EP3853558A1

EP3853558A1 - Sensor unit for a sensor/transmitter system and a sensor/transmitter system having such a sensor unit

Info

Publication number: EP3853558A1
Application number: EP19779749.1A
Authority: EP
Inventors: Jochen Bantel; Andreas Paul; Joachim Reichert; Anatol Schwersenz; Peter SELKA; Jürgen Ulm; Oliver Vogel
Original assignee: Kaco GmbH and Co KG
Current assignee: Kaco GmbH and Co KG
Priority date: 2018-09-20
Filing date: 2019-09-18
Publication date: 2021-07-28
Also published as: DE102018007529A1; CN112805537A; WO2020057771A1; US20210348952A1

Abstract

The sensor unit for a sensor/transmitter system is used to capture at least rotational and linear movements of a component (1) having magnetic poles. The sensor unit has at least one sensor which is at least one electrically conductive conductor bar (5) which is transverse with respect to the direction of movement of a magnetic field of the component (1). The relative movement between the magnetic field and the conductor bar (5) produces a voltage at said conductor bar, which voltage can be supplied to evaluation electronics (4).

Description

Sensor unit for a sensor-transmitter system and a sensor-transmitter

System with such a sensor unit

The invention relates to a sensor unit according to the preamble of claim 1 and a sensor-transmitter system according to the preamble of claim 9.

Magnetic and optical measuring systems or comparable measuring systems are used for measuring tasks on rotating shafts or linear movements in industrial applications and in the automotive industry. For example, knowledge of the current position of the crankshaft is essential for controlling fuel injection and the ignition point in internal combustion engines. The sensor systems used for this usually have Hall sensors. They are used to detect or change the magnetic field, which is caused by the rotation of either a permanently excited encoder wheel as an encoder or a steel encoder wheel with a corresponding sensor with a magnet. The sensors and the encoder are positioned according to the application. Evaluation electronics interpret the signal curve and make it available to control electronics. The known sensor units and sensor-encoder systems for determining the absolute position detection or the detection of the direction of rotation are complex and expensive, especially when the highest levels of accuracy are required. In particular, the sensors usually have to be positioned mechanically with high precision on housing areas to the sensor wheel.

The accuracy of the signals or the uniformity of the signal profiles is often restricted. On the one hand, the positioning of the sensors in the housing is usually very tolerant. Hall ICs in particular are sensitive to mechanical stresses in the housing. There is no compensation for such shape and position tolerances of the shafts and the housing. These inaccuracies can be found in the signal curve. In addition, most sensors are limited in terms of their operating temperature. The invention has for its object to design the generic Sensorein unit and the generic sensor-transmitter system so that they are simple and inexpensive to manufacture, easy to assemble and still meet the highest accuracy requirements.

This object is achieved in the generic sensor unit according to the invention with the characterizing features of claim 1 and in the gat device sensor system according to the invention with the characterizing features of claim 9.

The sensor unit according to the invention is characterized in that only a simple conductor rod is used as the sensor, which extends transversely to the direction of movement of a magnetic field of the assigned component. During the movement of the component, there is a relative movement between the magnetic field and the conductor bar, which creates a tension in the conductor bar. It is recorded and fed to the evaluation electronics.

The electrically conductive conductor rod is a cost-effective component that can be installed directly in the respective unit, for example directly in a seal that seals a rotating shaft. The conductor rod can be used to record very precise signal profiles. As a result, it is simple and yet reliably possible to reduce shape and position deviations of the component. If the sensor unit is used, for example, in an internal combustion engine of a motor vehicle, the efficiency of the internal combustion engine can be increased in this way. It can also reduce emissions and conserve resources. No expensive and rare materials are required in the sensor itself.

The sensor-encoder system, which has the sensor unit according to the invention, can not only perform rotary and linear movements, but also, for example, the speed, torque, frequency, position, direction of movement or deviations in position and shape Detect magnetic pole component. This list is not to be understood cumulatively.

The conductor bar ensures a long service life.

Since the conductor rod can be integrated directly into a component, for example a seal or sealing system, the conductor rod can supply corresponding output signals from which the desired information, such as the speed, direction of rotation or an angular position of a shaft, can be derived can be. This information can be used for intelligent engine management.

The conductor bar can be used at very low and very high temperatures without any problems, so that a sensor failure cannot occur.

The voltage is advantageously generated by a charge separation in the conductor bar. This charge separation occurs when the conductor bar is in the motion field of the magnetic field. Due to the relative movement between the magnetic field and the conductor bar, the charge is separated, which leads to the voltage to be evaluated in the conductor bar. This voltage can be evaluated by the evaluation electronics and used for regulation and / or control.

With a structurally very simple design, the conductor bar is part of a conductor wire. As a result, the conductor bar can be formed very easily and aligned with respect to the magnetic field of the moving component.

In a particularly advantageous embodiment, the conductor bar is located on a carrier, which can be a flexible printed circuit board, for example. The conductor bar can, for example, also be printed on or in a 3D matrix. It enables the sensor unit to be used in a wide variety of applications due to its high flexibility. It is possible to provide at least one conductor bar on both sides of the carrier. Then both conductor bars can be used for different functions.

