BALL JOINT FOR A VEHICLE WITH A TILT ANGLE MEASURING DEVICE

Abstract

A ball joint (1) for a vehicle, with a housing (2) and a ball stud (3) that extends in an axial direction (A) and includes a joint ball (4) which, with its joint ball (4), is fitted into and can pivot in the housing (2) and which extends outward through an opening (8) of the housing (2). At least one sensor (6) serves to detect a tilt angle (a) between the ball stud (3) and the housing (2). The joint ball (4) has a flattened area (5) and the at least one sensor (6) is a distance sensor arranged on a wall (7) of the housing (2), opposite the flattened area (5) of the joint ball (4), for detecting a distance (d) from the flattened area (5) and, from the detected distance (d) from the flattened area (5), deriving the tilt angle (a).

Claims

1-14. (canceled)

15. A ball joint (1) for a vehicle comprising: a housing (2), a ball stud (3) that extends in an axial direction (A) and comprises a joint ball (4), the ball stud and the joint ball (4) being fitted into and pivotable in the housing (2), and the ball stud extends outward through an opening (8) of the housing (2), and at least one sensor (6) for detecting a tilt angle (a) between the ball stud (3) and the housing (2), wherein the joint ball (4) has a flattened area (5), and the at least one sensor (6) is a distance sensor arranged on a wall (7) of the housing (2), opposite the flattened area (5) of the joint ball (4), for detecting a distance (d) from the flattened area (5), and for deriving the tilt angle () from the detected distance from the flattened area.

16. The ball joint (1) according to claim 15, wherein the flattened area (5) extends essentially perpendicularly to the axial direction (A) of the ball stud (3).

17. The ball joint (1) according to claim 15, wherein the flattened area (5) is a flat plane.

18. The ball joint (1) according to claim 15, wherein the flattened area (5) is substantially a circular surface.

19. The ball joint (1) according to claim 15, wherein the at least one sensor (6) determines the distance (d) on a basis of at least one of an inductive, a capacitative, and an optical measurement method.

20. The ball joint (1) according to claim 15, wherein the at least one sensor (6) is arranged on the wall (7) of the housing (2) symmetrically in relation to a specified pivoting axis (10) of the ball joint (1) so that when the tilt angle (), between the housing (2) and the ball stud (3), is zero degrees, the at least one sensor (6) determines the distance (d) relative to a defined diameter (11) of the flattened area (5) which is parallel to the specified pivoting axis (10).

21. The ball joint (1) according to claim 15, wherein the at least one sensor (6) is arranged on the wall (7) of the housing (2) such that when the tilt angle (), between the housing (2) and the ball stud (3), is zero degrees, the at least one sensor (6) is opposite a center point (9) of the flattened area (5) and so determines the distance (d) from the center point (9).

22. The ball joint (1) according to claim 15, wherein the ball joint (1) comprises an evaluation unit (15) which serves to determine the tilt angle () based on a distance value that corresponds to the detected distance (d).

23. The ball joint (1) according to claim 15, wherein the at least one sensor (6) is arranged on the wall (7) of the housing (2) asymmetrically in relation to a specified pivoting axis (10) of the ball joint (1) such that when the tilt angle (), between the housing (2) and the ball stud (3), is zero degrees, the at least one sensor (6) detects the distance (d) relative to a defined chord (12) of the flattened area (5) parallel to the specified pivoting axis (10), such that the chord (12) does not correspond to any diameter (11) of the flattened area (5).

24. The ball joint (1) according to claim 15, wherein a first sensor (6a) and a second sensor (6b) are arranged asymmetrically in relation to a specified pivoting axis (10) of the ball joint (1) so that when the tilt angle (), between the housing (2) and the ball stud (3), is zero degrees, the first sensor (6a) detects a first distance (d.sub.a) from a first chord (19) of the flattened area (5) and the second sensor (6b) detects a second distance (d.sub.b) from a second chord (12) of the flattened area (5), the first chord (19) and the second chord (12) extend parallel to one another and parallel to a diameter (11) of the flattened area (5), the first chord (19) extends in a first partial zone (Ta) of the flattened area (5) and the second chord (12) extends in a second partial zone (Tb) of the flattened area (5), and the first partial zone (Ta) and the second partial zone (Tb) are separated from one another by the diameter (11) of the flattened area (5).

25. The ball joint (1) according to claim 23, wherein the ball joint (1) comprises an evaluation unit (15) which serves to determine the tilt angle () with reference to first and second distance values (d.sub.a, d.sub.b) that correspond to the detected first and the second distances (d.sub.a, d.sub.b), and the evaluation unit (15) subtracts the first distance value (d.sub.a) from the second distance value (d.sub.b).

