Determining a lift of a solenoid valve

Patent metadata

Field	Value
Publication number	US-10563633-B2
Application number	US-201715783308-A
Country	US
Kind code	B2
Filing date	Oct 13, 2017
Priority date	Apr 15, 2015
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A device and a method are provided for determining a stroke of an armature of a magnetic valve which has a coil and the armature is displaceable by magnetic force, including: providing at least one reference data set which includes a magnitude of a current through the coil and a magnitude of the magnetic flux in the case of a known magnitude of the stroke; generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element coupled to the armature; determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element; and determining the magnitude of the stroke based upon the determined magnitude of the magnetic flux and the reference data set.

First claim

The invention claimed is:

1. A method for determining a stroke of an armature of a magnetic valve which has a coil and the armature which is displaceable by magnetic force, the method comprising:
providing at least one reference data set which comprises a magnitude of a current through the coil and a magnitude of magnetic flux of the coil in the case of a known magnitude of the stroke;
generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element;
determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element; and
determining the magnitude of the stroke on the basis of the determined magnitude of the magnetic flux and the reference data set,
wherein the magnitude of the magnetic flux is determined before a first state is attained, in which the armature begins to displace the closure element, and
wherein a magnitude of a working stroke of the armature is determined on the basis of the determined magnitude of the magnetic flux.

2. The method as claimed in claim 1 , wherein the reference data set is representative of a curve in a coordinate system in which the current through the coil is plotted on one axis and the magnetic flux is plotted on another axis.

3. The method as claimed in claim 1 , further comprising:
determining a deviation of the determined magnitude of the magnetic flux from a magnitude of the magnetic flux of the reference data set assigned to the same current value; and
using an already-known sensitivity of the magnitude of the magnetic flux as a function of the magnitude of the stroke, or an already-known sensitivity of the magnitude of the stroke as a function of the magnitude of the magnetic flux, in order to determine the magnitude of the stroke.

4. The method as claimed in claim 1 ,
wherein the magnitude of the magnetic flux of the magnetic field is determined after a further state is attained, proceeding from which an idle stroke of the armature has been overcome and the armature abuts against the driver of the closure element, and
wherein the magnitude of the working stroke of the armature is determined on the basis of the determined magnitude of the magnetic flux.

5. The method as claimed in claim 1 , further comprising considering pairs of the magnitude of the current and the magnitude of the magnetic flux, in a graph, which correspond to a state trajectory of the armature during a closing process of the magnetic valve, wherein the first state is associated with at least one of the pairs in the case of which a sign of a gradient changes along the state trajectory.

6. The method as claimed claim 1 , wherein the magnetic valve includes a pole piece, and the reference data set are carried out by measurement at the magnetic valve in the case of different set pole piece positions in the magnetic valve.

7. The method as claimed in claim 1 , further comprising, for the generation of the current flow through the coil, applying firstly a boost voltage, between 3 V and 65 V, and subsequently a holding voltage, between 6 V and 14 V, wherein the armature comprises a slotted ferromagnetic material or layers of ferromagnetic material which are electrically insulated with respect to one another.

8. A method for actuating a magnetic valve which has a coil and an armature which is displaceable by magnetic force and with the aid of which, by a controllable closure element coupled to the armature, fuel is injected into a combustion chamber, the method comprising:
determining a stroke of an armature of the magnetic valve, comprising:
providing at least one reference data set which comprises a magnitude of a current through the coil and a magnitude of a magnetic flux of the coil in the case of a known magnitude of the stroke;
generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element;
determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element;
determining the magnitude of the stroke on the basis of the determined magnitude of the magnetic flux and the reference data set; and

actuating the coil of the magnetic valve on the basis of the determined stroke,
wherein a duration between application of a boost voltage for opening the magnetic valve and application of a voltage for closing the magnetic valve is reduced or increased upon a determination that the stroke has increased or decreased, respectively, in relation to a previous stroke, and
further comprising, for the generation of current flow through the coil, applying firstly a boost voltage and subsequently a holding voltage, wherein the armature comprises a slotted ferromagnetic material or layers of ferromagnetic material which are electrically insulated with respect to one another.

9. The method of claim 8 , wherein the magnitude of the magnetic flux is determined before a first state is attained, in which the armature begins to displace the closure element, and wherein a magnitude of a working stroke of the armature is determined on the basis of the determined magnitude of the magnetic flux.

10. The method of claim 9 , wherein the magnitude of the magnetic flux of the magnetic field is determined after a further state is attained, proceeding from which an idle stroke of the armature has been overcome and the armature abuts against the driver of the closure element, and wherein the magnitude of the working stroke of the armature is determined on the basis of the determined magnitude of the magnetic flux.

11. The method of claim 9 , further comprising considering pairs of the magnitude of the current and the magnitude of the magnetic flux, in a graph, which correspond to a state trajectory of the armature during a closing process of the magnetic valve, wherein the first state is associated with at least one of the pairs in the case of which a sign of a gradient changes along the state trajectory.

12. The method of claim 8 , wherein the magnetic valve includes a pole piece, and the reference data set are carried out by measurement at the magnetic valve in the case of different set pole piece positions in the magnetic valve.

13. The method of claim 8 , wherein the boost voltage is between 3 V and 65 V and the holding voltage is between 6 V and 14 V.

14. A device for determining a stroke of an armature of a magnetic valve which has a coil and the armature is displaceable by magnetic force, the device comprising:
a memory providing at least one reference data set which is stored in the memory, the at least one reference data set comprises a magnitude of a current through the coil and a magnitude of a magnetic flux of the coil in the case of a known magnitude of the stroke;
a driver generating a current flow through the coil of the magnetic valve in order to generate a magnetic field and to generate the magnetic force on the armature, which magnetic force displaces the armature in a direction for opening a closure element of the magnetic valve coupled to the armature; and
a determination module coupled to the memory and which is configured
to determine a magnitude of the magnetic flux when the armature abuts against a driver of the closure element, and
to determine the magnitude of the stroke on the basis of the determined magnitude of the magnetic flux and the reference data set,

wherein the magnitud

Assignees

• Continental Automotive Gmbh
• Vitesco Tech Gmbh

Inventors

• Rösel Gerd
• Hauser Christian
• Stutika Markus

Classifications

• H01F7/1844 Primary

  Monitoring or fail-safe circuits (for relays H01H47/002) · CPC title

• F02D2041/2055

  with means for determining actual opening or closing time · CPC title

• F02D2200/063

  Lift of the valve needle · CPC title

• H01F2007/1855

  using a stored table to deduce one variable from another · CPC title

• F02D2041/2003

  using means for creating a boost voltage, i.e. generation or use of a voltage higher than the battery voltage, e.g. to speed up injector opening · CPC title