HK1139730B - Device for the detection of an actuation angle of an element rotatable about a shaft - Google Patents

Description

Device for detecting the adjustment angle of a pivotable element

The invention relates to a device for detecting an adjustment angle (Stellwinkel) of more than 180 DEG of an element that can be rotated or pivoted about an axis.

DE 10133492 a1 discloses a device for detecting the adjustment angle of a pivotable or rotatable element in the form of a foot pedal, the permanent magnet of which is assigned to two hall sensors of a hall sensor arrangement, so that a rotational movement of the foot pedal in the direction of one hall sensor is detected as a positive angular movement and a rotational movement of the foot pedal in the other direction of the other hall sensor is detected as a negative angular movement. In this case, the two hall sensors are located on both sides of the pole pitch of the annular permanent magnet, so that each hall sensor is only at a distance from the pole pitch in an angular range of < 90 °.

In the case of this known device, only a limited angular range of ± < 90 ° can therefore be detected and analyzed. This is not sufficient for some applications.

The object of the present invention is therefore to provide a device of the type mentioned at the outset for detecting an adjustment angle of an element that can be rotated or pivoted about an axis, in which case it is also possible to detect adjustment angles of more than 90 ° in the same direction, and in particular such adjustment angles of more than 180 °.

In order to solve this object, a device for detecting an adjustment angle of an element that can be rotated or pivoted about an axis of rotation of the type in question has a sensor device which outputs an electrical signal as a function of the angle of rotation and which has an annular permanent magnet that is connected to the rotatable or pivoted element in a non-movable manner, wherein the sensor device has a stationary hall sensor device with two or more individual hall sensors arranged at angular intervals around the annular permanent magnet, from which hall sensors a microcontroller selects the hall sensor in each case within the linear range of its characteristic line as a function of the current position of the rotatable or pivoted element.

By the measure according to the invention, angles of more than 180 ° can be evaluated, since a plurality of sensors are distributed over the circumference of the annular permanent magnet. In this case, the signals of the hall sensors in the most favorable range of their characteristic lines are used in each case, wherein the microcontroller or its electronic circuit determines which of the hall sensors is selected and evaluated as active in a specific angular range. By arranging three hall sensors instead of two hall sensors, a complete rotation of 360 ° of the rotatable element can be analyzed. Furthermore, if the analysis should be redundant, additional sensors may be arranged. A preferred embodiment of the selectable criteria of the microcontroller in this respect can be derived as follows: the microcontroller can successively select the hall sensors whose characteristic lines are in the linear or most linear range, respectively, such that the resulting total or output characteristic line thus combined remains linear or linear over an adjustment angle range of 0 ° to 360 °; or between the linear characteristic lines of the two hall sensors when the maximum adjustment angle ranges from 210 ° to 220 °.

A convenient and technically advantageous embodiment of the device can be obtained as follows. According to one embodiment, the sensor arrangement has two hall sensors which are at an angle of 80 ° to one another. According to another embodiment, the rotatable or rotating element is mounted on the shaft by means of a sliding sleeve which is preferably axially spaced. According to another embodiment, the shaft is made of steel and the sliding sleeve is made of sintered bronze. According to another embodiment, the rotatable or swiveling element is equipped with a preferably single permanent magnet. According to another embodiment, the permanent magnet is held adhesively on the rotatable or swiveling element. According to another embodiment, the rotatable or rotatable element has an annular flange, the radial inside of which is connected to the sliding sleeve and on the radial outside of which the permanent magnet is held centrally.

According to an exemplary embodiment of the rotatable or swiveling element, the rotatable or swiveling element is designed as an input wheel.

An advantageous embodiment of the sensor holder can be derived as follows. The device for detecting the angle of adjustment of an element that can be rotated or pivoted about an axis is provided with a sensor holder which is equipped with a chamber for accommodating the hall sensor. According to another embodiment, the hall sensor is held in place in a corresponding chamber of the sensor holder. According to a further development, pressure ribs are provided in the chamber, preferably on both sides. According to a further development, the sensor holder is fixedly connected to the shaft. According to another embodiment, the flange of the shaft is injection molded by the sensor holder. According to a further development, the sensor holder is embodied in the form of a cap and is clamped with its housing surface containing the chamber in the radial direction between the permanent magnet and the outer circumferential edge of the rotatable or rotating element or input wheel.

