STEERING COLUMN FOR A MOTOR VEHICLE AND METHOD FOR PRODUCING A STEERING COLUMN

Abstract

A steering column includes a jacket tube with a clamping section with a slot extending longitudinally. A clamping collar has transversely opposed legs are interconnected via an arcuate section between which the clamping section of the jacket tube is at least partially accommodated. An actuating unit is arranged in the jacket tube, with a steering spindle rotatably mounted therein around the longitudinal axis. A clamp fixes the actuating unit longitudinally relative to the jacket tube and in a release position unclamps the clamping collar and frees the actuating unit longitudinally and presses the legs toward each other transversely to the longitudinal axis in the fixing position. Driver elements are arranged on the jacket tube in opposite edge regions of the slot, and the legs include contact elements which in the fixing position can be pressed against the outer sides of the driver elements.

Claims

1-14. (canceled)

15. A steering column for a motor vehicle, comprising: a jacket unit with a jacket tube, which comprises at least one clamping section with a slot which extends in the direction of a longitudinal axis, a clamping collar, with two legs which lie opposite each other transversely to the longitudinal axis and are interconnected via an arcuate section, and between which the clamping section of the jacket tube is at least partially accommodated, an actuating unit arranged in the jacket tube, with a steering spindle which is rotatably mounted therein around the longitudinal axis, a clamping device, which in a fixing position clamps the clamping collar on the jacket tube, wherein the clamping section is clamped on the actuating unit and fixes the actuating unit in the direction of the longitudinal axis relative to the jacket tube and in a release position unclamps the clamping collar and frees an adjustment of the actuating unit relative to the jacket tube in the direction of the longitudinal axis, wherein the clamping device presses the legs toward each other transversely to the longitudinal axis in the fixing position, wherein driver elements are arranged on the jacket tube in the oppositely disposed edge regions of the slot, and the legs, on their sides facing each other, comprise contact elements which are configured to, in the fixing position, be pressed against the outer sides of the driver elements, facing away from each other, transversely to the longitudinal axis.

16. The steering column of claim 15, wherein the driver elements project radially outward from the jacket tube.

17. The steering column of claim 15, wherein at least one of the driver elements is designed as a bend of the jacket tube in at least one section of the edge region of the slot.

18. The steering column of claim 15, wherein at least one of the contact elements projects inward in the circumferential direction from a leg transversely to the longitudinal axis.

19. The steering column of claim 15, wherein at least one of the contact elements is formed on an end region of at least one leg which is bent round toward the jacket tube.

20. The steering column of claim 15, wherein the clamping collar is a sheet metal formed part.

21. The steering column of claim 15, wherein the jacket tube is supported between two side cheeks of a support unit which is configured to be attached to a vehicle body.

22. The steering column of claim 15, wherein the clamping device further comprises a clamping pin which passes through the legs transversely to the longitudinal axis and which is connected to a counter bearing and to a clamping gear, wherein the counter bearing is supported on the outside on the one leg and the clamping gear is supported on the outside on the other leg.

23. The steering column of claim 15, wherein the slot comprises a widened section in the circumferential direction on at least one end.

24. A method for producing a jacket tube for a steering column, which comprises a clamping section with a slot which extends from one end of the jacket tube in the direction of the longitudinal axis, comprising: providing a tube section with a rough inside diameter and a rough outside diameter, introducing a slot into the tube section from one end in the axial direction, wherein the slot has a rough slot width between its oppositely disposed edge regions transversely to the longitudinal extent and has a slot length in the axial direction, bending up the edge regions of the slot radially outward to form driver elements which project outward from the tube section, wherein the slot has a nominal slot width between the driver elements.

25. The method of claim 24, comprising compressing the tube section in the radial direction over a clamping section length to a nominal inside diameter which is smaller than the rough inside diameter.

26. The method of claim 24, wherein for the bending up of the edge regions a forming tool, comprising a mandrel with a radially projecting forming wedge, the width of which corresponds to the nominal slot width, is inserted into the tube section in the axial direction from the end, wherein the forming wedge is moved through the slot.

27. The method of claim 26, wherein the forming tool comprises a sleeve which coaxially encompasses the mandrel, wherein the mandrel has an outside diameter which corresponds to the nominal inside diameter in the clamping section, and the sleeve has an inside diameter which corresponds to the outside diameter of the tube section which within the clamping section length is compressed to the nominal inside diameter.

28. The method of claim 15, comprising introducing a widened section into an end region of the slot with a width in the circumferential direction which is larger than the rough slot width or the nominal slot width.

