Dosing method and solenoid valve for carrying out dosing method

Abstract

The invention relates to a dosing method for carrying out at least one dosing process, comprising the following steps: providing a switching signal to or from a valve control device; providing a coil current from the valve control device to a magnetic drive as a function of a switching signal, the magnetic drive being designed to move a valve member of the solenoid valve between a rest position and an operating position; determining a start of a first movement of the valve member from the rest position to the working position; determining an on-duration between providing a coil current and the start of the first movement; a provision duration for the switching signal is determined, in which provision of the coil current takes place over a duration of a coil current period corresponding to a sum of the provision duration and the ON duration.

Description

Technical Field

[0001] The invention relates to a metering method and a solenoid valve for carrying out the metering method. Background Art

[0002] The solenoid valve known from the prior art for carrying out the metering method has a valve member, a valve body, a sealing element assigned to the valve member, a solenoid coil and a valve seat. The solenoid coil is designed for magnetic interaction with the valve member, which is also called an armature or valve magnet. When a coil current is supplied to the solenoid coil, a magnetic force is exerted on the valve member in order to cause a relative movement relative to the solenoid coil. By means of this relative movement, the sealing element can either be lifted from the valve seat in order to bring the solenoid valve into an operating position, in particular into an open position, or can be pressed sealingly against the valve seat in order to bring the solenoid valve into a rest position, in particular into a closed position. Summary of the invention

[0003] The object of the present invention is to provide a metering method and a solenoid valve for carrying out a metering method which is to be carried out cost-effectively and quickly.

[0004] This task is achieved by a dosing process with the following characteristics:

[0005] According to the present invention, the metering method for performing at least one metering process includes the following steps: providing a switching signal (Schaltsignal) to a valve control device (Ventilsteuerung) or providing a switching signal from the valve control device; providing a coil current from the valve control device to a magnetic drive according to the switching signal, wherein the magnetic drive is designed to move a valve member of a solenoid valve between a static position and a working position; determining the beginning of a first movement (Bewegungsbeginn) of the valve member from the static position to the working position; determining an on-duration (Einschaltdauer) between providing the coil current and the beginning of the first movement; determining a supply duration for the switching signal, wherein the coil current is provided within the duration of a coil current period, which corresponds to the sum of the supply duration and the on-duration.

[0006] The valve control can be assigned directly to the magnetic drive or, as a separate component, can also be designed for actuating several magnetic drives.

[0007] The switching signal can be provided by a circuit device arranged in the valve control device, in particular a microprocessor, or provided to the valve control device by a superior control device of the valve control device, for example a machine control device of a metering system. Here, a control device that controls the valve control device should be understood as a superior control device. For example, such a superior control device can control multiple valve control devices. The switching signal is used to make the valve control device provide a coil current to the magnetic drive. For example, the valve control device includes a microprocessor and an electrical output stage device (Endstufenanordnung) connected thereto, wherein the microprocessor controls the output stage device when the switching signal is present so as to provide the coil current provided by the power supply to the magnetic drive.

[0008] In addition to the valve member, the magnetic drive also has an electromagnetic coil to which a coil current is supplied. The valve member is designed as a component of a magnetic circuit in this case, wherein the magnetic flux in the magnetic circuit depends on the characteristics of the electromagnetic coil, the coil current and the characteristics and positioning of the valve member. The valve member is moved between a rest position (Ruhestellung) and a working position (Funktionsstellung) according to the energization of the electromagnetic coil. In the rest position, the valve member blocks the valve seat; in the working position, the valve member releases the valve seat. Here, the valve member can rest directly on the valve seat in the rest position, in which case the valve member preferably carries a rubber elastic sealing element, the rest position is then referred to as the closed position, and the working position is referred to as the open position. Alternatively, the valve member can be separated from the valve seat, for example, by a flexible membrane, so that the valve member presses the membrane onto the valve seat in the rest position.

