EP3365571A1

EP3365571A1 - Ball joint for a vehicle with a tilt angle measuring device

Info

Publication number: EP3365571A1
Application number: EP16775642.8A
Authority: EP
Inventors: Michael Klank; Klaus HASKAMP
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 2015-10-23
Filing date: 2016-09-28
Publication date: 2018-08-29
Also published as: CN108138836A; KR20180074722A; JP2019501337A; US20180231051A1; WO2017067766A1; DE102015220757A1

Abstract

The invention relates to a ball joint (1) for a vehicle, comprising a housing (2) and a ball stud (3) extending in an axial direction (A)and comprising a ball joint (4), which is pivotably moveably mounted in the housing (2) with its ball joint (4) and extends out through an opening (8) of the housing (2), and at least one sensor (6) which functions to detect a tilt angle (α) between the ball stud (3) and the housing (2), wherein the ball joint (4) has a flattened area (5), and wherein the at least one sensor (6) is a distance sensor which is arranged on a wall (7) of the housing (2) and lies opposite the flattened area (5) of the ball joint (4) in order to detect a distance (d) with respect to the flattened area (5) and to derive the tilt angle (α) from this.

Description

BALL JOINT FOR A VEHICLE WITH TILTING ANGLE MEASURING DEVICE

The invention relates to a ball joint for a vehicle, comprising a housing and a ball pin extending in an axial direction and comprising a joint ball, which is pivotally mounted with its ball joint in the housing and extending through an opening of the housing, and at least one sensor which serves to detect a tilt angle between the ball stud and the housing.

Ball joints of this type are known from the prior art. For example, the German patent application DE10350640B4 describes a ball joint for a motor vehicle, with a housing having a recess, a ball pin having a pin and a ball joint, which is rotatably and pivotally mounted in the recess of the housing with its ball joint. The pin extends through an opening provided in the housing and a sealing bellows is provided, which is arranged between the housing and the pin. Furthermore, a multi-part measuring arrangement is disclosed which has at least one signal generator and at least one sensor, wherein the measuring arrangement is arranged between the housing, in the region of the journal-side end of the joint ball and the journal-side end of the sealing bellows.

Furthermore, the German patent application DE102010052885A1 discloses a load carrier or bicycle carrier for a motor vehicle, the load carrier having a fastening device with clamping components, wherein the clamping components in a housing for receiving by the action of a holding drive, a ball head of a trailer hitch clamp the ball head, wherein the housing is pivotable relative to the ball head. The housing further has two sensors which determine the distance to the ball head. If the two sensors determine the same distance to the ball head, the holding drive is turned on to ensure a certain alignment of the housing or load carrier with respect to the ball head. For this purpose, the sensors are arranged on the upper wall of the housing and measure a distance to a flattening of the ball head. German Patent Application DE 102010030246 A1 discloses a ball joint for a vehicle which has a housing and a ball stud. An angle measuring device with field-providing component is described, by means of which a movement of the ball pin relative to the housing can be detected, wherein the field-providing components are arranged opposite to a joint ball of the ball stud. The joint ball has a surface area that deviates from the spherical surface of the joint ball. This surface area interacts with the magnetic field of the field-providing components.

A disadvantage of the solutions described in the prior art, inter alia, that a high processing cost of the joint ball is necessary in the production. Furthermore, conventional ball joint measuring devices often use magnetically based sensors that are sensitive to external magnetic field disturbances.

It is an object of the invention to propose a robust ball joint, which is inexpensive to manufacture, and allows the detection of the tilt angle between the housing and the ball stud in a simple manner.

The object is achieved by a ball joint according to claim 1. Advantageous embodiments of the invention are the subject of the dependent claims.

