ROLL STABILIZER AND SENSOR UNIT FOR A ROLL STABILIZER

Abstract

Disclosed is a roll stabilizer (1) for a motor vehicle, comprising a sensor unit (10), which operates according to the principle of inverse magnetostriction, for acquiring torque (M) acting between stabilizer portions (6a, 6b), characterized in that the sensor unit (10) includes a magnetic field generation device, which preferably comprises a transmitter coil (12) and is used for magnetizing a measurement element (4; 6a) affected by torsional stress during operation, and a plurality of magnetic field detection devices, each of which preferably comprises a receiver coil (13) and which are used for acquiring parameters of the magnetic field of the measurement element (4; 6a). Also disclosed is a corresponding sensor unit (10) for a roll stabilizer (1) of the aforementioned type.

Claims

1. A roll stabilizer (1) for a motor vehicle, comprising a sensor unit (10), which operates according to the principle of inverse magnetostriction, for acquiring a torque (M) acting between stabilizer portions (6a, 6b), characterized in that the sensor device (10) includes at least one magnetic field generation device (20) for magnetizing a measurement element (4; 6a) affected by torsional stress during operation, and at least one first magnetic field detection device (21) for acquiring a first magnetic field parameter that changes as result of the stress in the measurement element (4; 6a), and at least one second magnetic field detection device (22) for acquiring a second magnetic field parameter that changes a result of the stress in the measurement element (4; 6a).

2. The roll stabilizer according to claim 1, characterized in that the magnetic field generation device (20) and the magnetic field detection devices (21, 22, 31, 32) are arranged on a sensor unit (11) which is spaced in particular radially from the measurement element (4; 6a) and/or are integrated into a sensor housing.

3. The roll stabilizer according to claim 2, characterized in that the sensor device (10) comprises several sensor units (11, 11a, 11b).

4. The roll stabilizer according to claim 3, characterized in that 4.1 a first sensor unit (11a) and a second sensor unit (11b) are arranged at diametrically opposite positions with respect to a center (3) of the measurement element (4; 6a) or 4.2 said several sensor units (11) are distributed in a ring shape around the center (3) of the measurement element (4; 6a) or 4.3 a first sensor unit (11a) is arranged for measuring torsional stress of a first stabilizer portion (6a), and a second sensor unit (11b) is arranged for measuring torsional stress of a second stabilizer portion (6b).

5. The roll stabilizer according to any of the preceding claims, characterized in that 5.1 the magnetic field generation device (20) or at least one of several magnetic field generation devices and/or at least one, several or all of the magnetic field generation devices (21, 22, 31, 32) are arranged radially inside the measurement element (4; 6a) and/or 5.2 the magnetic field generation device (20) or at least one of several magnetic field generation devices (21, 22, 31, 32) and/or at least, one, several or all of the magnetic field generation devices are arranged radially outside the measurement element (4; 6a).

6. The roll stabilizer according to any of the preceding claims, characterized in that the sensor unit (11) has a surface (17), in particular a convex surface, which is substantially complementary to the inner side of the measurement element.

7. The roll stabilizer according to any of the preceding claims, characterized in that sensor device (10) includes at least one third magnetic field detection device (31) for detecting a third magnetic field parameter that changes as a result of the stress in the measurement element (4; 6a), and at least one fourth magnetic field detection device (32) for detecting a fourth magnetic field parameter that changes as a result of the stress in the measurement element (4; 6a).

8. The roll stabilizer according to any of the preceding claims, characterized in that the magnetic field generation device (20) comprises at least one transmitter coil (12) and/or in that the magnetic field detection devices (21, 22, 31, 32) each comprise at least one receiver coil (13).

9. The roll stabilizer according to claim 8, characterized in that the transmitter coil (12) is arranged between at least two receiver coils (13).

10. The roll stabilizer according to any of claim 8 or 9, characterized in that several receiver coils (13) are positioned relative to each other in such a way that they form a polygon, in particular a square, in the center of which the transmitter coil (12) is arranged.

11. The roll stabilizer according to any of claims 8-10, characterized in that the sensor device (10) comprises a control unit (14) which is electrically connected to the transmitter coil (12) and the receiver coils (13) and with which, for the temporary generation of a magnetic field, the transmitting coil (12) can be energized during a time window and/or with which a signal from the receiving coils (13) can be received within this time window.

12. The roll stabilizer according to any of the preceding claims, characterized in that the sensor unit (10) has at least one shielding device (28) for shielding the at least one magnetic field generation device (20) and the magnetic field detection devices (21, 22, 31, 32) from external magnetic field influences.