[0009] When the solenoid coil is supplied with a coil current, the magnetic flux in the magnetic circuit changes. This results in a force being introduced into the valve member with the goal of moving the valve member relative to the solenoid coil. Since the change in the magnetic flux, for example due to the self-inductance of the solenoid coil, is not time-synchronized with the supply of the switching signal and the coil current, and since, in addition, the valve member may stick in the corresponding position, in particular the working position or the rest position, if the magnetic drive is not actuated for a longer period of time, a time offset occurs between the supply of the switching signal and the supply of the coil current to the solenoid coil and the actual movement of the valve member.

[0010] The switch-on duration is therefore that duration or period between the supply of the solenoid coil with a coil current and the start of the first movement of the valve member and represents a variable variable that depends on the conditions of use of the solenoid valve. Since the switch-on duration can vary depending on the conditions of use of the magnetic drive and the valve member, but the most accurate possible opening time for the valve seat should be achieved in order to carry out the metering method, the method according to the invention provides that the period between the supply of the switching signal and the actual movement of the valve member is determined as the switch-on duration and is taken into account when actuating the magnetic drive.

[0011] The provision duration determined when carrying out the method is a time period between the first provision of a switching signal to or from the valve control device and the end of the provision of the switching signal and thus describes the time period over which the switching signal is provided. In principle, the provision duration describes the period during which the solenoid valve is switched from a rest position to an operating position by energizing the solenoid coil, wherein the rest position is usually a closed position and the operating position is usually an open position of the solenoid valve.

[0012] Since the solenoid valve does not immediately switch from the rest position to the working position by applying the coil current due to the above-mentioned use conditions, but the actual time period during which the solenoid valve is in the working position is crucial for accurate metering, the valve control device compensates for this, by which, in particular, the switch-on period is compensated. For this purpose, it is provided that the sum of the supply period and the switch-on period is provided as the time period for supplying the coil current, wherein this time period is referred to as the coil current period. The coil current period thus corresponds to the time during which the coil voltage and thus the coil current are applied or supplied to the solenoid coil by means of the valve control device.

[0013] The above-mentioned adhesion or sticking of the sealing element to the valve seat occurs to an increased extent, in particular in the case of a longer idle state of the solenoid valve, i.e., when the solenoid valve is in a rest position for a longer period of time. In order to still ensure the desired opening time of the solenoid valve, so-called pre-shots can be carried out according to the prior art, in which the substrate is ejected through the solenoid valve to reduce the adhesion. Such substrates cannot be used any more, which leads to increased material costs, especially in the case of expensive reagents. In addition, the duration of the pre-treatment delays the actual metering application, thereby increasing the production time.

[0014] By determining the on-time and extending the coil current period by said on-time, it can be ensured that the solenoid valve remains in the operating position at least until the desired amount of substrate has passed through the solenoid valve. In this way, regardless of the time of the off-state of the solenoid valve, pretreatment by pre-injection can be omitted, thereby reducing substrate losses and production times.

[0015] Further features which develop the invention are the subject matter of the dependent claims having the following features:

[0016] According to an advantageous extension, after the supply of the coil current ends, the start of a second movement of the valve member from the working position to the rest position, in particular from the open position to the closed position, is determined, and the shutdown duration is determined as the period between the end of the supply of the coil current and the start of the second movement of the valve member.

[0017] The movement of the valve member accompanying the start of the second movement is in the opposite direction to the movement accompanying the start of the first movement. The switch-off duration corresponds to the time required to move the valve member from the working position, in particular the open position, in the direction of the rest position, in particular the closed position. As with the movement of the valve member accompanying the start of the first movement, there is a delay caused by the coil current in the movement of the valve member accompanying the start of the second movement. The delay caused by the coil current is due to the fact that the coil current does not drop suddenly with the end of the supply of the coil voltage, but drops with a delay caused by the electromagnetic coil. This delay is reflected in the switch-off duration.

[0018] The second movement begins after the end of the supply of the coil current and is caused, for example, by a restoring force on the valve member, which causes the valve member to move back from the working position to the rest position after the magnetic flux in the magnetic circuit is reduced and the magnetic force effect on the valve member is reduced. For example, the restoring force can be provided by a spring, such as a compression spring.

[0019] The switch-off duration, like the switch-on duration, has an influence on the metering process performed by the solenoid valve, since the metering process is prolonged by the duration of the switch-off duration and thus becomes less precise. In order to be able to reduce this inaccuracy during the metering process, it is preferably provided that in a subsequent metering process, the coil current period is shortened by the switch-off duration determined in the preceding metering process.

