjustment, mechanically actuates and drives the dispenser in the adjustment direction.

[0030] The piston pump comprises a piston-cylinder unit with a piston guided in the cylinder and sealed along the cylinder axis. Preferably, the cylinder axis can be oriented in the direction of adjustment. The piston and cylinder define a pump chamber. This chamber can preferably be connected to the storage chamber via an inlet valve and to the applicator device via an outlet valve. The inlet and outlet valves can preferably be designed as one-way or check valves, e.g., as reed or diaphragm valves, so that the lubricant can flow exclusively from the storage chamber into the pump chamber through the inlet valve and exclusively from the pump chamber to the applicator device through the outlet valve.This pressure on the piston, aimed at reducing the volume of the pump chamber, causes a piston stroke, which pumps the lubricant in the pump chamber towards the thread. An increase in the volume of the pump chamber, achieved by a return stroke of the piston opposite to the initial piston stroke, ensures that lubricant flows from the reservoir chamber into the pump chamber.

[0031] The alternating back-and-forth, intermittent stroke movement of the piston relative to the cylinder can preferably be generated by the piston being axially supported on a linearly movable adjusting component, and the cylinder on the other adjusting component or an actuating element connected thereto, or vice versa.

[0032] It is possible that the cylinder and piston are axially supported between the two adjustment components. It is also possible that the cylinder or piston has an inlet valve. Furthermore, it may be provided that the cylinder or piston has an exhaust valve. As a further development, the exhaust valve may have a predefined limit value.

[0033] The alternating back-and-forth, intermittent stroke movement of the piston relative to the cylinder can preferably be generated by the piston being axially supported on one adjusting component, and the cylinder on the other adjusting component or an actuating element connected thereto, or vice versa.

[0034] It is possible that the outlet valve has a predefined limit value. This predefined limit value represents a pressure threshold that must be exceeded for the outlet valve to release the flow of lubricant to the sliding surface. This ensures that during normal operation, when the actuator is driven to its limit with the normal operating force against an actuating element, the lubricant pressure within the pump chamber remains below the pressure threshold, and no lubricant is released through the outlet valve. Only when the actuator is driven to its limit with a defined, higher operating force relative to normal operation—which can be referred to as a service or maintenance force—is the pressure threshold exceeded, and lubricant is delivered to the sliding surface.This allows a lubrication routine to be initiated in a targeted and automated manner, preferably depending on predefined operating or maintenance parameters.

[0035] In an alternative embodiment, the lubricant reservoir may have a volume-variable storage chamber. This volume-variable storage chamber can be filled with a substantially incompressible lubricant, such as grease, and has an outlet. In practice, it may, for example, be a diaphragm bellows, a corrugated bellows, or the like, made of metallic material or plastic. The volume-variable storage chamber may also be designed as a bladder or pouch made of a flexible or rubbery and / or stretchable material. In any case, it can be compressed by an external force so that the grease contained therein can be forced out through the outlet. Alternatively or additionally, the bellows may be in an expanded state or the stretchable diaphragm in a stretched state due to the filling with lubricant, so that the bellows or...The diaphragm is mechanically under tension. This tension causes the bellows or diaphragm to pressurize the lubricant, thus forming a pressure-building mechanism as described above.

[0036] The outlet can, for example, have an outlet valve that releases the lubricant above a predetermined pressure threshold; that is, even in this design, the outlet valve can have a predefined limit value. An applicator device or the like can be connected to the outlet valve, as described above.

[0037] The lubricant reservoir can consist, at least in part, of a sponge-like, porous storage medium. This can absorb a free-flowing lubricant and release it again when compressed.

[0038] It is possible for an adjustment drive to include the adjustment components. For example, an adjustment drive can be designed as a linear spindle drive with a threaded spindle and a spindle nut, which can be driven by a motor to rotate relative to each other around the axially extending spindle axis. Lubricant can be delivered into the thread gap via the lubrication device. A spindle drive can be used, for example, to adjust a steering column or as a steering actuator.

[0039] Alternatively or additionally, it can be provided that lubricant is applied by the dispenser device to a linear sliding guide of axially adjustable adjustment components of the adjustment drive.

