Electromagnetic positioning system and operating method
10910137 · 2021-02-02
Assignee
Inventors
Cpc classification
H01F2007/1669
ELECTRICITY
International classification
Abstract
An electromagnetic positioning system (1), including a valve train adjustment system for combustion engines, including a bistable electromagnetic positioning device (2) having a positioning element (3) for interacting with a positioning partner, the positioning element being adjustable between a retracted position (E) and an extended position (A) along an axis of adjustment (A) and having permanent magnet means (5) at least in sections.
Claims
1. An electromagnetic positioning system (1), in particular a valve train adjustment system for combustion engines, comprising a bistable electromagnetic positioning device (2) having a positioning element (3) for interacting with a positioning partner, said positioning element (3) being adjustable between a retracted position (E) and an extended position (A) along an axis of adjustment (V) and having permanent magnet means (5) at least in sections, the permanent magnet means (5) being adjustable between axially spaced first and second core parts (8, 9) by adjustment of the positioning element (3) along the axis of adjustment (V) and adhering to the first core part (8) with a permanent-magnetic holding force when the positioning element (3) is in the retracted position (E) and adhering to the second core part (9) with a permanent-magnetic holding force when the positioning element (3) is in the extended position (A), and the positioning device (2) having first and second coils which can be controlled via control means, and the control means being configured to control the first and second coil means (10, 11) in such a manner that, in a first operating mode for adjusting the positioning element (3) from the retracted position (E) into the extended position (A), the first coil (10) responds to an electrical control signal of the control means by generating a counterforce which counteracts the holding force of the permanent magnet means (5), repels the permanent magnet means (5) and detaches them from the first core part (8), and in a second operating mode for adjusting the positioning element (3) from the extended position (A) into the retracted position (E), the second coil (11) responds to an electrical control signal of the control means by generating a counterforce which counteracts the holding force of the permanent magnet means (5), repels the permanent magnet means (5) and detaches them from the second core part (9), wherein evaluating means (13) for detecting an induction signal which can be generated by adjustment of the positioning element (3) from the retracted position (E) into the extended position (A) along the axis of adjustment (V) are assigned to the second coil (11), and the control means are configured in such a manner that they de-energize the second coil (11) in the first operating mode at least during a detection phase for detecting the induction signal, and/or that evaluating means (13) for detecting an induction signal which can be generated by adjustment of the positioning element (3) from the extended position (A) into the retracted position (E) along the axis of adjustment (V) are assigned to the first coil (10), and the control means are configured in such a manner that they de-energize the first coil (10) in the second operating mode at least during a detection phase for detecting the induction signal.
2. The electromagnetic positioning system according to claim 1, wherein the evaluating means (13) are configured to respond to the absence of an induction signal and/or to a delayed induction signal by outputting an error signal and/or by storing error information and/or wherein the evaluating means are configured to respond to an induction signal by outputting an acknowledgement signal and/or by storing acknowledgement information.
3. The electromagnetic positioning system according to claim 1, wherein the control means (12) are configured to respond to the absence of an induction signal by outputting a new control signal to the first or second coil (10, 11).
4. The electromagnetic positioning system according to claim 1, wherein the positioning element (3) is disposed so as to have a tappet portion (4) axially passing through the second core part (9).
5. The electromagnetic positioning system according to claim 1, wherein the positioning element (3) is disposed so as to interact with a positioning partner which is configured and disposed so as to not exert any mechanical restoring force for adjusting the positioning element (3) from the extended position (A) into the retracted position (E).
6. The electromagnetic positioning system according to claim 1, wherein the first coil (10) is configured to generate a stronger magnetic field than the second coil (11) when both coils are energized to the same degree.
7. The electromagnetic positioning system according to claim 1, wherein the permanent magnet means (5) are at least partially disposed axially between the axially spaced coils (10, 11).
8. The electromagnetic positioning system according to claim 1, wherein the evaluating means (13) and the control means are formed by shared logic means.
9. A method for operating an electromagnetic positioning system (1) according to claim 1, wherein in the first operating mode, the control means supply a control signal to the first coil (10), which causes the positioning element (3) to be adjusted from the retracted position (E) into the extended position (A), and during said adjustment movement an induction signal generated in the second coil (11) by the adjustment of the positioning element (3) is detected by the evaluating means (13) assigned to the second coil (11), and that the control means de-energize the second coil (11) in the first operating mode at least during a detection phase for detecting the induction signal, and/or in the second operating mode, the control means supply a control signal to the second coil (11), which causes the positioning element (3) to be adjusted from the extended position (A) into the retracted position (E), and that during said adjustment movement an induction signal generated in the first coil (10) by the adjustment of the positioning element (3) is detected by the evaluating means (13) assigned to the first coil (10), and the control means de-energize the second coil (10) in the second operating mode at least during a detection phase for detecting the induction signal.
10. A use of an electromagnetic positioning system (1) according to claim 1 for adjusting a cam follower of a valve train of a combustion engine, in a motor vehicle.
