DE102012022869A1 - Steering angle sensor for device for combined acquisition of angle and rotational torque of steering column, has magnetic code track formed by magnetic ring of torque sensor connected to shaft portion and magnetic field sensor - Google Patents

Abstract

The steering angle sensor (3) has two magnetic code-tracks containing angle information (psi ,theta ) from which angle (phi ) of the shaft portion (4) of the steering column is judged. One of the magnetic code tracks is formed by multi-pole magnetic ring (9) of torque sensor (2) connected to the first shaft portion and a magnetic field sensor (11). An independent claim is included for device for combined acquisition of angle and rotational torque of steering column.

Description

The invention relates to a steering angle sensor, by means of which an angle of a steering column is determined and a device for the combined detection of an angle and a torque.

From the DE 195 06 938 A1 is such a steering angle sensor known. For this purpose, a first gear is arranged on the steering column, which rotates with the steering column. With the first gear on the steering column two other gears are connected, which have a different number of teeth. On the other two gears magnets are arranged, whose position is sensed by magnetic field sensors, in particular AMR sensors (anisotropic magnetoresistive - sensor). From the two angular positions of the two other gears can then be deduced by the angle of the steering column. The two angle information of the two other gears can also be referred to as a magnetic code track. The calculation is for example in the DE 10 2006 006 359 A1 described.

To reduce measurement errors, it is from the DE 199 62 241 A1 known to resiliently clamp the two other gears with the teeth on the steering column.

From the DE 202 20 388 U1 such as DE 10 2005 018 286 A1 there is known an apparatus for determining a torque applied to a shaft, the shaft having a first shaft portion and a second shaft portion. The two shaft sections are rotatable against each other. The first shaft portion is connected to a multi-pole magnetic ring surrounding the first shaft portion. A stator holder is secured to the second shaft portion, two stator elements being mounted on the stator holder and each stator element having axially projecting fingers uniformly distributed at least over part of the circumference and having gaps therebetween. The fingers of each stator element are connected to one another via a magnetic flux ring, wherein the magnetic flux rings are spaced apart and a magnetic field sensor is arranged between the magnetic flux rings, at least one magnetic flux concentrator being associated with the magnetic field sensor, the magnetic flux concentrator being provided between the magnetic flux rings.

From the WO 2012/019947 A1 a device is known, comprising a torque sensor for determining a torque of a steering shaft and a rotation angle sensor for determining a rotation angle of the steering shaft, wherein the torque sensor operates with the aid of a magnetic field, the rotation angle sensor comprises a permanent magnet and a magnetic field detector, wherein the magnetic field detector is adapted to Detecting direction of the magnetic field, and the torque sensor and the rotation angle sensor are arranged adjacent, wherein between the torque sensor and rotation angle sensor, a shielding device for magnetic fields is arranged and / or the permanent magnet of the rotation angle sensor is formed bipolar axially with a major axis.

The invention is based on the technical problem of providing a steering angle sensor which is easy to combine with a torque sensor and to provide a device for the combined detection of an angle and a torque. The solution of the technical problem results from the objects with the features of claims 1 and 7. Further advantageous embodiments of the invention will become apparent from the dependent claims.

The steering angle sensor, by means of which an angle of a steering column is determined, wherein the steering column has a first shaft portion and a second shaft portion which are rotatable against each other (preferably via a torsion bar) has two magnetic code tracks, from the angle information on the angle of the steering column, In particular, the angle of the first shaft portion is closed, wherein a magnetic code track of the steering angle sensor is formed by a first multipole magnet ring of a torque sensor which is connected to the first shaft portion and which is associated with a magnetic field sensor. That is, the multipole magnetic ring of the torque sensor is used for a magnetic code track of the steering angle sensor, so that the component cost is reduced. For this purpose, the magnetic ring is widened, that a part of the magnet ring protrudes from the sensor part of the torque sensor. The protruding from the sensor part of the torque sensor part of the magnetic ring then rotates with the first shaft portion and a magnetic field sensor can convert the magnetic values into angles.

