EP1192369A1

EP1192369A1 - Device for detecting a position of an adjusting element

Info

Publication number: EP1192369A1
Application number: EP00965966A
Authority: EP
Inventors: Tilo Marschall; Reiner Keller
Original assignee: ZF Friedrichshafen AG
Current assignee: ZF Friedrichshafen AG
Priority date: 1999-09-15
Filing date: 2000-09-12
Publication date: 2002-04-03
Also published as: WO2001020197A1; DE19944203A1

Abstract

The invention relates to a device for detecting a position of adjusting element (11, 12), comprising at least one signal transmitter (15 to 19, 21 to 25, 27 to 31), which interacts with a sensor (13, 14) that is extended in a direction of adjustment (7), which serves as a reference point and which generates a signal corresponding to the position of the signal transmitter (15 to 19, 21 to 25, 27 to 31) in relation to the direction of adjustment. According to the invention, the adjusting element (11, 12) can be moved in two directions of adjustment (7, 8 or 9). The sensor (13, 14) is oriented in a first direction of adjustment (7) and its length corresponds to at least the maximum path of adjustment (6) in this direction of adjustment (7, 8 or 9). Several signal transmitters (15 to 19, 21 to 25, 27 to 31) are offset from each other in a second direction of adjustment (8, 9).

Description

Device for detecting a position of an actuator

The invention relates to a device for detecting a position of an actuating element according to the preamble of claim 1.

Methods and devices for detecting the movements of shafts are widely known and are necessary for control purposes in particular in motor vehicle technology. So it is e.g. It is customary to determine the speed and the direction of rotation of a rotary drive by means of two Hall sensors arranged offset by 90 ° to one another. For this purpose, a ring magnet is non-rotatably connected to the rotary drive axis. When the ring magnet rotates, the two Hall sensors arranged on the side of the ring magnet are each penetrated by a variable magnetic field. The magnetic field changes occurring at the two sensors are converted into mutually offset binary pulse sequences. The speed can be counted by the

Number of pulses per unit of time and the direction of rotation of the rotary drive can be determined by comparing the two pulse sequences.

From DE 40 38 284 AI a method for detecting the position and the direction of movement of translationally or rotationally moving parts of an assembly is known. From a rotary drive of the unit, counting pulses are derived in pulse sequence coded rotation direction or counting pulses with form coded in the direction of rotation. For this purpose, a disk connected to the rotary drive is provided, on which a ring is formed from a predetermined number of marks arranged in succession. Next to the disc is in the Area of the ring a Hall element responsive to these brands.

DE 42 43 549 AI describes a method and a device for detecting the speed and the direction of rotation of a rotary drive, in particular for window regulators and sunroofs for motor vehicles, using a signal-emitting or signal-changing element which is connected to the rotary drive in a rotationally fixed manner, a sensor and an electronic evaluation unit, wherein when the signal-emitting or signal-changing element rotates, a periodic, direction-coded signal is produced, which is detected by the sensor and fed to the electronic evaluation unit. The periodic, direction-coded signal has at least one extreme value. When approaching the extreme value from different sides, there are differently increasing or decreasing signal amplitudes and / or the extreme values are distributed unevenly with respect to a 360 ° period, with at least one division which is not equal to the ratio of 360 ° to the number of extreme values. The signaling element has at least one permanent magnet, which generates a magnetic field which is coded in the direction of rotation on the sensor when rotating.

Finally, DE 196 53 785 AI describes a release device for a hydraulically operated friction clutch. This comprises a housing in which an annular piston is axially displaceably guided on a guide sleeve. The ring piston acts on a release lever of the friction clutch via a release bearing. The disengaging device comprises a sensor system for detecting the travel of the ring piston, which is arranged on the end face of the housing there is an annular Hall sensor which interacts with a pulse generator enclosing the annular piston.

In manual transmissions in motor vehicles, which are switched with traction power interruption, there is often a desire to determine the shifting state of the transmission via electrical signals, even when the vehicle is stationary or the transmission is not currently being shifted. With such information, strategies for powertrain management can be defined, synchronization processes can be controlled and circuits can be automated.