[0040] Alternatively, the adjustment drive can have a rack and pinion drive with a rotatably driven pinion that engages the teeth of a rack that can be displaced linearly relative to a housing. The housing or parts attached to the housing, such as a pressure piece for supporting the lateral forces acting on the rack, and the rack itself can represent the adjusting components that can slide relative to each other. The lubrication device according to the invention can provide lubrication for the teeth and / or the sliding bearings, e.g., of the rack against the pressure piece or other sliding bearing elements located in the housing. A rack and pinion drive can, for example, be used as a steering gear or steering actuator in a rack and pinion steering system, where the pinion can be driven manually or alternatively by a motor.

[0041] It is possible for the adjustment components to have axially adjustable outer shell elements. These shell elements can have two or more telescopically extendable and retractable outer shell tubes or profiles, for example, an inner shell that extends into an outer shell. The sliding surfaces can be formed by the outer surface of the inner shell and the inner surface of the outer shell. The lubrication gap can be correspondingly annular around the longitudinal axis.

[0042] In a steering system comprising an adjusting device which has two adjusting components which are adjustable relative to each other along an adjustment direction, it can be provided according to the invention that at least one adjusting device is designed according to one of the embodiments or combinations thereof described above.

[0043] The invention further comprises a method for operating an adjustment device according to one of the embodiments described above, in which a dispenser of the lubrication device is actively actuated during adjustment by the two adjustment components in order to dispense lubricant from the lubricant reservoir onto at least one sliding surface of at least one of the adjustment components. It is advantageous that active delivery or supply of the lubricant to the sliding surface is achieved solely by the relative movements of the adjustment components occurring during operation.

[0044] In all the aforementioned designs and methods, it is possible for the two adjusting components of the adjusting device to be adjusted relative to each other manually or by a motorized adjustment drive. With a motorized adjustment drive, an automated lubrication routine can be advantageously provided, whereby, after predetermined time intervals and / or upon the occurrence of predetermined operating conditions, the two adjusting components are adjusted relative to each other to such an extent that the dispenser is activated. Description of the drawings

[0045] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. Specifically, they show: Fig. 1 a schematic perspective view of a steering column according to the invention, Fig. 2 another perspective view of the steering column according to Fig. 1. From a different perspective, Fig. 3 a steering column according to Fig. 1 and Fig. 2 in a first side view, Fig. 4 a longitudinal section through a lubrication device according to the invention in a first embodiment, Fig. 5 an excerpt from Fig. 3 in a first adjustment state of the adjustment drive according to Fig. 3, Fig. 6a a view analogous to Fig. 5 in a second adjustment state (end stop), Fig. 6b a partial longitudinal section from Fig. 4 during the adjustment state according to Fig. 6a, Fig. 7a a view analogous to Fig. 6a in a third adjustment state, Fig. 7b a view as in Fig. 6b during the adjustment state according to Fig. 7a, Fig. 8 the steering column according to Fig. 1 and Fig. 2 in a second side view (to Fig. 3 opposite), Fig. 9 a longitudinal section through an adjustment drive according to the invention with a lubrication device in a second embodiment in a first adjustment state (analogous to Fig. 4) Fig. 10a a view analogous to Fig. 9 in a second adjustment state (end stop), Fig. 10b a partial longitudinal section from Fig. 9 during the adjustment state according to Fig. 10a, Fig. 11a a view analogous to Fig. 10a in a third adjustment state, Fig. 11 b a view as in Fig. 10b during the adjustment state according to Fig. 11 a, Fig. 12 a schematic perspective view of a steering column according to the invention with a dispenser device in a second embodiment, Fig. 13 a longitudinal section through the pumping device according to Fig. 12, Fig. 14 a schematic representation of a steer-by-wire steering system with an adjusting device according to the invention in a third embodiment. Embodiments of the invention

[0046] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0047] Fig. Figure 1 shows a steering column 1 according to the invention in a schematic perspective view obliquely from above to the rear end, in relation to the direction of travel of a vehicle not shown, where a steering wheel not shown here is held in the operating area. Fig. Figure 2 shows the steering column 1 in a view from the opposite side, i.e., seen from the top right. Fig. Figure 3 shows a side view perpendicular to the direction of travel, seen from the left side, and Fig. 8 a side view seen from the opposite (right) side.