[0020] Preferably, the switch-off duration is averaged with at least one stored switch-off duration of a past metering process. For this purpose, during preferably a plurality of previous metering processes, the respective second start of movement of the valve member from the working position to the rest position is determined, and the switch-off duration is determined in each case as the duration between the respective end of the supply of the coil current and the respective start of the second movement. In this way, inaccuracies that occur when determining the switch-off duration can be compensated.

[0021] In the subsequent metering process, preferably, the supply of the coil current from the valve control device to the magnetic drive is delayed by the magnitude of the off-duration from the time point when the switching signal is provided to the valve control device or from the valve control device, wherein the coil current period is reduced by the magnitude of the off-duration. It can be ensured thereby that the solenoid valve does not stay in the working position for longer than the desired time, thereby improving the metering accuracy. The delay of the supply of the coil current is carried out at the beginning of the metering process, i.e., from the time point when the switching signal is provided to the valve control device or from the valve control device, so that the supply duration of the metering process can be determined before the coil current period reduced by the magnitude of the off-duration should be ended again after the coil current period of time has passed. Otherwise, since the coil current period is determined according to the supply duration, it cannot be ensured in other cases that the coil current period is actually reduced by the magnitude of the off-duration. On the contrary, if the off-duration is longer than the on-duration and thus makes the coil current period smaller than the supply duration, it may happen that the supply of the coil current ends at a time point when the switching signal is still provided and therefore the supply duration cannot be determined.

[0022] Preferably, the start of the first movement and / or the start of a possible second movement is determined based on the course of the coil current supplied to the magnetic drive and / or based on at least one sensor signal of at least one sensor, in particular a pressure sensor and / or a flow sensor, assigned to the electromagnetic valve. The one or more sensors can be arranged in the substrate flow direction before and / or after the valve seat. If the start of the first movement and / or the start of a possible second movement is to be determined based on the course of the coil current supplied to the magnetic drive, this is preferably done as follows.

[0023] If the valve member starts to move away from the valve seat, a current in the opposite direction to the coil current will be induced, thereby causing the coil current to drop briefly. This short-term drop can be determined as the start of the first movement. Similarly, in the case where the coil current drops at the end of the provision of the coil current, when the valve member starts to move in the direction of the valve seat, a brief increase in the coil current caused by the backflow occurs. This can be detected as the start of the second movement. If a pressure or flow sensor is used, the start of the first and / or possible second movement can be determined by changes in pressure or flow. If data from multiple sensors are used, it is preferably checked for rationality of these data, thereby more accurately determining the start of the first and / or possible second movement. This can improve the dosing accuracy.

[0024] According to an advantageous embodiment, the switching signal is provided to the valve control device by a control device that is superior to the valve control device. This makes it possible to control a plurality of control devices, for example a plurality of valve control devices, by means of the superior control device. As a result, a corresponding circuit arrangement for providing the switching signal does not have to be provided in each valve control device, but is provided only in the superior control device. This reduces the manufacturing costs for the valve control device.

[0025] Preferably, the provision duration is compared with a plurality of individual provision durations of a plurality of individual previous dosing processes, wherein in the case of small differences between the provision duration and the individual provision durations of the previous dosing processes, a switching signal for the duration of the average value of the individual provision durations of the previous dosing processes is provided to the valve control device. In this case, differences in the interval of 1% to 20%, preferably 2% to 10%, are represented as small differences. In this way, time fluctuations of the control device providing the switching signal can be compensated, so that the dosing accuracy can be increased. In addition, the minimum volume that can be dosed by the solenoid valve can be reduced in this way. Time fluctuations occur due to the cycle time of the control device. Preferably, the compensation is carried out by another control device downstream of the control device providing the switching signal, wherein the other control device has a shorter cycle time than the control device providing the switching signal.

