Device for detecting movement and / or position of an object

Abstract

The invention relates to a device for detecting the movement and / or position of a rotating shaft, wherein, depending on the movement and / or position of the shaft, a voltage pulse is generated in at least one coil by at least one magnetic field which is moved relative to the coil and which loads the coil, wherein the coil has a coil housing which is composed of a first housing part and a second housing part, the housing parts of the coil being held together in a manner wound by coil wire and forming a cavity in the interior, in which cavity, under the influence of the magnetic field, a leaf spring composed of magnetically permeable material is moved abruptly to and fro, wherein a first region of the leaf spring is arranged movably in the cavity, while a second region of the leaf spring is fixed between the first housing part and the second housing part.

Description

Technical Field

[0001] The invention relates to a device for detecting the movement and / or position of a rotating shaft. Background Art

[0002] Conventional rotary encoders are used to detect measured variables such as the angular position, speed, direction of rotation and / or angular acceleration of a rotating shaft of a drive and to transmit them to a control system for controlling or regulating the drive.

[0003] This device for detecting the movement and / or position of a rotating shaft comprises a magnetic or optical dimension standard and a contactless scanning unit, which provides raw measurement data for calculating angle or position information. The scanning unit requires a voltage supply to operate it. If the voltage supply or the mains supply fails and the rotating shaft to be measured continues to move, no further measurement data can be detected or provided.

[0004] When detecting these measured variables, it must be ensured that the movement and / or position of the rotating shaft can be detected reliably. This means that the functionality of detecting the measured variables must continue to be ensured even if the voltage supply of the device fails.

[0005] To counteract erroneous detection of measured values ​​due to grid failures, rotary encoders are either equipped with batteries or powered by generators that draw their energy from a changing magnetic field. In this case, the encoder has an energy supply unit with a generator containing the necessary electronic components, such as a voltage converter.

[0006] Rotary encoders with batteries for energy supply have the disadvantage that the batteries must be replaced. This means that the service life of these variants is very limited.

[0007] For example, a battery-free rotary encoder with an autonomous energy supply is known from European Patent Document EP 1 687 592 B1.

[0008] The voltage pulses in the coil are generated by a leaf spring that moves back and forth in the coil, wherein the reciprocating movement of the leaf spring is caused by a magnetic field acting on the leaf spring. In this case, the leaf spring is made of a magnetically conductive material. Summary of the Invention

[0009] The object of the present invention is to advantageously improve the generator of the device for detecting the movement and / or position of a rotating shaft known from EP 1 687 592 B1, in particular by means of a simplified and particularly cost-effective construction and an increased service life.

[0010] According to the invention, this object is achieved by a device for detecting the movement and / or position of a rotating shaft, wherein, depending on the movement and / or position of the shaft in at least one coil, a voltage pulse is generated in the coil by at least one magnetic field which performs a relative movement relative to the coil and acts on the coil, wherein the coil has a coil housing which consists of a first housing part and a second housing part, the housing parts of the coil being held together by being wound with coil wire and forming a cavity in the interior, in which cavity a leaf spring made of a magnetically conductive material performs a sudden reciprocating movement under the influence of the magnetic field, wherein a first region of the leaf spring is movably arranged in the cavity, and a second region of the leaf spring is fixed between the first housing part and the second housing part.

[0011] That is, in the device, voltage pulses are generated in the coils, depending on the movement and / or position of the shaft, by performing relative movement relative to the coils and applying a magnetic field to the coils. These voltage pulses in the coils are generated by the magnetoresistance effect of a leaf spring made of a magnetically conductive material, which reciprocates under the influence of the magnetic field in the coils. The magnetic field is generated by at least one magnet pair consisting of two adjacent magnets of opposite polarity, arranged one behind the other in the direction of motion of the object, with their longitudinal axes, and thus the longitudinal axis of the coils, oriented substantially perpendicularly to the direction of motion of the object. The leaf springs suddenly reverse the polarity of the magnetic field effective in the coils, thereby generating a strong voltage pulse in the coils surrounding the leaf springs.

[0012] The coil housing serves as the structure of the coil, and the coil wire is arranged around the coil housing. The coil housing comprises a first housing part and a second housing part. These two housing parts form the mechanical structure of the coil housing.

[0013] The housing part forms a cavity in the inner region in order to realize a space in which the leaf spring can be arranged. The leaf spring is arranged in the cavity so that it is also surrounded by the coil.

[0014] The advantage of the present invention is that the quasi-modular construction of the generator unit enables simple assembly and thus low-cost production. In addition, the generator unit constructed in this way can be easily adjusted and installed due to slight size changes of individual components with different configurations.