Thus, the object is achieved with a ball and socket joint for a vehicle, comprising a housing and a ball pin extending in an axial direction and comprising a joint ball, which is pivotally mounted with its ball joint in the housing and extends through an opening of the housing, and at least one sensor operable to detect a tilt angle between the ball stud and the housing, the wrist ball having a flattened area, and wherein the at least one sensor is a distance sensor disposed on a wall of the housing and the flattened area of the housing Opposite ball is opposite to detect a distance from the flattened area and to close from it to the tilt angle. Of the Sensor can be mounted on the surface on the inner side of the housing by means of customary fastening methods, for example by means of gluing and / or screws. The at least one sensor can also be used in the housing wall. For example, an opening, a blind hole or a through hole can be provided for this purpose. It is also possible that the wall of the housing is prefabricated and that the sensor is integrated as part of the prefabricated wall. Thus, it is possible to position the sensor in the housing and then shed or overmold. In the context of this invention, the term flattened region is to be understood as meaning a surface section of the joint ball which quite generally has a curvature reduced in relation to the ball curvature (in the sense of a flattening). The curvature of the flattened area may in a preferred case be zero, so that it forms a straight plane. The flattened region of the ball joint, unlike the processed surfaces, can be easily manufactured as described in the prior art. The use of a distance sensor further allows insensitivity to magnetic noise.

In one embodiment of the ball joint, the flattened region extends substantially orthogonal to the axial direction of the ball stud. The distance sensor always detects the distance between the sensor and this flattened area. As the ball stud moves in the housing, this flattened area will tilt. If the tilt angle between the ball stud and the housing changes, the distance between the sensor and the flattened area also changes accordingly. If the relationship between distance and tilt angle is known, the ball joint can close by means of this relationship on the basis of the distance on the tilt angle.

As already mentioned above, in a preferred embodiment, the flattened region forms a straight plane. The relationship between the distance and the tilt angle can thus be described by a simple mathematical formula. It is still possible to create a simple algo- to determine the tilt angle based on this distance. The error range of the tilt angle detection can thus be reduced.

In one embodiment, the flattened area essentially forms a circular area. The production of the ball joint is thus simplified. In contrast to this, in the prior art, for example in DE1020130246 A1, the surface of the joint ball is processed using complex production methods. Or in DE10110738, for example, a blind hole is drilled in the joint ball in order to store magnetic field generators. The circular surface area of the ball joint thus brings significant advantages in terms of manufacturing costs.

The at least one sensor is a sensor that is used on the basis of an inductive, capacitive and / or optical measuring method to detect the distance. A ball joint for a vehicle may be regularly in an area of influence of an external magnetic field. A sensor that works on the basis of an inductive, capacitive and / or optical measuring method has the advantage that it is not affected by these magnetic fields. A ball joint of this kind is therefore very robust against magnetic interference.

In one embodiment, the at least one sensor is arranged symmetrically with respect to a predetermined pivot axis of the ball joint on the wall of the housing, so that the sensor when the tilt angle between the housing and the ball stud is zero degrees, the distance from a parallel to the predetermined Pivot axis defined diameter of the flattened area detected. In other words, the sensor is mounted in the middle of the pivot axis on the housing wall. The sensor thus measures the distance to the center of the flattened area when the tilt angle is at zero degrees. As the ball stud tilts in a pivoting direction, the flattened area tilts relative to the sensor. The distance between the sensor and the flattened area is thus reduced. From the detected distance thus the tilt angle can be determined clearly. However, the pivot direction can not be determined or the ball joint can not between a positive tilt angle and a negative tilting Distinguish angles. The ball stud can move in relation to the housing in a predetermined range of motion. For example, the ball stud may sway 40 degrees relative to the housing. In the context of the invention, a tilt angle, which is zero degrees, denotes the state in which the ball stud is in the middle of its range of motion. Thus, the ball stud, for example, between + 20 degrees and - 20 degrees fluctuate.

In one embodiment, at least one sensor is arranged on the wall of the housing, that the sensor, when the tilt angle between the housing and the ball stud is zero degrees, the center of the flattened area opposite and thus detects the distance from the center. The sensor or the ball joint can thus detect an absolute amount, the distance or the tilt angle regardless of the pivoting direction. In this case, the sensor is always located opposite to a diameter of the flattened area.

In one embodiment, the ball joint has an evaluation unit which serves to determine the tilt angle on the basis of a distance value, the distance value corresponding to the detected distance.