[0048] The steering column 1 comprises a support unit 2, which has fastening means 21 in the form of fastening holes, for attachment to a vehicle body not shown.

[0049] The support unit 2 holds an actuating unit 3, which is housed in a shell unit 4 - also referred to as a guide box or box rocker.

[0050] The actuating unit 3 has an inner casing (shell tube) 31 in which a steering spindle 32 is rotatably mounted about a longitudinal axis L, which extends axially in the longitudinal direction, i.e., in the direction of the longitudinal axis L. At the rear end, a mounting section 33 is formed on the steering spindle 32, to which a steering wheel (not shown) can be attached.

[0051] The actuating unit 3 is mounted in the shell unit 4 in a telescopically displaceable manner in the direction of the longitudinal axis L in order to be able to position the steering wheel connected to the steering spindle 32 forwards and backwards in the longitudinal direction relative to the support unit 2, as indicated by the double arrow parallel to the longitudinal axis L.

[0052] A first adjusting drive 5 for longitudinal adjustment of the adjusting unit 3 relative to the outer casing 4 in the direction of the longitudinal axis L has a spindle drive with a spindle nut 51 having an internal thread extending along an axis G, into which a threaded spindle 52 is screwed with its thread 520, i.e., with its external thread into the corresponding internal thread of the spindle nut 51. The spindle axis of the threaded spindle 52 is identical to the axis G and runs essentially parallel to the longitudinal axis L.

[0053] The adjusting drive 5 forms an adjusting device within the meaning of the invention. Accordingly, the spindle nut 51 forms a first component which can be linearly displaced relative to a second component, which is formed by the threaded spindle 52, in the direction of the axis G.

[0054] The spindle nut 51 is rotatably mounted about the axis G in a bearing housing 53, which is fixedly connected to the outer casing 4. The spindle nut 51 is axially supported on the outer casing 4 via the bearing housing 53 in the direction of the axis G. The adjustment drive 5 is accordingly a so-called plunge spindle drive with a spindle nut 51 that can be driven in a rotating manner relative to the adjustable components. The sliding surfaces that move against each other during adjustment are located on the threads of the internal and external threads.

[0055] The threaded spindle 52 is connected to the actuating unit 3 via a transmission element 34 by means of a fastening element 54 formed at its rear end, which may be designed as a clevis head, and is fixed in the direction of the axis G or the longitudinal axis L and is fixed with respect to rotation about the axis G.

[0056] The transmission element 34 extends from the rear end of the threaded spindle 52 to the actuating unit 3.

[0057] The adjustment drive 5 has an electric motor (drive motor) 55, which can rotate the spindle nut 51 relative to the stationary threaded spindle 52 about the axis G. The rotating spindle nut 51 and the fixed threaded spindle 52 together form a so-called plunge spindle drive. Depending on the direction of rotation of the motor 55, the rotating spindle nut 51 causes the threaded spindle 52 to be displaced translationally along the axis G relative to the spindle nut 51, thus adjusting the adjusting unit 3 connected to the threaded spindle 52 relative to the outer casing unit 4 connected to the spindle nut 51 along the longitudinal axis L.

[0058] The actuating unit 3 and the casing unit 4 accordingly form two adjusting components that can be adjusted relative to each other by the first adjusting drive 5 in accordance with the invention.

[0059] The casing unit 4 is pivotally mounted on the support unit 2 in a pivot bearing 22 about a horizontal pivot axis S lying transversely to the longitudinal axis L. At the rear, the casing unit 4 is connected to the support unit 2 via an actuating lever 41. By rotating the actuating lever 41, the casing unit 4 can be pivoted relative to the support unit 2 about the pivot axis S, which is horizontal in the installed state. This allows for the vertical adjustment H of a steering wheel attached to the mounting section 33, as indicated by the double arrow.