The central shift element in such a transmission is the main shift shaft, which is both rotated and axially displaced, i. H. which carries out a rotary and a translational positioning movement. As a result, the detection of torsion and displacement provides an exact statement about the gear condition. Desirable and evaluable information is the description of the engaged gear and a statement about the adhesion (neutral, synchronous phase, engaged gear). In the case of mechanical manual transmissions, the position of the manual lever can be used to infer the shift situation in the transmission. If hydraulic or electrical switching devices are used, this is only possible to a limited extent and reliably, in particular if the switching is carried out automatically by a control unit.

It has already been proposed to decouple the sizes to be measured, path and angle, and to detect them by means of two independent sensors. These can be two displacement sensors or two angle sensors or a combination of displacement sensor and angle sensor. The invention has for its object to provide a device for detecting a position of an actuating element, in particular the main shift shaft of a manual transmission, which is reliable in use, inexpensive to manufacture and extremely space-saving. It is solved according to the invention by the features of claim 1. Further refinements result from the subclaims.

According to the invention, the control element is adjustable in two control directions and the sensor in a first

Direction of adjustment aligned. Its length corresponds at least to the maximum travel in this direction. Furthermore, a plurality of signal transmitters are arranged offset in relation to one another in a second setting direction and assume positions so defined that only one signal transmitter cooperates with the sensor at the same time and generates a signal specific for its position in the second setting direction. The first and second adjustment directions can correspond to translatory or rotary adjustment movements. In the case of a selector shaft as the control element, the rotary movement about an axis of rotation is generally used to select a shift gate, while a translational adjustment in the direction of the axis of rotation is used to shift the individual gears. In principle, however, it is also possible to select the alleys by means of the translatory movement, while the individual gears are shifted by the rotational movement.

In the device according to the invention, only one sensor is required which, together with signal transmitters which differ in their position relative to the sensor, in the type and / or strength of their signals, and thus in connection with the sensor, generate specific sensor signals which are produced by a sensor - ner electronic evaluation unit with respect to the position of the signal transmitter on the control element and their relative position to the sensor can be evaluated.

This allows the position of the control element, e.g. the position of the main shift shaft in a multi-speed transmission can be determined in two directions. The effort and space required are very small.

According to one embodiment of the invention, the measuring range of the sensor is a multiple of the maximum travel in the first direction, the multiple corresponding to the number of signal transmitters. The measuring range is divided into a corresponding number of ranges, with each range being assigned a signal generator which, together with the sensor, generates a signal which identifies the position of the respective signal generator in the first actuating direction. Since the signal transmitters are arranged offset to one another in the second actuating direction and only one signal transmitter interacts with the sensor at the same time, the sensor signal can clearly determine both the position of the signal transmitter and thus the actuating element in the first actuating direction and the position of the actuating element be closed in the second setting direction. In this embodiment, the signal transmitters of the individual areas can advantageously be identical to one another.

According to a further embodiment of the invention, it is proposed that the signal transmitters are designed differently according to their position in the second setting direction and correspondingly generate different signals on the sensor. It is not necessary that the measurement range of the sensor is a multiple of the maximum travel. The device and, in particular, the sensor are shorter, since their position in the second setting direction can be clearly recognized by the differences in the signal transmitters. However, both configurations of the invention can also be combined with one another in order to enlarge the signal spacings.

The signal transmitters can differ from one another in different ways, e.g. in its extension in

Direction of the first actuating direction, in the type of its signal in relation to the frequency and wavelength and in the strength of its signal, which among other things can be varied by the effective distance between the signal generator and the sensor, e.g. have a different distance from the axis of rotation.

A linear inductive, non-contact displacement sensor arranged in the vicinity of the actuating element, for example the control shaft, is suitable as the sensor and is controlled as a signal generator by at least one permanent magnet connected to the control shaft. Such a sensor, which can be controlled by a permanent magnet, is already offered by the Siemens company under the name PLCD displacement sensor, the sensor essentially consisting of a special non-magnetic core, which is wound over its entire length by a coil and on each end carries another short coil. A permanent magnet approximated to the sensor leads to a local magnetic saturation of the core, the position of this saturated area along the sensor axis being able to be determined by the coil system at the ends of the soft magnetic core. An electronic module assigned to this sensor generates a suitable Nete operating frequency and processes the sensor signals by phase-sensitive rectification, with a linear current dependent on the location of the permanent magnet is available at the output, which is a function of the ratio of the voltages emitted by the two coils. This

Ratio corresponds to the position of the permanent magnet within the measuring range determined by the longitudinal dimension of the sensor, namely in the first setting direction.