In one embodiment of the ball joint, the at least one sensor is arranged asymmetrically with respect to a predetermined pivot axis of the ball joint on the wall of the housing, so that the sensor when the tilt angle between the housing and the ball stud is zero degrees, the distance to a parallel to detected chord of the flattened area detected the predetermined pivot axis, wherein the chord does not correspond to a diameter of the flattened area. In other words, the sensor is positioned off-center. Thus, upon pivoting of the ball stud, a functional relationship forms between the distance and the tilt angle which, while not linear, allows for discrimination between positive and negative tilt angles over a particular range of movement of the ball stud.

In a further development, a first sensor and a second sensor are arranged asymmetrically with respect to a predetermined pivot axis of the ball joint on the wall of the housing, wherein, when the tilt angle between the housing and the ball stud is zero degrees, the first sensor detects the distance from a first chord of the flattened area, and the second sensor detects the distance from a second chord of the flattened area, the first chord and second chord being parallel to each other and parallel to a diameter of the flattened area And the second chord extends in a second portion of the flattened portion, the first portion and second portion being separated by the diameter of the flattened portion. By using two sensors, one to the right and one to the left of the center, one can determine a unique and linear relationship between tilt angle and distance. The entire range of motion of the ball stud can thus be covered by the sensors, so that a clear assignment of the tilt angle for removal is possible. Further, when the sensors are placed at the same distance from the diameter, the characteristics representing the relationship between the distance and the tilt angle can be subtracted from each other. The result is a characteristic that represents a linear relationship between distance and tilt angle.

In one embodiment, the ball joint has an evaluation unit which serves to determine the tilt angle on the basis of a first distance value and a second distance value, wherein the distance values correspond to the detected first distance and second distance, and wherein the evaluation unit is adapted to the first Subtract the distance value from the second distance value.

In one embodiment, at least two sensors are arranged on the wall of the housing, wherein the at least two sensors are used to detect the tilt angle between the ball stud and the housing relative to two mutually different pivot directions.

The object of the invention can furthermore be achieved by a device comprising an evaluation unit and a ball joint, the device having a communication path which connects the evaluation unit and the ball joint. det, and wherein the evaluation unit serves to determine the tilt angle on the basis of one of the detected distance corresponding distance value.

Alternatively, the object can also be achieved by a device comprising an evaluation unit and a ball joint, wherein the device has a communication path which connects the evaluation unit and the ball joint, and wherein the evaluation unit serves to increase the tilt angle based on a first distance value and a second distance value determine, wherein the distance values of the detected first distance and second distance correspond, and wherein the evaluation unit is adapted to subtract the first distance value from the second distance value.

The invention will be explained in more detail below with reference to the following figures. It shows:

Fig. 1a, b is a schematic representation of a first embodiment of a ball joint, and a graphical representation of the relationship between distance and tilt angle of the embodiment shown in Figure 1a;

Fig. 2a, b is a schematic representation of a second embodiment of a

Ball joint, as well as a graphical representation of the relationship between distance and tilt angle of the embodiment shown in Figure 2a;

Fig. 3a, b is a schematic representation of a third embodiment of a ball joint, and a graphical representation of the relationship between distance and tilt angle of the embodiment shown in Fig. 3a.

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

Fig. 1b shows in graphic form the relationship between the distance d and the tilt angle. When the tilt angle α is 0 degrees, the distance d between the sensor 6 and the flattened area 5 is of course greatest. When the ball pivot 3 pivots to one side or to the other, the distance d between the flattened region 5 and the sensor 6 decreases. However, as can be seen in FIG. 1b, it is not possible to distinguish between positive and negative to distinguish negative angles. Ie. at a certain detected distance d, the ball joint 1 can not perform a unique assignment, but the ball joint 1 can only an absolute amount of the tilt angle | a | output.

FIG. 2a shows a schematic representation of a second embodiment of a ball joint 1. Here, as in FIG. 1a, three positions L, M, N of the ball pin 3 with respect to the housing 2 are shown. The essential difference from the embodiment shown in FIG. 1 a is that the sensor 6 is arranged asymmetrically on the housing wall 7. This asymmetry refers to a diameter 11 of the flattened region 5, which can be defined on the basis of the pivot axis 10. The diameter 11, which is parallel to the pivot axis 10, is taken as a reference line to divide the flattened area 5 into two halves. In FIG. 2a, the sensor 6, which is arranged asymmetrically on the housing wall 7, detects the distance d from a chord 12 of the flattened region 5 when the tilt angle α between the ball stud 3 and the housing 2 is zero degrees. The Sen- Sor 6 thus detects the distance d between the housing wall 7 and a point in a predetermined half of the flattened area 5.

