阅读说明：本技术 用于切换电磁阀的方法 (Method for switching solenoid valves ) 是由 D·波登查兹 E·路德维希 D·弗希 S·本斯勒 于 2018-04-05 设计创作，主要内容包括：本发明涉及一种用于切换电磁阀(1)的方法,该电磁阀具有在第一位置和第二位置之间可移动的阀体(4),其中该方法至少包括以下方法步骤：a)将开关电流(8)设置为预通电电流强度(I<Sub>1</Sub>)达第一时间段(11),在该电流强度下阀体(4)保持在当前位置,并且b)将开关电流(8)设置为第一切换电流强度(I<Sub>2</Sub>)达第二时间段(12),该第一切换电流强度引起阀体(4)的切换运动。(The invention relates to a method for switching a solenoid valve (1) having a valve body (4) that is movable between a first position and a second position, wherein the method comprises at least the following method steps: a) setting the switching current (8) to a pre-current intensity (I) 1 ) For a first time period (11), at which the valve body (4) remains in the current position, and b) the switching current (8) is set to a first switching current intensity (I) 2 ) For a second period of time (12), the first switchThe current intensity causes a switching movement of the valve body (4).)

1. Method for switching a solenoid valve (1) having a valve body (4) movable between a first position and a second position, wherein the method comprises at least the following method steps:

a) setting the switch current (8) toIs set to a pre-energizing current intensity (I)₁) For a first time period (11), the valve body (4) remains in the current position at the pre-current intensity, and

b) setting the switching current (8) to a first switching current intensity (I)₂) For a second time period (12), the first switching current intensity causes a switching movement of the valve body (4).

2. Method according to claim 1, wherein the second period of time (12) is quantified such that the switching of the solenoid valve (1) has not been completed after the second period of time (12).

3. The method according to any one of the preceding claims, further comprising the method steps of:

c) setting the switching current (8) to a decaying current intensity (I)₃) For a third time period (13), the decay current level is adapted to the speed of the switching movement.

4. Method according to any of the preceding claims, wherein the solenoid valve (1) can be switched from the first position to the second position by the presence of the switching current (8) having a current intensity higher than an upper limit current intensity (9), wherein the pre-energizing current intensity (I) is₁) Below said upper current level (9).

5. Method according to claim 4, wherein the pre-energizing current intensity (I)₁) At least 90% of the upper current limit.

6. Method according to any of the preceding claims, wherein the solenoid valve (1) can be switched from the second position to the first position by the presence of the switching current (8) having a current intensity below a lower limit current intensity (10), wherein the pre-energizing current intensity (I) is₁) Above the lower current limit (10).

7. Root of herbaceous plantMethod according to claim 6, wherein the pre-energizing current intensity (I)₁) At most 110% of the lower current limit.

8. The method according to any one of the preceding claims, further comprising the method steps of:

d) setting the switching current (8) to a second switching current strength (I)₄) The switching of the solenoid valve (1) is ensured by the second switching current intensity.

9. Method according to claim 8, wherein the setting of the solenoid valve (1) is monitored at least for the duration of step d).

10. Method according to claim 8 or 9, wherein a plurality of homogeneous switching processes are carried out, wherein the acceleration of the valve body (4) in the second time period (12) is increased in a subsequent switching process as long as a switching of the solenoid valve (1) in step d) has been recognized in at least one previous switching process.

11. Method according to one of claims 8 to 10, wherein a plurality of homogeneous switching processes are carried out, wherein the acceleration of the valve body (4) in the second time period (12) is reduced in a subsequent switching process as long as no switching of the solenoid valve (1) in step d) has been recognized in at least one previous switching process.

12. A controller (15) for switching a solenoid valve (1) with a switching current (8) according to the method of any one of the preceding claims.

13. A computer program arranged to perform all the steps of the method according to any one of claims 1 to 11.

14. A machine-readable storage medium on which a computer program according to claim 13 is stored.

Background

Valves that can be switched by an electrical signal are known for various fields of application. In particular, solenoid valves are known which can be switched in particular by changing the magnetic force. However, when switching the solenoid valve, undesirable noise is often generated.

Disclosure of Invention

In this case, a particularly advantageous method for switching a solenoid valve is proposed. The dependent claims describe particularly advantageous developments of the method.