According to one embodiment of the invention, a printed circuit board is provided on which the hall sensor is held with its electrical connection terminals. According to a further embodiment, the connection terminals or legs of the hall sensor are guided by the sensor holder to a printed circuit board located above the sensor holder. This positioning of the hall sensors is simpler than assigning a separate printed circuit board to each hall sensor individually.

Further details of the invention can be gathered from the following description, wherein the invention is further explained and illustrated by means of embodiments shown in the drawings.

Fig. 1 shows a device for detecting an adjustment angle of an input element rotatable about an axis of more than 180 ° according to a preferred embodiment of the invention in a sectional view parallel to a top view along the line I-I of fig. 2 with two sensors.

Figure 2 shows a cross-section along the line II-II of figure 1,

figure 3 shows an enlarged partial view of circle III according to figure 1,

fig. 4 shows an enlarged partial view of circle IV according to fig. 2, an

Fig. 5 shows a diagram of the analog-to-digital-converted signal voltages of the two sensors and the analog-to-digital-converted output voltage selected from them as a function of the adjustment angle.

The device 10 shown in the figures is used, for example, for adjusting and detecting an adjustment angle of 90 ° or more or 180 ° and more in the same direction of rotation of an element 11 rotatable about an axis 12, which is referred to here as an input element 11, for an armrest of a tractor or for an output shaft coupling agricultural equipment to a tractor. The adjustment and detection of the setting angle is carried out by means of a magnetic field sensor arrangement, which is formed by a hall sensor arrangement 13, and an annular permanent magnet 14, as a result of which the component to be driven and adjustable in terms of its setting angle is driven or set in a manner not shown. A single annular permanent magnet 14 is arranged on the wheel-shaped input element 11, while the hall sensor device 13 is held on the sensor holder 15, the wheel-shaped input element 11 being rotatable concentrically in the same direction relative to the sensor holder 15 by an angle of > 90 ° or > 180 ° (in the exemplary embodiment shown by an angle of 210 ° to 220 °) and in this case also by up to 360 °, for example.

The sensor holder 15, which is located on the head, for example in the form of a pot, is formed in its entirety from a plastic base 16 and a surrounding cover 17. The base 16 of the sensor holder 15 is centrally penetrated by a hollow metal shaft 18 and is connected in a rotationally fixed manner to this shaft 18 in that a radial flange 19 of this hollow shaft 18 of the base 16 is injection molded. This allows precise positioning of the hollow shaft 18, which is preferably made of steel, relative to the sensor holder 15.

The housing 17 of the sensor holder 15 has in this exemplary embodiment two recesses 22 which are arranged at an angular distance of slightly less than 90 ° (80 ° in this case) from one another and which issue from their axis toward the housing surface 21 and which are arranged axially through the ring switch surface23 to a smaller diameter through hole 24. Into said recess 22 or cavity, respectively, a single hall sensor 25 or 25' of the hall sensor device 13 is inserted, the connecting leg of which passes through the through hole 24 and protrudes from the bottom 16. Each hall sensor 25, 25 'is positioned in the recess 22 in a positionally precise manner, and more precisely in the recess 22, by the recess or chamber 22, which in this exemplary embodiment is trapezoidal in cross section, for example, being provided with pressure ribs 27, 27' on two sides perpendicular to one another, the hall sensors 25, 25 'being held between the pressure ribs 27, 27'. Whereby the hall sensors 25, 25' are always pressed into the same corner of the chamber 22. In this embodiment the short side of the chamber 22 has a single compression rib 27, while the long side extending at right angles to the short side is provided with two compression ribs 27' arranged at a distance. It should be understood that the number of compression ribs 27, 27' or the cross-section of the chamber 22 may be formed in other ways.