[0060] In Fig. 2, which shows a perspective view of the steering column 1 from the in Fig. As shown on the rear side, a second adjustment drive 6 for height adjustment H is attached to the steering column 1. This adjustment drive 6 comprises a spindle nut 61, in the internal thread of which a threaded spindle 62 with its thread 620 engages along an axis G. The threaded spindle 62 is rotatably mounted about the axis G in a bearing housing 63, which is attached to the outer casing 4, and axially supported on the outer casing 4. It can be driven by an electric motor (drive motor) 65 to rotate in either direction about the axis G. Accordingly, the adjustment drive 6 is a so-called rotary spindle drive with a threaded spindle 62 that can be driven to rotate relative to the adjustable components.

[0061] The spindle nut 61, which may be made of plastic or of a non-ferrous metal such as brass or the like, is fixed to one end of the two-armed actuating lever 41 with respect to rotation about the axis G. The lever 41 is rotatably mounted on the support unit 2 about a pivot bearing 23, and the other arm of which is connected at its other end to the shell unit 4.

[0062] By rotating the threaded spindle 62, depending on the direction of rotation of the motor 65, the spindle nut 61 can be displaced translationally relative to the threaded spindle 52 in the direction of the axis G, so that the outer casing unit 4, which is connected to the spindle nut 61 via the adjusting lever 41, together with the adjusting device 3 contained therein, can be adjusted up or down relative to the support unit 2 in the height direction H, as indicated by the double arrow.

[0063] The support unit 2 and the casing unit 4, or the associated actuating unit 3, accordingly form two adjusting components that can be adjusted relative to each other by means of the second actuating drive 6 in accordance with the invention.

[0064] At the axial end that is forward with respect to the direction of travel, in Fig. 1 and Fig. In a first embodiment, a lubrication device 7 according to the invention is attached to the threaded spindle 52 of the first adjusting drive 5 (3 on the left). An actuating element 42 is fixedly attached to the housing unit 4 and is axially fixed relative to the adjusting drive 5, specifically relative to the spindle nut 51 mounted in the bearing housing 53. The actuating element 42 projects into the linear path of movement of the threaded spindle 52 and forms a front end stop for it. This allows the threaded spindle 52, with its front end and thus also with the lubrication device 7 attached there, to mechanically abut the actuating element 42, i.e., to be brought to a stop. The function of the lubrication device 7 in conjunction with the actuating element 42 is described below. Fig. 4 to 7b are explained in more detail.

[0065] Fig. Figure 4 shows a longitudinal section through the lubrication device 7 in normal adjustment operation of the adjustment drive 5, for example during an adjustment movement to retract the actuating unit 3 into the casing unit 4 in the direction of travel forward, as shown in the Fig. 5 shown excerpt from Fig. 3 is indicated by the arrow pointing to the left.

[0066] Fig. Figure 4 shows an enlarged detail view of the lubrication device 7 in its rest state, i.e., in normal adjustment operation. It has a dispenser 70 designed as a piston pump, which has a piston 72 mounted axially displaceable in a cylinder 71 in the direction of the axis G. The cylinder 71 and the piston 72 define a pump chamber 73. A storage chamber 74 filled with lubricating grease (not shown here) is connected to the pump chamber 73 via an inlet valve 75 designed as a one-way valve (check valve), so that lubricant, for example, lubricating grease, can flow from the storage chamber 74 through the inlet valve 75 into the pump chamber 73. This is connected via an outlet valve 76, also designed as a one-way valve and arranged in the piston 72, to an applicator device 77, which here is designed as an applicator chamber enclosing the thread 520 of the threaded spindle 52.Lubricant can flow from the pump chamber 73 into the applicator chamber 77 through the outlet valve 76.

[0067] The piston 72 is axially fixed to the front face of the threaded spindle 52. An axially acting compression spring 78 elastically loads the piston 72 axially outwards from the cylinder 71, so that the pump chamber 73 is held at its maximum volume by the spring tension.

[0068] The lubrication device 7, in this example, has a housing 79 which includes the cylinder 71 and the storage chamber 74. As shown, it can be formed in one piece and, for example, made of metal or plastic. The housing 79 is axially resiliently supported against the piston 72, which in turn is axially supported against the front face of the threaded spindle 52.