26. The ball joint (1) according to claim 15, wherein at least two sensors (6) are arranged on the wall (7) of the housing (2), the at least two sensors (6) serve to determine the tilt angle () between the ball stud (3) and the housing (2) in relation to two pivoting directions (10a, 10b) which are different from one another.

27. A device comprising: an evaluation unit (15) and a ball joint (1) for a vehicle, the ball joint having a housing (2) and a ball stud (3) extending in an axial direction (A) and comprising a joint ball (4), the ball stud and the joint ball (4) being fitted into and pivotable in the housing (2), the ball stud extending outward through an opening (8) of the housing (2), and at least one sensor (6) for detecting a tilt angle () between the ball stud (3) and the housing (2), wherein the joint ball (4) has a flattened area (5), the at least one sensor (6) is a distance sensor arranged on a wall (7) of the housing (2) opposite the flattened area (5) of the joint ball (4) for detecting a distance (d) from the flattened area (5) and, from the distance from the flattened area, deriving the tilt angle (), the device comprises a communication path (16) that connects the evaluation unit (15) and the ball joint (1), and the evaluation unit (15) serves to determine the tilt angle () with reference to a distance value (d) that corresponds to the detected distance (d).

28. The device comprising an evaluation unit (15) and a ball joint (1) according to claim 27, wherein the device comprises the communication path (16) that connects the evaluation unit (15) and the ball joint (1), and the evaluation unit (15) serves to determine the tilt angle () with reference to first and second distance values (d.sub.a, d.sub.b) that correspond to detected first and second distances (d.sub.a, d.sub.b), and the evaluation unit (15) is designed to subtract the first distance value (d.sub.a) from the second distance value (d.sub.b).

29. A ball joint for a vehicle, the ball joint comprising: a housing and a ball stud, the ball stud having a joint ball that is pivotably mounted within the housing, the ball stud extending in an axial direction through an opening in the housing, and the joint ball having a flattened area; at least one sensor being a distance sensor for detecting distance, the at least one sensor being mounted on a housing wall within the housing and opposite from the flattened area of the joint ball, and the at least one sensor detecting a distance between the at least one sensor and the flattened area of the joint ball; and an evaluation unit being connected to the at least one sensor, the evaluation unit determining a tilt angle of the ball stud, relative to the housing, based on the detected distance between the at least one sensor and the flattened area of the joint ball.

30. The ball joint according to claim 29, wherein the at least one sensor being mounted on the housing wall within the housing such that a change in the distance between the at least one sensor and the flattened area of the joint ball corresponds to a change of the tilt angle of the ball stud, relative to the housing, as the ball stud pivots relative to the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Below, the invention is explained in more detail with reference to the following figures, which show:

[0023] FIGS. 1 a,1 b: A schematic representation of a first embodiment of a ball joint, and a graphical representation of the relationship between distance and tilt angle in the embodiment shown in FIG. 1a;

[0024] FIGS. 2a, 2b: A schematic representation of a second embodiment of a ball joint, and a graphical representation of the relationship between distance and tilt angle in the embodiment shown in FIG. 2a;

[0025] FIGS. 3a, 3b: A schematic representation of a third embodiment of a ball joint, and a graphical representation of the relationship between distance and tilt angle in the embodiment shown in FIG. 3a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] FIG. 1a shows a ball joint 1 with a housing 2 and a ball stud 3. The ball stud 3 has a joint ball 4 and the joint ball 4 has a flattened area 5. Opposite this flattened area 5 is arranged a sensor 6 on the housing wall 7. The sensor 6 is a distance sensor. The ball stud 3 extends out of the housing 2 in an axial direction A through an opening 8. The ball joint 1 is shown in three different positions L, M and N. In the first position L there is a negative tilt angle between the ball stud 3 and the housing 2. In the second position M the tilt angle between the ball stud 3 and the housing 2 is 0 degrees, and in the third position N there is a positive tilt angle + between the ball stud 3 and the housing 2. The axial direction A of the ball stud 3 is in each case indicated by a straight line A. When the tilt angle between the ball stud 3 and the housing 2 is 0 degrees, as shown in the second position M in FIG. 1a, it is easy to see that the sensor 6 is positioned directly opposite a center point 9 of the flattened area 5.

[0027] FIG. 1b shows in graphical form the relationship between the distance d and the tilt angle . When the tilt angle is 0 degrees, the distance d between the sensor 6 and the flattened area 5 is plainly a maximum. When the ball stud 3 pivots to one side or the other, the distance d between the flattened are 5 and the sensor 6 decreases. However, as can be seen in FIG. 1b it is not possible to distinguish between positive and negative angles. In other words, with a particular measured distance d the ball joint 1 cannot carry out any specific assignment but the ball joint 1 can only deliver an absolute value || of the tilt angle.

