Valve inspection device and method for inspecting solenoid valve

Abstract

The invention relates to a valve checking device (10) and a method for checking a solenoid valve (14). A time-dependent actual voltage (U) is applied to the coil (12) of the solenoid valve (14) during a predetermined or self-determined checking time interval, and the coil (12) of the solenoid valve (14) is energized during the checking time interval according to a predetermined time-based current intensity change curve, in this way, the armature (16) of the solenoid valve (14) is at least temporarily displaced during the checking time interval. Determining a time curve of the voltage induced by means of the armature (16) shifted at least temporarily during a test time interval, taking into account a time-dependent actual voltage (U) applied during the test time interval (delta) in order to comply with the time-based current intensity curve, and determining at least one physical quantity relating to a spring device (18) of the solenoid valve (14) and / or relating to static friction and / or sliding friction of the armature (16), taking into account a time curve of the voltage induced during the test time interval.

Description

Technical Field

[0001] The present invention relates to a valve inspection device, a method for inspecting a solenoid valve, and a method for electrically adjusting the spring preload of a spring device of a solenoid valve. Background Art

[0002] Solenoid valves for controlling liquid and / or gaseous media are known from the prior art, for example DE 10 2021 207 906 A1. Such solenoid valves generally have at least one coil, by energizing the coil a magnetic field can be generated, so that an armature of a corresponding solenoid valve, which is pressed or pulled away from a first limit position in the solenoid valve and to a second limit position in the solenoid valve by means of a spring device of the corresponding solenoid valve, can be displaced by means of the magnetic field against the spring force of the spring device. Summary of the invention

[0003] The invention provides a valve inspection device, a method for inspecting a solenoid valve and a method for electrically adjusting a spring preload force of a spring device of a solenoid valve.

[0004] According to the present invention, a valve inspection device is provided, which has:

[0005] an electronic device, which is designed and / or programmed in such a way that, by means of the electronic device, a time-varying actual voltage can be applied to at least one coil of the solenoid valve during a predetermined or self-determined test time interval, so that the at least one coil of the solenoid valve can be energized during the test time interval according to a predetermined time-based setpoint current intensity profile, so that the armature of the solenoid valve can be displaced at least temporarily during the test time interval;

[0006] The electronic device can determine the time profile of the voltage induced during the test time interval by means of the at least temporarily displaced armature, taking into account the actual voltage that changes over time and is applied during the test time interval in order to comply with the time-based desired current intensity profile, wherein:

[0007] The electronic system is additionally designed and / or programmed in such a way that at least one physical variable about the spring device of the solenoid valve and / or about the static friction and / or sliding friction of the armature can be determined by means of the electronic system taking into account a determined time profile of the voltage induced during the test time interval.

[0008] According to the present invention, a method for checking a solenoid valve is also provided, comprising the following steps:

[0009] During a predetermined or self-determined inspection time interval, a time-varying actual voltage is applied to at least one coil of the solenoid valve in such a way that the at least one coil of the solenoid valve is energized during the inspection time interval according to a predetermined time-based desired current intensity variation curve, so that the armature of the solenoid valve is at least temporarily displaced during the inspection time interval; and

[0010] determining a time profile of a voltage induced by the armature at least temporarily displaced during the check time interval, taking into account an actual voltage which varies over time and is applied during the check time interval in order to comply with the time-based desired current intensity profile;

[0011] Among them, there are the following steps:

[0012] Taking into account the determined time profile of the voltage induced during the test time interval, at least one physical variable is determined regarding the spring device of the solenoid valve and / or regarding the static friction and / or the sliding friction of the armature.

[0013] The present invention provides an advantageous possibility for checking a solenoid valve with respect to its spring device and / or with respect to the static friction and / or sliding friction of its armature, without having to allow a liquid and / or gaseous medium to be controlled by means of the solenoid valve to flow through in order to check the corresponding solenoid valve. Therefore, when using the present invention, the inspection performed on the corresponding solenoid valve will not be related to the consumption of the liquid and / or gaseous medium to be controlled by means of the corresponding solenoid valve. Therefore, the present invention also provides a possibility for checking the corresponding solenoid valve at low cost. In addition, with the help of the present invention, the corresponding solenoid valve can be checked without the use of a pressure sensor and without the use of a flow measuring element. Therefore, compared with the prior art, the present invention provides the possibility for checking the corresponding solenoid valve more quickly and more accurately. In addition, as shown according to the following description, the present invention can be used for a variety of different solenoid valve types.