In an advantageous embodiment, the conductor wire can be formed, for example, in a meandering shape or in a parallel arrangement by a suitable manufacturing process of at least two or more conductor bars.

The conductor bars on the two sides of the carrier are advantageously connected to one another in an electrically conductive manner.

To reduce the overall reluctance and thus to increase the magnetic flux and the magnetic flux density in the magnetic circuit, it is advantageous if a highly permeable layer is present behind the outermost circuit board. This highly permeable layer can consist, for example, of mu-metal. The highly permeable materials also have the advantage that they can shield external external fields, so that the measuring accuracy cannot be impaired by such external external fields.

In an advantageous embodiment, the conductor bar on one side of the carrier detects the movement of the component and the conductor rod on the other side of the carrier detects an inaccuracy of movement and / or shape / position deviation of the component. If the component is a shaft, for example, the rotational speed can be recorded with one conductor rod and the shaft eccentricity with the other conductor rod, for example.

In a particularly advantageous embodiment, the carrier has at least one bending line. This makes it possible to bend the sensor element or its carrier so that the conductor bars lie in a plurality of carrier elements lying one on top of the other. In addition, a suitable arrangement of the conductor bars in the several levels achieves an optimal signal level.

There is the advantageous possibility of integrating several sensors in the multiple levels by means of a suitable arrangement and interconnection of the conductor bars.

Instead of bending the carrier, it is also possible, for example, to wrap the carrier to the desired extent, as a result of which the conductor bars also come to lie on several levels.

In an advantageous embodiment, the carrier is connected directly to the evaluation electronics. Then the carrier and the evaluation electronics form the sensor unit, which is delivered as a prefabricated unit and can be installed by the customer, for example.

The sensor-transmitter system according to the invention is characterized in that it has the sensor unit according to the invention which is assigned to the moving component which is provided with the magnetic poles. If the component moves with the magnetic poles, a relative movement occurs between the magnetic field resulting from the magnetic poles and the sensor unit, which leads to the voltage to be detected being formed in the respective conductor rod.

The component is preferably an encoder, for example a sensor wheel. The encoder surrounds a shaft, the movements of which can be reliably detected with the sensor unit.

The magnetic poles are advantageously located on the circumference or on the end face of the encoder.

The magnetic poles are formed by permanent or electromagnets, which can be seen, for example, on the circumference or the end face of the encoder. However, the magnetic poles can also be formed in that the encoder consists, for example, of a sheet metal part with soft magnetic properties, on the circumference of which magnetic particles are arranged, from which the poles are produced by a magnetization process.

In a preferred application, the sensor unit is used on a rotating shaft which has a multi-pole, permanently magnet-excited sensor wheel in a rotationally fixed manner. One or more sensor units are assigned to this sensor wheel, for example diametrically opposite one another. If, in a preferred embodiment, they are provided with the flexible supports, for example printed circuit boards, the sensor units can be built curved in accordance with the curvature of the sensor wheel. At least one conductor bar is advantageously arranged on both sides of the carrier, which is preferably formed from a plurality of sensor wires which are meandering and are electrically connected to one another. Alternatively, winding the rod arrangement is also possible. Copper is preferably used for the conductor rod or the conductor wire.

In order for the induced voltages of the individual conductor bars to add up on the curved sensor unit, they must be at the same angular distance from one another as the poles on the encoder wheel.

With such a design, for example, the conductor bar with which the rotational speed is detected is located on the inner layer of the sensor unit. Correspondingly, on the outer layer of the carrier there is the conductor bar with which a wave of the wave is detected.

The signals generated by the conductor bars located on the inside of the carrier are superimposed and serve to detect the speed and the speed of the sensor wheel. These inner conductor bars represent the reference quantity for the signal evaluation of the shaft detection. The signals from the conductor bars on the outside of the sensor units are superimposed. If the shaft has no eccentricity (the shaft runs smoothly), a horizontal line with the sensor voltage 0 results in a voltage-time diagram.

However, if a shaft eccentricity occurs, the two sensor units with their external conductor bars provide different voltage-time curves that are approximately sinusoidal and differ from one another.

The extent of the amplitudes of these curves is a measure of the size of the shaft eccentricity.

The sensor unit advantageously has at least two conductor bars, it extends over 360 ° and has a magnetization pattern with uniform pole pitch.

It is further possible that the magnetization pattern with uniform pole pitch has at least one reference mark.

In another advantageous embodiment, the sensor unit we have at least two conductor bars, extends over 360 ° and is provided with a magnetization pattern with an uneven pole pitch.

If the sensor unit is designed in such a way that a plurality of conductor bars are provided on the carrier for different signal evaluations, different functions can be detected with the sensor unit, such as, for example, the rotational speed, a wave run and the like.

At least two sensor units are advantageously arranged along the component, as a result of which the signal can be picked up reliably.