[0028] FIG. 2a shows a schematic representation of a second embodiment of a ball joint 1. Here too, as in FIG. 1a, three positions L, M, N of the ball stud 3 relative to the housing 2 are shown. The essential difference from the embodiment shown in FIG. 1a is that the sensor 6 is arranged asymmetrically on the wall 7 of the housing 2. This asymmetry is relative to a diameter 11 of the flattened area 5, which can be defined with reference to the pivoting axis 10. The diameter 11, which is parallel to the pivoting axis 10, is taken as a line of reference which divides the flattened area 5 into two halves. In FIG. 2a the sensor 6, which is positioned asymmetrically on the housing wall 7, detects the distance d relative to a chord 12 of the flattened area 5 when the tilt angle between the ball stud 3 and the housing 2 is zero degrees. Thus, the sensor detects the distance d between the housing wall 7 and a point in a given half of the flattened area 5.

[0029] FIG. 2b shows a graphical representation of the functional relationship between the distance d and the tilt angle of the embodiment shown in FIG. 2a. In this case it should be recognized that over a specified range of movement 13 of the ball stud 3 a clear association between the distance d and the tilt angle is possible. However, there is another range of movement 14 within which this clear association is not apparent. Moreover, the functional relationship is not linear.

[0030] FIG. 3a shows a schematic representation of a third embodiment of a ball joint 1. In FIG. 3a the ball joint 1 is shown with a housing 2, a ball stud 3, the joint ball 4 and a sensor 6. As in FIGS. 1a and 2a the joint ball 4 has a flattened area 5, and at least one sensor 6 is arranged on a wall 7 of the housing 2 opposite the flattened area 5. In FIG. 3a two sensors 6a and 6b are shown. As in FIG. 2a these two sensors 6a, 6b are arranged asymmetrically. The asymmetry is in relation to the longitudinal axis A of the ball stud 3 when the ball stud 3 is tilted by 0 degrees relative to the housing 2. However, the asymmetry can also be in relation to a diameter 11 of the flattened area 5, the diameter 11 extending parallel to the pivoting axis 10 of the ball joint 1.

[0031] As shown in FIG. 3b, there is a functional relationship between the distance d and the tilt angle for each of the sensors 6a, 6b. By virtue of that functional relationship a clear association between distance d and tilt angle is possible over a specified free range of movement (between and +) of the ball stud 3. With the use of two sensors 6a, 6b as shown in FIG. 3a, it is possible to cover the full range of movement ( to +) of the ball stud 3 with clear functional relationships. It is also possible, as shown in FIG. 3b, to derive a linear functional relationship from the individual functional relationships of the two sensors 6a, 6b. In this case, that can be done, for example, by subtracting the distance d.sub.a detected by a first sensor 6a from the distance d.sub.b detected by a second sensor 6b. This gives a linear functional relationship between the distance measurement values d.sub.a, d.sub.b and the tilt angle . In general, the distance sensors 6a, 6b can use various measurement principles. In particular, inductive measurement methods, capacitative measurement methods and/or optical measurement methods can be used. The sensors 6a, 6b detect the distance d and transmit a measurement value to an evaluation unit 15. The evaluation unit 15 accepts this distance value or measurement value as an input, processes the measurement value in accordance with the specifications of an algorithm and emits a value that corresponds to the tilt angle between the ball stud 3 and the housing 2. The evaluation unit 15 can either be arranged on the ball joint 1 itself, as shown in the first position L in FIG. 3a, or a communication path 16 to an external evaluation unit 15 can be provided. For example a connection 17 to a CAN bus can be provided and the evaluation unit 15 can be arranged on a main control system 18 of the vehicle (see the third position N in FIG. 3a).

INDEXES

[0032] 1 Ball joint [0033] 2 Housing [0034] 3 Ball stud [0035] 4 Joint ball [0036] 5 Flattened area [0037] 6 Sensor [0038] 7 Wall of the housing [0039] 8 Opening in the housing [0040] 9 Center point of the flattened area [0041] 10 Pivoting axis [0042] 11 Diameter [0043] 12 (Second) chord [0044] 13 First range of movement [0045] 14 Second range of movement [0046] 15 Evaluation unit [0047] 16 Communication path [0048] 17 Connection [0049] 18 Central control system of a vehicle [0050] 19 First chord [0051] Tilt angle [0052] d Distance or gap [0053] A Axial direction of the ball stud