[0014] In an advantageous embodiment of the valve testing device, the armature, which is pressed or pulled by means of the spring device in the direction away from the first extreme position toward the second extreme position, is displaced from its first extreme position by means of an actual voltage applied over time during a testing time interval, wherein the electronic device is designed and / or programmed such that a first actual current intensity flowing through at least one coil of the solenoid valve, which has an amount exceeding a predetermined or determined first threshold value with a simultaneous decrease in the induced voltage over time, is determined by means of the electronic device within the testing time interval as the current intensity at which the armature leaves its first extreme position. Knowing the first actual current intensity, the first force required to displace the armature from its first extreme position can be counteracted.

[0015] Alternatively or additionally, the armature, which is pressed or pulled in the direction away from the first extreme position toward the second extreme position by means of the spring device, can be displaced out of its second extreme position by means of the actual voltage applied during the test time interval and which varies over time, wherein in this case the electronic device is preferably designed and / or programmed in such a way that a second actual current intensity flowing through at least one coil of the solenoid valve, which increases over time with the induced voltage and exceeds a predefined or determined second threshold value, is determined by means of the electronic device within the test time interval as the current intensity at which the armature leaves its second extreme position. The second actual current intensity reflects in particular the spring preload of the spring device of the corresponding solenoid valve, by means of which the armature is pressed or pulled out of its first extreme position toward its second extreme position.

[0016] In an advantageous embodiment of the valve testing device, the electronic device is further designed and / or programmed such that, by means of the electronic device, at least one electrical signal can be output to a spring preload adjustment device of the solenoid valve, so that the spring preload of the spring device of the solenoid valve is changed by means of the spring preload adjustment device controlled by the at least one electrical signal, so that the first actual current intensity can be adjusted to a predetermined first desired current intensity value and / or the second actual current intensity can be adjusted to a predetermined second desired current intensity value. The embodiment of the valve testing device described here thus enables an electrical adjustment of the spring preload of the corresponding solenoid valve, which electrical adjustment can be performed in a significantly reduced adjustment time compared to the prior art.

[0017] In an advantageous embodiment of the valve inspection device, the armature pressed or pulled by means of the spring device in the direction away from the first extreme position toward the second extreme position is excited by means of the actual voltage applied during the inspection time interval, which varies over time, first to perform a first displacement movement in a first displacement direction, then to be briefly at rest between its first extreme position and its second extreme position, and then to perform a second displacement movement in a second displacement direction opposite to the first displacement direction, wherein the electronic device is designed and / or programmed in such a way that, by means of the electronic device, at least one physical quantity about the static friction of the armature, about the sliding friction of the armature and / or about the difference in friction between the static friction of the armature and the sliding friction of the armature can be determined from the difference in the voltage induced by the armature displaced from the armature rest state to the second displacement movement. Thus, by means of the valve inspection device embodiment described here, it is possible to implement an automatic measurement / inspection of the pilot characteristic and / or friction value anomalies of the corresponding solenoid valve.

[0018] Executing a corresponding method for inspecting a solenoid valve can also bring about the above advantages. It should be explicitly pointed out that the method for inspecting a solenoid valve can be expanded according to the above valve inspection device embodiment.

[0019] Furthermore, a corresponding method for electrically adjusting the spring preload of a solenoid valve spring device also provides the above advantages. It is also to be noted that the method for electrically adjusting the spring preload of a solenoid valve spring device can also be expanded according to the above valve testing device embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features and advantages of the present invention are explained below with reference to the accompanying drawings. In the accompanying drawings:

[0021] Figures 1a to 1c shows a coordinate system for explaining a first specific embodiment of the method for testing a solenoid valve,

[0022] Figures 2a to 2f shows a coordinate system for explaining a second specific embodiment of the method for testing a solenoid valve,

[0023] Figure 3a and 3b A coordinate system is shown for explaining a method for electrically adjusting a spring preload of a solenoid valve spring device; and

[0024] Figure 4 A schematic diagram shows an embodiment of a valve testing device and a solenoid valve cooperating therewith. DETAILED DESCRIPTION

[0025] Figures 1a to 1c A coordinate system is shown for explaining a first specific embodiment of the method for testing a solenoid valve.

[0026] The method described below can be implemented with (almost) any solenoid valve having at least one energizable coil, an armature that can be displaced by means of a magnetic field generated by energizing the at least one coil, and a first limit position P in the solenoid valve. C Towards the second extreme position P in the solenoid valve O Therefore, the feasibility of the method described below is not limited to a specific solenoid valve type.