The component is advantageously magnetized such that amplitude and / or frequency modulation is possible. As a result, an absolute position detection (angular position detection) of a shaft is possible in an advantageous manner. Absolute position detection is also possible using the vernier principle.

In order to be able to optimally adapt the signal level to the application, the poles of the component can be arranged differently in the y direction.

The subject of the application results not only from the subject matter of the individual claims, but also from all the details and features disclosed in the drawings and the description. They are claimed as essential to the invention, even if they are not the subject of the claims, insofar as they are new compared to the prior art, individually or in combination.

Further features of the invention result from the further claims, the description and the drawings.

The invention will be explained in more detail using some of the embodiments shown in the drawings. Show it

Fig. 1 shows a schematic representation of a first embodiment of a sensor-transmitter system according to the invention,

2 shows a schematic representation of a further embodiment of a sensor-transmitter system according to the invention with indicated wireless communication,

3 shows a further embodiment of a sensor-encoder system according to the invention in a representation corresponding to FIG. 1,

4 an enlarged view of a conductor bar of the sensor unit according to the invention, 5 shows an exemplary embodiment of a sensor unit according to the invention in a schematic illustration,

Fig. 6

to

8 different magnetization patterns of an encoder of the sensor-encoder system according to the invention,

Fig. 9

to

1 5 an encoder of the sensor-encoder system according to the invention for the use of the vernier principle,

1 6 shows a further embodiment of a sensor unit according to the invention,

1 7 shows a schematic representation of the sensor unit according to FIG. 1 6 in the folded state,

1 is a schematic representation of a further embodiment of a sensor unit according to the invention,

19 shows the signals of a sensor wheel and a sensor unit of the sensor-sensor system according to the invention,

Fig. 20

and

21 shows a schematic representation of the circuitry of three conductor bars of a sensor unit according to the invention,

22 shows a schematic representation of a further exemplary embodiment of a sensor-transmitter system according to the invention, 23 shows a schematic representation of a two-track sensor wheel with two sensors,

24 shows a schematic representation of the detection of a shaft runout of a sensor wheel by the sensor-sensor system according to the invention,

Fig. 25 in a schematic representation an inventive sensor

Encoder system with an even magnetization and an uneven arrangement of the conductor bars,

26 is a schematic representation of an inventive sensor

Encoder system with an even arrangement of conductor bars and an uneven magnetization.

The exemplary embodiments of sensor systems described below, with which an absolute or relative position detection and / or a detection of the direction of rotation of rotating components are possible, are distinguished by the fact that they can be produced inexpensively, yet guarantee high detection accuracy, have a long service life and over a wide temperature range can be used. The sensor systems are used in industrial applications and especially in the automotive industry. A preferred area of application is the use of the sensor system in a crankshaft sealing flange in which the sensor system is integrated.

The sensor system comprises a sensor sensor wheel system. In Fig. 1, a sensor wheel 1 is shown, for example, as an encoder, which is non-rotatably seated on a rotating machine part, in particular a shaft. The encoder wheel 1 is provided on the circumference with (not shown) magnets which cooperate with a sensor element 2 when the encoder wheel 1 is rotated about its axis. The sensor element 2 extends over part of the order of the sensor wheel and is connected via signal lines 3 to an evaluation electronics 4 connected. In the exemplary embodiment, sensor element 2 and evaluation electronics 4 form a sensor unit.

The sensor element 2 is provided in a manner to be described later with conductor bars 5, which consist of electrically conductive material. The encoder wheel 1 rotating about its axis with its permanent magnets generates a temporally changing magnetic field which, due to the Lorentz force, leads to a charge shift in the conductor bars 5. This charge shift leads to an analog sensor signal which is fed to the evaluation electronics 4 via the signal lines 3. It processes the analog sensor signals and digitizes them. The digital output signal of the evaluation electronics 4 is fed via signal lines 6 to a control unit 7, which evaluates the output signals. Depending on the design of the sensor element 2, the signals emitted by it can hold information about the speed or the direction of rotation of the sensor wheel or other information.

The control unit 7 can also serve to provide the evaluation electronics 4 with the necessary supply voltage 8.

The sensor element 2 can be integrated directly into the application without additional centering and mounting devices.

Fig. 2 shows a schematic representation of a sensor system that is energy-efficient. Sensor wheel 2 with conductor bars 5 is assigned to sensor wheel 1. The sensor signals are fed via the signal lines 3 to the evaluation electronics 4.

In contrast to the embodiment according to FIG. 1, the bidirectional data transmission between the evaluation electronics 4 and the control device 7 takes place wirelessly. The sensor element 2 supplies the evaluation electronics 4 with the necessary supply voltage 8. Otherwise, this embodiment has the same design as the previous embodiment.

The sensor system according to FIG. 3 corresponds to the embodiment according to FIG. 1. The difference is that the sensor element 2 extends not only over part of the circumference of the sensor wheel 1, but over the entire circumference.

2, the sensor element 2 can also be designed as a 360 ° sensor element according to FIG. 3.