According to the invention, the position of the main shift shaft in a gearbox for determining the respective shift gate and the gear engaged can be done by either dividing the shift shaft in the axial direction into several linear sections, with a plurality of permanent magnets being arranged on the outside of the shift shaft, both in the axial direction Direction as well as in the circumferential direction are offset from each other, or by the fact that on the outside of the selector shaft several permanent magnets of different dimensions are arranged in the same axial area, which are offset in the circumferential direction to each other and thus cover and characterize different rotation angle ranges, in both cases the permanent magnets with interact with a linear inductive non-contact sensor described above.

According to a further embodiment of the invention, the sensor is a radiation sensor and the signal transmitters are radiation sources and / or radiation reflectors. Optical displacement sensors such as CCD line sensors are suitable as sensors. With these sensors, both the position of the excited cell and the width of the excited area can be read out. Light-emitting components that display visible or Send out visible light, such as LED components or laser components. The rays can differ in frequency and wavelength. It is possible to use a separate radiation source for each signal generator.

According to an embodiment of the invention, however, only one radiation source is advantageously provided, which is arranged parallel to the sensor and interacts with reflectors on the actuating element, which serve as signal transmitters. The reflectors reflect the rays emitted by the radiation source in accordance with the position of the actuating element on the sensor and thus generate corresponding sensor signals. For switching purposes in manual transmissions, it makes sense to arrange the signal transmitters in the second actuating direction in order of the shift gates, in order to be able to better detect clear switching positions. The grading depends on the extension of the signal generator in the second direction. In order to obtain a finer gradation, it can be expedient for signal generators which are offset from one another in the first actuating direction to partially overlap in the second actuating direction. The overlap areas can then be identified as additional position areas.

If the individual signal transmitters differ from one another, it may be expedient for the differences in the second setting direction to merge into one another so that the positions in the second setting direction of the actuating element can be recorded continuously. If two positioning positions are recorded one after the other, the travel distance can be determined from the difference in the result. Taking the time into account, the positioning speed, the positioning acceleration, etc. can be calculated by differentiating the travel distance according to the time.

Further advantages result from the following description of the drawing. Exemplary embodiments of the invention are shown in the drawing. The description and claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Show it:

1 shows a circuit diagram of a multi-step transmission, FIG. 2 shows a device according to the invention with permanent magnets as signal transmitters, FIG. 3 shows a view of a device according to FIG. 2 in the longitudinal direction,

Fig. 4 shows a variant of FIG. 2,

Fig. 5 shows a view of a device according to FIG. 4 in the longitudinal direction,

Fig. 6 a device according to the invention with radiation sources as signal transmitters,

Fig. 7 shows a view of a device according to FIG. 6 in the longitudinal direction,

Fig. 8 shows a variant of FIG. 6,

9 is a view of a device according to FIG. 8 in the longitudinal direction,

Fig. 10 shows a variant of FIG. 8,

Fig. 11 a device according to the invention with reflectors as signal transmitters, 12 shows a view of a device according to FIG. 11 in the longitudinal direction, FIG. 13 shows a variant of FIG. 11,

14 is a view of a device according to FIG. 13 in the longitudinal direction and

15 shows a variant of FIG. 13.

2 to 9 and FIGS. 11 to 14, a selector shaft of a manual transmission, not shown, is shown as the actuating element 11. The adjusting element 11 can be moved in a first adjusting direction 7 in the direction of its axis of rotation 20 and in a second Stellri ^'rect be rotated about the axis of rotation 20. 8 In the second setting direction 8, the lanes I, II, III, IV of the transmission are selected (FIG. 1), in which, starting from a neutral position N, five forward gears 1 to 5 and one reverse gear R can be shifted in the second setting direction 8. At the ends of a maximum adjustment path 6 in the first adjustment direction 7, a first shift position S1 for the reverse gear R and the forward gears 1, 3, 5 and a second shift position S2 for the forward gears 2 and 4 are achieved symmetrically to the neutral position N.