[0026] The object is also achieved by a solenoid valve having the following features:

[0027] The solenoid valve according to the present invention comprises a valve control device, a magnetic drive and a valve member, wherein the solenoid valve is designed to perform the metering method as described above. The valve control device is configured to perform the following steps: provide or receive and process a switching signal, and provide a coil current to the magnetic drive according to the switching signal. The valve control device is preferably configured to further perform the following steps: determine the start of the first movement of the valve member from the rest position to the working position, determine the start of the first movement of the coil current and the start of the first movement, and determine the on-duration between the switching signals and determine the supply duration for the switching signal.

[0028] According to an advantageous embodiment, the valve control device is arranged in a connecting cable arranged on the solenoid valve or in the solenoid valve. Preferably, the connecting cable connects the valve control device, the magnetic drive and a control device superordinate to the valve control device, wherein the switching signal is supplied to the valve control device via the superordinate control device. The switching signal is then supplied from the superordinate control device to the valve control device via the connecting cable, and the coil current is supplied from the valve control device to the magnetic drive.

[0029] If the valve control device is arranged in a connecting cable arranged on the solenoid valve, the functions provided by the valve control device can be represented by the already existing solenoid valve. In addition, the same valve control device can preferably be used for a plurality of solenoid valves, thereby reducing costs. If the valve control device is arranged in the solenoid valve, the required installation space can be reduced in particular.

[0030] The valve control device preferably comprises a permanent power supply and / or a switching signal input. With the permanent power supply, the magnetic drive can be supplied with current in the manner described above. Providing the switching signal input ensures that signals, in particular switching signals, can be received from the valve control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be explained in more detail below with reference to the accompanying drawings, in which:

[0032] Figure 1 shows the solenoid valve in the rest position,

[0033] Figure 2 Shown in working position Figure 1 The solenoid valve shown in

[0034] Figure 3 Another solenoid valve is shown, the valve control of which is arranged in the connecting cable,

[0035] Figure 4 Another solenoid valve with a valve control device is shown, wherein the valve control device has a permanent power supply and a switching signal input.

[0036] Figure 5 A diagram showing a metering process with a short switch-on period,

[0037] Figure 6 The diagram shows another metering process with a long switch-on period,

[0038] Figure 7 The diagram shows a further metering process with a coil voltage whose provision is extended by the magnitude of the switch-on period.

[0039] Figure 8 The diagram shows a further metering process with a coil voltage, in which the provision of the coil voltage is prolonged by the magnitude of the switch-on period and shortened by the magnitude of the switch-off period,

[0040] Fig. 9 The dosing method is shown.

[0041] Fig.10 An alternative solenoid valve is shown in a rest position, and

[0042] Fig.11 Shown in working position Fig.10 Alternative solenoid valve shown. DETAILED DESCRIPTION

[0043] Figure 1 The electromagnetic valve 100 is shown in a rest position 101. The electromagnetic valve 100 has a magnetic drive 110, a sealing element 115, a valve body 118, a valve seat 119, an input connection 104 and an output connection 105. The magnetic drive 110 preferably has a valve member 111 and an electromagnetic coil 113 surrounding the valve member 111. The valve member 111 is preferably designed as a valve magnet. In this case, the electromagnetic coil 113 is shown in cross section. The sealing element 115 is arranged on the valve member 111 and rests on the valve seat 119. In this way, it is prevented that the fluid can pass between the sealing element 115 and the valve seat 119 and reach the output connection 105 from the input connection 104, that is, the electromagnetic valve 100 is in the rest position 101. Since the valve member 111 with the sealing element 115 rests directly on the valve seat 119, this rest position is also called the closed position.

[0044] The solenoid valve 100 also preferably has a pressure spring 117, which presses the valve member 111 and thus the sealing element 115 against the valve seat 119. In this way, it can be ensured that the solenoid valve 100 is reliably sealed in the static position 101. The solenoid valve 100 also preferably has a valve control device 120, which is connected to the magnetic drive 110, in particular to the electromagnetic coil 113. The valve control device 120 is preferably configured to provide a coil current 343 (see Figures 5 to 8 To this end, a coil voltage 345 is applied to the electromagnetic coil 113 (see Figures 5 to 8 ), thereby causing the coil current 343 to flow in the electromagnetic coil 113. While the coil current 343 passes through the electromagnetic coil 113, a magnetic field is generated to act on the valve member 111 in such a way that the following magnetic force acts on the valve member, which acts in the opposite direction to the force generated by the pressure spring 117. As a result, the valve member 111 and thus the sealing element 115 are lifted from the valve seat 119, thereby causing the electromagnetic valve 100 to move to the position where the valve member 111 is located. Figure 2 The working position 102 shown in the figure is referred to as the open position here in correspondence with the rest position 101 referred to as the closed position. In the working position 102, the sealing element 115 is spaced apart from the valve seat 119 in such a way that the fluid can pass between the sealing element 115 and the valve seat 119 and thus reach the outlet connection 105 from the input connection 104.