Fig. 4 shows an enlarged representation of the conductor bar 5, which is designed as an electrical conductor. It is provided in a fixed position and lies at a short distance from the rotating encoder wheel 1. The fixed mounting of the conductor bar 5 is marked by xo.

The sensor voltage arises from a charge separation in the conductor bar 5. If the conductor bar cuts the magnetic field lines 10 of the rotating sensor wheel 1 due to a relative movement, the Lorentz force FL acts on the charge carriers 9 (electrons) present in the conductor bar 5.

Because of this charge separation, an electric field E is built up along the conductor rod 5 with the length l _y , which counteracts the charge separation. In the stationary case, there is a balance of forces between the electrostatic force Fei and the Lorentz force FL:

FL = -Fei

The following applies to the Lorentz force FL

FL = e B v. It is assumed here that the speed vector v is perpendicular to the vector of the magnetic flux density B. Here e is the total charge of the charge carriers 9.

The following applies to the electrostatic force Fei

Fei = e E.

If these relationships are inserted into the above equation, the following results: e B _z · Vx = -e · E.

It follows

Bz v _x = -E.

With the familiar relationship arises with it

U = -Bz ly · Vx.

Here ly means the length of the conductor bar 5.

In this way, the voltage U on the conductor bar 5 can be calculated. By rotating the encoder wheel 1, the magnetic field has a transverse direction of movement. The stationary conductor rod 5 is in the transverse magnetic field B, which moves through the conductor rod 5 at a speed v _x . This leads to the charge separation described and thus to an electrical voltage drop along the conductor bar 5 electrical repulsive forces Fei and the Lorentz force FL form a state of equilibrium. In the absence of the external magnetic field B, the charge separation is canceled again.

The amplitude of the sensor output signal can be adapted by suitable design, for example the number or length of the rods or multilayer.

5 shows an exemplary embodiment of the sensor element. It has two conductor rod groups 13 and two conductor rod groups 14 which are located on different levels. Each conductor bar group 13, 14 is provided with conductor bars 5, 5 'lying parallel to one another. Behind the conductor bar groups 13 and 14 there is advantageously a highly permeable material, such as mu-metal. The overall reluctance is reduced by such a material, as a result of which the magnetic flux and thus the magnetic flux density in the magnetic circuit are increased. In addition, external foreign fields can be shielded by such a material.

In the exemplary embodiment, each conductor rod group 13, 14 has conductor rods 5, 5 ′ which are parallel to one another and which extend perpendicular to the speed vector v of the magnetic field. The conductor bars 5, 5 'of each conductor bar group 13, 14 are electrically conductively connected to one another. Preferably, a conductor wire is used which follows a meandering course so that the conductor bars 5, 5 'lying parallel to one another are formed.

The conductor bar groups 13, 14 are connected to a reference potential 15 and connected to the evaluation electronics 4.

The conductor bar groups 13 arranged in two different levels,

14 are connected to one another at via points 16, which penetrate the intermediate layer located between the conductor bar groups 13, 14. 5 shows a part of the encoder wheel 1 with its permanent magnets 17 on the circumference. The permanent magnets 17 are arranged alternately in series as north and south poles. The pole pitch t is constant.

The conductor bars 5, 5 'are aligned such that they are parallel to the axis of rotation of the encoder wheel 1 and perpendicular to the speed vector v.

When the sensor wheel 1 is turned, a charge separation is produced in the conductor bars 5, 5 'due to the relative movement between the magnetic field lines of the permanent magnets 17 of the sensor wheel 1 and the conductor bars 5, 5', so that the voltage on the conductor bars 5, 5 ' U arises, which is evaluated and processed by the evaluation electronics 4, for example in order to determine the direction of rotation, the speed or the angular position of the rotating machine part.

The sensor system is characterized by a very compact design. The conductor bar groups 13, 14 can be designed such that a relatively high number of conductor bars 5, 5 'is formed with compact dimensions. The result is a very high useful signal level, which enables reliable evaluation of the signals supplied by the sensor element. The sensor element is advantageously designed as a multi-layer circuit board. The conductor bar groups 13, 14 are located on both sides of the circuit board and are connected to one another in an electrically conductive manner in a known manner via the plated-through holes 16.

6 and 7 show two exemplary magnetization patterns and their voltage profile for the sensor wheel 1, for a single-rod sensor, for example. The permanent magnets 17 of the encoder wheel 1 are shown.

6 shows a frequency-modulated magnetization pattern. The amplitude is corrected by the double poles in the y direction. This applies at a constant speed. The frequency modulation is achieved by a corresponding different, measured in the x-direction width of the permanent magnets 17. The width of the individual permanent magnets 17 initially decreases over the circumference and then increases again. The Fre- The course of the sequence over the circumference of the sensor wheel with respect to the voltage U ind shows that the amplitude of the curve is the same, while half the frequency T varies over the circumference of the sensor wheel. The narrower the individual poles of the permanent magnets 17, the greater the frequency T becomes. The frequency Ti in the area of the widest permanent magnet 17 and the frequency Tn in the area of a narrower pole are shown as examples.