Description

DESCRIPTION OF THE DRAWINGS

[0053] Advantageous embodiments of the invention are explained in more detail in the following text with reference to the drawings. In detail in the drawings:

[0054] FIG. 1 shows a steering column according to the invention in a perspective view,

[0055] FIG. 2 shows the steering column according to FIG. 1 in a partially exploded view,

[0056] FIG. 3 shows a detailed view of the steering column according to FIG. 2,

[0057] FIG. 4 shows a detailed view according to FIG. 3 in an exploded view,

[0058] FIG. 5 shows a cross sectional view through the steering column according to FIG. 1,

[0059] FIG. 6 shows a cross sectional view through the clamping section of the steering column according to FIG. 1,

[0060] FIG. 7a shows a schematic longitudinal view of a jacket tube in a first production state (jacket tube blank),

[0061] FIG. 7b shows a cross section through the jacket tube according to FIG. 7a,

[0062] FIG. 8a shows a schematic longitudinal view of a jacket tube in a second production state,

[0063] FIG. 8b shows a cross section through the jacket tube according to FIG. 8a,

[0064] FIG. 8c shows a cross section through the forming tool according to FIG. 8a,

[0065] FIG. 9a shows a schematic longitudinal view of a jacket tube in a third production state,

[0066] FIG. 9b shows a cross section through the jacket tube according to FIG. 9a,

[0067] FIG. 10 shows a further schematic longitudinal view of a jacket tube in a production step following the production state according to FIG. 9a,

[0068] FIG. 11 shows a schematic longitudinal view of a jacket tube in a fourth production state.

EMBODIMENTS OF THE INVENTION

[0069] In the various figures, the same parts are always provided with the same designations and as a rule are therefore also named or mentioned only once in each case.

[0070] FIG. 1 shows a steering column 1, which comprises a jacket unit 2 with a jacket tube 21, in which is accommodated an actuating unit 3 with a steering spindle 31 which is rotatably mounted therein around the longitudinal axis 22. A steering wheel, not shown, can be fastened on a rear fastening section 32 with regard to the direction of travel.

[0071] The jacket tube 21, on its end region facing the viewer, comprises a clamping section 23 on which is arranged a clamping collar 4. In the clamping section 23, the jacket tube 21 comprises a slot 7 which extends parallel to the longitudinal axis 22 in the longitudinal direction and is open toward the rear end of the jacket tube 21which is the end facing the viewer in FIGS. 1 to 4.

[0072] A support unit 5, with a support element 51 which can be attached on a vehicle body, not shown, accommodates the jacket tube 21 in the region of the clamping section 23 between two side cheeks 52a and 52b which project from the top transversely to the longitudinal axis 22. The clamping collar 4, which encompasses the clamping section 23 of the jacket tube 21, is located between the side cheeks 52a and 52b. The side cheek 52b comprises a stiffening section 521b so that the side cheek 52b is of a more flexurally rigid design than the side cheek 52a.

[0073] A clamping device 6 comprises a clamping pin 61 which extends through openings 55a and 55b in the side cheeks 52a and 52b transversely to the longitudinal axis 22. Attached to the clamping pin 61 is an operating lever 62 by means of which it can be rotated manually around an axis. The clamping pin 61 is connected to a clamping gear 63 which is designed as a lift gear, for example a cam gear, a wedge gear or a tilting pin gear, and which is supported on the one side cheek 52a on the outside. Via a counter bearing 64 (see FIG. 5), the clamping pin 61 is supported on the other side cheek 52b on the outside on the side facing away from the viewer. If the clamping device 63 is brought into the fixing position by rotary operation of the operating lever 62, the clamping pin 61, by means of the clamping gear 63, is lifted out or drawn out relative to the side cheek 52a and in the process pulls the other side cheek 52b by the clamping force S toward the one side cheek 52a. In this case, the side cheeks 52a and 52b are pressed toward each other by the clamping force S in this way, as indicated in FIG. 2 and FIG. 5 by the force arrows S.

[0074] In the fixing position, the clamping collar 4, and with it the jacket tube 21, are clamped between the side cheeks 52a and 52b in a frictionally engaging manner. As a result of the clamping force S exerted in this case, the actuating unit 3 is also clamped in the clamping section 23 in a frictionally engaging manner, as is explained in more detail further down.

[0075] If the clamping device 6 is brought into a released or disengaged position, the clamping force S which is exerted upon the side cheeks 52a and 52b is relaxed, as a result of which the clamping collar 4 is unclamped and releases the clamping section 23 so that the frictional engagement between jacket tube 21 and actuating unit 3 is released. Consequently, a displacement of the actuating unit 3 in relation to the jacket tube 21 in the longitudinal direction Lparallel to the longitudinal axis 22for adjustment of the steering wheel position is possible.