[0045] Figure 3 Another solenoid valve 100 is shown, which is Figure 1 and Figure 2 The difference of the solenoid valve 100 shown is that the other solenoid valve does not have a valve control device 120. The connecting cable 130 in which the valve control device 120 is arranged is preferably connected to Figure 3 The solenoid valve 100 is shown. Figure 3 The embodiment shown and Figure 1 and Figure 2 In the embodiment shown, the valve control device 120 is also connected to the magnetic drive 110 . Figure 3 The solenoid valve 100 is shown in FIG. 1 in a rest position 101 .

[0046] Figure 4 Another solenoid valve 100 is shown, which is Figure 1 and Figure 2 The solenoid valve 100 shown differs in that the valve control device 120 preferably has a permanent voltage source 140 and a switching signal input 150. The coil voltage 345 (see Figures 5 to 8 ) can be supplied to the electromagnetic coil 113 by the valve control device 120 via the permanent voltage source 140, for which purpose preferably corresponding connections are provided. A switching signal 341 can be received from the valve control device 120 via the switching signal input 150 (see Figures 5 to 8). The switching signal 341 is preferably processed by the valve control device 120 in such a way that, depending on the switching signal 341, a coil voltage 345 provided by the permanent voltage source 140 is applied to the electromagnetic coil 113 and, therefore, a coil current 343 is provided to the magnetic drive 110. Alternatively, the valve control device 120 can be configured to provide the switching signal 341 itself, so that the valve control device 120 does not have to have a switching signal input 150. According to another alternative, the permanent power supply 140 can be arranged outside the valve control device 120.

[0047] The valve control device 120 is preferably configured to perform the following steps: provide or receive and process the switching signal 341; provide the coil current 343 to the magnetic drive 110 according to the switching signal 341; determine whether the valve member 111 is moving from the static position 101 (see Figure 1 , Figure 3 and Figure 4 ) to the working position 102 (see Figure 2 ) of the first movement begins; determine the on-duration 303 between providing the coil current 343 and the start of the first movement (see Figures 5 to 8 ); and determining the duration 301 for providing the switching signal 341 (see Figures 5 to 8 ).

[0048] Figure 5 The diagram 300 shows a metering process during which the aforementioned steps are carried out by the valve control device 120. In the diagram 300, the corresponding course of the switching signal 341 on the time axis 321 and the corresponding course of the coil current 343 and the coil voltage 345 are plotted on the value axis 323. At the time t0, i.e. at the beginning, i.e. at the left end of the time axis 321, the full magnitude is provided simultaneously. Switching signal 341 and coil voltage 345. From this point in time, coil current 343 begins to increase. For simplicity, Figure 5 The increase is shown linearly, but in practice the increase may also extend in another way, for example as an exponential function.

[0049] The rising straight line (Anstieggerade) of the coil current 343 is interrupted by a short drop at the time point t1. At the time point t1, the valve member 111 begins to move away from the valve seat 119, thereby inducing a current in the opposite direction to the coil current 343, which causes the above-mentioned short drop. The time point t1 is preferably detected as the time point when the first movement starts, so that the connection duration 303 can be determined between the provision of the coil current 343 at the time point t0 and the start of the first movement at the time point t1. Alternatively, the time point when the first movement starts can be determined based on at least one sensor signal assigned to the solenoid valve 100, in particular a pressure sensor and / or a flow sensor.