11. The electromagnetic positioning system according to claim 1, wherein the evaluating means (13) are assigned to the second coil (11) and are configured in such a manner that they de-energize the second coil (11) during the entire first operating mode.
12. The electromagnetic positioning system according to claim 1, wherein the evaluating means (13) are assigned to the first coil (10) and are configured in such a manner that they de-energize the first coil (10) during the entire second operating mode.
13. The electromagnetic positioning system according to claim 2, wherein the evaluating means are configured to respond to a timely induction signal.
14. The electromagnetic positioning system according to claim 4, wherein the tappet portion (4) axially passes through only the second core part.
15. The electromagnetic positioning system according to claim 5, wherein the positioning partner is a cam follower.
16. The electromagnetic positioning system according to claim 7, wherein the permanent magnet means (5) are entirely disposed axially between, at an axial distance from, the axially spaced coils (10, 11).
17. The electromagnetic positioning system according to claim 8, wherein the shared logic means is an engine control unit.
18. The method according to claim 9, wherein the control means de-energize the second coil (11) during the entire first operating mode.
19. The method according to claim 9, wherein the control means de-energize the first coil (10) during the entire second operating mode.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The only
DETAILED DESCRIPTION
(2) Highly schematized,
(3) The permanent magnet means 5 are located within a positioning device housing 15 which conducts the magnetic flux and via which the two magnetic flux circuits generated, preferably alternately, by the two coils 10, 11 are closed.
(4) In the extended position A, which is axially spaced apart from the retracted position E, the positioning element 3 analogously adheres to a second core part 9 via a permanent-magnetic adhering force of the permanent magnet means 5, said second core part 9 being axially spaced apart from the first core part 8. At the same time, the core parts 8, 9 form axial stops for the positioning element 3 in that the pole disks 6, 7 are in contact with the respective core part 8, 9 in the corresponding position.
(5) Furthermore, the positioning device 2 comprises a first coil 10, which radially surrounds the first core part 8 at the outside in the case at hand. Additionally, the positioning device 2 comprises a second coil 11, which is axially spaced apart and surrounds the second core part 9. Control means 12 and evaluating means 13, which will be explained later, are assigned to the two coils 10, 11, the control means 12 and the evaluating means 13 being formed by shared logic means 14. In a first operating mode, the control means 12 control the first coil 10 with a control signal (electrical energization), based on which the first coil 10 generates a magnetic field that counteracts the permanent-magnetic magnetic field. In other words, because of the control signal, the first coil 10 generates a counterforce to the permanent-magnetic holding or adhering force of the permanent magnet means 5, whereby the permanent magnet means 5 and the positioning element 3 are repelled from the first core part 8 in the direction of the extended position A, whereby the positioning element 3 moves into its extended position A, causing the tappet portion 4 to be axially moved further out of the positioning device housing 15 so as to interact with a positioning partner (not shown), preferably with a cam follower in the case at hand, in a manner known per se.
(6) As can be seen, for this purpose, the positioning element 3 passes through a centric passage opening 16 in the second core part 9; the first core part 8 is closed, i.e. does not have a passage opening 16. During this first operating mode, the control means 12 de-energize the second coil 11, which has less power than the first coil 10. During said time, the second coil 11 has the function of a sensor coil in which an induction signalan electric voltage in the case at handis generated by the adjustment movement from the retracted position E into the extended position A as explained above. This voltage is detected by the evaluating means 13 and processed, in particular in cooperation with the control means 12. In this way, it becomes possible to monitor the extending process or actuating process for actuating the positioning partner. This means that it can be detected whether the desired or prompted adjustment movement of the positioning element 3 actually takes place or has taken place.
(7) In a second operating mode, the positioning element 3 located in the extended position A is returned into the illustrated retracted position E. For this purpose, the control means 12 control the second coil 11 with a control signal that exerts a repelling counterforce to the permanent-magnetic holding force onto the positioning element 3, whereby the latter is repelled from the second core part 9 in the direction toward the first core part 8. During this second operating mode, the control means 12 de-energize the first coil 10, which thus has the functionality of a sensor coil and detects an induction signal generated in the winding of the first coil 10 in the form of an electric voltage by the axial adjustment movement of the positioning element 3 with its permanent magnet means 5. This induction signal, which is an electric voltage signal in the case at hand, is detected by the evaluating means 13 and processed, preferably with the aid of the control means 12. In this way, it is possible to monitor an adjustment movement of the positioning element 3 from the extended position A back into the retracted position E.
REFERENCE SIGNS
(8) 1 electromagnetic positioning system 2 bistable electromagnetic positioning device 3 positioning element 4 tappet portion of the positioning element 5 permanent magnet means of the positioning element 6 pole disk of the positioning element 7 pole disk of the positioning element 8 first core part 9 second core part 10 first coil 11 second coil 12 control means 13 evaluating means 14 logic means 15 positioning device housing 16 passage opening E retracted position A extended position V axis of adjustment