[0027] exist Figure 1aIn the coordinate system of , the abscissa is the time axis t (unit: seconds), and the ordinate reflects the current intensity value of the predetermined time-based desired current intensity variation curve I0 (unit: ampere), which is to flow through at least one coil of the solenoid valve during the inspection time interval Δ. In order to ensure that at least one coil of the solenoid valve is energized according to the predetermined time-based desired current intensity variation curve I0 during the inspection time interval Δ, the current intensity can be measured at high frequency and regulated in a closed control loop according to the desired current intensity variation curve I0 using the voltage as the regulating variable. This results in that, when executing the method described herein, an actual voltage U that varies with time is applied to at least one coil of the solenoid valve during the inspection time interval Δ. Figure 1b In the coordinate system of , the abscissa is also the time axis t (in seconds), while the ordinate shows the actual voltage U (in volts) applied to at least one coil of the solenoid valve. The inspection time interval Δ can be a (fixed) predetermined or autonomously determined time interval. For example, the predetermined time-based desired current intensity variation curve I0 is also repeated frequently until a satisfactory inspection of the solenoid valve is completed.

[0028] During the inspection time interval Δ, Figure 1b The time-varying actual voltage U shown in the coordinate system of is applied to at least one coil of the solenoid valve, causing the at least one coil of the solenoid valve to be energized during the test time interval Δ in fact while also precisely complying with the predefined time-based desired current intensity profile I0. During the test time interval Δ, energizing the at least one coil of the solenoid valve according to the predefined time-based desired current intensity profile I0 causes a time-varying magnetic field in the solenoid valve, which interacts with the armature of the solenoid valve. Furthermore, the time-based desired current intensity profile I0 is predefined in such a way that during the test time interval Δ, the armature of the solenoid valve is at least temporarily displaced by means of the induced magnetic field.

[0029] The displacement movement of the armature triggered by the interaction of the armature with the time-varying magnetic field during the test time interval Δ leads to an induced voltage U in the at least one coil of the solenoid valve during the test time interval Δ. ind In particular, the acceleration / braking of the armature in the induced magnetic field leads to magnetic induction (motion induction). Figure 1c In the coordinate system of , the abscissa shows the corresponding current intensity value (in ampere) of the predetermined time-based current intensity variation curve I0, and the ordinate shows the induced voltage U in at least one coil at the corresponding current intensity value. ind (Unit: Volts). In the method described here, the voltage U induced by the at least temporarily displaced armature during the test time interval Δ is determined. indThis can be easily implemented based on the actual voltage applied over time during the check time interval Δ in order to comply with the time-based desired current intensity curve I0 (U ind (t)=U(t)-R*I0(t)). Induced voltage U ind Therefore, it can be calculated more accurately and relatively reliably.

[0030] Depend on Figure 1c From the coordinate system of , it can be seen that multiple variables and characteristics characterizing the corresponding solenoid valve can be read from the induced voltage during the inspection time interval Δ. The quality and repeatability of the signal variation curve and the quality of the characterizing variables associated therewith can be improved by appropriate filtering of the measured values. In addition, before the start of the inspection, that is, before applying the target current I0, the magnetic circuit can be brought into a defined saturation state, because the initial state usually has an influence on the result.

[0031] Therefore, in the method described here, the voltage U induced during the test time interval Δ is taken into account. ind In the case of the determined time-based variation curve, at least one physical quantity about the spring device of the solenoid valve and / or about the static friction and / or sliding friction of its armature can be determined. In particular, the voltage U induced during the test time interval Δ can be considered. ind In the case of relatively accurate and reliable determination of the spring preload of the solenoid valve spring device, the spring force exerted on the armature of the solenoid valve by the spring device due to the spring preload and / or the current intensity guided by at least one coil of the solenoid valve for overcoming the spring force of the spring device.

[0032] The method described here is implemented for checking a solenoid valve, the spring device of which (e.g. Figure 2e ) The armature of the solenoid valve leaves the (first) limit position P C Towards the (second) extreme position P O The limit position P C The "closed" position of the armature is understood merely as an example, in which the armature is pressed or pulled against the seat of the solenoid valve by the spring device, so that the solenoid valve is in its closed state. Accordingly, in the example described here, the limit position P0 is the "open" position of the armature, in which the armature is stopped on the travel stop of the solenoid valve with the maximum armature travel relative to the solenoid valve seat, so that the solenoid valve is in its fully open state.