[0069] In the Fig. 5, Fig. 6a and Fig. 7a are in an excerpt of Fig. Figure 3 schematically shows the movement states that follow one another during the execution of a service routine for lubricating the adjustment drive 7 according to the method according to the invention. Fig. Figure 4 shows the lubrication device in the state of Fig. 5, and accordingly, the in Fig. 6b and Fig. The excerpts shown in 7b depict the states according to Fig. 6a and Fig. 7a.

[0070] The adjusting drive 5 is designed as a plunge spindle drive, in which the spindle nut 51 is driven in a rotating manner, and the threaded spindle 52 is stationary relative to it.

[0071] In Fig. Figure 5 schematically illustrates how the adjusting drive 5 is moved forward, whereby the actuating unit 3 is retracted forward into the housing unit 4, and the lubrication device 7 is moved axially along the axis G towards the actuating element 42. The direction of movement is indicated by the left-pointing arrow. The lubrication device is in the rest position as shown. Fig. 4. The storage chamber 74 and the pump chamber 73 are filled with lubricant, and the inlet valve 75 and the outlet valve 76 are closed.

[0072] In Fig. 6a The lubrication device 7 strikes axially against the actuating element 42, so that the end stop of the adjustment is reached. The adjusting force is exerted on the piston 72 via the threaded spindle 52, so that it is pushed into the cylinder 71, which is supported against the actuating element 42 by the housing 79. This is in Fig. 6b is indicated by the left-pointing arrow. In this process, the pump chamber 73 is compressed, and the compression spring 78 is elastically compressed and tensioned. Due to the pressure increase, the lubricant in the pump chamber 73 is forced through the outlet valve 76 into the applicator chamber 77. This is indicated by the wavy arrow. There, it forms a lubricating film on the thread 520 of the threaded spindle 52. During subsequent operating cycles of the adjusting drive, the lubricant applied to the thread reaches the spindle nut 51 as the threaded spindle 52 moves axially back and forth, spreads into its internal thread, and is subsequently distributed along the entire axial length of the thread 520 of the threaded spindle 52.

[0073] According to the inventive method, the adjusting force at the stop is determined according to Fig. 6a and Fig. 6b is set sufficiently high so that the hydraulic pressure increase in the pump chamber 73 is high enough for the lubricant to pass the pressure threshold specified by the outlet valve 76.

[0074] In Fig. 7a The adjustment direction, i.e., the axial direction of movement of the threaded spindle 52, is reversed, and the lubrication device 7 is released from the stop and moved backwards away from the actuating element 42, as indicated by the right-pointing arrow. As in Fig. As shown in Figure 7b, the piston 72 is pushed out of the cylinder 71 to the rear by the spring force of the tensioned compression spring 78, as indicated by the arrow pointing to the right. The resulting increase in the volume of the pump chamber 73 creates a hydraulic vacuum, which causes lubricant to be drawn from the storage chamber 74 into the pump chamber 73 through the inlet valve 75, as indicated by the curved arrow.

[0075] When the piston 72 has been completely moved back to its starting position by the spring force of the compression spring 78, the following occurs again: Fig. The resting state shown in section 4 has been reached. The pump chamber 73 is refilled with lubricant, and if necessary, further lubrication can be carried out according to the instructions in the Fig. The steps of the inventive method shown in 4 to 7b are carried out.

[0076] At the axial end furthest from the direction of travel, in Fig. 2 and Fig. On the left side, a lubrication device 8 according to the invention is attached to the threaded spindle 62 of the second adjustment drive 6 in a second embodiment. An actuating element 66 is fixedly attached to the spindle nut 61. The spindle nut 61 is axially displaceable relative to the threaded spindle 62 during adjustment. The actuating element 66 projects into the linear path of movement of the second lubrication device 8 attached to the threaded spindle 52 and forms a front end stop for it. This makes it possible for the lubrication device 8 to mechanically abut against the actuating element 66 when the spindle nut 61 is maximally retracted rearward from the threaded spindle 62. Fig. 2, Fig. 8, Fig. 9 and Fig. 10a is moved away to the left, as in Fig. 9 and Fig. 10a is indicated by the arrow. The stop of the lubrication device 8 against the actuating element 66 mechanically limits the adjustment travel of the adjusting drive 6, i.e., the adjusting drive 6 is brought to its limit. The function of the lubrication device 8 in conjunction with the actuating element 66 is described below with reference to the Fig. Sections 9 to 11b are explained in more detail.