The described solenoid valve can be used in particular in a brake system, in particular of a motor vehicle. However, the described solenoid valve can also be used for any other application.

The solenoid valve has a movable valve body that is adjustable between at least a first position and a second position. The solenoid valve can be designed such that it is closed in a first position of the valve body and open in a second position of the valve body. However, it is also possible for the solenoid valve to be open in the first position of the valve body and closed in the second position of the valve body.

The arrangement of the solenoid valve can be specified in particular by the position of the valve body. Thus, the first position of the solenoid valve corresponds to the first position of the valve body, and the second position of the solenoid valve corresponds to the second position of the valve body. Preferably, but not necessarily, there is no (defined) intermediate position between the first position and the second position of the valve body (or solenoid valve). Without an intermediate position, the solenoid valve can only be (fully) opened or (fully) closed. In the switching between the open state and the closed state, the intermediate position is present only for a very short time.

For example, a solenoid valve may have a passage between an inlet and an outlet. At the inlet, the medium can flow into the channel (from the inflow solenoid valve). Depending on the position of the valve body, the passage may be blocked or released by the valve body. In one position of the solenoid valve, the passage is released and the solenoid valve opens. In this case, the medium can flow through the valve body to the outlet via the passage and thus flow out of the solenoid valve. When the valve body blocks the passage, the solenoid valve is closed and the medium cannot flow out of the solenoid valve or from the outlet.

The valve body can be adjusted in the solenoid valve, in particular by magnetic force. The valve body is preferably at least partially magnetic, so that a magnetic force can act on the valve body. However, the magnetic force may alternatively act on a magnetic element connected to the valve body. In this case, the valve body can also be embodied non-magnetically. The magnetic force is preferably generated by one or more electrical coils (also referred to as electromagnets). The magnetic force is dependent on the current flowing through the one or more electrical coils. If in the following the current intensity is mentioned, the current intensity refers to the current intensity of the current flowing through the one or more electrical coils.

The valve body is preferably mounted such that the valve body is translatably adjustable. The magnetic force is preferably oriented in a first direction. While a restoring force preferably acts on the valve body in a second direction opposite to the first direction. The restoring force can be generated in particular by a spring. Depending on the current intensity (of the current flowing through the one or more electrical coils), the magnetic force dominates (thereby generating a resultant force in the first direction), or the spring force dominates (thereby generating a resultant force in the second direction).

The valve body is preferably adjustable between a first stop and a second stop. In this case, the valve body preferably abuts against a first stop in the first position and preferably abuts against a second stop in the second position. The valve body can be held at the stop, in particular, by means of a respective holding current intensity. For example, the valve body may be held in one position by applying a first holding current strength of zero. As a result, only a restoring force acts, which presses the valve body against the respective stop. Similarly, the first holding current strength may also be different from zero, but the current strength value is dimensioned so small that the restoring force is greater than the magnetic force. In a further position, the valve body can be held with a second holding current strength that is non-zero and that generates a magnetic force of a greater magnitude opposite the restoring force, so that the valve body is held at the respective stop.

To switch the solenoid valve between the first and second positions (i.e., from the first to the second position or vice versa), the current flowing through the one or more electrical coils will be varied. The current flowing through the one or more electrical coils during or for switching shall be referred to as switching current. The switching current may also have a current strength of zero.

In step a) of the method, the switching current is set to a pre-energization current level, at which the valve body remains in the current position, for a first period of time.

The valve body remaining in the current position means that the pre-energizing current intensity is too weak to cause switching of the solenoid valve. According to the method, if the valve body is in the first position before switching, for example, the valve body is held in the first position even if the switching current is set to the pre-energization current level.

The length of the first time period is preferably in the range of 1 to 100 milliseconds, in particular in the range of 5 to 10 milliseconds.

In step b) of the method, the switching current is set to a first switching current intensity for a second time period, which first switching current intensity causes a switching movement of the valve body.

The first switching current strength is in particular set such that the resultant of the magnetic force and the restoring force generated by the one or more electrical coils acts in a direction moving the valve body for switching.

The first switching current level may be in particular a first closing current level when switching the solenoid valve from the open position of the solenoid valve to the closed position of the solenoid valve. The first switching current strength can be in particular a first opening current strength when switching the solenoid valve from the closed position of the solenoid valve to the open position of the solenoid valve.