[0015] Due to the modular arrangement of the elements of the generator unit, a compact arrangement or construction of the device for detecting the movement and / or position of a rotating shaft is possible.

[0016] The solution according to the invention can be further improved by different, individually advantageous and arbitrarily combinable embodiments. These embodiments and the advantages associated therewith will be discussed below.

[0017] According to one embodiment, the first and the second housing part can be connected to one another at at least one end by means of a tenon connection.

[0018] In one embodiment, the mortise and tenon connection can include a mortise hole provided in the first housing part and a tenon in the second housing part that fits in the mortise hole in a form-fitting manner. This has the advantage that the two housing parts can be connected to one another in a simple manner during production. This embodiment is relatively inexpensive and, in addition, results in a favorable orientation of the housing parts relative to one another due to the tenon that fits in the mortise hole in a form-fitting manner.

[0019] In order to reduce the effort involved in aligning the leaf spring relative to the coil housing, the leaf spring can have an opening in the second region of the leaf spring, through which the tongue of the second housing part can be inserted, so that the leaf spring can be fixed in the cavity by means of the tongue-and-groove connection. The leaf spring can thus be advantageously fixed in the cavity of the coil housing.

[0020] The opening of the leaf spring has a geometry that positively matches the tenon. The tenon can thus be passed through the leaf spring in the opening to orient the leaf spring. Advantageously, the opening can have a geometry that positively matches the tenon, in which the tenon passes through the leaf spring until it abuts against the first housing part.

[0021] According to one embodiment, the housing components each have a groove on their outer sides, into which the coil wire is wound. The coil wire thus surrounds both housing components and holds them together to form a coil housing. The coil wire forms the coil winding and is arranged in the grooves on the outer sides of the housing components, thereby holding the housing components together. This structure stabilizes the leaf spring secured between the housing components.

[0022] The groove has a depth that accommodates the coil wire and does not allow it to protrude outside the coil housing. This allows the coil to be installed without erroneous contact, which could occur if the coil winding protrudes outside the coil housing.

[0023] Furthermore, the housing parts can be adhesively bonded to at least one joint in the region of the tenon connection. Preferably, the housing parts are adhesively bonded to one another in the region of the tenon connection at two joints.

[0024] According to one embodiment, the first and second housing parts are made of glass-fiber reinforced plastic.

[0025] The cavity is formed by two recesses facing each other and formed in the housing part. The depth of the recess increases along the housing longitudinal axis of the housing part from a minimum depth to a maximum depth.

[0026] The leaf spring is arranged in the cavity so that the movable region of the leaf spring is directed toward the maximum depth of the recess of the housing part. This enables optimal movement of the leaf spring in the cavity.

[0027] According to one embodiment, the cavity has a tapering or flared cross-section along the longitudinal axis of the housing. This has the advantage that the movement of the leaf spring is restricted, so that the leaf spring can only reciprocate in a specific area due to the magnetic field acting on it. This prevents overloading of the leaf spring, thereby increasing its service life.

[0028] The magnetic field that loads the leaf spring can be generated by a magnet pair, for example a pair of block magnets with alternating polarity (N, S), which is located on a rotating disk, which is in this case connected to a moving or rotating shaft.

[0029] The described design advantageously allows the leaf spring to be positioned in the coil housing in a simple assembly step, taking into account the necessary tolerances. The leaf spring is enclosed by the coil and precisely positioned so that each individual reciprocating movement of the free, movable end of the leaf spring does not exceed the maximum deflection, namely half the cavity width. This increases the service life of the leaf spring and, therefore, the device.

[0030] The leaf spring is surrounded by coil wire wound around the housing. Due to the magnetically conductive material, the leaf spring is ultimately moved abruptly within the coil cavity by the magnetic field acting on it when the block magnet pair passes by. This induces a voltage pulse in the coil. This voltage pulse is transmitted to the electronics via suitable contact mechanisms.

[0031] The device according to the invention enables energy-autonomous signal generation, in particular when the mains supply to the device is interrupted.

[0032] The device according to the invention is suitable for use in applications in which power supply failures are expected, since it can generate the supply voltage required for determining the position signal and the sensor electronics required therefor, independently of the power supply. Furthermore, in such applications, the device contributes to increased system stability, as it reduces interference, is independent of alternative energy sources such as batteries, and contributes to the robustness of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is explained in detail below by way of example with reference to the accompanying drawings. The feature combinations shown by way of example in the illustrated embodiments can be supplemented by further features, corresponding to the properties of the device and / or method according to the invention that are necessary for a particular application, according to the embodiments described above. Similarly, individual features can be omitted from the described embodiments if this is not essential for their effectiveness in a specific application.