In addition to Fig. 6, Fig. 7 shows a pole pattern with which a pure

Amplitude modulation is achieved. In contrast to the magnetization pattern according to FIG. 6, the permanent magnets 17 have the same width in the x direction. As a result, the amplitude level varies over the circumference of the transmitter wheel, while half the frequency T is the same over the circumference of the transmitter wheel.

A combination of frequency and amplitude modulation is also conceivable.

8 shows such an example. The desired modulation curve can be set by appropriately designing the permanent magnets 1 7 or pole pattern. Both the frequency and the amplitude change over the circumference of the encoder wheel. The pole patterns described by way of example according to FIGS. 6 to 8 show that the sensor system can be optimized depending on requirements and / or application.

As an example, the pole patterns from FIGS. 6 and 7, recorded with a sensor arranged over 360 °, can output a uniform incremental signal and additionally by detecting with a single-rod sensor, the respective frequency and / or amplitude-modulated signal.

Alternatively, signal modulations can also be achieved using a suitable rod arrangement. It is also possible to represent the magnetization pattern described as a multipole encoder. Magnetic particles are embedded on the circumference of the encoder wheel 1 and are embedded in a binding compound. The permanent magnet poles are formed on the circumference of the encoder wheel 1 by a magnetization process.

With reference to FIGS. 9 to 11, an absolute coding according to the vernier principle is described as an example, which can be used in the sensor-encoder system. Since this principle is known, it will only be explained briefly. The encoder wheel 1 has three incremental tracks with different numbers of teeth. 9 to 11 these incremental tracks are shown in a playful manner as three encoder wheels 1, which have 12, 15 and 16 teeth (pole pairs). These three incremental tracks are scanned and digitized separately.

The upper right illustrations of FIGS. 9 to 11 show the sine signals of the three tracks over an angle of rotation of 360 °. The phase angles ai to co are determined from these sine curves by digitization.

The phase relationships ßi (Fig.

12) and ß2 (Fig. 14) determined. The curve shape with respect to the phase relationship ßi is determined according to the relationship ßi = CM-02 and the phase angle ß2 according to the relationship ß2 = CM-03.

The angle value a can be calculated from the phase relationships ßi and ß2. This angle value is shown in FIGS. 13 and 15. The angle value a (FIG. 13) resulting from the phase relationship βi runs linearly over an angular range of 360 °.

15 schematically shows how the angle value a can be calculated from the angle relationships β1, β2. The value CM provides the fine resolution. Depending on the application of the sensor system and the sensor wheel used, the number and / or the distance of the conductor bars 5, 5 'from one another can be changed. For example, a 0 ° sensor can be produced simply by the sensor element 2 having only a single conductor bar 5.

The sensor elements 2 can be formed from a 0 ° sensor element to a 360 ° sensor element, a corresponding number of conductor bars 5, 5 'being used, which can also be located on different layers. The type of sensor elements depends on the number of poles of the permanent magnets 17 used.

The conductor bars 5 can be arranged at equal distances from one another. Instead of such a periodic arrangement, an aperiodic arrangement of the conductor bars 5, 5 'along the circumference of the encoder wheel 1 can also be provided. A combination of a periodic and an aperiodic arrangement of the conductor bars 5, 5 'is also possible. In this way, the sensor-transmitter system can be adapted to the intended application in such a way that an exact measurement of the speed and / or direction of rotation and / or other signal information is possible.

The number of layers of conductor bars can also be adjusted depending on the application. 5, the conductor bar groups 13, 14 are arranged in two layers one above the other. However, the sensor element can also be designed so that it is four-layer, six-layer, eight-layer, ... This can also influence the size of the signal level.

Another setting option is to adapt the distance between the conductor bars 5, 5 'to the application. For example, it is possible for the distance between the conductor bars 5, 5 'to correspond to one fifth of the pole pitch t. The distance between the conductor bars 5, 5 'is in any case chosen so that reliable charge separation is ensured. Fig. 1 6 shows a sensor layout for a sensor element 2, which consists of six layers (layer 1 to layer 6). As a printed circuit board, the sensor element has a flexible, film-like carrier 21, which has, for example, a rectangular outline and is made of polyimide, for example.

The carrier 21 is folded along the bending lines 22 running transversely to its longitudinal direction in such a way that the layers 1 to 6 lie on one another (FIG.

1 7). Layers 1 to 6 each have the same width, so that they lie congruently on top of each other when folded.

Each layer 1 to 6 is provided near the longitudinal edges of the carrier 21 with through openings 23. If layers 1 to 6 lie on top of one another, then the through openings 23 also lie congruently on top of one another. Fasteners can then be inserted through them in order to firmly connect the layers 1 to 6 lying on top of one another.