[0077] The operating principle of the lubrication device 8 corresponds in principle to that of the lubrication device 7, with the differences arising from the adaptation to the adjustment drive 6 designed as a rotary spindle drive, which differs from the plunge spindle drive of the adjustment drive 5 by the reversed kinematics.

[0078] The lubrication device 8 can strike axially against the actuating element 66 in the end stop, which is located on the spindle nut 61 on the front axial end face, in Fig. 9 is arranged on the left.

[0079] Fig. Figure 9 shows a longitudinal section along the axis G through the adjusting drive 6, analogous to Figure 4, during the adjusting movement, in which the spindle nut 61 moves linearly forward on the threaded spindle 62, as in Fig. 9 is indicated by the arrow pointing to the left.

[0080] Fig. 10a shows analogous to Fig. 6a the axial stop, and Fig. 10.b analogous to Fig. 6b the resulting actuation of the lubrication device 8. Fig. 11a shows analogous to Fig. 7a the dissolved state, and Fig. 11b analogous to Fig. 7b the lubrication device 8.

[0081] Fig. 9, Fig. 10b and Fig. Figure 11b shows details of the lubrication device 8. This device has a dispenser 80 designed as a piston pump, with a piston 82 axially displaceable in a cylinder 81 and a pump chamber 83 bounded between them. This pump chamber is connected to a storage chamber 84 via an inlet valve 85 and to an applicator device 87, designed as an applicator chamber, via an outlet valve 86. An axially acting compression spring 88 is arranged between the piston 82 and the cylinder 81. The cylinder 81 and the storage chamber 84 are arranged in a housing 89, which, as in the example shown, can be designed as a single piece or as a single unit.

[0082] The cylinder 81 is fixed to the housing 89 on the threaded spindle 62. The piston 82 is mounted so as to be axially displaceable relative to the cylinder 81 and relative to the threaded spindle 62.

[0083] In Fig. Figure 9 shows a movement state during adjustment in which the spindle nut 61 moves linearly forward relative to the threaded spindle 62, as indicated by the left-pointing arrow. In this process, the actuating element 66, located on the front face of the spindle nut 61, is moved axially towards the piston 82 of the lubrication device 8.

[0084] In Fig. 10a is - analogous to Fig. 6a - shows the situation when the end stop of the adjusting drive 6 is reached. The actuating element 66 strikes axially against the piston 82, as shown in Fig. 10b is recognizable, so that it is inserted into cylinder 81. This is in Fig. Figure 10b is indicated by the left-pointing arrow. In this process, the pump chamber 83 is compressed, and the compression spring 88 is elastically compressed and tensioned. Due to the pressure increase, the lubricant in the pump chamber 83 is forced through the outlet valve 86 into the applicator chamber 87. This is indicated by the wavy arrow. There, it forms a lubricating film on the thread 620 of the threaded spindle 62. During subsequent operating cycles of the adjusting drive, the lubricant applied to the thread 620 is distributed from the spindle nut 61 along the entire axial length of the thread 620 of the threaded spindle 62 by the axial reciprocating motion of the spindle nut 61.

[0085] According to the inventive method, the adjusting force at the stop is determined according to Fig. 10a and Fig. 10b is set sufficiently high so that the hydraulic pressure increase in the pump chamber 83 is high enough for the lubricant to pass the pressure threshold specified by the outlet valve 86.