For the second necessary magnetic code track, a second multipole magnetic ring with associated magnetic field sensor can be used, wherein preferably the number of pole pairs of the first and second multipole magnetic ring is different, so that again a calculable by vernier signal is available.

The second multipole magnetic ring can in principle be arranged on the first shaft section or on the second shaft section, wherein the arrangement on the first shaft section is preferred, since then the two angle information of the Multipole magnet rings no longer need to be converted. In an arrangement on the second shaft portion, however, the rotation of the two shaft sections must still be taken into account.

In an alternative embodiment, the second magnetic code track is formed by a toothed wheel which meshes with a toothing of the steering column, preferably of the first shaft section, wherein a magnet is arranged on the toothed wheel, whose rotating magnetic field is detected by a further magnetic field sensor. The number of teeth of the gear is preferably selected such that a nonius calculable signal is available, d. H. the number of teeth is selected as a function of the pole pairs of the multipole magnet ring.

In a further embodiment, the magnetic field sensors of the steering angle sensor are designed as MR sensors (magnetoresistive sensors), in particular as AMR sensors (anisotropic magnetoresistive sensors) or as GMR sensors (giant magnetoresistance).

The device for combined detection of an angle and a torque on a steering column comprises a torque sensor and a steering angle sensor, wherein the steering column has a first shaft portion and a second shaft portion which are rotatable relative to each other. The first shaft portion is connected to a multipole magnet ring of the torque sensor surrounding the first shaft portion. On the second shaft portion, a stator holder is mounted, wherein the steering angle sensor has two magnetic code tracks from the angle information is closed on the angle of the steering column, wherein a magnetic code track of the steering angle sensor is formed by the multipole magnet ring of the torque sensor, which is associated with another Megnetfeldsensor ,

The second magnetic code track is formed by a second multipole magnetic ring with an associated magnetic field sensor, wherein the second multipole magnetic ring is preferably arranged on the first shaft section. Alternatively, the second magnetic code track may be formed by a gear meshing with a toothing of the steering column with a magnet disposed on the gear.

The invention will be explained in more detail below with reference to preferred embodiments. The figures show:

1 a schematic side view of a steering angle sensor with two multipole magnet rings and

2 a schematic plan view with a gear as a second magnetic code track.

In the 1 is schematically a device 1 for the combined detection of an angle φ of a steering column and a torque on the steering column shown. The device 1 includes a torque sensor 2 and a steering angle sensor 3 , The steering column comprises a first shaft section 4 and a second shaft portion 5 that have a torsion bar 6 are rotatable against each other. The greatly simplified torque sensor 2 includes a stator holder 7 on the second wave section 5 is attached. Furthermore, the torque sensor comprises 2 a holder 8th for a multipole magnetic ring 9 , where the holder 8th fixed to the first shaft section 4 the steering column is connected. The multipole magnetic ring 9 lies above the torsion bar 6 , In this case, the torque sensor comprises 2 continue a magnetic field sensor 10 which is disposed between non-illustrated magnetic flux rings. With regard to the specific structure of the torque sensor 2 For example, on the DE 202 20 388 U1 or the DE 10 2005 018 286 A1 to get expelled. In contrast to the torque sensors shown there according to the invention is the multipole magnet ring 9 wider, so in particular a part of the multipole magnet ring 9 from the stator holder 7 protrudes. This outstanding part of the multipole magnet ring 9 is a magnetic field sensor 11 assigned. The outstanding part of the multipole magnet ring 9 and the magnetic field sensor 11 form a first magnetic code track of the steering angle sensor 3 , Indicates the multipole magnet ring 9 For example, eight pole pairs, so an angular resolution for θ of 22.5 ° can be achieved. Next, the steering angle sensor 3 another multipole magnetic ring 12 on top of a holder 13 on the first shaft section 4 is attached. The second multipole magnet ring 12 is another magnetic field sensor 14 associated with the second magnetic code track of the steering angle sensor 3 form. In this case, the number of pole pairs of the second multipole magnet ring is 12 different from the number of pole pairs of the first multipole magnet ring 9 , so that a vernier method for the angle φ of the first wave section 4 can be carried out. For this purpose, the angle information θ of the magnetic field sensor 11 and the angle information ψ of the magnetic field sensor 14 to an evaluation unit 15 transmitted.

