Steering column for a motor vehicle

Abstract

Steering column (1) for a motor vehicle, comprising a support unit (2) which can be attached to a vehicle body and which has two side cheeks (21) which extend flatly parallel to a longitudinal direction and are spaced apart parallel to each other transversely to the longitudinal direction, between which an adjusting unit (3) is adjustably held, and which are connected to one another via cross members (22), wherein the support unit (2) has fastening means (24), and the side cheeks (21) and the cross members (22) have sheet metal parts, wherein a cross member (22) is designed as a flat sheet metal plate which extends transversely to the longitudinal direction (L) and to the side cheeks (21) and is U-shaped with two parallel legs (221), characterized by that the cross member (22) is designed as a continuously flat, one-piece sheet metal blank, wherein the legs (221) engage around the side cheeks (21) from the outside and are welded to the side cheeks (21).

Description

Prior ArtThe invention relates to a steering column for a motor vehicle, comprising a support unit which can be attached to a vehicle body and has two side cheeks which extend in a planar manner parallel to a longitudinal direction and are situated opposite one another transversely to the longitudinal direction at a distance, between which side cheeks an adjusting unit is held in an adjustable manner, and which side cheeks are connected to one another via cross members, wherein the side cheeks and the cross members have sheet metal parts, wherein a cross member is designed as a planar sheet metal plate which extends transversely to the longitudinal direction and to the side cheeks and is designed in a U-shaped manner with two parallel limbs.The steering column of a motor vehicle comprises an adjusting unit, having a steering spindle which extends in the longitudinal direction and on which a manual steering handle, for example a steering wheel for inputting steering commands, is mounted at the rear end in the direction of travel. The steering spindle is rotatably mounted in a jacket unit about its longitudinal axis, which is held by a support unit connectable to the vehicle body. For adjusting the steering wheel relative to the driver position, the adjusting unit is adjustable relative to the support unit and can be releasably fixed by means of a clamping unit.The support unit has two elongate, planar side cheeks which extend in parallel with one another in the longitudinal direction and are at a distance transversely thereto, in which the adjusting unit is accommodated. The two side cheeks are fixedly connected to one another at the top, i.e. on the top side facing the mounting of the vehicle body, by means of one or more cross members. This forms a mounting for the adjusting unit which is substantially U-shaped in cross section and open at the bottom.In accordance with the generic type, the support unit is designed as a sheet metal construction. The side walls and the cross members are designed as sheet metal shaped parts, as is described in the prior art, for example, in DE 10 2019 214 557 A1 or CN 1 14 954 627 A. The cross members are formed as complex, three-dimensionally formed sheet metal pressed parts which are connected to the side walls, for example by welding. As a result, a high rigidity can be realized in an advantageous manner, and the fastening means for attachment to the vehicle body can be formed integrated into the cross members.The structural and production-related outlay for providing such complex shaped sheet metal parts is, however, relatively high. The production and adaptation to different types of steering columns are correspondingly complicated.A steering column of the type mentioned at the beginning is known from DE 10 2006 056 582 A1.In view of the problems explained above, it is an object of the present invention to enable a reduced outlay.SUMMARY OF THE INVENTIONThis object is achieved according to the invention by the steering column having the features of claim 1.In a steering column for a motor vehicle, comprising a support unit which can be attached to a vehicle body and has two side cheeks which extend in a planar manner parallel to a longitudinal direction and are situated opposite one another transversely to the longitudinal direction at a distance, between which side cheeks an adjusting unit is held in an adjustable manner, and which side cheeks are connected to one another via cross members, wherein the support unit has fastening means, and the side cheeks and the cross members have sheet metal parts, wherein a cross member is designed as a planar sheet metal plate which extends transversely to the longitudinal direction and to the side cheeks, wherein a cross member is designed as a planar sheet metal plate which extends transversely to the longitudinal direction and to the side cheeks and is designed in a U-shaped manner with two parallel limbs, it is provided according to the invention that the cross member is designed as a continuously planar, one-piece sheet metal blank, wherein the legs engage around the side cheeks from the outside and are welded to the side cheeks.According to the invention, the cross members are designed as simple flat parts which can be provided in a structurally simple manner and with relatively little production outlay by means of a two-dimensional shaping. A cross member according to the invention extends as a whole continuously parallel to a transverse plane extending transversely to the longitudinal direction and has