13. The roll stabilizer according to any of the preceding claims, characterized by an acceleration sensor (29).

14. A sensor device (10) for a roll stabilizer (1) of a motor vehicle, in particular for a roll stabilizer according to any of the preceding claims, for acquiring torque (M) acting between stabilizer portions (6a, 6b) according to the principle of magnetostriction, characterized by a magnetic field generation device (20) for magnetizing a measurement element (4; 6a) affected by torsional stress during operation, and a first magnetic field detection device (21) for acquiring a first magnetic field parameter that changes as a result of the stress in the measurement element (4; 6a), and a second magnetic field detection device (22) for acquiring a second magnetic field parameter that changes as a result of the stress in the measurement element (4; 6a).

Description

[0036] Embodiments of the invention will be described in the following with reference to the attached drawings from which further features and advantageous effects of the embodiments of the invention are apparent. In the drawings it is shown by:

[0037] FIG. 1 an adjustable roll stabilizer of a motor vehicle in schematic view;

[0038] FIG. 2 a simplified schematic representation of a roll stabilizer with measurement inside the actuator housing, in accordance with one embodiment of the invention;

[0039] FIG. 3 a simplified schematic representation of a sensor unit in a plan view of a housing;

[0040] FIG. 4 a simplified schematic representation of a sensor unit in an axial section through an actuator housing;

[0041] FIG. 5 a simplified schematic representation of a roll stabilizer with measurement inside the stabilizer portion, in accordance with one embodiment of the invention;

[0042] FIG. 6 a simplified schematic representation of a roll stabilizer with measurement outside the stabilizer portion, in accordance with one embodiment of the invention;

[0043] FIG. 7 a simplified schematic representation of a roll stabilizer with measurement outside the stabilizer housing, in accordance with one embodiment of the invention;

[0044] FIG. 8 a simplified schematic representation of a roll stabilizer with measurement inside two stabilizer portions, in accordance with one embodiment of the invention;

[0045] FIG. 9 an exploded view of one embodiment of a sensor unit;

[0046] FIG. 10 a simplified schematic representation of the section through the actuator housing of the roll stabilizer, with measurement inside the actuator housing by means of several sensor units at different positions;

[0047] FIG. 11 a simplified schematic representation of a section through the actuator housing, with measurement inside the actuator housing by means of sensor units distributed around the inner circumference of the actuator housing.

[0048] To illustrate the field of application of the invention, FIG. 1 first shows an adjustable roll stabilizer 1 for a motor vehicle in a simplified schematic perspective view. The adjustable roll stabilizer 1 is part of a chassis of a motor vehicle (not shown). A first wheel 7a and a second wheel 7b on the opposite side of the vehicle are each connected to the vehicle body via a wheel suspension 8a or 8b (shown in simplified form). The wheel 7a and wheel suspension 8a or the wheel 7b and wheel suspension 8b are respectively coupled to an outer end of an associated stabilizer portion 6a or 6b of the adjustable roll stabilizer 1. Both stabilizer portions 6a and 6b are connected to each other centrally of the vehicle via an actuator 2.

[0049] The adjustable roll stabilizer 1 is supported to be rotatable about an axis of rotation 3 relative to the vehicle body in a manner known per se (bearing not shown in detail). The actuator 2, shown in simplified form as a cylindrical body, essentially comprises an actuator housing 4 which is rotationally symmetrical with respect to the axis of rotation 3 and in which an electric motor 15 as well as a multistage planetary gear are arranged (both are not shown in this representation; cf. FIGS. 2, 5, 6 and 7). The stabilizer portions 6a and 6b are drivingly connected via the electric motor and the multistage planetary gear. At a standstill of the electric motor, both stabilizer portions 6a, 6b are rigidly connected to each other via the actuator 2. By the operation of the electric motor, the stabilizer portions 6a, 6b can be rotated relative to one another, depending on the direction of rotation about the axis of rotation 3. This is how the adjustable roll stabilizer 1 can be adjusted in a manner known per se.

[0050] According to the schematic representation shown, the stabilizer portion 6a is fixed to the housing, which means that it is connected to one end 5a of the actuator housing 4 in a rotationally fixed manner. On the other hand, the stabilizer portion 6b is connected to the actuator 2 at its output end 5b. That is, the stabilizer portion 6b is rotatably mounted relative to the actuator housing 4, but is drivingly connected to the transmission output of the actuator 2. Depending on the operating condition of the motor vehicle, a torque M acts between the stabilizer portions 6a, 6b, which is indicated in FIG. 1 as a double arrow acting about the axis of rotation 3. The amount and direction of the torque M depend on the operating condition.