[0033] If with the help of Figure 1c As shown by the arrow A1 in the coordinate system of , the time-based desired current intensity variation curve I0 is predetermined so that the armature moves from its extreme position P during a subinterval Δ1 of the test time interval Δ by means of the applied actual voltage U which varies over time.C Come out and move to the limit position P O For this purpose, the desired current intensity profile I0 over time is predetermined in such a way that during the subinterval Δ1 the current intensity value changes from the minimum current intensity value I min Initially, preferably with a constant slope, the current is increased to a maximum current intensity value I max It may be considered that, in the case of the time-based current intensity variation curve I0, the initial time interval Δ of the subinterval Δ1 is i In the case of the induced voltage U ind Fluctuations occur, which are important in evaluating the induced voltage U ind However, in the case of the time-based current intensity variation curve I0, in the initial time interval Δ of the subinterval Δ1 i Inductive voltage U ind The fluctuations occurring in Δ 1 contain further variables (especially those that characterize the magnetic circuit of the solenoid valve) which can be used to verify whether the measurement was performed correctly (even though this is not discussed in more depth here). i The actual current intensity I then flows through at least one coil of the solenoid valve Cl With the induced voltage U ind , and at the same time exceeds a predetermined or determined threshold value over time, the actual current intensity can be reliably used as the current intensity I Cl It is determined that at this current intensity I C1 When the armature leaves its limit position P C During the subinterval Δ1 and perhaps during the initial time interval Δ i The actual current intensity I then flows through at least one coil of the solenoid valve Oa and an induced voltage U ind , and simultaneously decreases over time by an amount exceeding a predetermined or determined (another) threshold value, optionally as current intensity I Oa is determined, at a current intensity I Oa When the armature reaches its limit position P O .

[0034] exist Figure 1c The arrow A2 in the coordinate system shows that during a further subinterval Δ2 of the test time interval Δ, the armature is displaced from the extreme position Po to the extreme position P by means of the applied actual voltage U which varies over time. C The subinterval Δ2 may optionally be present before or after the subinterval Δ1. In particular, the desired current intensity variation curve I0 based on time is predetermined in such a way that the current intensity value thereof changes from the maximum current limiting intensity value I to the maximum current limiting intensity value I during the subinterval Δ2. maxInitially, preferably with a constant slope, the current is reduced to a minimum current intensity value I min It is also conceivable that, in the case of the desired time-based current intensity curve I0, in the final time interval Δ of the subinterval Δ2 e In the case of the induced voltage U ind Strong fluctuations also occur in the evaluation of the induced voltage U ind During subinterval Δ2 and perhaps in the final time interval Δ e The actual current intensity I previously flowing through at least one coil of the solenoid valve O1 With the simultaneous decrease over time of the induced voltage by an amount exceeding a predefined or determined threshold value, the actual current intensity is taken as the current intensity I O1 is determined, at a current intensity I O1 When the armature leaves its limit position P O The actual current intensity I flowing through the at least one coil of the solenoid valve during the subinterval Δ2 and possibly before the final time interval Δe Ca With the induced voltage U ind , and at the same time exceeds a predetermined or determined (another) threshold value over time, which can optionally also be used as the current intensity I Ca It is also determined that at the current intensity I Ca When the armature reaches its limit position P C .

[0035] The actual current intensity I determined in this way Ca ,I Cl ,I Oa and I Ol are characteristic variables of the solenoid valve, which vary with the spring preload of the spring device. The method described here is therefore a discontinuous measurement method, with the help of which the actual current intensity I can be determined within a relatively short measuring and evaluation time, for example within a measuring and evaluation time of up to 1 second. Ca ,I Cl ,I Oa and I Ol Furthermore, the measuring method described here can be used to reliably determine the spring preload at which the armature leaves or takes up the corresponding limit position P. C or P O The actual current intensity I Ca ,I Cl ,I Oa and I Ol, without having to guide the liquid and / or gaseous medium through the respectively checked solenoid valve. Thus, when carrying out the method described here, the otherwise necessary consumption of the corresponding liquid and / or gaseous medium is also avoided. In order to carry out the method described here, pressure measuring devices and flow measuring devices are also not required. By omitting such measuring devices, when determining the actual current intensity I Ca ,I Cl ,I Oa and I Ol and possibly the spring preload of the spring device, an increased precision can be achieved.

[0036] Figures 2a to 2f A coordinate system is shown for explaining a second specific embodiment of the method for testing a solenoid valve.

[0037] according to Figure 2a and 2b As can be seen from the coordinate system in the method described here, the actual voltage U that varies with time is also applied to at least one coil of the respectively checked solenoid valve during the inspection time interval Δ, so that at least one coil is applied to the at least one coil during the inspection time interval Δ according to the predetermined time-based desired current intensity variation curve I O In this way, the armature of the solenoid valve is at least temporarily displaced during the test time interval Δ, whereby the voltage U induced by the at least temporarily displaced armature during the test time interval Δ can be determined. ind The time-based change curve of Figure 2a In the coordinate system, the horizontal axis is the time axis t (unit: second), and the vertical axis represents the predetermined time-based current intensity change curve I O The current intensity value (unit: ampere). Figure 2b In the coordinate system of , the abscissa is also the time axis t (unit: seconds), while the ordinate shows the actual voltage U (unit: volt) applied to at least one coil of the solenoid valve. Figure 2c and 2d The abscissa of the coordinate system shows the predetermined desired current intensity profile I O (Unit: Ampere) corresponds to the current intensity value. Figure 2c and 2d The ordinate (unit: volt) shows the voltage U induced during the test time interval Δ in the coordinate system of ind ,in, Figure 2d The coordinate system shows Figure 2c An enlarged portion of the coordinate system.