An elongated sensor 13, 14 is aligned parallel to the actuating element 11, which in the exemplary embodiments according to FIGS. 2 to 5 is an inductive, contactless displacement sensor, which essentially consists of a special soft magnetic core, and which has a length of one Coil is wrapped. At its ends it carries a short coil 39, 40, which are connected via terminals 41, 42 to a generally electronic evaluation unit 43. For reasons of clarity, only two of the four selection positions for lanes I to IV are shown in FIG. 2 and the following figures, namely the selection position for lanes I and II. In the embodiment according to FIGS. 2 and 3, two essentially identical permanent magnets 15 and 16 are attached to the actuating element 11 as signal generators, namely in the second actuating direction 8, that is to say offset in the circumferential direction of the actuating element 11 by the distance which corresponds to the distance between alleys I and II. In the axial direction, ie in the first adjustment direction 7, they are offset by at least an amount that corresponds to the maximum adjustment path 6. The sensor 13 has a measuring range 10, which corresponds to at least a multiple of the maximum travel 6, which is determined by the number of permanent magnets 15, 16. Each of the permanent magnets 15 and 16 is thus assigned a sub-area of the measuring area 10 which corresponds at least to the maximum actuating travel 6. Since only one permanent magnet 15 or 16 interacts with the sensor 13 due to the offset in the second setting direction 8, certain signal areas of the sensor 13 can be assigned to a specific signal transmitter 15 or 16 and thus to a specific gate I to IV. The position of the permanent magnets 15, 16 acting as signal generators in the second setting direction 8 can be defined by the rotational angle positions φ _τ and φ _π .

4 and 5 differs from the previous embodiment in that the permanent magnets 17, 18, 19 acting as signal transmitters have a different length 36, 37, 38 in the first setting direction 7 and thus generate specific, identifiable sensor signals , The measuring range 10 of the sensor 13 therefore only needs to correspond to the maximum travel 6 in order to To be able to clearly identify the position of the adjusting element 11 in the first adjusting direction 7 and in the second adjusting direction 8.

The embodiment according to FIGS. 6 and 7 and according to FIGS. 9 and 10 are similar to the previously described embodiments. They differed from them essentially in that radiation sources 21 to 25 serve as signal transmitters. 6 and 7, these are offset in the circumferential direction corresponding to the distance of the lanes I to IV in the second actuating direction 8 to the actuating element 11, while the radiation sources 23 to 25 differ from one another in terms of their radiation quality, for example in that first adjustment direction 7 have different lengths 36 to 38. The radiation sources 21 to 25 emit any visible or invisible rays and work together with appropriate sensors. For example, light-emitting LED components or laser elements can work together with an optical sensor 14, for example a CCD line sensor, with which both the position of the excited cell and the width of the excited measuring zone 33, 34 can be read out. This information can be used to determine which of the radiation sources 23 to 25 is currently interacting with the sensor 14 and what its position is in relation to the first actuating direction 7. The second adjusting direction 8 of the adjusting element 11 does not necessarily have to be a direction of rotation, two translatory adjusting movements and corresponding positions can also be determined. 10 shows an actuating element 12 with two linear actuating directions, namely a first actuating direction 7 and a second actuating direction 9. The beams 35 of the different radiation sources 23 to 25 hit a measuring zone 34 of the sensor 14. They generate sensor signals there, which are also characterized by the position of the measuring zone 34 in the first setting direction 7, so that for each position in the first and second

Setting direction 7, 8 a distinctive sensor signal is created.

6 to 10 can be simplified in that a stationary radiation source 26 interacts with reflectors 27 to 31, which are attached to the actuating element 11 or 12 as signal transmitters. The radiation source 26 emits rays 32 which reflect the reflectors 27 to 31 onto the sensor 14 in a measuring zone 34 or 35. The signals obtained from the sensor 14 are evaluated by an evaluation unit 43 in the same way as in the other embodiments.

The signals of the permanent magnets 15 to 19 serving as signal generators, the radiation sources 21 to 25 and the reflectors 27 to 31 can also be differentiated by the signal strength, for example by having a different effective distance 44 (FIG. 3) from the sensor 13, 14 , The effective distance 44 can be determined by the distance of the signal generator from the axis of rotation 20. reference numeral

