CLAMPING APPARATUS FOR A STEERING COLUMN AND STEERING COLUMN FOR A MOTOR VEHICLE

Abstract

A clamping apparatus may include a stroke-generating disk that is rotatable about a clamping axis and is connected via a first stroke-generating gearing and a second stroke-generating gearing to a pressure disk, which is stationary relative to the rotation of the stroke-generating disk. The first stroke-generating gearing converts a relative rotation of the stroke-generating disk in a first actuating angle range in the clamping direction into a first axial stroke relative to the pressure disk. The second stroke-generating gearing converts a further rotation of the stroke-generating disk following the first actuating angle range in a second actuating angle range into a second axial stroke between the stroke-generating disk and the pressure disk. At least one of the stroke-generating gearings is a tilting pin gearing, with at least one tilting pin supported in the direction of its pin axis between corresponding bearing points on the stroke-generating disk and the pressure disk.

Claims

1.-13. (canceled)

14. A clamping apparatus for a steering column, the clamping apparatus comprising: a stroke-generating disk that is rotatable about a clamping axis and is connected to a pressure disk via a first stroke-generating gearing and a second stroke-generating gearing, with the pressure disk being stationary relative to rotation of the stroke-generating disk, wherein the first stroke-generating gearing is configured to convert a relative rotation of the stroke-generating disk in a first actuating angle range in a clamping direction into a first axial stroke relative to the pressure disk, wherein the second stroke-generating gearing is configured to convert further rotation of the stroke-generating disk following the first actuating angle range in a second actuating angle range into a second axial stroke between the stroke-generating disk and the pressure disk, wherein at least one of the first or second stroke-generating gearings is a tilting pin gearing with a tilting pin that is supported in a direction of a pin axis between corresponding bearing points on the stroke-generating disk and the pressure disk.

15. The clamping apparatus of claim 14 wherein the second stroke-generating gearing is a tilting pin gearing.

16. The clamping apparatus of claim 14 wherein either the first stroke-generating gearing is the tilting pin gearing and has a larger transmission ratio than the second stroke-generating gearing, or the second stroke-generating gearing is the tilting pin gearing and has a larger transmission ratio than the first stroke-generating gearing.

17. The clamping apparatus of claim 14 wherein the stroke-generating disk is attached to and rotates with a drive element.

18. The clamping apparatus of claim 14 wherein the stroke-generating disk is rotatable with a clamping bolt about the clamping axis.

19. The clamping apparatus of claim 14 wherein the first and second stroke-generating gearings are coaxial.

20. The clamping apparatus of claim 14 wherein the bearing points have bearing pockets molded in a recessed manner into at least one of the stroke-generating disk or the pressure disk.

21. The clamping apparatus of claim 14 comprising a positioning element configured for defined positioning of the tilting pin relative to at least one of the stroke-generating disk or the pressure disk.

22. The clamping apparatus of claim 21 wherein the positioning element comprises a spring element that loads the tilting pin resiliently against at least one of the stroke-generating disk or the pressure disk.

23. The clamping apparatus of claim 14 wherein the tilting pin gearing has a stable clamping position in which the stroke-generating disk and the pressure disk are rotated counter to each other beyond a maximum stroke of the tilting pin gearing, wherein in the stable clamping position stop means strike against one another in a circumferential direction and block further rotation beyond the stable clamping position.

24. The clamping apparatus of claim 14 wherein the first stroke-generating gearing is a cam gearing, wherein cams on the stroke-generating disk are directed axially against a complementary slotted guide mechanism on the pressure disk.

25. The clamping apparatus of claim 14 wherein the first and second stroke-generating gearings are tilting pin gearings.

26. A steering column comprising: a supporting unit; an actuating unit; and the clamping apparatus of claim 14, wherein the clamping apparatus is operatively connected to the supporting unit and to the actuating unit and is configured to exert a clamping force for bracing the supporting unit and the actuating unit.