By setting the switching current to the pre-energization current level, the subsequent switching process (caused by the application of the first switching current level in step b) can be made particularly reliable. The switching process can be independent of fluctuations in the supply voltage or the supply current level. For example, if the switching current is switched directly from the holding current strength to the first switching current strength, various effects such as inductive effects may cause the switching current to reach the first switching current strength after a time delay. In this case, the time profile of the switching current can be flattened in particular in such a way that the switching current does not change abruptly (as desired) in a step-like manner from the holding current level to the first switching current level, but rather continuously. In the switching current curve flattened in this way, the switching current is applied with the first switching current intensity only for a part of the first time period. This portion of the first time period may be too short for the switching of the solenoid valve. In order to take account of the flattened switching current curve, the first time period can in principle be extended accordingly. It should be noted, however, that the switching current may be flattened differently under different conditions. Various influences of the supply voltage network on the supply voltage and thus on the switching current may result in the switching current being flattened differently in different operating situations of the supply voltage network. However, in order to achieve a particularly reliable switching, the switching current is first set to the pre-energization current level. The jump to the first switching current level is thereby particularly small, so that the switch current curve can be flattened only in a particularly short time period, so that the switching of the solenoid valve is only influenced to a particularly small extent.

The solenoid valve is preferably connected to a controller which is intended and arranged for carrying out the method. The controller preferably has, in particular, an input via which a request for switching the solenoid valve can be received. The input may comprise a user interface for user operation and/or an interface for connection to an electronic system. The controller can be connected in particular to the electronics of the motor vehicle. Furthermore, the control unit is preferably connected to one or more electrical coils of the solenoid valve, wherein the current flowing through the one or more electrical coils can be set by the control unit.

In a preferred embodiment of the method, the length of the second time period is dimensioned such that the switching of the solenoid valve has not been completed after the second time period.

When switching the solenoid valve, the valve body can be accelerated in particular over the entire second time period. The longer the second time period lasts, i.e. the longer the duration of the acceleration of the valve body by the switching current intensity, the greater the speed of the switching movement of the valve body, i.e. the speed of the movement of the valve body from the first position to the second position or vice versa. If the valve body strikes the respective stop at a particularly high speed, this may be perceived as an unpleasant loud noise (particularly popping). In order to prevent or at least reduce such impact sounds that occur when the valve body strikes the stop, the switching current intensity is applied only during a second time period, which is dimensioned such that the switching of the solenoid valve is not yet completed after the second time period. The acceleration of the solenoid valve by the switching current intensity preferably lasts only for the time required for the switching. After the end of the second time period, the valve body can be moved further in the direction of the respective stop, in particular by inertia, even without further acceleration, so that the switching process can be completed after the second time period.

In a preferred embodiment, the method further comprises the following method steps:

c) the switching current is regulated to a decaying current intensity for a third time period, the decaying current intensity being adapted to the speed of the switching movement.

In particular, the occurrence of noise can be prevented or at least reduced particularly well by the valve body being braked before striking the respective stop. This can be carried out in particular according to step c). In this case, the damping current intensity is preferably (in particular also in coordination with the switching current intensity, the duration of the second time period and the third time period) dimensioned such that the valve body accelerated according to step b) reaches the respective stop at a particularly low speed, so that the noise generated is particularly low.

In a further preferred embodiment of the method, the solenoid valve can be switched from the first position into the second position by the presence of a switching current having a current intensity above an upper current intensity, wherein the pre-energization current intensity is below the upper current intensity.

If an electric current with an upper current intensity flows through one or more electric coils, a force balance will be reached between the restoring force and the magnetic force. At amperages above the upper amperage limit, the valve body is preferably in the second position or moved to the second position (in particular if the valve body was previously in the first position and such amperages were not present for long enough).

In particular when the solenoid valve is switched from the first position to the second position, it is advantageous for the pre-energization current level to be lower than the upper-limit current level. Thus, the switching of the solenoid valve has not been initiated by the pre-energization amperage. It is also advantageous to select a pre-energizing current level at least below the upper current level when switching from the second position to the first position. Otherwise, when setting the first switching current level, particularly large and therefore particularly unfavorable jumps in the switching current occur (which may lead in particular to a particularly strong flattening of the switching current curve).