a constant material thickness or thickness perpendicularly thereto. The cross members span the distance between the side walls. An advantage is that the required rigidity of the support unit can be easily predefined by adapting the thickness of the cross members. The adaptation to the outer dimensions of the support unit, which are substantially determined by the outer distance of the side walls, can be adapted structurally and in terms of production with little outlay solely by the configuration of the outer contour of the cross members.In the sense of the present disclosure, a distance is understood to mean a distance greater than zero.It is preferred that the plane of the sheet metal plate (transverse plane) is perpendicular or at least substantially perpendicular to the longitudinal direction and to the side cheeks or a planar or substantially planar section of the side cheeks.Essential advantages over the cross members known in the prior art and produced by three-dimensional shaping such as bending, deep-drawing or the like are reduced construction and production outlay, and simpler and more cost-effective adaptation to different types of steering columns. Furthermore, a saving in weight is possible. In this case, by an optimized connection of the cross members to the side cheeks, a high dimensional rigidity of the support unit can be ensured. It is advantageous that the fastening means for attaching the support unit to a vehicle body are attached directly to the side walls, so that the flat sheet metal plate of the cross member according to the invention does not have any fastening means such as a through opening or the like. This allows the shaping of the cross member to be simplified and high dimensional rigidity is ensured.According to the invention, it is provided that a cross member is formed as a continuously planar, one-piece sheet metal blank. Such a two-dimensionally planar sheet metal blank can be manufactured simply and cost-effectively from sheet metal material, preferably from steel sheet, by punching, fine cutting, laser cutting or the like.The cross member is U-shaped with two parallel legs which, according to the invention, engage around the side cheeks from the outside. The U-shape, which is situated as a whole in the plane of the sheet metal plate of the cross member, is formed by a connecting portion which extends continuously transversely over the distance between the two side walls and from which two limbs project. The inner distance between the inner sides of the legs measured transversely to the longitudinal direction substantially corresponds to the outer dimension between the outer sides of the side cheeks facing away from the outside, measured transversely to the longitudinal direction, so that the inner sides of the legs facing one another can be connected directly to the outer sides, for example by a weld seam. The outer dimension can be equivalently referred to as the lateral cheek width of the support unit, which is surrounded from the outside by the cross members according to the invention. The sheet metal plate of the cross member stands from the outside perpendicularly on a preferably planar outer surface of the side walls and is there connected to the outer side of the side wall forming an angle structure. This allows an advantageously high torsional rigidity of the support unit to be realized.It is provided according to the invention that the legs are welded to the side cheeks. The cross members, like the side walls, are preferably made of sheet steel, so that a firm material connection can be produced efficiently by welding.It is advantageous that outwardly protruding fastening elements are attached to the side cheeks, each of which has a planar fastening section arranged transversely to the side cheek and to the cross member. The fastening elements protruding outward on both sides from the support unit are preferably designed as shaped sheet metal parts, preferably as are the side walls and the cross members made of sheet steel. In the fastening section, they have fastening means for attachment to the vehicle body, for example through-openings or the like. The fastening section preferably extends continuously planar in a fastening plane which is arranged transversely, preferably substantially perpendicularly, to the plane of the side cheek and to the plane of the cross member. As a result, a particularly torsionally rigid three-dimensional sheet metal node can be formed.It is preferred that the legs of the cross members are welded to the fastening elements in the fastening section (). Due to the fact that the free end edges of the U-shaped protruding legs, which are preferably substantially perpendicular to the fastening section, are welded thereto, and the inner sides of the legs are welded to the outer side of the side cheeks, which is preferably perpendicular to the fastening section and to the cross member, a light and torsionally rigid structure, which is simple to produce by welding from a manufacturing standpoint, can be produced.It is advantageous that a fastening element is designed as a U-profile. The U-profile has the planar fastening section, from which U-profile legs are angled. Along the U-shaped edge, the profile can be welded to the side cheek. As a result, a high degree of dimensional rigidity can be realized with low weight and manufacturing complexity. This is particularly high due to the combination with the cross members according to the invention.It can be provided that the side cheeks have, in a front end section, a transversely