[0038] To carry out the method described here, a solenoid valve is used, the spring device of which moves the armature of the solenoid valve out of the limit position P C Towards the limit position P OThe limit position P is merely an example of the C Understood as the "closed" position of the armature, see limit position P O This is understood to be the "open" position of the armature.

[0039] Unlike the previously described embodiments, Figures 2a to 2f In the method, the armature is excited to perform a plurality of different motion processes by means of an actual voltage U applied during the inspection time interval Δ and varying over time. Figure 2c and 2d Arrow A in 10 As shown, the armature is firstly in a subinterval Δ of the test time interval Δ by means of the applied actual voltage U 10 During this period, the first displacement movement along the first displacement direction is excited. In particular, the time-based desired current intensity variation curve I O is predetermined in such a way that its current intensity value is within the subinterval Δ 10 During the period from the minimum current intensity value I min Initially, preferably with a constant slope, the current intensity is increased up to a first intermediate current intensity value I1. Figure 2c and 2d From the coordinate system, we can see that in the subinterval Δ 10 During the actual current intensity I C1 When the armature is displaced from the limit position P C come out.

[0040] In another subinterval Δ following the inspection time interval Δ 11 During this period, the armature is placed in a stationary state. To this end, the current intensity value of the current intensity variation curve I0 should be within the sub-interval Δ 11 Keep constant during this period.

[0041] In the subinterval Δ 11 Then, using the actual voltage varying with time, the subsequent subinterval Δ of the inspection time interval Δ is checked. 12 During this time, the armature is excited to perform a second displacement movement along a second displacement direction opposite to the first displacement direction. The current intensity value of the desired current intensity variation curve I0 based on time is in the sub-interval Δ 12 The period starts from a first intermediate current intensity value I1 and decreases preferably with a slope having a constant magnitude to a second intermediate current intensity value I2. 12 After the start, the armature is still in its static state, such as with Figure 2c and 2d Arrow A in 11 As shown. At the actual current intensity I release1 Only then is the static friction of the armature overcome and the armature is placed in the second displacement movement represented.

[0042] Then, in another subinterval Δ of the inspection time interval Δ 13 During this time, the armature is brought back to rest. Preferably, the predetermined time-dependent current intensity variation curve I0 is in the sub-interval Δ 13 During this period, the current intensity value remains stable. Figure 2c and 2d Middle Arrow A 13 Indicates the stationary state of the armature.

[0043] In the subinterval Δ of the inspection time interval Δ 14 During this time, the armature is again excited to perform a first displacement movement along the first displacement direction. The current intensity value of the desired current intensity variation curve I0 based on time is in the sub-interval Δ 14 The period starts from the second intermediate current intensity value I2 and preferably increases with a constant slope to the maximum current intensity value I max . As with arrow A 14 As shown, the static friction of the armature is release2 is overcome and the armature is at the actual current intensity I Oa时 The armature reaches its limit position P O .

[0044] In order to better understand the different motion processes of the armature, Figure 2e In the coordinate system, the horizontal axis represents the current intensity value (unit: ampere) of the required current intensity I0 based on time, and the vertical axis represents the armature relative to its extreme position P C The stroke h (unit: micron).

[0045] exist Figure 2f In the coordinate system, the abscissa shows the current intensity value (unit: ampere) of the required current intensity variation curve I0 based on time, and the ordinate shows the corresponding induced voltage U ind (Unit: Volts). Figure 2f The curves g1 to g5 are plotted in the coordinate system of , which represent different solenoid valves with different static friction and sliding friction. According to the comparison of the curves g1 to g5, when in the sub-interval Δ 10 to Δ 12 When the direction is reversed or in the sub-interval Δ 12 to Δ 14 When the direction is reversed, the behavior of the armature of each solenoid valve is related to the corresponding static friction and sliding friction of the corresponding armature. release1 or between the second intermediate current intensity value I2 and the corresponding actual current intensity I release2The difference in current intensity between is a measure of the static friction. If the corresponding armature has a significant difference between its static friction and sliding friction, the armature will make a "jump" after overcoming the static friction, and this jump is reflected in the induced voltage U ind The change curve is shown as "overshoot ". Thus, when carrying out the method described here, the voltage U induced by the armature which is displaced from the rest state of the armature to the second displacement movement can be used. ind At least one physical quantity about the static friction of the armature, about the sliding friction of the armature and / or about the difference in friction between the static friction of the armature and the sliding friction of the armature can be determined with relatively high accuracy by the difference between the current level when the current gradient is reversed and the current level when the armature movement in the opposite direction is detected (i.e. I1-I2). release1 or I2-I release2 ,See Figure 2a and Figure 2d ).