In the 2 is part of the steering angle sensor 3 shown in an alternative embodiment. The second magnetic code track is a gearwheel 16 with a magnet 17 formed, with the magnet 17 is preferably designed as a bar magnet. The gear 16 stands thereby with a gearing 18 on the first shaft section 4 in connection. This will be the number of teeth of the gear 16 chosen such that a calculable by vernier signal in comparison to the signal of the first multipole magnet ring 9 is produced.

LIST OF REFERENCE NUMBERS

1

contraption

2

torque sensor

3

Rotation angle sensor

4

shaft section

5

shaft section

6

torsion bar

7

stator

8th

holder

9

Multi-pole magnetic ring

10

magnetic field sensor

11

magnetic field sensor

12

Multi-pole magnetic ring

13

holder

14

magnetic field sensor

15

evaluation

16

gear

17

magnet

18

gearing

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19506938 A1 [0002]
• DE 102006006359 A1 [0002]
• DE 19962241 A1 [0003]
• DE 20220388 U1 [0004, 0017]
• DE 102005018286 A1 [0004, 0017]
• WO 2012/019947 A1 [0005]

Claims (9)

Steering angle sensor ( 3 ), by means of which an angle (φ) of a steering column is determined, wherein the steering column has a first shaft section (FIG. 4 ) and a second shaft section ( 5 ), which are mutually rotatable, wherein the steering angle sensor ( 3 ) has two magnetic code tracks, from the angle information (ψ, θ) on the angle (φ) of the steering column, in particular the angle (φ) of the first shaft section is closed, characterized in that a magnetic code track of the steering angle sensor ( 3 ) by a first multipole magnetic ring ( 9 ) of a torque sensor ( 2 ) formed with the first shaft portion ( 4 ) and a magnetic field sensor ( 11 ) assigned. Steering angle sensor according to claim 1, characterized in that the second magnetic code track by a second multipole magnetic ring ( 12 ) with associated magnetic field sensor ( 14 ) is formed. Steering angle sensor according to claim 2, characterized in that the number of pole pairs of the first and the second multipole magnet ring ( 9 . 12 ) are different. Steering angle sensor according to claim 2 or 3, characterized in that the second multipole magnetic ring ( 12 ) with the first shaft section ( 4 ) or the second shaft section ( 5 ) connected is. Steering angle sensor according to claim 1, characterized in that the second magnetic code track by a gear ( 16 ) formed with a toothing ( 18 ) of the steering column is engaged, wherein on the gear ( 16 ) a magnet ( 17 ) is arranged. Steering angle sensor according to one of the preceding claims, characterized in that the magnetic field sensors ( 11 . 14 ) are designed as MR sensors. Contraption ( 1 ) for combined detection of an angle (φ) and a torque on a steering column, the device comprising a torque sensor ( 2 ) and a steering angle sensor ( 3 ), wherein the steering column has a first shaft section ( 4 ) and second shaft section ( 5 ), which are rotatable against each other, wherein the first shaft portion ( 4 ) with a multipole magnetic ring ( 9 ) of the torque sensor ( 2 ) connecting the first shaft section ( 4 ), wherein at the second shaft portion ( 5 ) a stator holder ( 7 ) of the torque sensor ( 2 ), wherein the steering angle sensor ( 3 ) has two magnetic code tracks, from the angle information (ψ, θ) on the angle (φ) of the steering column is closed, wherein a magnetic code track of the steering angle sensor ( 3 ) through the multipole magnetic ring ( 9 ) of the torque sensor ( 2 ), to which a magnetic field sensor ( 11 ) assigned. Apparatus according to claim 7, characterized in that the second magnetic code track by a second multipole magnetic ring ( 12 ) with associated magnetic field sensor ( 14 ) is formed. Apparatus according to claim 7, characterized in that the second magnetic code track by a gear ( 16 ) formed with a toothing ( 18 ) of the steering column is engaged, wherein on the gear ( 16 ) a magnet ( 17 ) is arranged.

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