Fig. 2b shows a graphical representation of the functional relationship between distance d and tilt angle α of the embodiment shown in Fig. 2a. It can be seen here that a definite assignment between distance d and tilt angle α is possible over a predetermined range of movement 13 of the ball stud 3. However, there is another range of motion 14 where this uniqueness is absent. Furthermore, the functional relationship is not linear.

3a shows a schematic representation of a third embodiment of a ball joint 1. In Fig. 3a, the ball joint 1 with a housing 2, ball stud 3, ball joint 4 and a sensor 6 is shown. As in FIGS. 1 a and 2 a, the joint ball 4 has a flattened region 5, and at least one sensor 6, which is arranged on a wall 7 of the housing 2 opposite this flattened region 5. In Fig. 3a, two sensors 6a, 6b are shown. These two sensors 6a, 6b are arranged asymmetrically as in FIG. 2a. This asymmetry refers to the longitudinal axis A of the ball stud 3 when the ball stud 3 is at 0 degrees with respect to the housing 2. However, this asymmetry may also relate to a diameter 11 of the flattened region 5, wherein the diameter 11 extends parallel to the pivot axis 10 of the ball joint 1.

As shown in Fig. 3b, there is a functional relationship between distance d and tilt angle α for each sensor 6a, 6b. From this functional relationship, a definite allocation between distance d and tilt angle α is possible via a predetermined freedom of movement (between -α and + a) of ball stud 3. With the use of two sensors 6a, 6b, as shown in Fig. 3, it is possible to cover the entire range of motion (-a to + a) of the ball joint 3 with unique 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, this can be done by, for example, subtracting the distance d _a from a first sensor 6a from the distance d _{b of} a second sensor 6b. This results in a linear, radio- tional relationship between the distance measurements d _a , d _b and the tilt angle a. In general, the distance sensors 6a, 6b can use different measuring principles. In particular, inductive measuring methods, capacitive measuring methods and / or optical measuring methods can be used. The sensors 6a, 6b detect the distance d and transmit a measured value to an evaluation unit 15. The evaluation unit 15 accepts this distance value or measured value as input, processes the measured value in accordance with the specifications of an algorithm and outputs a value which interpolates the tilt angle α Ball stud 3 and housing 2 corresponds. The evaluation unit 15 can either be arranged on the ball joint 1 itself, as shown in the first position L in FIG. 3 a, or a communication path 16 to an external evaluation unit 15 can be provided. For example, a connection 17 can be provided to a CAN bus and the evaluation unit 15 can be arranged on a main control 18 of the vehicle (see the third position N in FIG. 3a).

reference numeral

1 ball joint

2 housings

3 ball studs

4 joint ball

5 flattened areas

6 sensor

7 wall of the housing

8 opening in the housing

9 Center of the flattened area

10 pivot axis

11 diameter

12 (second) tendon

13 first movement area

14 second range of motion

15 evaluation unit

16 communication path

17 connection

18 central control of a vehicle

19 first tendon

α tilt angle

d distance or distance

A axial direction of the ball stud

Claims

claims

A ball and socket joint (1) for a vehicle, comprising a housing (2) and a ball pin (3) extending in an axial direction (A) and comprising a joint ball (4) pivoting in the housing with its joint ball (4) (2) is mounted and extends through an opening (8) of the housing (2) and at least one sensor (6), which serves to a tilt angle (a) between the ball stud (3) and the housing (2) to capture,

characterized in that

the joint ball (4) has a flattened region (5), and that

the at least one sensor (6) is a distance sensor arranged on a wall (7) of the housing (2) and facing the flattened area (5) of the joint ball (4) by a distance (d) from the flattened area (Fig. 5) and to deduce the tilt angle (et).

2. Ball joint (1) according to claim 1, characterized in that the flattened region (5) extends substantially orthogonal to the axial direction (A) of the ball stud (3).

3. Ball joint (1) according to claim 1 or 2, characterized in that the flattened region (5) forms a straight plane.

4. ball joint (1) according to at least one of the preceding claims, characterized in that the flattened portion (5) forms a substantially circular surface.