continuous bearing bore in which a pivot axis of the adjusting unit can be accommodated. As a result, a height adjustment axis can be realized in the front region of the adjusting unit with respect to the installation position in the direction of travel, about which the adjusting unit can be pivoted up and down relative to the support unit for height adjustment of the steering wheel attached to the rear end.It is preferred that the side cheeks have in a rear end section a height adjustment slot extending transversely to the longitudinal direction. In the rear end section with respect to the direction of travel, a clamping device of the support unit can engage, by means of which a clamping stroke can be generated, by means of which the side cheeks are moved relative to one another, and as a result can be releasably clamped to the actuating unit accommodated between the side cheeks. The clamping device can have a lifting device in a manner known per se, for example a wedge-disc, ball ramp, tilting pin or other lifting mechanism which is supported from the outside on one of the side cheeks and which can be actuated by rotation of a clamping axis in order to generate a clamping stroke in the direction of the clamping axis. This is passed transversely through the two height adjustment slots of both side cheeks, each of which is introduced into a planar section of the side cheek, and is supported from the outside against the other side cheek. The height adjustment slots are designed as elongated holes which are elongated in the height direction, transversely to the longitudinal direction and which are preferably designed in the shape of radii (arc or banana). As a result, the adjusting unit together with the clamping axis supported thereon can be adjusted upwards or downwards relative to the support unit for height adjustment by pivoting about the height adjustment axis predefined by the bearing bore, and can be fixed or released by actuating the clamping device.It is advantageous that two cross members are arranged at a distance from one another between the bearing bore and the height adjustment slot. This allows an advantageously high rigidity to be realized.In an advantageous development, it can be provided that the side cheek comprises a toothed rail adjacent to the height adjustment slot. This toothed rail can be formed directly in the side cheek or fixed to it as a separate element. Preferably, two toothed rails are provided for each height adjustment slot, wherein these are arranged with respect to one another such that the height adjustment slot is arranged between them. The toothed rail can be brought into engagement with a form-fitting element, which is part of the clamping device and is movable together with the adjusting unit in the height direction, in order to provide a form-fitting fixing of the adjusting unit relative to the supporting unit. This makes it possible to achieve improved fixing compared to fixing based only on frictional engagement.The support unit is preferably made of steel sheet. The side walls can be designed as stamped and pressed parts, and the cross members according to the invention can be designed as stamped parts made of sheet steel that are easy to produce.It is expedient for the adjusting unit to have a jacket unit in which a steering spindle is mounted rotatably about its longitudinal axis. At the rear end of the actuator unit, there is mounted manual steering input means such as a steering wheel.It is advantageous that the adjusting unit is longitudinally adjustable. For adaptation to the driver position, the adjusting unit can be configured to be telescopically adjustable axially, i.e. in the direction of the longitudinal axis. For this purpose, the jacket unit can have an inner jacket in which the steering spindle is rotatably mounted about its longitudinal axis. The inner jacket is accommodated in an axially adjustable manner in an outer jacket which is held between the side cheeks of the support unit. By means of the clamping device, in the fixing position the outer jacket can be clamped externally on the inner jacket in such a way that fixing takes place in the longitudinal direction. In the release position, the clamping is released so that the inner jacket together with the steering spindle having the steering wheel can be telescopically adjusted forwards or backwards.Preferably, it can be provided that an energy absorption device is arranged between the support unit and the adjusting unit. If, in the event of a crash, a body striking the steering wheel exerts a high force in the longitudinal direction on the steering spindle, which force exceeds a predefined limit value, the steering column can yield, wherein the adjusting unit moves relative to the supporting unit in at least one adjustment direction. In the energy absorption device, which is coupled in between the adjusting unit and the supporting unit, the kinetic energy introduced by the relative movement is absorbed and converted into deformation work, so that the body striking the steering wheel is braked in a controlled manner and the risk of injury is reduced.The energy absorption device can have an energy absorption element which is inserted between an inner and outer jacket of the jacket unit, and / or between the jacket unit and the support unit. A deformation section of the energy absorption element is plastically deformed by the relative movement between the outer jacket and the adjusting unit in the event of a crash, with absorption of kinetic energy, for example by bending a bending