[0046] The method described here enables rapid inspection of guide characteristics and / or friction value anomalies in a corresponding solenoid valve. By correspondingly selecting the first intermediate current intensity value I1 and / or the second intermediate current intensity value I2, the friction conditions at different locations in the guide device of the corresponding armature can be checked. In this way, the entire guide area of ​​the corresponding armature can be scanned with any resolution with respect to the static friction characteristics and / or sliding friction characteristics of the armature.

[0047] All methods described here make it possible not only to characterize the spring device and / or the friction characteristics but also to further process the spring device and / or the friction characteristics for a predictive KI model. This characterization can also be performed on the installed solenoid valve after the solenoid valve has been electrically contacted. It can therefore also be used in the "aftermarket" to control the functions of the corresponding solenoid valve. The measurement data obtained by means of the methods described here can be stored in the controller of the corresponding solenoid valve for determining correction values. In this way, the laborious characteristic curve measurement performed during production in order to detect discontinuities or "errors" in the characteristic curve of the corresponding solenoid valve can be omitted.

[0048] Figure 3a and 3b A coordinate system is shown for explaining an embodiment of a method for electrically adjusting a spring preload of a solenoid valve spring arrangement.

[0049] The method described below can be used for (almost) any solenoid valve having at least one energizable coil, an armature that can be displaced by means of a magnetic field generated by energizing the at least one coil, a first limit position P in the solenoid valve, a second ... C Towards the second limit position P in the solenoid valve OA spring device for compression or tension and a spring preload adjustment device that can be controlled by means of at least one electrical signal. The controllable spring preload adjustment device can be, for example, an electrically displaceable screw of a solenoid valve. The feasibility of the method described below is not limited to a specific configuration of the controllable spring preload adjustment device.

[0050] By means of the method described here, the current actual current intensity I of the solenoid valve is determined at least once. C1 (At this actual current intensity, the armature of the solenoid valve leaves its first limit position P C ) and / or the actual current intensity I of the solenoid valve O1 (At this actual current intensity, the armature of the solenoid valve leaves its second limit position P O ). In order to determine the actual current intensity I C1 and I O1 The method steps to be performed are already in Figures 1a to 1c The actual current intensity I Ca and I Oa Also determined together.

[0051] In determining the actual current intensity I Cl , I Ca , I Ol and / or Oa After at least one of the above is completed, at least one electrical signal is output to the spring preload force adjusting device of the solenoid valve, thereby changing the spring preload force of the spring device of the solenoid valve by means of the spring preload force adjusting device controlled by the at least one electrical signal. The change of the spring preload force of the spring device is preferably achieved by continuously determining the actual current intensity I Cl , I Ca , I Ol and / or Oa At least one of the above is carried out until the actual current intensity I Cl , I Ca , I Ol and / or Oa At least one of them is set to a respectively predetermined desired current intensity value. In this way, the spring preload force of the solenoid valve spring device can be electrically adjusted to a preferred value, for example to compensate for manufacturing differences in the spring preload force.

[0052] Unlike conventional spring preload adjustment procedures, in which the spring preload force of the spring device is changed until the desired pneumatic or hydraulic flow is set at the corresponding solenoid valve, the method described here can be carried out significantly faster. The duration required for the method described here depends only on how often the actual current intensity I Cl , I Ca , IOl and / or Oa At least one of the above is measured until the corresponding setpoint value is reached. Since the effect of the operation of the corresponding spring preload adjustment device, for example the effect of the screwing of an electrically adjustable screw of a solenoid valve (due to the thread pitch of the corresponding screw) on the spring preload is generally known, it is generally expected that less than 10 measurements are necessary in order to reach at least one corresponding setpoint value. In addition, the flow of the corresponding solenoid valve with liquid and / or gaseous medium is not required in order to identify the current pneumatic or hydraulic flow.

[0053] exist Figure 3a and 3b In the coordinate system of , the abscissa shows the corresponding current intensity value (in ampere) of the predetermined time-based current intensity variation curve I0, and the ordinate shows the voltage U induced in at least one coil at the corresponding current intensity value. ind (unit: volt), where Figure 3b The coordinate system representation Figure 3a In addition, in Figure 3a and 3b Draw a graph g0, g in the coordinate system 45° , g 90° , g 135° , g 180° and g 225° These graphs show the initial condition before screw tightening (g0), the effect of screw tightening 45° after the initial condition (g 45° ), the effect of screwing 90° after the initial condition (g 90° ), the effect of screwing 135° after the initial condition (g 135° ), the effect of screwing 180° after the initial condition (g 180° ), the effect of screwing 225° after the initial condition (g 225° ). In this way, the spring preload of the spring device can be quickly and reliably adjusted to an optimum value.