[0076] On a second support element 53, which can also be attached to the vehicle body, the rear end of the jacket tube 21 is pivotably mounted around a pivot axis 54 lying transversely to the longitudinal axis 22. In the released position of the clamping device 6, the jacket tube 21 can be pivoted around this pivot axis 54, wherein the clamping pin 61 can be moved in the vertical direction H in the slot-like openings 55a and 55b in order to adjust the height position of the steering wheel. In the fixing position, the jacket tube 21 is fixed via the clamping collar 4 on the side cheeks 52a and 52b in a frictionally engaging manner in the adjusted height position.

[0077] FIG. 3 shows a partial view of the jacket tube 21, where the clamping collar 4 encompasses the clamping section 23 which is formed in the rear end region of the jacket tube 21. FIG. 4 shows in the same perspective the clamping collar 4 removed from the clamping section 23 wherein it is shown withdrawn to the rear in the longitudinal direction L.

[0078] It can be seen in FIGS. 3 and 4 how the slot 7 extends over a length j in the longitudinal direction L from the open end of the jacket tube 21, i.e. is open toward this end. In the depicted example, the length j is greater than the length k of the clamping collar 4, which corresponds to the length of the clamping section 23. The clamping collar 4 has two legs 41a and 41b which lie opposite each other on both sides of the slot 7 and are interconnected via an arcuate section 42. In the region of their free ends, the legs 41a, 41b comprise an opening 43 through which passes the clamping pin 61 transversely to the longitudinal axis 22 in the assembled state according to FIG. 1, as can be gathered from the cross-sectional view of FIG. 5.

[0079] Formed along the slot 7, along the oppositely disposed slot edges which extend in the longitudinal direction, are driver elements 71 according to the invention, which driver elements in the depicted example are formed by wall regions of the jacket tube 21 which are radially bent up outward by approximately 90, as FIG. 6 shows. The driver elements 71 have inner surfaces 72 opposite each other in the circumferential directioni.e. with regard to the circumference of the clamping section 23 in the tangential directionand outer surfaces, which form contact surfaces 73, facing away from each other in the circumferential direction. The contact surfaces 73 and the inner surfaces 72 lie parallel to each other and to a longitudinal plane in which lies the longitudinal axis 22 and which extends radially outward through the middle of the slot 7. The driver element 71 comprises a cutout 711 through which the clamping pin 61 extends. In the case of a collision of the vehicle due to an accident, the possibility arises of the clamping pin 61 being supported on the edge of the driver element 71 in the direction of the longitudinal axis 22.

[0080] The free ends of the legs 41a and 41b are inwardly bent round for forming contact elements 44 which project up to the edge regions of the slot 7. There, the contact elements come up against the radially projecting contact surfaces 73 of the driver elements 71 in the circumferential direction, i.e. in the tangential direction with regard to the outer circumference of the jacket tube 21 in the clamping section 23.

[0081] If the clamping device 6 is brought into the fixing position, the clamping force S is applied from the outside to the legs 41a and 41b of the clamping collar 4 by the clamping pin 61 via the side cheeks 52a and 52b. Owing to the fact that the legs are supported by their contact elements 44 in the circumferential direction against the outer contact surfaces 73 of the driver elements 71, the driver elements 71 are pressed toward each other with the clamping force S by the oppositely disposed edges of the slot 7. In other words, the clamping force S works toward a reduction of the width of the slot 7, wherein the clamping force S is introduced into the circumference of the jacket tube 21 in the clamping section. In this way, according to the invention a force introduction, which is uniform over the circumference, is carried by the clamping collar 7 into the clamping section 23 which is correspondingly uniformly clamped on the actuating unit 3.

[0082] Arranged on the inner side of the clamping section 23 can be longitudinally extending clamping elements 24 which project radially inward, extend in a segment-like manner over a section of the circumference, are formed for example by radial end formings in the jacket tube 21, and enable a locally adapted force introduction of the clamping force S into the actuating unit 3.

[0083] A method according to the invention for producing a jacket tube 21 is explained in the following text with reference to production states shown schematically in FIG. 7a to FIG. 11.

[0084] First of all, provision is made for a tube section 200, cut to size lengthwise, according to FIGS. 7a and 7b, which comprises a free end 201 and a rough outside diameter Ra and a rough inside diameter Ri.