[0034] The accompanying drawings show:

[0035] Figure 1 shows a schematic diagram of the device according to the invention in assembled form according to an exemplary embodiment;

[0036] Figure 2 A schematic diagram of the device according to the invention according to an exemplary embodiment is shown as an exploded view;

[0037] Figure 3 A schematic detail view showing a housing component of the device according to the invention;

[0038] Figure 4 A schematic detail view A showing a cutout in a housing part of the device according to the invention; and

[0039] Figure 5 The device according to the invention is shown with a magnetic field generating unit. DETAILED DESCRIPTION

[0040] In the following detailed description, reference is made to the accompanying drawings, which form a part of this document and in which specific embodiments are shown as illustrations in which the present invention can be explained. It should be understood that other embodiments can also be used and structural or logical changes can be made without departing from the design concept of the present invention. Therefore, the following detailed description should not be understood as limiting. It should also be understood that, unless otherwise specifically stated, the features of the different embodiments described herein can be combined with each other.

[0041] Although some aspects of the present invention are described only in the context of the apparatus, it is readily apparent that these aspects are also descriptions of corresponding methods, where, for example, a block, module, unit, or device corresponds to a function of a method step or process step. Similarly, aspects described in the context of a method step are also corresponding descriptions of blocks, modules, units, or features of a device.

[0042] Aspects and embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals generally refer to like elements. In the following description, for illustrative purposes, numerous specific details are set forth in order to facilitate a thorough understanding of one or more aspects of the present invention.

[0043] Below, refer to Figure 1 and Figure 2 A device for detecting the movement and / or position of a rotating shaft according to the present invention is described. Figure 3 and Figure 4 , depicts a second housing part 6 and a detailed view A of the second housing part 6 belonging to the device 1 according to the invention. Figure 5 An embodiment variant of a device having a magnetic field generating unit is described.

[0044] Figure 1 A perspective view of a coil 1 with a leaf spring 2 in the installed state is shown. Together with the leaf spring 2, the coil 1 forms part of a self-sufficient energy supply unit and is part of a device for detecting the movement and / or position of a rotating shaft, such as a drive shaft (not shown). Furthermore, a magnetic field is provided that induces relative movement relative to the coil 1 and impinges upon it. The coil 1 includes contact means 14a, which establish an electrical connection with a printed circuit board. The printed circuit board contains, in particular, electronic components for signal detection and evaluation.

[0045] In response to the rotational movement of the drive shaft, voltage pulses are generated in coil 1 by relative movement relative to coil 1 and by applying a magnetic field to the coil. In this case, coil 1 comprises a coil housing 4 , which consists of a first housing part 5 and a second housing part 6 . Coil wire 3 is wound around housing parts 5 and 6 of coil 1 . Coil 3 holds first and second housing parts 5 and 6 together. When assembled, housing parts 5 and 6 form a cavity 10 within their interiors. In cavity 10, leaf spring 2 , made of a magnetically conductive material, reciprocates under the influence of the magnetic field.

[0046] Figure 2 The arrangement of the leaf spring 2 inside the housing parts 5 and 6 can be seen in FIG. The first region 2a of the leaf spring 2 is movably arranged in the cavity 10, while the second region 2b of the leaf spring 2 is fixed between the first housing part 5 and the second housing part 6. The coil 1 consisting of the tightly wound coil wire 3 is schematically shown in FIG. Figure 2 Shown in.

[0047] The magnetic field acting on the coil 1 is generated by four block magnets 17a, 17b, 17c and 17d with alternating polarity, i.e., north and south poles, arranged on a disk 21, according to the rotational movement of the shaft. The disk 21 is connected to the shaft. A variant embodiment of this is shown in FIG. Figure 5However, it is also conceivable that only two block magnets 17 with alternating polarities, ie south poles and north poles, are provided on the disk 21 .

[0048] The rotational motion of the block magnets 17a, 17b, 17c and 17d provided on the disk 21 and their magnetic fields cause the Figure 2 The leaf spring 2 shown in FIG. 1 reciprocates within a cavity 10 formed by the connection of the first housing part 5 and the second housing part 6 . The two housing parts 5 and 6 thus form the mechanical structure of the coil housing 4 .

[0049] The leaf spring 2 is made of a magnetically conductive material. The first and second housing parts 5 and 6 form a coil housing 4, which is wound with coil wire 3 and forms the coil 1 with the coil wire 3. The sudden reciprocating movement of the leaf spring 2 within the cavity 10 generates a voltage pulse in the coil 1. This voltage pulse in the coil 1 is generated by the magnetoresistance effect of the leaf spring 2, which is made of a magnetically conductive material. The leaf spring 2 suddenly reverses the polarity of the magnetic field effective in the coil 1, thereby generating a strong voltage pulse in the coil 1 surrounding the leaf spring 2.