tab, separating a tear tab, widening a slot or the like. Friction elements can also be provided which convert kinetic energy into frictional heat. Such and further energy absorption elements and combinations thereof are known in principle from the prior art.DESCRIPTION OF THE DRAWINGSAdvantageous embodiments of the invention are explained in more detail below with reference to the drawings. In detail, the following show: FIG. 1 shows a steering column according to the invention in a schematic perspective view, FIG. 2 shows the support unit of the steering column according to FIG. 1 designed according to the invention in an exposed perspective view, FIG. 3 shows the support unit according to FIG. 2 in a side view.Embodiments of the InventionIn the various figures, identical parts are always provided with the same reference numerals and are therefore generally also designated or mentioned only once in each case.FIG. 1 shows a steering column 1 according to the invention as a whole in a schematic perspective view, wherein the end lying at the front in the direction of travel with respect to the installation position points to the left, and correspondingly the rear end points to the right.The steering column 1 has a support unit 2 designed according to the invention, which is shown separately exposed in FIG. 2 in a perspective view analogous to FIG. 1, and in FIG. 3 in a side view.The support unit 2 has two side cheeks 21 which are aligned elongate in a longitudinal direction along a longitudinal axis L. They extend flat and are parallel to the longitudinal axis L on both sides and to each other. They are designed as sheet metal formed parts, preferably as pressed stamped parts made of steel sheet.Between the parallel inner sides of the two side cheeks 21 facing one another, an adjusting unit 3 is accommodated and held in an adjustable manner. This has a jacket unit 31, in which a steering spindle 32 is rotatably mounted, in the illustrated setting position about the longitudinal axis L. The steering spindle 32 has, at its rear end facing the driver position, a fastening section 33 for attaching a steering wheel, not shown here.The two side walls 21 are connected by two cross members 22. According to the invention, a cross member 22 is each designed as a flat sheet metal plate which extends in a transverse plane transversely to the longitudinal axis L. It is formed in a two-dimensional U-shaped manner with a connecting section 220 which spans the transverse distance between the side walls 21 and from which two U-legs 221 extend-in the installation position shown downwards. The sheet metal plate can be manufactured in one piece as a flat sheet metal stamped part, preferably from sheet steel.The cross members 22 engage around the side cheeks 21 from the outside, wherein the U-limbs 221 abut with their mutually facing inner edges from the outside against the outer sides of the side cheeks 21, and are preferably connected in a materially integral manner by means of a weld seam 4.On the outer sides of the side walls 21, outwardly protruding fastening elements 23 are attached, which each have a planar fastening section 231 arranged transversely to the side wall and to the cross member. In this, a through-opening 24 is formed as a fastening means. The fastening elements 23 can have an angled, in the example U-shaped cross section, preferably as a steel sheet profile. This is welded to the side cheek 21.The cross members 22 are connected to the fastening elements 23 by means of a weld seam 4 with the protruding front edge of the U-legs, preferably in the planar fastening section 231. As a result, a particularly rigid, three-dimensional sheet metal knot is formed in the connecting region comprising the cross member 22, the side cheek 21 and the fastening section 23.In the front region, the side cheeks 21 have bearing bores 25 which lie on a pivot axis 26 which is perpendicular to the longitudinal axis L. The adjusting unit 3 is mounted on the support unit 2 so as to be pivotable about this pivot axis 26, so that the fastening section 33 with the steering wheel attached thereto is adjustable in a height direction H for height adjustment, as is indicated in FIG. 1.The jacket unit 31 can be configured telescopically longitudinally adjustable in the direction of the axis of rotation, so that a longitudinal adjustment of a steering wheel attached to the steering spindle 32 is made possible.In the rear region, the side cheeks 21 have height adjustment slots 27 which are elongate in the height direction H. A clamping device 5 has a clamping axle 51 which is mounted on the actuating unit 3. The clamping axle 51 extends through the height adjustment slots 27 and is displaceable therein in the height direction H.The clamping device 5 has a lifting device known per se, for example a wedge-disc, ball ramp, tilting pin or other lifting mechanism which is supported from the outside on one of the side walls 21 and which can be actuated by rotation of the clamping axis 51, for example by manual actuation of a clamping lever 52, in order to generate a clamping stroke in the direction of the clamping axis 51. The clamping axle 51 is axially supported on the other side cheek 21 from the outside. As a result, the adjusting unit 3 can be selectively braced or released between the side cheeks 21 by actuating the lifting mechanism, as a result of which a releasable fixing for height adjustment of the adjusting unit is made possible.Adjacent to the height adjustment slots 27, toothed rails 271 are arranged. These tooth bars 271 are