[0050] After the coil current 343 increases, from time point t2, the coil current 343 is maintained at a constant level until the coil voltage 345 decreases at time point t3, and then the coil current 343 also decreases. Figure 5 300 is accompanied by a decrease in the switching signal 341. The decrease in the coil current 343 and its increase are shown in a simplified linear manner. The descending straight line of the coil current 343 is interrupted by a short increase at the time point t4. At the time point t4, the valve member 111 begins to move in the direction of the valve seat 119, thereby inducing a current in the opposite direction to the coil current 343, which causes the short increase described in the previous 5.

[0051] The start of the second movement is preferably detected. The detection of the start of the second movement is preferably carried out in the same way as the detection of the start of the first movement. Preferably, the switch-off duration 305 is determined between the end of the supply of the coil current 343, i.e. the time point t3, and the start of the second movement, i.e. the time point t4. The duration between the time point t1 and the time point t4 is referred to as the metering duration 307 and corresponds to the duration during which the fluid can pass through the sealing element 115 and the valve seat 119 and reach the output connection 105 from the input connection 104.

[0052] Figure 6 A diagram 300 shows another metering process. Figure 6 The dosing process shown is similar to Figure 5 The dosing process shown differs in that the first movement begins at a later point in time. Figure 6 In, with Figure 5 Unlike the example shown, the brief drop in coil current 343 does not occur during the rise of coil current 343, but only occurs when the coil current is maintained at a constant level. Figure 6 In the diagram shown, time point t1 is after time point t2. As a result, Figure 6 The switch-on duration 303 of the metering process shown is Figure 5The switch-on period 303 of the metering process shown is longer.

[0053] In order to ensure that the switch-on time 303 has different lengths (see as an example Figure 5 and Figure 6 ) and also ensure that the desired amount of substrate passes through the solenoid valve 100, according to the invention: the coil current 343 is provided during the duration of the coil current period, wherein the coil current period corresponds to the sum of the provision duration 301 and the switch-on duration 303. Figure 7 In , at the end of the providing duration 301, that is, from the time point t3 to the time point t5, the correction duration 309 follows. Figure 7 In the metering process shown in FIG. 3 , the correction duration 309 corresponds to the switch-on duration 303 . Therefore, the metering duration 307 is obtained as the sum of the provision duration 301 and the switch-off duration 305 .

[0054] exist Figure 7 In the illustrated metering process, the metering duration 307 is longer than the provision duration 301, so that more substrate than desired can pass through the solenoid valve 100. This can be neglected for larger metering amounts or shorter switch-off durations 305. However, in the case of smaller metering amounts or longer switch-off durations 305, the metering accuracy can no longer remain within the required range.

[0055] To ensure that the dosing accuracy remains within the required range, Figure 8 As shown, preferably the supply of the coil current 343 from the valve control device 120 to the magnetic drive 110 is delayed from the time point t0 until the time point t6 by the size of the switch-off period 305, wherein the coil current period now corresponds to the supply period 301 and the switch-on period 303 minus the switch-off time 305, and the coil current period now corresponds to the sum of the supply duration 301 and the switch-on duration 303 minus the switch-off duration 305. Figure 8 In the illustrated metering process, the correction duration 309, ie the time period between t3 and t5, corresponds to the switch-on duration 303 minus the switch-off duration 305. The metering duration 307 corresponds accordingly to the provision duration 301.

[0056] Fig. 9 A metering method 200 is shown for performing at least one metering process by the following steps. In a first step 201, a switching signal 341 is provided to or from the valve control device 120. In a subsequent step 202,

[0057] The valve control device 120 supplies the coil current 343 to the magnetic drive 110 according to the switching signal 341. This dependency can be that the coil current 343 is also directly provided by the switching signal 341 (see Figures 5 to 7 This dependency can also be such that, after the switching signal 341 has been provided for the first time, the coil current 343 is provided in a delayed manner, preferably in a delayed manner by the size of the switch-off duration 305 (see Figure 8 ). In a step 203 following step 202, the start of a first movement of the valve member 111 from the rest position 101 to the working position 102 is determined. In a subsequent step 204, an on-duration 303 between the provision of the coil current 343 and the start of the first movement is determined. Finally, in a final step 205, a provision duration 301 for the switching signal 341 is determined, wherein the provision of the coil current 343 takes place for the duration of a coil current period, wherein the coil current period corresponds to the sum of the provision duration 301 and the on-duration 303.