The carrier 21 is provided with four conductor wires 24 to 27, which are connected to the electronics 4. These conductor wires can for example consist of copper, silver, gold, platinum or nickel. The conductor wires 24 and 25 are arranged approximately meandering in such a way that the conductor bars 5 are formed which extend perpendicular to the longitudinal direction of the carrier 21. In the exemplary embodiment, the conductor bars 5 have the same distance from one another. They are designed so that they each have a distance from the adjacent longitudinal edges 28, 29 of the carrier 21. The conductor bars 5 form two sensors.

The conductor wires 24, 26 are each bent such that both ends are connected to the evaluation electronics 4.

In the embodiment shown, the carrier 21 has the six layers (layers 1 to 6) which are connected to one another by bending along the bending lines 22. A very compact design of the sensor element can thereby be achieved. The two sensors are located on both sides of the carrier 21. A highly permeable material is provided behind the last layer of the sensors, preferably mu-metal. Mu-metal has a high permeability, which causes the magnetic flux of low-frequency magnetic fields to concentrate in the material. In particular, the use of this material results in an amplification of the useful signal by inference formation, but also a shielding from interference fields. Such interference fields can be generated in a motor vehicle, for example by electric motors or starters. Ferritic foils, thin transformer sheets or hard or soft magnetic materials are also considered as highly permeable materials.

Depending on the application, any variants can ultimately be created and manufactured. In this way, multi-layer, such as three, four, five-layer ... layouts can be created and manufactured. The number of layers is dependent, for example, on the speed of the rotating machine part and / or on the distance between the encoder wheel 1 and the sensor element 2 and / or on the pole position of the encoder wheel 1. The lower the speed of the rotating component, the lower the voltages that can be achieved by the conductor bars 5. That is why more layers are used at lower speeds. Even with a smaller pole pitch, it is advantageous to use a correspondingly larger number of layers.

Fig. 1 7 shows a concrete example of a multi-fold, multi-layer sensor element 2, which is connected to the evaluation electronics 4.

If the sensor element is used for rotary applications, it can be shaped according to the diameter of the rotating component.

Here, the sensor element 2 can be designed such that it extends only over part of the circumference of the sensor wheel 1, as is shown by way of example in FIGS. 1 and 2. To increase the measuring accuracy, the sensor element 2 can also extend over an angular range of 360 ° (FIG. 3). In order to achieve absolute rotational position detection by magnetizing the encoder wheel 1, additional information can be integrated into the magnetization pattern of the encoder wheel 1. Such additional information is, for example, the frequency or the amplitude of the induced voltage U ind. The absolute rotation position detection can also be achieved by periodically / aperiodically recurring magnetization patterns. This has been explained by way of example with reference to FIGS. 6 to 8.

By means of a suitable combination of a uniform and / or non-uniform arrangement of the conductor bars 5, 5 ′ and a uniform and / or non-uniform magnetization of the encoder 1, an exact incremental rotational position (angular position) detection can be realized.

25 shows an example of the combination of a uniform magnetization and an uneven arrangement of the conductor bars 5, 5 '. The poles 17 are of identical design, while the conductor bars 5, 5 ′ are arranged such that they are at different distances from one another, as seen over the length of the encoder 1.

Fig. 26 shows an embodiment in which a uniform rod arrangement is combined with an uneven magnetization. The conductor rods 5, 5 'have the same distance from one another over the length of the encoder, while the poles 17 of the encoder 1 are designed differently.

The simple construction of the sensor element 2 offers the possibility of simply positioning several sensor elements 2 relative to the sensor wheel 1. This allows the signal to be tapped at one point. These multiple sensor elements 2 can be implemented in parallel with a multi-track sensor wheel 1. But it is also possible to train several sensor elements 2 out of phase. In this case, a single-track encoder wheel 1 is sufficient as an encoder.

The multi-lane, which is often realized in encoder wheels, can also be implemented in a corresponding sensor arrangement. In extreme cases it can With a number x of sensor elements 2 and a number y of tracks on the encoder wheel 1 as an encoder, a multidimensional bit space is generated.

Fig. 1 8 shows an example of a sensor layout with three sensors A, A 'and B, each having the conductor bars 5. They have the same length and the same distance to each other within their group. The sensors A and A 'are offset from each other by half the bar spacing. Sensor B recognizes the reference mark. The conductor bars 5 are arranged on the carrier 21 of the sensor element 2. The ends of the conductor wires forming the conductor rods 5 are connected to the evaluation electronics 4, which is only indicated in FIG. 18. As in the previous exemplary embodiments, the conductor bars 5 extend transversely to the direction of rotation of the sensor wheel 1 (FIG. 5). The conductor bars 5 are part of conductor wires, the ends of which are connected to the electronics 4.

The multilayer design of the sensor element 2 leads to an increase in the signal level and thus to an improvement in the measurement accuracy. The multilayer of the sensor element 2 can, as described, be achieved by folding the carrier 21. A multilayer can also be achieved, for example, by winding the carrier 21.

By folding the sensor element 2, several sensors in the form of the conductor bars 5, 5 'or conductor wires 24 to 27 can be arranged in several planes. The described material used enables a higher temperature resistance and temperature stability of the sensor than the conventional sensors, such as Hall or AMR sensors, which have long been used. As a result, the sensor element can be integrated into components that have to be subjected to vulcanization.