[0086] In Fig. 11a The adjustment direction, i.e., the axial direction of movement of the threaded spindle 62, is reversed, and the lubrication device 8 is released from the stop with the spindle nut 61 by moving the actuating element 66 (in the direction of travel) forward away from the lubrication device 8, as indicated by the right-pointing arrow. As in Fig. As shown in Figure 11b, the piston 82 is pushed out of the cylinder 81 to the rear by the spring force of the tensioned compression spring 88, as indicated by the arrow pointing to the right. The resulting increase in the volume of the pump chamber 83 creates a hydraulic vacuum, which causes the lubricant to be drawn from the storage chamber 84 into the pump chamber 83 through the inlet valve 85, as indicated by the curved arrow.

[0087] When the piston 82 has been completely moved back to its starting position by the spring force of the compression spring 88, the following occurs again: Fig. The lubrication device 8 has reached the rest state shown in section 9. The pump chamber 83 is again filled with lubricant, and if necessary, further lubrication can be carried out according to the instructions in the... Fig. The steps of the inventive method shown in sections 9 to 11b are carried out.

[0088] Fig. Figure 12 shows a steering column 1 similar to the one in Fig. 1-3 shown in the illustration, where the same reference numerals are used for identical parts.

[0089] The adjusting unit 3, and thus the outer casing 31, is mounted in the casing unit 4 in a telescopically sliding manner in the axial adjustment direction given by the longitudinal axis L, as indicated by the double arrow parallel to the longitudinal axis L. Accordingly, an adjusting device is formed.

[0090] Fig. Figure 13 shows a partial longitudinal section along the longitudinal axis L.

[0091] The outer surface of the casing tube 31, which can be cylindrical, forms one sliding surface, and the inner surface of the casing unit 4 forms the other sliding surface. A circumferential lubrication gap 43 is formed between these.

[0092] A lubrication device 9 according to the invention is mounted on the outer tube 31. This device is functionally similar to the lubrication device 8. Like the latter, it has a dispenser 90 with an annular cylinder 91 rotating about the longitudinal axis L, in which an axially movable annular piston 92 adapted to it is mounted. The lubrication device 9 has a storage chamber 94 which, analogous to the lubrication device 8, is connected to a pump chamber 93 via inlet and outlet valves.

[0093] The pump chamber 93 is radially open towards the jacket tube 31, so that an applicator device is formed which surrounds the surface and is designed as an applicator chamber.

[0094] If the outer tube 31 is retracted into the outer casing unit 4 until it reaches its end stop - in Fig. 13 to the left, the piston 92 strikes axially against the front actuating surface 44 of the jacket unit 4, and is thereby pushed into cylinder 91, as shown in Fig. 13 is indicated by the arrows pointing to the right. This pumps lubricant from the storage chamber 94 and applies it to the outer circumferential sliding surface of the jacket tube 31, as described above for the dispenser device 80.

[0095] During the subsequent axial adjustment of the actuating unit 3 or the outer tube 31, the lubricant is distributed and enters the lubrication gap 43.

[0096] Fig. Figure 14 shows a schematic representation of a steer-by-wire steering system 100 of a motor vehicle. The steering column 1 has electrical sensors that convert manual operation of a steering wheel 35 attached to the steering spindle 32 into electrical control signals for controlling an electric steering actuator 110. This actuator has a rack 111 which is connected to steerable wheels 113 via tie rods 112. The rack 111 can be moved linearly along an adjustment direction T by a motor-driven pinion 114 engaged with it, as indicated by the double arrow, in order to generate a steering angle.