[0050] As in Figure 2 As shown in FIG, the first and second housing parts 5 and 6 are connected to one another at one end by means of a mortise and tenon connection 11. Mortise and tenon connection 11 consists of a mortise hole 13 provided in the first housing part 5 and a tenon 12 in the second housing part 6 that fits in the mortise hole 13 in a form-fitting manner. This has the advantage that the two housing parts 5 and 6 can be connected to one another in a simple manner during the manufacturing process. This embodiment is relatively inexpensive and, in addition, results in a favorable orientation of the housing parts 5 and 6 relative to one another due to the tenon 12 that fits in a form-fitting manner relative to the mortise hole 13.

[0051] In order to reduce the effort involved in aligning the leaf spring 2 relative to the coil housing 4, an opening 9 is provided in the leaf spring 2 at a second region of the leaf spring 2, through which a tongue 12 of the second housing part 6 can be inserted, so that the leaf spring 2 can be fixed in the cavity 10 by means of a tongue-and-groove connection 11. This advantageously allows the leaf spring 2 to be fixed in the cavity 10 of the coil housing 4.

[0052] The opening 9 of the leaf spring 2 has a geometry that positively matches the tongue 12. To orient the leaf spring 2, the tongue 12 can be passed through the leaf spring 2 in the opening 9. Advantageously, the opening 9 can have a geometry that positively matches the tongue 12, in which the tongue 12 passes through the leaf spring 2 until it stops on the first housing part 5.

[0053] Therefore, according to Figure 2The tongue 11 can be advantageously connected to the tongue 13 of the first housing part 5 via the leaf spring 2 passing through it, which serves not only to assemble the coil housing 4 but also to secure the oriented leaf spring 2. This allows the leaf spring 2 to be secured between the housing parts 5 and 6 and the coil housing 4 to be assembled in one step. This simplifies the construction and manufacture of the device while ensuring reproducible accuracy in the position of the leaf spring 2 relative to the coil housing 4.

[0054] exist Figure 2 shows an exploded view of the coil 1 with the leaf spring 2. To achieve an optimal connection between the first and second housing parts 5 and 6, two joints 16a and 16b are provided in the region of the tenon joint 11, at which the two housing parts 5 and 6 can be adhesively bonded. This has the advantage that any mechanical play between the housing parts 5 and 6 can be compensated. Furthermore, the adhesive bonding at the two joints 12, 13 ensures a stable mechanical connection between the housing parts 5 and 6.

[0055] from Figure 3 and Figure 4 The optimal geometry of the cavity 10 is known from Figure 3 and Figure 4 A detail of the second housing part 6 is shown by way of example. Figure 4 Here is Figure 3 Detailed view of view A.

[0056] The cavity 10 is formed by two recesses 10 facing each other and formed in the housing parts 5 and 6, wherein, for example, Figure 4 1 shows a recess 10b of the second housing part 6. The depth of the recess 10b increases along the housing longitudinal axis 8 of the second housing part 6 from a minimum depth 10c to a maximum depth 10d.

[0057] The leaf spring 2 is arranged in the cavity 10 such that the movable second part 2 a of the leaf spring 2 points toward the maximum depth of the recesses of the housing parts 5 and 6 . This allows for an optimal movement of the leaf spring 2 within the cavity 10 .

[0058] Preferably, as in Figure 4 As shown in FIG, cavity 10 has a tapering or flared cross section along housing longitudinal axis 8. This has the advantage that the movement of leaf spring 2 is limited, so that leaf spring 2 can only reciprocate in a specific range depending on the magnetic field acting on it. This prevents overloading of leaf spring 2, thereby increasing its service life.

[0059] The magnetic field that loads the leaf spring 2 can be generated by a magnetic field generating device, such as, for example, Figure 5As shown in FIG. The magnetic field generating device is composed of a pair of block magnets 17a, 17b, 17c and 17d with alternating polarity (N, S), wherein the block magnets 17a, 17b, 17c and 17d are arranged on a rotating disk 21. In this case, the rotating disk 21 is connected to the rotating drive shaft ( Figure 5 The optical or magnetic measuring body can also be arranged on the disk 21 (not shown) in connection with a corresponding detection unit for determining the rotational speed and / or position of the drive shaft.