[0054] Figure 4 A schematic diagram shows an embodiment of a valve testing device and a solenoid valve cooperating therewith.

[0055] exist Figure 4The valve testing device 10 schematically depicted in FIG. 1 has an electronic device 10 a, by means of which, during a predetermined or self-determined testing time interval, a time-varying actual voltage U can be applied / applied to at least one coil 12 of a solenoid valve 14 in such a way that the at least one coil 12 can be energized / energized during the testing time interval according to a predetermined time-based desired current intensity profile. In this way, the armature 16 of the solenoid valve 14 can be displaced / displaced at least temporarily during the testing time interval. In addition, by means of the electronic device 10 a, taking into account the time-varying actual voltage U applied during the testing time interval in order to comply with the time-based desired current intensity profile, the time profile of the voltage induced during the testing time interval by means of the at least temporarily displaced armature 16 can be determined / determined. Furthermore, the electronic device 10a is designed and / or programmed in such a way that, with the aid of the electronic device 10a, taking into account a determined temporal profile of the induced voltage during a check time interval, at least one physical quantity relating to the spring device 18 of the solenoid valve 14 and / or to the static friction and / or sliding friction of the armature 16 can be determined / is determined.

[0056] The solenoid valve 14 checked by means of the valve checking device 10 is preferably a current-regulated solenoid valve. For example, the solenoid valve 14 can be a proportional valve. Figure 4 In the example of FIG. 1 , the solenoid valve 14 is a HGI, i.e. a pneumatic valve, which can be used as a proportional valve in a closed-loop control circuit to meter hydrogen into the fuel cell. Figure 4 The solenoid valve 14 schematically shown in FIG. 1 is called a hydrogen dosing valve.

[0057] By means of the spring device 18 of the solenoid valve 14, the armature 16 is pressed or pulled away from the first extreme position in the solenoid valve 14 towards the second extreme position in the solenoid valve 14. Figure 4 The middle armature 16 is pressed / pulled by the spring device 18 against the seat 20 of the solenoid valve 14, wherein the solenoid valve 14 is in its closed state when the armature is in its second extreme position in which it is in mechanical contact with the seat 20. However, the armature can be displaced out of its second extreme position against the spring force of the spring device 18, so that the armature stops on the stop 22 in its first extreme position and the solenoid valve is in its fully open state.

[0058] The electronic device 10a can be selectively designed / programmed to perform at least one of the above methods. For example, the electronic device 10 can be used to determine a first actual current intensity flowing through at least one coil 12 of the solenoid valve 14, at which the armature 16 leaves its first limit position, and / or a second actual current intensity flowing through at least one coil 12, at which the armature 16 leaves its second limit position. As an optional development, the electronic device 10a can be additionally designed / programmed to output at least one electrical signal 24 to a spring preload adjustment device 26 of the solenoid valve 14, so that the spring preload of the spring device 18 is changed by means of the spring preload adjustment device 26 controlled by the at least one electrical signal 24, so that the first actual current intensity is adjusted to a predetermined first desired current intensity value and / or the second actual current intensity is adjusted to a predetermined second desired current intensity value. The spring preload adjustment device 26 can be, for example, an adjustment screw 26 for the spring preload of the spring device 18.

Claims

1. A valve inspection device (10), comprising: An electronic device (10a) which is designed and / or programmed in such a way that, by means of the electronic device (10a), a time-varying actual voltage (U) can be applied to at least one coil (12) of a solenoid valve (14) during a predetermined or self-determined test time interval (Δ), so that the at least one coil (12) of the solenoid valve (14) can be energized during the test time interval (Δ) according to a predetermined time-based desired current intensity variation curve (I0), so that the armature (16) of the solenoid valve (14) can be displaced at least temporarily during the test time interval (Δ); in, By means of the electronic device (10a), a voltage (U) induced during the test time interval (Δ) by means of the at least temporarily displaced armature (16) can be determined taking into account the actual voltage (U) which is applied over time during the test time interval (Δ) in order to comply with the time-dependent desired current intensity profile (I0). ind ) time variation curve, characterized in that, The electronic device (10a) is additionally designed and / or programmed in such a way that, by means of the electronic device (10a), a voltage (U ) induced during the test time interval (Δ) is taken into account. ind ), at least one physical variable relating to the static friction and / or the sliding friction of the spring device (18) of the solenoid valve (14) and / or the armature (16) can be determined from the determined time curve.