In a further preferred embodiment of the method, the pre-energization amperage is at least 90%, preferably at least 95%, of the upper limit amperage.

In this embodiment, the pre-energization amperage is selected to be just below the upper-limit amperage. This is advantageous in particular when the solenoid valve is switched from the first position to the second position. Although the pre-energization current level thus selected has not yet initiated the switching of the solenoid valve from the first position to the second position, the pre-energization current level is already close to the upper limit current level required for such switching. As a result, a particularly small jump in the switching current occurs when setting the first switching current strength.

In a further preferred embodiment of the method, the solenoid valve can be switched from the second position into the first position by the presence of a switching current having a current intensity below a lower current intensity, wherein the pre-energization current intensity is above the lower current intensity.

If an electric current with a lower limit current intensity flows through one or more electric coils, a force balance will be reached between the restoring force and the magnetic force. At amperages below the lower amperage limit, the valve body is preferably in the first position or moved to the first position (in particular if the valve body was previously in the second position and such amperage was not present for a long enough time).

The upper and lower amperages are preferably spaced apart from each other. This may be the case in particular if the magnetic forces in the first and second positions of the valve body differ in magnitude. This may be due, for example, to the valve body being at different distances from the one or more electrical coils in the first and second positions. It is also possible to provide a retaining element for the valve body at one stop or at both stops. For example, a projection at the valve body can engage in a corresponding groove as a retaining element at the stop. However, it is also conceivable for the upper and lower current levels to coincide.

The fact that the pre-energization amperage is higher than the lower-limit amperage is advantageous in particular when the solenoid valve is switched from the second position to the first position. Thus, the switching of the solenoid valve has not been initiated by the pre-energization amperage. It is also advantageous to select a pre-energizing current intensity that is at least higher than the lower limit current intensity when switching from the first position to the second position. Otherwise, when setting the first switching current level, particularly large and therefore particularly unfavorable jumps in the switching current occur (which may lead in particular to a particularly strong flattening of the switching current curve).

In a further preferred embodiment of the method, the pre-energization amperage is at most 110% of the lower limit amperage.

In this embodiment, the pre-energization amperage is selected to be just above the lower limit amperage. This is advantageous in particular when the solenoid valve is switched from the second position to the first position. Although the pre-energization current level thus selected has not yet initiated the switching of the solenoid valve from the second position to the first position, the pre-energization current level is already close to the lower limit current level required for such switching. As a result, a particularly small jump in the switching current occurs when setting the first switching current strength.

In a further preferred embodiment, the method further comprises the following method steps:

d) the switching current is set to a second switching current level, by means of which switching of the solenoid valve is ensured.

As already mentioned, the switching of the solenoid valves according to steps a) to c) of the method can be carried out with particularly low noise. For this purpose, the valve body strikes the stop at a particularly low speed. Such switching at low speeds of the valve body may result in the switching process not being completely completed, so that the valve body is not moved by the switching process (unlike desired). This may be due in particular to the fact that: in the switching according to steps a) to c) of the method, even small external influences can cause the valve body to brake further in addition to the braking according to step c), so that the speed of movement of the valve body is no longer sufficient to reach the respective stop. In this case, for example, a magnetic force that brakes the valve body can be considered as an external influence. The valve body can also be braked by friction at the solenoid valve part (for example the receptacle in which the valve body is movably mounted).

By means of step d), the valve can be switched when the valve body is not moved as desired by the switching process according to steps a) to c) and in particular according to step b). For this purpose, a second switching current intensity is to be applied after step c) according to step d). The second switching current intensity is preferably higher than the first switching current intensity, at least higher than the upper limit current intensity, if the valve body is moved from the first position to the second position. The second switching current intensity is preferably lower than the first switching current intensity, at least lower than the lower limit current intensity, if the valve body is moved from the second position to the first position.

The fourth time period (in particular in combination with the second switching current intensity) is preferably set sufficiently long so that the switching of the solenoid valve takes place with a particularly high probability (unless it has been switched as desired according to steps a) to c)). It is also possible that the fourth time period is not limited, so that the second switching current level is applied until the solenoid valve is switched again. This can be the case in particular if a current strength of zero is selected both for the second switching current strength and for the first holding current strength.