[0051] FIGS. 2, 5, 6, 7, 8 and 10 and 11 show four examples of roll stabilizers according to the invention in a clearly simplified form with regard to the arrangement of the sensor device. First of all, the common features of the roll stabilizers shown there should be discussed:

[0052] Each of the roll stabilizers 1 shown in the FIGS. 2 and 5 to 8 and 10 to 11 has a sensor device 10 that works according to the principle of inverse magnetostriction. For reasons of simplification, the stabilizer portions 6a, 6b are shown in a shortened and simplified form as stubs which extend along the axis of rotation 3. The actuator 2 located between them, which interconnects the stabilizer portions 6a, 6b in a manner similar to that shown in FIG. 1, comprises an electric motor 15 and a multistage planetary gear 16 arranged coaxially with the electric motor, and both the electric motor and the multistage planetary gear together with an ECU 14 (electronic control unit) are arranged inside an actuator housing 4. As already discussed in connection with FIG. 1, the stabilizer portion 6a is rigidly connected to the actuator housing 4, whereas the stabilizer portion 6b is rotatably mounted relative to the actuator housing 4 and is connected to the output of the multistage planetary gear 16 in a rotationally fixed manner to be rotatable relative to the stabilizer portion 6a by means of the actuator 2. One end 5a of the actuator, which is fixed to the housing, is also connected to the stabilizer portion 6a, whereas on the output end 5b of the actuator, the stabilizer portion 6b is rotatably mounted relative to the actuator housing 4 and is drivingly connected to the multistage planetary gear 16 and the electric motor 15.

[0053] In the explanations given so far for FIG. 2, the embodiment shown in FIG. 2 is similar to the embodiments shown in FIGS. 5, 6 and 7. In order to avoid repetition, the following will therefore only deal with the differing special features of the individual embodiments:

[0054] In the roll stabilizer shown in FIG. 2, the sensor device 10 is designed in such a way that a sensor unit 11, for example in the form of a sensor head, is arranged inside the actuator housing 4, the actuator housing 4 also serving as the measurement element of the sensor device 10. The sensor unit 11 is thus arranged radially inside the measurement element 4 (equal to actuator housing 4). The actuator housing 4 can be magnetized by means of a magnetic field generation device arranged on the sensor unit 11, and parameters of the magnetic field generated by the actuator housing 4 can be acquired by means of a first magnetic field detection device and a second magnetic field detection device on the sensor unit 11.

[0055] FIGS. 3 and 4 schematically show the structure and arrangement of the sensor unit 11 used in this case in different views. FIG. 9 shows an exploded view of an embodiment of the sensor unit 11.

[0056] FIG. 3 shows the sensor unit 11 arranged inside the actuator housing 4 in a simplified form in a plan view. In plan view, the sensor unit 11 is located approximately centrally above the axis of rotation 3 of the actuator 2, in an area between the stabilizer portion 6a and the electric motor 15. A transmitter coil 12 and four receiver coils 13 are arranged on the sensor unit 11 as a structural unit. In this case, the transmitter coil 12 is arranged between a respective pair of receiver coils 13, the four receiver coils 13 being arranged in a square in the center of which the transmitter coil 12 is positioned.

[0057] According to FIG. 4, which shows the sensor unit 11 inside the actuator housing 4 of the actuator 2 in axial section along the axis of rotation 2, the sensor unit 11 has a surface 17 that is convex to the inside of the measurement element (equal to actuator housing 4). The coils 12, 13 arranged on the surface 17 thus have an equal distance to the actuator housing 4, whereby for each of the coils there is a similar interaction with respect to the actuator housing 4 serving here as measurement element.

[0058] The embodiments shown in FIGS. 5, 6, 7, 8, 10 and 11 differ from the embodiment described on the basis of FIG. 2 with regard to the arrangement of the sensor units 11.

[0059] According to the embodiment shown in FIG. 5, the sensor unit 11 is arranged radially inside the stabilizer portion 6a. In this case, the stabilizer portion 6a forms the measurement element—at least in sections—in that the stabilizer portion 6a can be magnetized by means of the transmitter coil and the magnetic field generated by the stabilizer portion 6a can be detected by means of the receiver coil(s).

[0060] According to the embodiment shown in FIG. 6, the sensor unit 11 is arranged radially outside the stabilizer portion 6a. Here, too, the stabilizer portion 6a forms the measurement element—at least in sections—in that the stabilizer portion 6a can be magnetized by means of the transmitter coil and the magnetic field generated by the stabilizer portion 6a can be detected by means of the receiver coil(s).

[0061] According to the embodiment shown in FIG. 7, the sensor unit 11 is arranged radially outside the actuator housing 4, which in this case again forms the measurement element. In contrast to the example shown in FIG. 2, however, the sensor unit 11 is now arranged radially outside the actuator housing 4. Such an arrangement can be useful, for example, if there is insufficient space inside the actuator housing 4 to accommodate the sensor unit 11.