Description

DESCRIPTION OF THE DRAWINGS

[0037] Advantageous embodiments of the invention will be explained in more detail below with reference to the drawings, in which, in detail:

[0038] FIG. 1 shows a steering column with a clamping apparatus according to the invention in a schematic perspective illustration,

[0039] FIG. 2 shows the steering column according to FIG. 1 with a schematically exploded illustration of the clamping apparatus,

[0040] FIG. 3 shows an enlarged exploded illustration of a clamping apparatus according to the invention,

[0041] FIG. 4 shows the stroke-generating disk of the clamping apparatus according to FIG. 3,

[0042] FIG. 5 shows the pressure disk of the clamping apparatus according to FIG. 3,

[0043] FIG. 6 shows the clamping apparatus according to FIG. 3 in a perspective view in the assembled state,

[0044] FIG. 7 shows the clamping apparatus according to FIGS. 2 to 6 in a release position in a lateral view,

[0045] FIG. 8 shows the clamping apparatus from FIG. 7 in an intermediate position,

[0046] FIG. 9 shows the clamping apparatus from FIGS. 7 and 8 at the maximum stroke in the yield position of the tilting pins,

[0047] FIG. 9a shows a detailed view of the tilting pin mounting from FIG. 9,

[0048] FIG. 10 shows the clamping apparatus from FIGS. 7, 8 and 9 in a stable clamping position,

[0049] FIG. 11 shows a clamping apparatus according to FIGS. 2 to 10 with an additional positioning element in an illustration as in FIG. 3,

[0050] FIG. 12 shows a partial sectional view of the clamping apparatus according to FIG. 11,

[0051] FIG. 13 shows a clamping apparatus in an alternative embodiment.

EMBODIMENTS OF THE INVENTION

[0052] In the various figures, identical parts are always provided with the same reference signs and will therefore generally also only be named or mentioned once in each case.

[0053] FIGS. 1 and 2 show, in a perspective view obliquely from the rear right (FIG. 1) and rear left, partially in an exploded illustration (FIG. 2)—with respect to the direction of travel of a vehicle, not shown—a steering column 1 which has a supporting unit 2. For connection to the body of a motor vehicle, not illustrated, the supporting unit 2 comprises fastening means 21. Mutually opposite side cheeks 22 and 23 extend from the supporting unit 2 and protrude downward in a fork-like manner from the supporting unit 2.

[0054] An actuating unit 3 is arranged between the side cheeks 22 and 23, with a steering spindle 31 which is mounted in an inner casing tube 32 so as to be rotatable about a longitudinal axis L. The casing tube 32 accommodated in an outer casing unit 33 so as to be longitudinally displaceable in the direction of the longitudinal axis L, as indicated schematically with a double arrow. At the rear end with respect to the direction of travel, the steering spindle has a fastening portion 34 for attaching a steering wheel, not illustrated, for rotation therewith.

[0055] The casing unit 33 is mounted on the supporting unit 2 so as to be pivotable about a pivot axis 24 which lies transversely with respect to the longitudinal axis L. The actuating unit 3 can thereby be moved to and fro in the vertical direction H relative to the supporting unit in order to adjust the height position of the steering wheel between the side cheeks 22 and 23, as indicated by a double arrow.

[0056] A clamping apparatus 4 is designed in order either to brace the actuating unit 3 in the fixing position relative to the supporting unit 2 or, in the enabling position, to permit an adjustment in the direction of the longitudinal axis L and/or in the vertical direction H.

[0057] The casing unit 33 has a slot 39 which extends in the direction of the longitudinal axis and forms a clip. In the fixing position, the width of the slot 39 is smaller than the width of the slot 39 in the enabling position, and therefore the casing tube 32 is clamped in the casing unit in the fixing position and is thus non-displaceable in relation to the casing unit 33 during normal operation.

[0058] The clamping apparatus 4 has a clamping bolt 41 which extends on a clamping axis S transversely with respect to the longitudinal axis L through elongated holes 25 in the mutually opposite side cheeks 22 and 23. The elongated holes 25 are extended in the vertical direction H. An actuating lever 42 is attached to one end of the clamping bolt 41 for rotation therewith while the other end is tightly mounted on the side cheek 23 in an abutment 43 so as to be rotatable.