[0085] Introduced into the tube section 200 from the free end 201, for example by milling, is a slot 700 which in the circumferential direction has a rough slot width bro and in the longitudinal direction a slot length j.

[0086] A forming tool 900, which has a mandrel 901 with a diameter Rs which corresponds to the diameter of the actuating unit 3, is positioned in front of the free end 201. Projecting radially from the mandrel 901 is a forming wedge 902 which has a width B measured in the circumferential direction. The width B coincides with the width of the finished slot 7, i.e. in FIG. 6 coincides with the gap between the inner surfaces 73 of the driver elements 71 in the circumferential direction.

[0087] The mandrel 901 is encompassed coaxially by a sleeve 903 which has an inside diameter Rh.

[0088] The inside diameter Rh of the sleeve 903 is smaller than the rough outside diameter Ra of the tube section: Rh<Ra.

[0089] The rough inside diameter Ri of the tube section 200 is larger than the diameter Rs of the mandrel 901 which corresponds to the diameter of the actuating unit: Ri>Rs.

[0090] The width B of the forming wedge 902 is preferably larger than the rough slot width bro, measured in each case in the circumferential direction: B>bro.

[0091] Starting from the situation shown in FIG. 8a, the forming tool 900 is pressed onto the free end 201 in the axial direction, from right to left in the direction of the arrow in the figures, specifically basically by a length k which corresponds to the length of the clamping collar 4 and which corresponds to the length of the clamping section 23. This is illustrated in FIGS. 9a and 9b.

[0092] By means of the sleeve 903, the tube section 200 is radially compressed to the sleeve inside diameter Rh, wherein the tube section 200 is pressed onto the mandrel 901 and like this acquires an inside diameter Rs. As a result, the clamping section 23 is formed and calibrated to this nominal inside diameter Rs.

[0093] During the previously described diameter calibration between the sleeve 903 and the mandrel 901, the wall of the tube section 200 spreads into the slot 700 in the circumferential direction, reducing the free rough slot width bro. There, the edge regions of the slot come up against the forming wedge 902 which is moved along in the slot 700 in the longitudinal direction. On account of the mandrel 901, which completely fills out the passage cross section of the compressed tube section 23, the referenced edge regions can get out of the way of the forming wedge 902 only radially outwardly. As a result, the edges of the slot 700 are outwardly bent up, forming the driver elements 71 which according to the invention project radially outward from the jacket tube 21 in the region of the clamping section 23. The slot 7 is consequently calibrated between the driver elements 71 to the slot width B corresponding to the width B of the forming wedge.

[0094] The forming tool 900 is then withdrawn from the clamping section 23 of the jacket tube 21, which is shown in FIGS. 10a and 10b.

[0095] In FIG. 11, the slot 7 is finished off by a widened section 74 being introduced on its end facing away from the tube end 201 in the form of a slot section extending in the circumferential direction, introduced for example by machining such as milling or the like. Overall, the slot 7 consequently acquires its final T-shape which reduces the occurrence of undesirable local material stresses during the fixing of the clamping device 6.

LIST OF DESIGNATIONS

[0096] 1 Steering column [0097] 2 Jacket unit [0098] 21 Jacket tube [0099] 22 Longitudinal axis [0100] 23 Clamping section [0101] 24 Clamping element [0102] 3 Actuating element [0103] 31 Steering spindle [0104] 32 Fastening section [0105] 4 Clamping collar [0106] 41a, b Legs [0107] 42 Arcuate section [0108] 43 Opening [0109] 44 Contact elements [0110] 5 Support unit [0111] 51 Support element [0112] 52a, b Side cheek [0113] 53 Support element [0114] 54 Pivot axis [0115] 55a, b Openings [0116] 6 Clamping device [0117] 61 Clamping pin [0118] 62 Clamping lever [0119] 63 Clamping gear [0120] 64 Counter bearing [0121] 7 Slot [0122] 71 Driver elements [0123] 72 Inner surfaces [0124] 73 Contact surfaces [0125] S Clamping force [0126] L Longitudinal direction [0127] j Length of slot [0128] H Vertical direction [0129] k Length of clamping collar/clamping section [0130] 200 Tube section [0131] 201 Free end [0132] 700 Slot [0133] 900 Forming tool [0134] 901 Mandrel [0135] 902 Forming wedge [0136] 903 Sleeve [0137] Ra Rough outside diameter of tube section [0138] Ri Rough inside diameter of tube section [0139] bro Rough slot width [0140] Rs Diameter of mandrel/inside diameter of clamping section [0141] B Width of forming wedge [0142] Rh Inside diameter of sleeve