[0097] The rack 111, together with a relatively fixed part of the body, a housing of the steering actuator 110, a pressure piece for receiving the pressure forces exerted on the rack 111 by the pinion 114, or the like, forms an adjusting device according to the invention. For this purpose, a lubrication device 10 is mounted on the rack 111, which can be actuated by the movement of the rack 111 during adjustment, analogous to the one described in Fig. 12 and Fig. Adjustment device shown in Figure 13. This allows lubricant to be applied to a linear sliding surface of the rack 111, and / or to the teeth of the rack 111 in the area of ​​the pinion 114. Reference symbol list 1 Steering column 2 carrying units 21 Fasteners 22, 23 Swivel bearing 3 Actuator 31 Jacket pipe 32 Steering spindle 33 Fastening section 34 Transmission element 35 Steering wheel 4 Sheath unit 41 adjusting levers 42 Actuating element 43 Lubrication gap 44 operating area 5, 6 Adjustment drive 51, 61 Spindle nut 52, 62 Threaded spindle 520, 620 thread (external thread) 53, 63 Bearing housing 54 Fastening element 55, 65 Motor (drive motor) 66 Actuating element 7, 8, 9, 10 Lubrication device 70, 80, 90 donor facility 71, 81, 91 cylinders 72, 82, 92 pistons 73, 83, 93 Pump chamber 74, 84, 94 storage chamber 75, 85 Inlet valve 76, 86 Exhaust valve 77, 87 Applicator device 78, 88 compression spring 79, 89 cases 100 steering system 110 Steering actuator 111 Rack and pinion 112 Tie rod 113 wheel 114 sprockets L Longitudinal axis H Altitude G-axis (threaded spindle axis) S swivel axis T Adjustment direction

Claims

[1] Adjustment device (1, 110) for a steering system of a motor vehicle, comprising two adjustment components (51, 52, 61, 62, 31, 4) adjustable relative to each other along an adjustment direction with sliding surfaces arranged to slide against each other, and comprising a lubrication device (7, 8, 9, 10) with a lubricant reservoir (74, 84, 94) in which a lubricant can be received and which can be discharged onto at least one sliding surface of at least one of the adjustment components (51, 52, 61, 62, 31, 4), characterized by , that the lubrication device (7, 8, 9, 10) has a dispenser device (70, 80, 90) which cooperates with one or both adjusting components (51, 52, 61, 62, 31, 4) for actuation. [2] Adjustment device according to claim 1, characterized by that the dispenser (70, 80, 90) has a pump device. [3] Adjustment device according to one of the preceding claims, characterized bythat the adjustment direction is linear in the direction of an axis (G, L). [4] Adjustment device according to one of the preceding claims, characterized by that the adjustment direction runs along an adjustment path that is at least partially curved. [5] Adjustment device according to one of the preceding claims, characterized by , that the lubrication device (7, 8, 9, 10) has a storage chamber. [6] Adjustment device according to one of the preceding claims, characterized by , that the lubrication device (7, 8, 9, 10) has an applicator device (77, 87). [7] Adjustment device according to one of the preceding claims, characterized by , that the lubrication device (7, 8, 9, 10) is connected to one adjusting component (51, 52, 61, 62, 31, 4) and interacts with an actuating element (42, 44, 66) connected to the other adjusting component (51, 52, 61, 62, 31, 4). [8] Adjustment device according to one of the preceding claims, characterized by , that the actuating element (42, 44, 66) is designed as a stop element. [9] Adjustment device according to one of the preceding claims, characterized by , that the dispenser device (70, 80, 90) has a piston pump comprising a piston (72, 82, 92) axially displaceable in a cylinder (71, 81, 91). [10] Adjustment device according to one of the preceding claims, characterized by , that the lubricant storage unit (74, 84, 94) has a volume-variable storage chamber. [11] Adjustment device according to one of the preceding claims, characterized by , that an adjustment drive (5, 6) has the adjustment components (51, 52, 61, 62). [12] Adjustment device according to one of the preceding claims, characterized by , that the adjusting components (4, 31) have axially adjustable outer shell elements (4, 31) in the direction of a longitudinal axis (L). [13] Steering system (100) comprising an adjustment device (1, 110) which has two adjustment components (51, 52, 61, 62, 31, 4) that are adjustable relative to each other along an adjustment direction, characterized by , that at least one adjusting device (1, 110) is designed according to one of the preceding claims 1 to 12. [14] Method for operating an adjustment device (1, 110) according to one of claims 1 to 12, characterized in that a dispenser device (70, 80, 90) of the lubrication device (7, 8, 9, 10) is actively actuated during adjustment by the two adjustment components (51, 52, 61, 62, 31, 4) in order to dispense lubricant from the lubricant reservoir (74, 84, 94) onto at least one sliding surface of at least one of the adjustment components (51, 52, 61, 62, 31, 4).

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