[0059] The clamping apparatus 4 has a two-stage stroke-generating gearing 5 in which a first and a second stroke-generating gearing according to the invention are integrated. The stroke-generating gearing 5 is illustrated in detail in FIGS. 3 to 12 below and comprises a stroke-generating disk 6, a pressure disk 7 (slotted guide disk) and, in the example shown, three tilting pins 8.

[0060] The stroke-generating disk 6 and the pressure disk 7 are arranged on the clamping bolt 41 coaxially with respect to the clamping axis S, wherein the stroke-generating disk 6 is connected to the clamping bolt 7 for rotation therewith. The pressure disk 7 is secured on the outside of the side cheek 22 in a stationary manner with respect to rotation. For this purpose, the pressure disk 7 has a projection 77 which engages in the one elongated hole 25 of the side cheek and thus limits or prevents rotation of the pressure disk 7 about the clamping axis S.

[0061] For the explanations below, the direction of rotation of the clamping bolt 41 and of the stroke-generating disk 6 relative to the pressure disk 7 for fixing purposes is defined as rotation counterclockwise, in a view from the outside of the stroke-generating disk 6, as indicated in FIG. 2. This direction of rotation of the fixing movement or fixing rotation is adopted and indicated schematically in the figures below.

[0062] The end side of the stroke-generating disk 6 facing the pressure disk 7 has three axially protruding cams 61 which extend radially in the form of segments of a circle. The cams 61 each have a sliding slope 62 on their side surface facing in the direction of rotation during a fixing rotation (counterclockwise). The sliding slope 62 forms a ramp-shaped sliding surface rising in the circumferential direction.

[0063] The pressure disk 7 is designed as a slotted guide disk, with slotted guide tracks which correspond to the cams 61 of the stroke-generating disk 6 and, beginning in each case in a valley 71 molded in axially, merge in the circumferential direction, with the direction of rotation during a fixing rotation, rising in a wedge-shaped manner into sliding slopes 72. In each case one valley 71 is designed as an axially molded depression which corresponds to in each case one cam 61.

[0064] The cams 61 together with the valleys 71 form a first stroke-generating gearing, namely a cam gearing, as is known in principle from the prior art.

[0065] FIG. 7 shows how the cams 61 in the release position axially enter the valleys 71. The sliding slopes 62 and 72 at least partially lie against each other in the circumferential direction. The stroke-generating gearing 5 is in a release position in which the stroke-generating disk 6 and the pressure disk 7, as measured over their mutually averted outer sides, are at an axial distance h1 which can also be referred to as an idle or release stroke.

[0066] If the stroke-generating disk 6 is rotated from the release position shown in FIG. 7 by a first actuating angle range in the fixing direction counterclockwise relative to the pressure disk 7, as indicated with the arrow, the sliding slopes 62 and 72 slide onto each other in the circumferential direction and, by means of their wedge shape, bring about a first stroke which is associated with an increase in the axial distance h1 to the distance h2, as shown in FIG. 8. The difference (h2-h1) accordingly corresponds to the first stroke.

[0067] A second stroke-generating gearing designed according to the invention as a tilting pin gearing has the tilting pins 8 which are arranged between the stroke-generating disk 6 and the pressure disk 7, as will be explained below.

[0068] Each tilting pin 8 is of cylindrical pin-shaped design and extends along its tilting pin axis K. At both ends has of a tilting pin 8, hemispherically rounded ball heads 81 are formed. With the one end, a tilting pin 8 is in each case mounted in a bearing pocket 73 which is formed in the circumferential direction between two valleys 71 in the pressure disk 7. The bearing pocket 73 is shaped as a joint socket corresponding to the ball head 81, in order to form a two-axis tilting joint. In the region of the ball head 81, the bearing pocket 83 preferably has a gothic cross-sectional profile with two circular arcs 731 which converge in a pointed manner at a center point M and which have a larger radius than the ball head 81, as can be seen in the enlarged view of FIG. 9a. As a result, the ball head lies in the bearing pocket 73 only on an annularly encircling bearing surface 82. It can also be provided that the bearing pocket 73 has a spherical cross section.

[0069] The ball head 81 is supported radially, axially and in the circumferential direction in the bearing pocket 73.