A printed circuit board 29 is located at the bottom 16 of the sensor holder 15 facing away from said cavity 22, which printed circuit board 29 is arranged centered on an axial annular flange of the bottom 16. The printed circuit board is fixedly connected to the bottom 16. The connecting legs 26 of the hall sensors 25, 25' are inserted through the conductive holes 31 of the printed circuit board 29 and soldered. The electrical wiring of the hall sensors 25, 25' is thus realized by the common printed circuit board 29.

Even if in this embodiment only two hall sensors 25 and 25' are arranged at an angular spacing of slightly less than 90 ° (i.e. here 80 °), it is to be understood that three or four hall sensors 25 can be arranged or provided in a respective plurality of chambers 22 on the circumference of the outer cover 21. An angular range of approximately 210 ° to 220 ° can be covered with two hall sensors 25, 25' according to the invention and an angular range of 360 ° can be covered with three hall sensors. A redundant evaluation of the adjustment angle of 360 ° can be carried out by means of four hall sensors 25.

The wheel-shaped input element 11 has a base 36 and a handle 37 which are integrally formed from plastic. The grip 37 is constructed in the form of an outer cover surface tapering from bottom to top in a conical dome, which is open toward the sensor holder 15 for enclosing the sensor holder.

The base 36 has in its entirety an inner sleeve 38 which projects in the axial direction to both sides of the base 36, wherein a sleeve section 39 located in the handle 37 is longer than a sleeve section 40 facing away from the handle 37. The central inner sleeve 38 is surrounded on its inner face by two sliding sleeves 41 and 42. The two identical sliding sleeves 41 and 42 are axially spaced centrally along the inner sleeve 38 and span the annular end faces of the sleeve sections 39 and 40 with their respective annular flanges 43 and 44 projecting axially outward. For an optimal arrangement, the two sliding sleeves 41, 42 are pressed into the inner sleeve 38 or onto the inner sleeve 38.

Permanent magnets 14 in the form of ring magnets are arranged and held between the circumferential surface of the inner sleeve 38 facing away from the sliding sleeves 41, 42 and the radially outermost, annular flange 45 projecting axially from the bottom. The annular permanent magnet 14 is here inserted and glued centrally into an annular recess of the bottom 36. The ring magnet extends up to the vicinity of the annular end face of the upper larger sleeve section 39.

The input element 11 is rotatably mounted on the hollow shaft 18 with a small play by means of two sliding bushings 41 and 42. This is also achieved in that the two sliding sleeves 41 and 42 are made of sintered bronze sleeves, which in combination with the hollow shaft 18 made of steel results in a very small arrangement of the play.

By the axial engagement of the input element 11 and the sensor holder 15 and the corresponding arrangement of the permanent magnet 14 and the hall sensors 25, 25', a precise assignment in the radial and axial direction is given in that the hall sensors 25, 25' are arranged at a fixed distance in the radial direction and at the center height of the annular permanent magnet 14 in the axial direction.

A microcontroller is preferably provided on the printed circuit board 29 in a manner not shown, by means of which the hall sensor 25 or 25', respectively, which is most advantageous in terms of position, is selected for the current position of the wheel-shaped input element 11 in order to precisely detect the relevant adjustment angle. This determines which of the two hall sensors 25, 25' is active or is to be active, respectively. This means that, according to the representation of the characteristic lines (digitally converted signal voltages according to the setting angle) of the sensors 25 (dashed lines) and 25 '(dashed-dotted lines) in fig. 5, the respective hall sensor 25, 25' whose characteristic line 33 (solid line) lies in the linear range for the respective setting angle is selected successively by the microcontroller in such a way that the resulting overall output characteristic line 33, which is combined therewith, is linear in the setting angle range, which is approximately 210 ° to 220 °. It is also possible, if this is necessary, to detect the respectively most linear characteristic by switching the respective hall sensor 25, 25'. For example, an optimum or optimized linearity of characteristic line 33 results over an angular range of 210 ° to 220 ° with an angular spacing of 80 ° between the two hall sensors 25 and 25'.