[0060] like Figure 5 As shown by way of example, disk 21 can include block magnets 17a, 17b, 17c, and 17d, each with different polarities N and S, arranged in an annular pattern on disk 21 without gaps therebetween. If disk 21 passes leaf spring 2 located in coil 1 at a corresponding distance, a voltage pulse is generated in coil 1 due to the sudden reciprocating motion of leaf spring 2 in coil 1 at each polarity change NS or SN. The advantageous, gap-free arrangement of the block magnets on disk 21 has the technical effect of generating a voltage pulse in coil 1 that exhibits neither undesirable back- and front-oscillations during its signal progression. Furthermore, this arrangement results in a significantly stronger magnetic field, and the distance, or air gap, between the magnetic field generating device (the block magnets arranged in an annular pattern on disk 21) and leaf spring 2 can be selected to be larger.

[0061] The described design advantageously allows the leaf spring 2 to be positioned in the coil housing 4 in a simple assembly step and while taking into account the necessary tolerances. The leaf spring 2 is enclosed by the coil 1 and precisely positioned so that each individual reciprocating movement of the free, movable end 2a of the leaf spring 2 does not exceed the maximum deflection, that is, half the width of the cavity 10. This increases the service life of the leaf spring 2 and, therefore, the service life of the device for detecting the rotational movement of a drive shaft.

[0062] Leaf spring 2 is surrounded by coil 3, which is wound around housing parts 5 and 6. Due to the magnetically conductive material, leaf spring 2 is suddenly moved back and forth within cavity 10 of coil 1 by the magnetic field acting upon it when block magnets 17a, 17b, 17c, and 17d, or pairs of block magnets 17a, 17b, and 17c, 17d, pass by. This induces a voltage pulse into coil 1. The voltage pulse is transmitted to the electronics via suitable contact mechanisms 14a, 14b.

Claims

1. A device for detecting the movement and / or position of a rotating shaft, wherein a voltage pulse is generated in at least one coil (1) by performing a relative movement relative to the coil (1) and applying at least one magnetic field to the coil (1), depending on the movement and / or position of the shaft, wherein the coil (1) has a coil housing (4) consisting of a first housing part (5) and a second housing part (6), the housing parts (5, 6) of the coil (1) being held together by being wound with a coil wire (3) and forming a cavity (10) in the interior, in which a leaf spring (2) made of a magnetically conductive material performs a sudden reciprocating movement under the influence of the magnetic field, wherein a first region (2a) of the leaf spring (2) is movably arranged in the cavity (10), and a second region (2b) of the leaf spring (2) is fixed between the first housing part (5) and the second housing part (6).

2. The device according to claim 1, wherein the first and second housing parts (5, 6) are connected to each other at at least one end by means of a tenon connection (11).

3. The device according to claim 2, wherein the mortise connection device (11) includes a mortise hole (13) arranged in the first shell part (5) and a mortise (12) in the second shell part (6) that is shape-fittingly matched to the mortise hole (13).

4. An apparatus according to claim 3, wherein the second area of ​​the leaf spring (2, 2b) has an opening (9), and the tenon (12) of the second housing part (6) can be inserted through the opening so that the leaf spring (2) can be fixed in the cavity (10) by means of the tenon connection device (11).

5. The device according to claim 2, wherein the housing parts (5, 6) are adhesively bonded at at least one joint (16) in the region of the tongue and tongue connection (11).

6. The device according to claim 1, wherein the housing parts (5, 6) each have a groove (18) on the outside, into which groove the coil wire (3) is wound.

7. The device according to any one of claims 1 to 4, wherein the first and second housing parts (5, 6) consist of glass-fiber reinforced plastic.

8. An apparatus according to any one of claims 1 to 4, wherein the cavity (10) is formed by two recesses (10a, 10b) facing each other and formed in the housing parts (5, 6), wherein the depth of the recesses (10a, 10b) increases along the housing longitudinal axis (8) of the housing parts (5, 6) from a minimum depth (10c) to a maximum depth (10d).

9. The device according to claim 8, wherein the leaf spring (2) is arranged in the cavity (10) so that the first region (2a) of the leaf spring (2) points to the maximum depth (10d) of the corresponding recess (10a, 10b) of the housing part (5, 6).

10. The device according to claim 9, wherein the cavity (10) has a tapered or flared cross section along the longitudinal axis (8) of the housing for limiting the movement of the leaf spring (2).

11. Apparatus according to any one of claims 1 to 4, wherein the magnetic field is generated by pairs of block magnets (17a, 17b; 17, 17c, 17d) having alternating poles (N, S).

12. The device according to claim 5, wherein the housing parts (5, 6) are adhesively bonded at two joints (16, 16a, 16b) in the region of the tenon connection (11).

Images