By using the highly permeable materials, the overall reluctance can be reduced, which increases the magnetic flux and the magnetic flux density in the magnetic circuit. Furthermore, by using the highly permeable materials in or on the sensor element, external external fields can be reliably shielded.

If several sensors in the form of conductor bars 5, 5 'are used, direction of rotation detection is possible.

The sensor element 2 can overlap over a defined area of the circumference of the sensor wheel. This effectively compensates for cumulative and subdivision errors. The maximum coverage can be up to 360 ° or even more. In addition, there is the possibility to arrange the sensor elements 2 over the circumference of the sensor wheel 1 or to arrange them in areas.

Since the sensor element 2 covers a defined area of the circumference, sum and division errors can be compensated for. In the maximum case, this overlap can go up to 360 °, as shown in FIG. 3. 1 9 shows the signal curve 30 for the sensor element 2 and the signal curve 31 for the sensor wheel 1. It is given as an example that the signal course 31 of the sensor wheel 1 has an irregularity. The sensor element 2, on the other hand, shows a uniform curve shape 30, in particular also in the area in which the curve 31 of the sensor wheel 1 has an error. This makes it possible to compensate for the error caused by the encoder wheel 1 by means of the signals from the sensor element 2.

Appropriate magnetization of the encoder wheel 1 (frequency / amplitude modulated) enables reliable absolute rotation position detection.

The sensor element 2 can be easily produced based on a printed circuit board, for example by means of 3-D printing, screen printing or other known methods.

The conductor bars 5, 5 'or the conductor wires 24 to 27 are advantageously made of copper, but can also be made of other materials with corresponding, possibly even better electrical properties can be produced.

The conductor bars 24 to 27 are simple metal wires and no longer semiconductors. This contributes to cost-effective production of the sensor element 2.

The exemplary embodiments relate to rotary applications. The sensor-encoder system can of course also be used for applications in which linear movements are carried out.

Any pole pattern can be applied to the encoder wheel 1, which is opposite a corresponding arrangement of the conductor bars 5, 5 'of the sensor element 2. This increases the measurement accuracy, the absolute position detection and the like.

The sensor-transmitter system works very energy-efficiently and can therefore be designed to be self-sufficient with little effort. The voltage is tapped on one side on the respective conductor wire 24 to 27. This contributes to a simple structure.

20 and 21 show the possibility of providing the sensor element with three sensors S1 to S3.

21 shows the corresponding circuit diagram. The sensors S1 to S3 are, for example, electrically connected to one another via a delta connection. By interconnecting sensors S1 to S3 in this way, the level of the sensor voltage can be increased. Other interconnections are also possible.

The three sensors S1 to S3 are each offset by 2/3 of a pole pitch t. This enables the angle of rotation of the shaft to be determined with high resolution. The encoder wheel 1 has the permanent magnets 17 with the pole pattern shown. The conductor bars 5 of the three sensors S 1 to S3 are perpendicular to the direction of movement v of the sensor wheel 1. The conductor bars 5 are connected at one end to the reference potential 15. The

other ends are linked with each other via the delta connection.

Each sensor S 1 to S3 has two conductor bars 5.

The evaluation electronics 4 can be supplied with energy by means of a power supply unit 7 based on the sensor principle, so that the entire sensor system can be energy self-sufficient. This is exemplified in Fig. 22 shown. Sensor element 2 is assigned to sensor wheel 1. The evaluation electronics 4 receives the supply voltage 8 and the sensor signals 3 ′ from the sensor-sensor element system.

Fig. 23 shows an example of a two-track encoder wheel 1, in which the permanent magnets 17 are arranged in two tracks 32 and 33. The permanent magnets 17 can have different pole patterns in the two tracks 32, 33, as can be seen from FIG. 23.

A sensor 34, 35 is assigned to each of the two tracks 32, 33. The sensors 34, 35 can be designed to play according to the described Ausführungsbei. The simple structure of the sensors, as explained on the basis of the various exemplary embodiments, enables very simple positioning relative to the encoder 1 or its tracks 32, 33. The sensors 34, 35 can, as shown, only over part of the circumference of the encoder , but also extend over 360 degrees.

A suitable sensor-encoder arrangement enables additional information to be acquired and used. In rotary applications, for example, a wave run can be determined easily and reliably. 24 shows a corresponding exemplary embodiment in a schematic illustration. A multi-pole, permanently excited sensor wheel 1 is shown, which has the permanent magnets 17 over its circumference. The system shows In addition, two sensors 36, 37 offset from one another by 180 degrees, which have, for example, a flexible printed circuit board as carrier 21. The sensor structure with the meandering conductor bars 5, which are connected to one another in an electrically conductive manner in the manner described, is located on both sides of the printed circuit board 21. So that the induced voltages of the conductor bars 5 on the partial arc-shaped sensor 36, 37 add up, the conductor bars 5 must be at the same angular distance from one another as the poles on the circumference of the encoder wheel 1.