formed directly in the side walls 21 by means of a so-called half-groove. Two toothed rails 271 are provided for each height adjustment slot 27, wherein these are arranged with respect to one another such that the height adjustment slot 27 is arranged between them. The toothed rail 271 is brought into engagement with a form-fitting element, which is part of the clamping device 5, in order to provide a form-fitting fixing of the adjusting unit 3 with respect to the supporting unit 2.Two projections 272 spaced apart in the height direction H are formed in one of the side walls 21 adjacent to the height adjustment slot 27. These projections 272 are part of a height adjustment limiting device which further comprises a projection of the adjusting unit 3 which is designed as a stop element and is arranged between the projections 272 and is movable together with the adjusting unit 3, so that this stop element can be brought into contact with the projections 272 in order to limit the adjustment of the adjusting unit 3 relative to the support unit 2.The two cross members 22 are arranged in the longitudinal direction at a distance from one another, from the bearing bores 25 and from the height adjustment slots 27.Between the support unit 2 and the adjusting unit 3, an energy absorption device 6 can preferably be incorporated. This has an energy absorption element in a manner known per se, which, in the event of a crash, when a body impacts the steering wheel at high speed and introduces a high crash force into the actuating unit 3 in the longitudinal direction, plastically deforms with energy absorption. The impact is thereby decelerated in a controlled manner.The clamping device 5 is preferably designed such that the energy absorption device 6 is active only in the fixed state, and an adjustment of the adjusting unit 3 relative to the support unit 2 is possible in the released state.The side parts 21, the cross members 22 and the fastening elements 23 are designed as sheet metal parts, preferably made of steel sheet, and are firmly connected to one another by welding.List of reference characters1 Steering column 2 Support unit 21 Side bolster 22 Cross member 220 Connecting portion 221 U leg 23 Fastening element 231 Fastening portion 24 Through hole 25 Bearing bore 26 Pivot axis 27 Height adjustment slot 3 Adjusting unit 31 Jacket unit 32 Steering spindle 33 Fastening portion 4 Weld seam 5 Clamping device 51 Clamping axis 6 Energy absorption device L Longitudinal axis H Height direction

Claims

Steering column (1) for a motor vehicle, comprising a support unit (2) which can be attached to a vehicle body and has two side cheeks (21) which extend flat parallel to a longitudinal direction and are situated opposite one another transversely to the longitudinal direction at a distance and parallel to one another, between which side cheeks an adjusting unit (3) is held in an adjustable manner, and which side cheeks are connected to one another via cross members (22), wherein the support unit (2) has fastening means (24), and the side cheeks (21) and the cross members (22) have sheet metal parts, wherein a cross member (22) is designed as a planar sheet metal plate which extends transversely to the longitudinal direction (L) and to the side cheeks (21) and is designed in a U-shaped manner with two parallel limbs (221), characterized in that the cross member (22) is designed as a continuously planar, one-piece sheet metal blank, wherein the legs (221) engage around the side cheeks (21) from the outside and are welded to the side cheeks (21).Steering column according to Claim 1, characterized in that fastening elements (23) protruding outwards are attached to the side cheeks (21), said fastening elements each having a planar fastening portion (231) arranged transversely with respect to the side cheek (21) and with respect to the crossmember (22).Steering column according to Claim 2, characterized in that the limbs (221) of the cross members (22) are welded to the fastening elements (23) in the fastening section (231).Steering column according to Claim 2 or 3, characterized in that a fastening element (23) is designed as a U profile.Steering column according to one of the preceding claims, characterized in that the side cheeks (21) have, in a front end section, a transversely continuous bearing bore (25), in which a pivot axis (26) of the actuating unit (3) can be accommodated.Steering column according to one of the preceding claims, characterized in that the side cheeks (21) have, in a rear end section, a height-adjusting slot (27) which extends transversely with respect to the longitudinal direction (L).Steering column according to Claims 5 and 6, characterized in that at least two cross members (22) are arranged at a distance from one another between the bearing bore (25) and the height-adjusting slot (27).Steering column according to one of the preceding claims, characterized in that the supporting unit (2) is formed from sheet steel.Steering column according to one of the preceding claims, characterized in that the adjusting unit (3) has a jacket unit (31) in which a steering spindle (32) is mounted rotatably about its longitudinal axis.Steering column according to one of the preceding claims, characterized in that the adjusting unit (3) is designed to be longitudinally adjustable.Steering column according to one of the preceding claims, characterized in that an energy absorption device (6) is arranged between the support unit (2) and the adjusting unit (3).

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