[0070] The bearing pocket 73 has a supporting surface 74 on its side lying opposite the fixing direction, and a counter surface 75 on its side lying at the front in the fixing direction.

[0071] In the release position shown in FIG. 7, the tilting pin 8 is maximally inclined toward the clamping axis S, and lies in its inoperative position against the supporting surface 74.

[0072] A bearing pocket 63 is formed in the stroke-generating disk 6, in each case in the region of a cam 61, said bearing pocket corresponding in each case to the ball head 81 of a tilting pin 8, the ball head facing away from the pressure disk 7. The bearing pocket 63 can preferably have a gothic cross-sectional profile, analogously to the cross section of the bearing pocket 73 according to FIG. 9a.

[0073] In the state shown in FIG. 8, the tilting pin 8 engages with its ball head 81 in the bearing pocket 63 such that it is supported radially, axially and in the circumferential direction therein during the further rotation in the fixing direction. The tilting pin gearing is thereby activated.

[0074] If the stroke-generating disk 6 is rotated from the intermediate position shown in FIG. 8 further in the fixing direction counterclockwise toward the pressure disk 7, the tilting pins 8, supported between the bearing pockets 73 and 63, are set upright and tilted, as seen from the end side of the pressure disk 7. The sliding slopes 62 and 72 are no longer in contact with each other here, and therefore the first stroke-generating gearing is inactive. The further second stroke takes place only by means of the tilting pin gearing, until the tilting pins 8 are maximally set upright and the clamping axis S lies parallel to the tilting pin axis X, as shown in FIG. 9. The maximum stroke h3 between the outer sides of the stroke-generating disk 6 and the pressure disk 7 is then reached. The second stroke caused by the tilting pin gearing has the value of the difference (h3-h2). The second stroke is preferably smaller than the first stroke.

[0075] The transition between the first stroke and second stroke preferably takes place in such a manner that, in a stroke actuating angle diagram, the pitch of the stroke can be differentiated at each point. In other words, the transmission ratio of the first and second stroke-generating gearing should not have an abrupt change in the transmission ratio at the transition between the stroke-generating gearings. By means of this measure, the operating comfort can be improved further since the transition between the first and second stroke-generating gearing can only be felt only very slightly, if at all.

[0076] In FIG. 9, the tilting pins 8 are in the dead center position or yield position. The stroke-generating disk 6 can be rotated from the yield position of the tilting pins 8 according to FIG. 9 further in the fixing direction until the stable clamping position shown in FIG. 10 is adopted, in which cams 61 strike against stop projections 78 of the pressure disk 7 and thereby block the further relative rotation. A stable clamping position is thereby produced in which the clamping force reacting axially from the outside on the stroke-generating disk 6 and the pressure disk 7 loads the tilting pin 8 and presses the cams 61 against the respective stop projections, thus preventing an automatic release counter to the fixing direction. The stroke h4 is somewhat smaller than the stroke h3, but the stroke h4 is greater than the stroke h2. The angle between the tilting pin axis K and the clamping axis in the clamping position is preferably greater than 0°, particularly preferably greater than 2°. It is particularly advantageous if the angle is smaller than 5° since too great a loss of clamping force can thereby be avoided.

[0077] FIGS. 11 and 12 show a development of the stroke-generating gearing 5 which additionally has positioning elements in the form of spring elements 9 which are attached to an annular spring support 91. The spring support 91 can coaxially surround the stroke-generating disk 6 and the pressure disk 7 and can be axially fixed relative thereto. The sectional illustration in FIG. 12 shows the release position as in FIG. 7. The tilting pins 8 with their ball heads 81 are located on one side in bearing engagement with the bearing pockets 73 of the pressure disk, but not with the bearing pocket 63 of the stroke-generating disk. By means of the spring element 9 protruding radially inwards from the spring support 91, the tilting pin 8 is pressed resiliently into the bearing pocket 73, with the tilting pin lying against the supporting surface 74. The tilting pin is thereby held with respect to the pressure disk 7 in a defined inoperative position. During the transition of the stroke movement between the first stroke-generating gearing, the cam gearing and the tilting pin gearing, it is thereby ensured that the tilting pins 8 enter with the ball head securely and in a defined manner into the bearing pockets 63 in the stroke-generating disk 6 and are mounted.

