Method for actuating a valve

Abstract

A method for actuating a valve with a magnetic valve drive, through which electric current is passed to open the valve, to close the valve, and to hold the valve in an open or closed position, includes receiving an opening signal. The method further includes varying the electric current that is passed through the valve drive as a first current signal to open the valve in response to the received opening signal. The method further includes receiving a closing signal and varying the electric current that is passed through the valve drive as a second current signal for closing the valve in response to the received closing signal. The second current signal has at least two variations of the electric current at separate times.

Claims

1. A method for actuating a valve with a magnetic valve drive, through which electric current is passed to open the valve, to close the valve, and to hold the valve in an open or closed position, comprising: receiving an opening signal; varying the electric current that is passed through the valve drive as a first current signal to open the valve in response to the received opening signal; receiving a closing signal; and varying the electric current that is passed through the valve drive as a second current signal for closing the valve in response to the received closing signal, wherein the second current signal has at least two variations of the electric current at separate times, a first of the at least two variations causing the valve to partly close, and a second of the at least two variations causing the valve to fully close, wherein the at least two variations of the electric current at separate times are in the form of successive pulses at the separate times and a value of the electric current is reduced to zero between the successive pulses.

2. The method according to claim 1, further comprising: operating the valve to partly close if the electric current is flowing through the valve drive; and operating the valve to open if no electric current is flowing through the valve drive.

3. The method according to claim 1, further comprising: energizing the valve for closing such that it is closed with three mutually adjoining partial strokes.

4. The method according to claim 1, wherein the at least two variations of the electric current at separate times are in the form of successive steps of a staircase.

5. The method according to claim 4, wherein the steps of the staircase each have a current level.

6. The method according to claim 1, further comprising: operating the valve as at least one of: (1) full strokes in a switching mode during the variation of the electric current as the first signal, and (2) volumetric flow-dependent partial strokes in a setting mode during the variation of the electric current as the second signal.

7. The method according to claim 1, wherein a computer program is configured to carry out the method.

8. The method according to claim 7, wherein the computer program is stored in a machine-readable memory medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The solution proposed here and the technical environment thereof are described in detail below using the figures. It should be noted that the disclosure shall not be limited by exemplary embodiments. In particular, it is also possible, if not explicitly shown otherwise, to extract partial aspects of the matters shown in the figures and to combine the same with other components and/or findings from other figures and/or the present description. In the figures:

(2) FIG. 1: shows schematically a (target) current profile with an associated valve position profile according to the prior art, and

(3) FIG. 2: shows schematically a (target) current profile with an associated valve position profile, which are produced with a method according to the disclosure.

DETAILED DESCRIPTION

(4) FIG. 1 shows schematically an (idealized) current profile 4 with an associated (idealized) valve position profile 5 according to the prior art. According to the illustration of FIG. 1, the profile of the electric current 1 against time 6 is plotted at the top and the profile of the valve position 7 against time 6 is plotted at the bottom. Regarding the profile of the valve position 7, it should be mentioned that the valve is fully closed at the level of the abscissa. For a further description of the current profile 4 and the valve position profile 5 in FIG. 1, refer to the above statements about the prior art.

(5) FIG. 2 shows schematically an (idealized) current profile 4 with an associated (idealized) valve position profile 5, which are produced with a method according to the disclosure. Also, according to the illustration of FIG. 2, the profile of the electric current 1 against time 6 is plotted at the top and the profile of the valve position 7 against time 6 is plotted at the bottom. Regarding the profile of the valve position 7, it should also be mentioned here that the valve is fully closed at the level of the abscissa.

(6) At the start of the current profile 4 shown in FIG. 2, the valve (not shown here), which here by way of example is a normally open solenoid valve, is energized with a closing current 14 that is dimensioned so that the valve is fully closed. After receiving an opening signal (not shown here), the electric current 1 that is passed through the valve drive (not shown here) to open the valve is varied in the manner of a first current signal 2. The first current signal 2 has the form of a square wave signal here, by way of example and idealized, with which the electric current 1 is suddenly reduced to zero to open the valve.

(7) The variation of the electric current 1 in the manner of the first current signal 2 results in a full stroke 8 according to the associated valve position profile 5, by which the maximum flow cross-section of the valve is opened because the valve is fully opened. During an opening time 12 following the reception of the opening signal, the valve continues to be actuated or energized with the first current signal 2, wherein in the case represented by way of example and in an idealized manner in FIG. 2, exactly zero electric current 1 is passed through the valve drive during the (entire) opening time 12.

(8) The valve is actuated with the first current signal 2 until a closing signal (not shown here) is received. After receiving the closing signal, the electric current 1 that is passed though the valve drive for closing the valve is altered in the manner of a second current signal 3. With the method presented here, the second current signal 3 comprises at least two variations 15 of the electric current 1 at separate times. According to the example shown in FIG. 2, the second current signal 3 comprises three variations 15 of the electric current 1 at separate times, wherein with the third variation 15 the closing current 14 with which the valve is fully closed is achieved again. There is a closing time 13 between receiving the closing signal and reaching the closing current 14.

(9) The variations 15 at separate times of the electric current 1 according to the second current signal 3 are shown here by way of example in the form of successive steps of a staircase, wherein the steps of the staircase each have a defined current level. In order to bring about a closing movement of the valve, in this case the current level of a later step of the staircase is higher than the current level of an earlier step of the staircase.

(10) According to the associated valve position profile 5, the variation of the electric current 1 in the manner of the second current signal 3 results in the valve being closed with three adjacent partial strokes, namely a first partial stroke 9, a second partial stroke 10 and a third partial stroke 11.

(11) According to the illustration of FIG. 2, the valve is operated in a switching mode during the opening time 12 that is characterized in that the valve is opened exclusively with full strokes, here with one full stroke 8. During the closing time 13, the valve is operated in a setting mode that is characterized in that the valve is operated with volumetric flow-dependent partial strokes, here being closed with the partial strokes 9, 10 and 11.

(12) The method contributes in particular to reducing a closing noise of the valve or the noise generation when closing the valve.