[0062] FIGS. 8, 10 and 11 show embodiments of the roll stabilizer in which the sensor device 10 has several sensor units 11.

[0063] According to the embodiment shown in FIG. 8, a first sensor unit 11 a is arranged radially inside the first stabilizer portion 6a to measure a torque at the first stabilizer portion 6a. A second sensor unit 11b is arranged radially inside the second stabilizer portion 6b to measure a torque at the second stabilizer portion 6b. The sensor device 10, and in particular the control unit 14, is adapted to compare and correlate the signals from the sensor units 11a, 11b.

[0064] In the embodiment of FIG. 10, a first sensor unit 11 a and a second sensor unit 11b are arranged radially inside the actuator housing 4 with respect to the center of the actuator housing 4 formed by the rotation axis 3 at diametrically opposite positions. For example, a first sensor unit 11 a points toward a portion of the actuator housing 4 directed toward a ground, while the second sensor unit 11b points toward a side of the actuator housing 4 directed toward the interior of the motor vehicle. If these different areas are influenced differently, for example by external influences such as spray water or the like, a more accurate signal can be achieved by comparing and checking the plausibility of the signals from the sensor units 11a, 11b.

[0065] According to the embodiment shown in FIG. 11, several sensor units 11, in this case for example a first to fourth sensor unit 11a-11d, are distributed over the circumference of the measurement element—for example the actuator housing 4.

[0066] In the following, an example of the sensor devices 10 or sensor units 11, 11a-11d that can be used in the different embodiments of the roll stabilizer shown here is explained in more detail on the basis of the illustration of FIG. 9.

[0067] The sensor unit 11 has a magnetic field generation device 20 as well as a first magnetic field detection device 21 and a second magnetic field detection device 22, a housing 23, an electronic unit 24 and a cover 27.

[0068] The housing 23 has a housing bottom 25 and a housing wall portion 26 formed of electrically conductive, magnetically shielding materials. The cover 27 is made of a material such as plastic, which allows magnetic fields to pass well. A shielding device 28 is formed by the housing 23 made of magnetically shielding materials.

[0069] The electronic unit 24 has, in particular, the control unit 14 (ECU) and, in the illustrated example, also an acceleration sensor 29.

[0070] The magnetic field generation device 20 has the transmitter coil 12. In alternative embodiments, the magnetic field generation device 20 has a plurality of transmitter coils 12 as a coil package (not shown).

[0071] The first magnetic field detection device 21 has a first receiver coil 13a. The second magnetic field detection device 22 has a second receiver coil 13b. The first and second receiver coils 13a, 13b and the transmitter coil 12 may be arranged together in an integrated manner in a coil package 30. In an embodiment not shown in more detail here, the coil module 30 has only two receiver coils 13a, 13b. The illustrated embodiment shows the arrangement with four receiver coils 13a-13d already discussed with reference to FIG. 3. The third receiver coil 13c and the fourth receiver coil 13d form a third magnetic field detection device 31 and a fourth magnetic field detection device 32, respectively.

[0072] Instead of the receiver coils 13, 13a-13d, other magnetic field detection elements, such as Hall sensors, can also be used in further embodiments not shown in more detail here. Such magnetic field detection elements are used to acquire parameters of the magnetic field. For example, an orientation and an angle of the magnetic field can be acquired by comparing the signals from the individual magnetic field detection devices 21, 22, 31, 32. Through these signals, a torque on the actuator housing 4 or the stabilizer portions 6a, 6b can be detected.

LIST OF REFERENCE SIGNS

[0073] 1 roll stabilizer [0074] 2 actuator [0075] 3 axis of rotation [0076] 4 actuator housing [0077] 5a end of actuator fixed to housing [0078] 5b output end of actuator [0079] 6a stabilizer portion (fixed to housing) [0080] 6b stabilizer portion (at output side) [0081] 7a, 7b wheel [0082] 8a, 8b wheel suspension [0083] 10 sensor device [0084] 11 sensor unit [0085] 12 transmitter coil [0086] 13 receiver coil [0087] 13a first receiver coil [0088] 13b second receiver coil [0089] 13c third receiver coil [0090] 13d fourth receiver coil [0091] 14 ECU [0092] 15 electric motor [0093] 16 multistage planetary gear [0094] 17 surface [0095] 20 magnetic field generation device [0096] 21 first magnetic field detection device [0097] 22 second magnetic field detection device [0098] 23 housing [0099] 24 electronic unit [0100] 25 housing bottom [0101] 26 housing wall part [0102] 27 cover [0103] 28 shielding device [0104] 29 acceleration sensor [0105] 30 coil component [0106] 31 third magnetic field detection device [0107] 32 fourth magnetic field detection device [0108] M torque