The second switching current level can be in particular a second closing current level when the solenoid valve is switched from its open position into its closed position. The second switching current level can be in particular a second opening current level when the solenoid valve is switched from its closed position into its open position.

In a further preferred embodiment of the method, the setting of the solenoid valve is monitored at least for the duration of step d).

The setting of the solenoid valve is preferably monitored in such a way that the position of the valve body is detected (for example as a distance from the first stop and/or from the second stop). Instead, it is preferably detected whether the valve body is in the first position or in the second position. The monitoring of the solenoid valve regulation can be carried out in particular by means of a sensor at the solenoid valve. The sensor is preferably connected to the controller.

The monitoring in step d) (monitoring the position of the valve body) can be carried out in particular by monitoring the current gradient. In particular, the switching of the solenoid valve can be recognized in the time profile of the current flowing through the current coil. For this purpose, a distinction must be made between an ideal time profile of the current and an actual time profile of the current. For example, if a voltage is suddenly applied or increased to the electric coil, the current flowing through the coil suddenly increases in an ideal manner. However, in practice there is a time delay for the increase in current due to self-induction in the electrical coil. The current increases in particular exponentially and approximates the value to which the current would ideally jump immediately.

The valve body is preferably designed to be at least partially magnetic and/or connected to a magnetic element, on which the magnetic force of the electric coil can act. The solenoid valve body or the magnetic element is preferably at least partially located in the magnetic field generated by the electric coil. In this case, the magnetic permeability of the solenoid valve body or of the magnetic element influences the magnetic field generated by the electric coil or the current flowing through the electric coil. If the valve body moves, the current flowing through the electrical coil will be affected by the induction. Based on the basic principle of electromagnetic induction, the moving valve body may in particular induce an electric current in the coil, which current will generate a magnetic field that suppresses the movement of the valve body. This means in particular that the current flowing through the electrical coil is attenuated when the valve body is moved (i.e. in particular when the solenoid valve is switched) when the second switching current level is increased. This appears as an artifact in the time profile of the current flowing through the current coil. In this way, the switching of the valve body can be recognized in the time profile of the current.

By monitoring the setting of the solenoid valve during the duration of step d), i.e. in particular during the fourth time period, it can preferably be recognized whether a switching of the solenoid valve has been carried out as desired according to steps a) to c) and in particular according to step b), or whether a switching of the solenoid valve has only been carried out in step d).

In a further preferred embodiment of the method, a plurality of similar switching processes are carried out, wherein the acceleration of the valve body in the second time period is increased in a subsequent switching process as long as a switching of the solenoid valve in step d) has been detected in at least one preceding switching process.

In a further preferred embodiment of the method, a plurality of similar switching processes are carried out, wherein the acceleration of the valve body in the second time period is reduced in a subsequent switching process as long as it has been recognized in at least one preceding switching process that the solenoid valve has not been switched in step d).

A plurality of similar switching processes is to be understood in particular to mean that the solenoid valve is switched back and forth between the first position and the second position repeatedly without further changes being required at the solenoid valve. The switching from the first position to the second position may be similar in particular to the switching from the second position to the first position. If a plurality of homogeneous switching processes are performed, the parameters of the method can be improved iteratively (i.e. e.g. from one switching process to the next) by evaluating one or more previous switching processes. In both embodiments of the invention, this can be achieved by iteratively adjusting the acceleration experienced by the valve body in step b) (i.e. during the second time period).

The acceleration of the valve body can be increased in particular by lengthening the second period of time and can be reduced by shortening the second period of time. Alternatively or additionally, the acceleration of the valve body may be adjusted by adjusting the intensity of the first switching current. When switching from the first position to the second position, the acceleration of the valve body can be increased by increasing the intensity of the first switching current. When switching from the second position to the first position, the acceleration of the valve body can be increased by decreasing the intensity of the first switching current.

On the one hand, the acceleration of the valve body in step b) is preferably particularly low, so that the noise generated (by the valve body striking the respective stop) is particularly low. On the other hand, however, the acceleration of the valve body in step b) is preferably at least large enough to make it sufficient to switch the solenoid valve (so that switching does not occur in step d)). According to both embodiments of the invention, the acceleration of the valve body can be iteratively adjusted, so that an acceleration can be found which makes it possible to switch according to steps a) to c) on the one hand, while the noise generated on the other hand is also particularly low.