1 First gear 29 reflector

2 second gear 30 reflector

3 Third gear 31 reflector

4 fourth gear 32 beam

5 fifth gear 33 measuring zone

6 travel range 34 measuring zone

7 First positioning direction 35 beam

8 Second adjustment direction 36 length

9 Second adjustment direction 37 length

10 measuring range 38 length

11 control element 39 coil

12 control element 40 coil

13 Sensor 41 clamp

14 Sensor 42 clamp

15 permanent magnet 43 evaluation unit

16 permanent magnet 44 effective distance

17 Permanent magnet Φi angle of rotation

18 permanent magnet ⁽ pn rotation angle

19 permanent magnet 20 axis of rotation

21 Radiation source I Erste Gasse

22 Radiation source II Second lane

23 Radiation source III Third Alley

24 Radiation source IV fourth alley

25 Radiation source R reverse gear 26 Radiation source N neutral position 27 Reflector 51 First switching position

27 Reflector 52 Second switching position

Claims

Patent claims

1. Device for detecting a position of an adjusting element (11, 12) with at least one signal transmitter (15 to 19, 21 to 25, 27 to 31), which cooperates with a sensor (13, 14) elongated in an adjusting direction (7), which serves as a reference point and generates a signal which corresponds to the position of the signal transmitter (15 to 19, 21 to 25, 27 to 31) in relation to the actuating direction, characterized in that the actuating element (11, 12) in two actuating directions (7, 8 or 9) is adjustable, the sensor (13, 14) is aligned in a first setting direction (7) and its length corresponds at least to the maximum setting path (6) in this setting direction (7, 8 or 9), with several signal transmitters (15 to 19, 21 to 25, 27 to 31) in a second setting direction (8, 9) are arranged offset to one another and assume positions so defined that only one signal transmitter (15 to 19, 21 to 25, 27 to 31) interacts simultaneously with the sensor (13, 14) and one for its location in the second actuating direction (8, 9) generates a specific signal.

2. Device according to claim 1, characterized in that the measuring range (10) of the

Sensor (13, 14) a multiple that corresponds to the number of signal transmitters (15, 16; 21, 22; 27, 28), the maximum travel (6) in the first direction (7) and in a corresponding number of areas (6 ), with each area (6) being assigned a signal transmitter (15, 16; 21, 22; 27, 28) which, together with the sensor (13, 14), generates a signal that corresponds to the position of the respective signal transmitter (15, 16; 21, 22; 27, 28) in the first setting direction (7).

3. Device according to claim 2, characterized in that the signal transmitters (15, 16; 21, 22; 27, 28) of the individual areas (6) are identical to one another.

4. Device according to one of claims 1 or 2, thereby g e k e n n z e i c h n e t that the signal transmitter

(17 to 19, 23 to 25, 29 to 31) are designed differently according to their position in the second setting direction (8, 9) and accordingly generate different signals on the sensor (13, 14).

5. Device according to one of claims 1 or 2, characterized in that the effective distances (44) of the signal transmitter (15 to 19, 21 to 25, 27 to 31) differ from the sensor (13, 14), so that differentiate the strength of the signals generated at the sensor (13, 14) accordingly.

6. Device according to one of the preceding claims, characterized in that the sensor (13) consists of an elongated magnetic core which is wound over its entire length by a coil and the two ends of each with a further short coil (39, 40) are provided, which are connected to an electronic evaluation unit (43), permanent magnets of the same or different length serving as signal transmitters (15 to 19), which lead to a variation in the local magnetic saturation of the core in the vicinity of the sensor (13).

7. Device according to one of claims 1 to 5, characterized in that the sensor (14) is a radiation sensor and the signal transmitters are radiation sources (21 to 25) and / or radiation reflectors (27 to 31).

8. Device according to one of claims 1 or 2, characterized in that the sensor (14) is an optical sensor and the signal transmitters (21 to 25, 27 to 31) are light-emitting components or light-reflecting reflectors.

9. Device according to one of the preceding claims, characterized in that the actuating element (11) is a selector shaft of a step transmission, the first actuating direction (7) of which is linear and the second actuating direction (8) of which is a direction of rotation or vice versa.

10. Device according to one of the preceding claims, characterized in that the signal transmitters (15 to 19, 21 to 25, 27 to 31) are offset from one another in steps and their extension in the second adjusting direction (8, 9) is smaller than the increment.

11. The device according to claim 2, characterized in that the signal transmitters (15, 16; 21, 22; 27, 28) overlap in the second actuating direction (8, 9).

12. Device according to one of the preceding claims, characterized in that the travel path is determined from two successively detected positions with an evaluation unit (43).

13. The apparatus according to claim 12, characterized in that the actuating speed, the actuating acceleration and / or the changes in the calculated variables are calculated over time by one-time or multiple derivation of the actuating path according to time.