[0078] The spring elements 9 can preferably be formed integrally with the spring support 91, for example as a plastics injection molded part, or as a sheet-metal shaped part.

[0079] By means of the first stroke-generating gearing, which is formed from the cams 61 in interaction with the valleys 71 of the cam track, together with the second stroke-generating gearing, which is formed as a tilting pin gearing by means of the tilting pins 8 interacting with the stroke-generating disk 6 and the pressure disk 7, a two-stage clamping apparatus can be realized. The tilting pin gearing preferably has a greater transmission ratio than the first stroke-generating gearing. This means that, when an actuation is provided, the constant rotation of the stroke-generating disk 6 in the fixing direction brings about the clamping movement from h1 to h2 with a greater stroke, but with a smaller clamping force, and from h2 to h3 by the tilting pin gearing with a smaller stroke, but with a greater clamping force.

[0080] The arrangement of the tilting pins 8 in the region of the cams 61 and the valleys 71 is particularly compact.

[0081] FIG. 13 illustrates a clamping device in an alternative variant embodiment. The clamping apparatus comprises a stroke-generating disk 6 which is rotatable about a clamping axis S and is connected via a first stroke-generating gearing, a second stroke-generating gearing, a third stroke-generating gearing and a fourth stroke-generating gearing to a pressure disk 7 which is stationary relative to the rotation of the stroke-generating disk 6, wherein an intermediate disk 600 is arranged between the stroke-generating disk 6 and the pressure disk 7 and is rotatable in relation to the stroke-generating disk 6 and the pressure disk 7, wherein the first and second stroke-generating gearings are arranged between the stroke-generating disk 6 and the intermediate disk 600, and the third and fourth stroke-generating gearings are arranged between the intermediate disk 600 and the pressure disk 7, wherein the first stroke-generating gearing is designed to convert a relative rotation of the stroke-generating disk 6 in a first actuating angle range in the clamping direction into a first axial stroke relative to the pressure disk 7, and the second stroke-generating gearing is designed to convert a further rotation of the stroke-generating disk 6 following the first actuating angle range in a second actuating angle range into a second axial stroke between the stroke-generating disk 6 and the pressure disk 7, and the third stroke-generating gearing is designed to convert a further rotation of the stroke-generating disk 6 following the second actuating angle range in a third actuating angle range into a third axial stroke between the stroke-generating disk 6 and the pressure disk 7, and the fourth stroke-generating gearing is designed to convert a further rotation of the stroke-generating disk 6 following the third actuating angle range in a fourth actuating angle range into a fourth axial stroke between the stroke-actuating disk 6 and the pressure disk 7. According to the invention, at least one of the stroke-generating gearings is designed as a tilting pin gearing, with at least one tilting pin 8, 800 which is supported in the direction of its pin axis K, K1 between corresponding bearing points 63, 73, 630, 730 on the stroke-generating disk 6 and the intermediate disk, or on the intermediate disk 600 and the pressure disk 7.

[0082] As illustrated in FIG. 13, the second stroke-generating gearing and the fourth stroke-generating gearing are designed as tilting pin gearings. The first and third stroke-generating gearings are designed as cam gearings. Four stroke-generating gearings are thus connected in series, wherein the stroke-generating disk 6 is rotatable in relation to the intermediate disk until they stroke against each other and thus are rotated synchronously in relation to the pressure disk 7 in order to transfer the clamping device from the enabling position, as illustrated in FIG. 13, into the fixing position. It can be provided that the maximum strokes of the individual stroke-generating gearings differ from one another, or the strokes of the first and third stroke-generating gearings are identical. The strokes of the tilting pin gearings are preferably always smaller than the strokes of the remaining stroke-generating gearings. The advantage of this arrangement is that a compact clamping device with a large stroke can be provided.

[0083] The arrangement of FIG. 13 can likewise be equipped with a spring support comprising a spring which hold and/or prestress the tilting pins in a defined position.

[0084] It is likewise conceivable and possible for three of the stroke-generating gearings to be designed as tilting pin gearings, or for all four stroke-generating gearings to be designed as tilting pin gearings.