If it is recognized in a plurality of switching processes that switching frequently takes place only in step d), the acceleration of the valve body is preferably increased in order to switch in a subsequent switching process as desired, as a rule according to steps a) to c) and in particular according to step b).

If it is recognized during the switching process that switching never takes place or only rarely in step d), the acceleration of the valve body is preferably reduced in order to generate particularly low noise.

The reduction or increase of the acceleration is preferably achieved by adjusting the first switching current strength.

The iterative adjustment can be carried out in particular by the controller. For this purpose, the control unit is preferably provided in particular with information about the acceleration of the valve body during the respective switching operation (i.e. in particular the magnitude of the first switching current intensity, the duration of the second time period and information about whether the switching of the solenoid valve takes place in step d). From this information, it can be determined, using corresponding software installed on the controller, how to select an acceleration for the subsequent switching process, wherein in particular the magnitude of the first switching current intensity and the duration of the second time period are determined for the subsequent switching process.

In another aspect, a controller is presented, wherein the controller is arranged to perform the method. Furthermore, a computer program is proposed, which is arranged to perform the method. Furthermore, a machine-readable storage medium is proposed, on which a computer program is stored. The specific advantages and design features of the above-described method may be adapted and transferred to the controller, computer program and machine-readable storage medium.

Drawings

Further details and embodiments of the invention will be explained in more detail with the aid of the drawings, without the invention being restricted to these embodiments.

Figure 1 shows a schematic view of a solenoid valve,

figure 2 shows a schematic switching current curve when the solenoid valve of figure 1 is switched from a first position to a second position,

FIG. 3 shows a schematic switching current curve when the solenoid valve of FIG. 1 is switched from the second position to the first position, and

fig. 4 shows a schematic switching current curve of the solenoid valve of fig. 1 when switching from the first position to the second position several times.

Detailed Description

Fig. 1 shows a solenoid valve 1 having a valve body 4, which valve body 4 can be adjusted between a first stop 16 and a second stop 17. At the first stop 16, the valve body 4 is in the first position. At the second stop 17, the valve body 4 (as shown in this figure) is in the second position. The solenoid valve 1 has a passage 5 between an inlet 6 and an outlet 7. In the second position of the valve body 4 (shown here), the passage 5 is released, so that the solenoid valve 1 is opened. In this case, the medium can flow through the valve body 4 from the inlet 6 through the channel 5 to the outlet 7 and thus out of the solenoid valve 1. If the valve body 4 blocks the passage, the solenoid valve 1 is closed and no medium can flow out of the solenoid valve 1 or from the outlet 7. In the solenoid valve 1, an electrical coil 2 is arranged, which exerts a magnetic force in a first direction (in this case upwards) on the valve body 4 as a function of the current flowing through the electrical coil. The valve body 4 is connected to a spring 3 which applies a force in a second direction 19, here downwards, to the valve body 4. The solenoid valve 1 is connected to a control unit 15, by means of which the solenoid valve 1 can be switched. For this purpose, the current shown in fig. 2 and 3 flows through the electrical coil 2.

In fig. 2 and 3, the current intensity I is plotted in time t (in arbitrary units, respectively). A time curve of the switching current 8 for switching the solenoid valve 1 of fig. 1 from the first position to the second position (fig. 2) or from the second position to the first position (fig. 3) is shown. The switching current 8 is shown in an ideal form. In addition, the actual switching current 21 is shown in a thinner line with respect to the switching current 8, wherein the change due to self-inductance is delayed in time. The first position corresponds to a first holding current strength I_AAnd the second position corresponds to a second holding current strength I_B. Furthermore, an upper limit amperage 9 is indicated, wherein the solenoid valve 1 can be switched from the first position into the second position by the presence of the switching current 8 having an amperage which is higher than the upper limit amperage 9. Furthermore, a lower limit amperage 10 is indicated, wherein the solenoid valve 1 can be switched from the second position to the first position by the presence of the switching current 8 having an amperage below the lower limit amperage 10.