5. Ball joint (1) according to at least one of the preceding claims, characterized in that the at least one sensor (6) based on an inductive, capacitive and / or optical measuring method detects the distance (d).

6. ball joint (1) according to at least one of the preceding claims, characterized in that the at least one sensor (6) symmetrically with respect to a predetermined pivot axis (10) of the ball joint (10) on the wall (7) of the Housing (2) is arranged, so that the sensor (6), when the tilt angle (a) between the housing (2) and the ball stud (3) is zero degrees, the distance (d) relative to a parallel to the predetermined pivot axis ( 10) defined diameter (11) of the flattened area (5) detected.

7. ball joint (1) according to at least one of the preceding claims, characterized in that the at least one sensor (6) on the wall (7) of the housing (2) is arranged so that the sensor (6) when the tilt angle ( a) between the housing (2) and the ball stud (3) is zero degrees, the center (9) of the flattened area (5) opposite and thus detects the distance (d) relative to the center (9).

8. Ball joint (1) according to at least one of the preceding claims, characterized in that the ball joint (1) has an evaluation unit (15) which serves to determine the tilt angle (a) based on the detected distance (d) corresponding distance value ,

9. ball joint (1) according to at least one of claims 1 to 5, characterized in that the at least one sensor (6) asymmetrically with respect to a predetermined pivot axis (10) of the ball joint (1) on the wall (7) of the housing ( 2) is arranged so that the sensor (6) when the tilt angle (a) between the housing (2) and the ball stud (3) is zero degrees, the distance (d) with respect to a parallel to the predetermined pivot axis (10) defined chord (12) of the flattened area (5) detected, wherein the chord (12) no diameter

(11) corresponds to the flattened area (5).

10. Ball joint (1) according to at least one of claims 1 to 5, characterized in that a first sensor (6a) and a second sensor (6b) asymmetrically with respect to a predetermined pivot axis (10) of the ball joint (1) on the wall (7) of the housing (2) are arranged such that when the tilt angle (a) between the housing (2) and the ball stud (3) is zero degrees, the first sensor (6a) is the distance (d _a ) from a first Chord (19) of the flattened area (5) and the second sensor (6b) detects the distance (d _b ) from a second line of vision ne (12) of the flattened region (5), wherein the first chord (19) and second chord (12) are substantially parallel to each other and parallel to a diameter (11) of the flattened region 5, and the first chord (19 ) extends in a first partial area (Ta) of the flattened area (5) and the second chord (12) extends in a second partial area (Tb) of the flattened area (5), wherein the first partial area (Ta) and second partial area (Tb) are separated from each other by the diameter (11) of the flattened area (5).

11. Ball joint (1) according to claim 9 or 10, characterized in that the ball joint (1) has an evaluation unit (15) which serves the tilt angle (a) on the basis of first and second distance values (d _a , d _b ), the to determine the detected first and second distances (d _a , db), wherein the evaluation unit (15) is adapted to subtract the first distance value (d _a ) from the second distance value (d _b ).

12. Ball joint (1) according to at least one of the preceding claims, characterized in that at least two sensors (6) on the wall (7) of the housing (2) are arranged, wherein the at least two sensors (6) serve the tilt angle ( a) between the ball stud (3) and the housing (2) based on two mutually different pivot directions (10 _a , 10 _b ) to detect.

13. Device comprising an evaluation unit (15) and a ball joint (1) according to at least one of claims 1 to 7, characterized in that the device has a communication path (16) which connects the evaluation unit (15) and the ball joint (1) , and that the evaluation unit (15) serves to determine the tilt angle (a) on the basis of a distance value (d) corresponding to the detected distance (d).

14. Device comprising an evaluation unit (15) and a ball joint (1) according to at least one of claims 9 to 11, characterized in that the device has a communication path (16) which connects the evaluation unit (15) and the ball joint (1) , and that the evaluation unit (15) serves to determine the tilt angle (a) on the basis of first and second distance values (d _a , d _b ) which preconceived first and second distances (d _a, db) corresponding to identify, with the evaluation unit (15) is adapted to the first distance value (d _a) of the second distance value (d _b) subtracted.