Furthermore, the microcontroller avoids the occurrence of jumps in the output characteristic line in the transition range, i.e. in the transition point from one hall sensor 25 to the next hall sensor 25 'or from one hall sensor 25' to the next hall sensor 25. It should be understood that this also applies in the case of three or four hall sensors when the adjustment angle is 360 °.

Claims (17)

1. A device (10) for detecting an adjustment angle of more than 180 DEG of an element (11) rotatable or pivoted about an axis (18) has a sensor device (13), the sensor device outputs an electrical signal as a function of the angle of rotation and has an annular permanent magnet (14) which is connected immovably to an element (11) which can be rotated or pivoted about an axis, characterized in that the sensor arrangement has a stationary Hall sensor arrangement with two or more individual Hall sensors (25) arranged at angular intervals around an annular permanent magnet (14), from which the microcontroller selects the Hall sensors (25) that are each located within the linear range of their characteristic line as a function of the current position of the pivotable or rotatable element (11) which is designed as an input wheel.

2. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 1, characterized in that the microcontroller is able to select successively in each case a hall sensor (25) whose characteristic line is in the linear or most linear range such that the resulting total or output characteristic line thus combined remains linear or linear during the adjustment angle range from 0 ° to 360 °.

3. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 1, characterized in that a choice is made between the linear characteristic lines of the two hall sensors (25, 25') in the maximum adjustment angle range of 210 ° to 220 °.

4. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to one of claims 1 to 3, characterized in that the sensor device (13) has two Hall sensors (25) at an angle of 80 ° to one another.

5. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to one of claims 1 to 3, characterized in that the element (11) rotatable or swivelling about an axis is arranged on the axis (18) by means of axially separated sliding bushings (41, 42).

6. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axle (18) according to claim 5, characterized in that the axle (18) consists of steel and the sliding bushing (41, 42) consists of sintered bronze.

7. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to one of claims 1 to 3, characterized in that the element (11) rotatable or swivelling about an axis is equipped with a single permanent magnet (14).

8. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 7, characterized in that the permanent magnet (14) is adhesively held on the element (11).

9. Device for detecting an adjustment angle of more than 180 ° about an axis (18) of a rotatable or swivelling element (11) according to claim 6, characterized in that the rotatable or swivelling element (11) has an annular flange, the radially inner side of which is connected with the sliding bushing (41, 42) and on the radially outer side of which the permanent magnet (14) is held centrally.

10. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to one of claims 1 to 3, characterized in that a sensor holder (15) is provided, which is equipped with a chamber (22) for accommodating the Hall sensor (25).

11. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 10, characterized in that the hall sensor (25) is held in place in a corresponding chamber (22) of the sensor holder (15).

12. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 11, characterized in that pressure ribs (27, 27') are provided on both sides in the chamber (22).

13. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 11, characterized in that the sensor holder (15) is fixedly connected with the axis (18).

14. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling around an axle (18) according to claim 13, characterized in that the flange of the axle (18) is injection-molded by the sensor holder (15).

15. Device for detecting an adjustment angle of more than 180 ° of a rotatable or swivelling element (11) about an axis (18) according to one of claims 1 to 3, characterized in that the sensor holder (15) is constructed in the form of a hood and is clamped with its outer lateral surface (21) containing the chamber (22) in the radial direction between the permanent magnet (14) and the outer circumferential edge (37) of the rotatable or swivelling element or input wheel (11).

16. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelable about an axis (18) according to one of claims 1 to 3, characterized in that a printed circuit board (29) is provided on which the Hall sensor (25) is held with its electrical connection terminals (26).

17. Device for detecting an adjustment angle of more than 180 ° of an element (11) rotatable or swivelling about an axis (18) according to claim 16, characterized in that the connection terminals or legs (26) of the hall sensor (25) are led through the sensor holder (15) to a printed circuit board (29) situated above it.