For example, the rotational speed of the sensor wheel 1 is detected with the inner layer of conductor bars 5 and a wave run of the sensor wheel 1 is detected with the conductor bars 5 of the outer layer of the sensor. The wave of the encoder wheel 1 is indicated by the eccentricity 38 of the encoder wheel 1. The result of the eccentricity measure 38 is that the distance to the two sensors 36, 37 changes when the sensor wheel 1 is rotated. This is indicated in FIG. 24 in the right illustration by the dashed line 39. This different distance between the rotation of the sensor wheel 1 and the sensor 36, 37 is detected by the conductor bars 5 on the outer layer of the sensors. In this way, an undesirable wave beat can be recognized immediately, so that measures can be taken at an early stage.

The described embodiments can be installed directly in the respective application. By integrating the sensor element 2 into the application, the tolerance chain can be kept small, which increases the measuring accuracy. No additional measures for centering, positioning and mounting a sensor-transmitter system are required, which significantly reduces the manufacturing costs.

I n Compared to the well-known complex Hall sensor system, the described sensor-transmitter system can be manufactured more cost-effectively.

The sensor (s) including other electrical / electronic components, in particular capacitors, can be ( Printing technology on flexible printed circuit boards can be produced easily and inexpensively. As a result of the structurally simple design and design of the sensor element 2, there is a high level of robustness and a very long service life.

The sensor can also be applied directly to the application or to corresponding components, for example by printing.

The sensor-encoder system described can be used for rotary (axial, radial) and for linear applications.

Claims

Expectations

1 . Sensor unit for a sensor-transmitter system for detecting at least rotational and linear movements of a component having magnetic poles, with at least one sensor,

characterized in that the sensor is at least one electrically conductive conductor bar (5, 5 ') lying transversely to the direction of movement of a magnetic field of the component (1), on which the relative movement between the magnetic field and the conductor bar (5, 5 ') a voltage (U) arises which can be fed to an evaluation electronics (4).

2. Sensor unit according to claim 1,

characterized in that the voltage (U) is generated by a charge separation in the conductor bar (5, 5 '), which advantageously sits on a support (21), which preferably has at least one bending line (22).

3. Sensor unit according to claim 1 or 2,

characterized in that the conductor rod (5, 5 ') is part of a conductor wire (24 to 27).

4. Sensor unit according to one of claims 1 to 3,

characterized in that at least one conductor bar (5, 5 ') is provided on both sides of the carrier (21).

5. Sensor unit according to one of claims 1 to 4,

characterized in that the conductor wire (24 to 27) is meandering.

6. Sensor unit according to one of claims 1 to 5,

characterized in that the conductor bars (5, 5 ') are connected to one another in an electrically conductive manner on the two sides of the carrier (21), and that advantageously a highly permeable layer lies behind the conductor bars (5, 5 ') of the carrier (21).

7. Sensor unit according to one of claims 1 to 6,

characterized in that the conductor rod (5, 5 ') on one side of the carrier (21) the movement of the component (1) and the conductor rod on the other side of the carrier (21) an inaccuracy of movement and / or shape / position deviation of the Component (1) detected.

8. Sensor unit according to one of claims 1 to 7,

characterized in that the carrier (21) is connected to the evaluation electronics (4).

9. Sensor-encoder system for detecting at least rotary and linear movements, with at least one magnetic pole having a component and at least one sensor unit assigned to the poles according to one of claims 1 to 8.

10. Sensor-encoder system according to claim 9,

characterized in that the component (1) is an encoder which is partially provided with the magnetic poles (1 7).

1 1. Sensor-transmitter system according to claim 9 or 10,

characterized in that the magnetic poles (1 7) by

Permanent magnets or electromagnets are formed, which are provided on the encoder (1), or that the encoder (1) is magnetized to form the poles (17).

12. Sensor-encoder system according to one of claims 9 to 1 1,

characterized in that the arrangement of the conductor bars (5) is adapted to the pole pitch.

1 3. Sensor-encoder system according to one of claims 9 to 12,

characterized in that the sensor unit at least two lines tersstangen (5, 5 '), extends over 360 ° and advantageously has at least one reference mark magnetization pattern with uniform pole pitch, or that the sensor unit we at least two conductor rods (5, 5'), extends over 360 ° and one Has magnetization patterns with uneven pole pitch.

14. Sensor-encoder system according to one of claims 9 to 13,

characterized in that a plurality of conductor bars (5, 5 ') are provided on the carrier (21) for different signal evaluations.

15. Sensor-encoder system according to one of claims 9 to 14,

characterized in that at least two sensor units (2) are arranged along the component (1).

16. Sensor-encoder system according to one of claims 9 to 15,

characterized in that the component (1) is magnetized such that amplitude and / or frequency modulation is possible, and / or that the component (1) is absolutely coded according to the vernier principle.

17. Sensor-encoder system according to one of claims 9 to 16,

characterized in that in order to influence the signal level, the poles (17) of the component (1) can be positioned differently in the y direction.