In fig. 2, the switching of the solenoid valve 1 from the first position to the second position is shown. In this case, the solenoid valve 1 reaches an initial time t₀Are all in the first position. For this purpose, a first holding current I is applied_A. At a starting point in time t₀And a first point in time t₁In the first time interval 11 in between, the switching current 8 is set to the pre-energization current level I₁At which the valve body 4 remains in the present position (i.e. the first position). Pre-current intensity I₁Below the upper current level 9. Furthermore, the pre-current intensity I₁Is 90% of the upper limit current intensity. It should be particularly noted here that fig. 2 is only schematically and not precisely scaled for the sake of clarity. At a first point in time t₁And a second point in time t₂In between, in a second time period 12, the switching current 8 is set to the first switching current strength I₂Which will initiate the switching movement of the valve body 4. The length of the second time period 12 is determined such that the switching of the solenoid valve 1 has not been completed after the second time period 12. At a second point in time t₂And a third point in time t₃In the third time period 13, the switching current 8 is set to the decaying current intensity I₃The decaying current intensity will regulate, in particular reduce, the speed of the switching movement. This can reduce noise generated when the valve body 4 hits the second stopper 17. At a third point in time t₃And a fourth time point t₄In the fourth time period 14, the switching current 8 is set to the second switching current level l4, so that switching of the solenoid valve 1 is ensured. At a fourth point in time t₄After that, the solenoid valve 1 is in the second position. Therefore, a second holding current strength I is applied_B。

In fig. 3, the switching of the solenoid valve 1 from the second position to the first position is shown. In this case, the solenoid valve 1 reaches an initial time t₀Are both in the second position. Applying a second holding current I for this purpose_B. At a starting point in time t₀And a first point in time t₁In the first time interval 11 in between, the switching current 8 is set to the pre-energization current level I₁At which the valve body 4 remains in the present position (i.e. the second position). Pre-current intensity I₁Above the lower current limit of 10. Furthermore, the pre-current intensity I₁110% of the lower limit current intensity. It should be particularly noted here that fig. 3 is only schematically and not precisely scaled for the sake of clarity. At a first point in time t₁And a second point in time t₂In between, in a second time period 12, the switching current 8 is set to the first switching current strength I₂Which will initiate the switching movement of the valve body 4. The length of the second time period 12 is determined such that the switching of the solenoid valve 1 has not been completed after the second time period 12. At a second point in time t₂And a third point in time t₃In the third time period 13, the switching current 8 is set to the decaying current intensity I₃The decaying current intensity will regulate, in particular reduce, the speed of the switching movement. This can reduce noise generated when the valve body 4 hits the first stopper 16. At a third point in time t₃And a fourth time point t₄In the fourth time period 14, the switching current 8 is set to the second switching current level l4, thereby ensuring that the solenoid valve 1 is operatedThe handover of (2). At a fourth point in time t₄After that, the solenoid valve 1 is in the first position. Therefore, a first holding current strength I is applied_A. The second switching current intensity I₄And a first holding current strength I_AAre all equal to zero. This means that the valve or valve body is held in the first position (only) by the restoring force and the magnet does not exert a force in the first position. However, here is shown a fourth time period 14 and a fourth point in time t₄In order to clarify the comparison with fig. 2.

The regulation of the solenoid valve 1 is monitored during a fourth time period 14, both when the solenoid valve 1 switches from the first position to the second position (fig. 2) and when the solenoid valve 1 switches from the second position to the first position (fig. 3). If a plurality of similar switching processes are carried out, the acceleration of the valve body 4 in the second time period 12 can be increased in the subsequent switching process, as long as the switching of the solenoid valve 1 is not detected in the fourth time period 14 in the previous switching process. If, however, no switching is detected in the fourth time period 14, the acceleration of the valve body 4 in the second time period 12 can be reduced during the subsequent switching operation.

Fig. 4 shows a schematic switching current curve of the solenoid valve 1 from fig. 1 when switching from the first position to the second position several times. Here, three switching processes are shown, which (as indicated by the dots) do not take place in the immediate vicinity of one another. As in fig. 2, the current I is plotted against the voltage t and the actual switching current 21 is shown. In the switching process shown on the left and right, the solenoid valve 1 is switched as desired. Whereas during the intermediate switching process an artifact 20 is visible in the actual switching current 21. The artifact 20 is generated due to the movement of the valve body 4 (i.e. due to the switching of the solenoid valve 1) based on electromagnetic induction. This artifact 20 indicates that the solenoid valve 1 is only due to the second switching current strength I₄Is switched over.