[0058] Fig.10 An alternative solenoid valve 100 is shown in a rest position 101 , Fig.11 The alternative solenoid valve 100 is shown in an operating position 102. The alternative solenoid valve 100 has a Figures 1 to 4 The solenoid valve 100 shown in FIG. Figures 1 to 4 The solenoid valve 100 shown differs in that the alternative solenoid valve 100 does not have a sealing element 115 arranged on the valve member 111, but has a membrane 116, on which the valve member 111 merely rests. The membrane 116 is connected to the valve body 118 and is designed and arranged on the valve seat 119 so that when the valve member 111 is at the bottom, that is, when the solenoid valve 100 is in the rest position 101, the membrane 116 is pressed onto the valve seat 119, so that the solenoid valve 100 is reliably sealed. If the valve member 111 is at the top, that is, if the solenoid valve 100 is in the working position 102, the membrane 116 is spaced apart from the valve seat 119 so that the fluid can pass between the membrane 116 and the valve seat 119 and reach the output connection 105 from the input connection 104.

Claims

1. A dosing method (200) for performing at least one dosing process, the method comprising the following steps: providing a switching signal (341) to a valve control device (120) or providing a switching signal (341) from the valve control device (120); providing a coil current (343) from the valve control device (120) to a magnetic drive (110) according to the switching signal (341), wherein the magnetic drive (110) is designed to move a valve member (101) of a solenoid valve (100) between a rest position (101) and a working position (102). 111); determining the start of a first movement of the valve member (111) from the rest position (101) to the working position (102); determining an on-duration (303) between providing the coil current (343) and the start of the first movement; determining a supply duration (301) for the switching signal (341), wherein the coil current (343) is provided for the duration of a coil current period, the coil current period corresponding to the sum of the supply duration (301) and the on-duration (303).

2. The dosing method (200) according to claim 1, characterized in that: After the supply of the coil current (343) ends, the start of the second movement of the valve member (111) from the working position (102) to the rest position (101) is determined, and the shutdown duration (305) between the end of the supply of the coil current (343) and the start of the second movement of the dosing process is determined.

3. The dosing method (200) according to claim 2, characterized in that: The switch-off duration (305) is averaged with at least one stored switch-off duration (305) of a past metering process.

4. The dosing method (200) according to claim 2 or 3, characterized in that: In the subsequent metering process, the provision of the coil current (343) from the valve control device (120) to the magnetic drive (110) is delayed by the magnitude of the shutdown duration (305) from the time point when the switching signal (341) is provided to the valve control device (120) or from the time point when the valve control device (120) provides the switching signal (341), wherein the coil current period is reduced by the magnitude of the shutdown duration (305).

5. The dosing method (200) according to any one of the preceding claims, characterized in that The start of the first movement and / or the start of a possible second movement is determined based on a change in a coil current (343) supplied to the magnetic drive (110) and / or based on at least one sensor signal assigned to the solenoid valve (100), in particular a pressure sensor and / or a flow sensor.

6. The dosing method (200) according to any one of the preceding claims, characterized in that The switching signal (341) is provided to the valve control device (120) by a control device (120) above the valve control device (120).

7. The dosing method (200) according to any one of the preceding claims, characterized in that The provision duration (301) is compared with a plurality of individual provision durations (301) of a plurality of individual previous dosing processes, wherein, in the event of a small difference between the provision duration (301) and the individual provision durations (301) of the previous dosing processes, a switching signal (341) for the duration of an average value of the individual provision durations (301) of the previous dosing processes is provided to the valve control device (120).

8. A solenoid valve (100), comprising a valve control device (120), a magnetic drive (110) and a valve member (111), wherein the solenoid valve (100) is designed to perform a metering method (200) according to any one of the preceding claims.

9. The solenoid valve (100) according to claim 8, characterized in that: The valve control device (120) is arranged in a connecting cable (130) arranged on the solenoid valve (100) or in the solenoid valve (100).

10. The solenoid valve (100) according to claim 8 or 9, characterized in that: The valve control device (120) comprises a permanent power supply (140) and / or a switching signal input terminal (150).

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