2. The valve inspection device (10) according to claim 1, wherein: By means of the spring device (18), the spring is moved away from the first extreme position (P O ) towards the second extreme position (P C ) can be moved from a first extreme position (P O ) is displaced out, and the electronic device (10a) is designed and / or programmed in such a way that the electronic device (10a) can determine during the inspection time interval (Δ) the current flowing through the at least one coil (12) of the solenoid valve (14) and the current flowing along with the induced voltage (U ind ) decreases over time and has a first actual current intensity (I O1 ) as such a current intensity (I O1 ): At this current intensity, the armature (16) leaves its first extreme position (P O ).

3. The valve inspection device (10) according to claim 1 or 2, wherein: By means of the spring device (18), the first limit position (P O ) towards the second extreme position (P C ) can be moved from a second extreme position (P) of the armature by means of a time-varying actual voltage (U) applied during a test time interval (Δ) C ) is displaced out, and the electronic device (10a) is designed and / or programmed in such a way that the voltage (U) flowing through the at least one coil (12) of the solenoid valve (14) and induced by the electronic device (10a) can be determined during the inspection time interval (Δ). ind ) and a second actual current intensity (I C1 ) as such a current intensity (I C1 ): At this current intensity, the armature leaves its second extreme position (P C ).

4. The valve inspection device (10) according to claim 2 or 3, wherein: The electronic device (10a) is designed and / or programmed in such a way that at least one electrical signal (24) can be output to a spring preload adjustment device (26) of the solenoid valve (14) by means of the electronic device (10a), so that the spring preload of the spring device (18) of the solenoid valve (14) can be changed by means of the spring preload adjustment device (26) controlled by the at least one electrical signal (24) so ​​that the first actual current intensity (I O1 ) is set to a predetermined first desired current intensity value and / or the second actual current intensity (I C1 ) is set to a predetermined second desired current intensity value.

5. The valve inspection device (10) according to one of the preceding claims, wherein: By means of the spring device (18), the first limit position (P O ) towards the second extreme position (P C ) direction, can be excited by means of a time-varying actual voltage (U) applied during the inspection time interval (Δ) to first perform a first displacement movement in a first displacement direction, and then to a first extreme position (P O ) and the second limit position (P C ), and then performs a second displacement movement in a second displacement direction opposite to the first displacement direction, and the electronic device (10a) is designed and / or programmed so that the electronic device (10a) can be used to generate a voltage (U) induced by the armature (16) when the armature is displaced from the rest state of the armature to the second displacement movement. ind ) to determine at least one physical quantity regarding the static friction of the armature (16), regarding the sliding friction of the armature (16) and / or regarding the friction difference between the static friction of the armature (16) and the sliding friction of the armature (16).

6. A method for inspecting a solenoid valve (14), comprising the following steps: During a predetermined or self-determined inspection time interval (Δ), a time-varying actual voltage (U) is applied to at least one coil (12) of the solenoid valve (14) in such a way that the at least one coil (12) of the solenoid valve (14) is energized during the inspection time interval (Δ) according to a predetermined time-based desired current intensity variation curve (I0), so that the armature (16) of the solenoid valve (14) is at least temporarily displaced during the inspection time interval (Δ); and Taking into account the actual voltage (U) which varies over time and is applied during a test time interval (Δ) in order to comply with the desired current intensity profile (I0) over time, a voltage (U) induced by the armature (16) which is at least temporarily displaced during the test time interval (Δ) is determined. ind )’s time variation curve; It is characterized in that The following steps are involved: Considering the voltage (U ind ) is used to determine at least one physical quantity regarding the static friction and / or the sliding friction of the spring device (18) of the solenoid valve (14) and / or the armature (16) under the determined time curve.

7. The method according to claim 6, wherein: By means of the spring device (18), the spring is moved away from the first extreme position (P O ) towards the second extreme position (P C ), the armature (16) pressed or pulled in the direction of the induced voltage (U) is displaced from the first limit position (PO) of the armature by means of the actual voltage (U) applied during the inspection time interval (Δ) and varying with time, and the current flowing through the at least one coil (12) of the solenoid valve (14) during the inspection time interval (Δ) and varying with the induced voltage (U) is determined. ind ) decreases over time and has a first actual current intensity (I O1 ) as such a current intensity (I O1 ): At the current intensity, the armature (16) leaves the first limit position (P O ).

8. The method according to claim 6 or 7, wherein: By means of the spring device (18), the first limit position (P O ) towards the second extreme position (P C ) is pressed or pulled in the direction of the armature (16) from the second extreme position (P) of the armature by means of the actual voltage (U) applied during the inspection time interval (Δ) which varies with time. C ) is shifted out, and a voltage (U) flowing through the at least one coil (12) of the solenoid valve (14) during the inspection time interval (Δ) is determined along with the induced voltage (U ind ) and a second actual current intensity (I C1 ) as such a current intensity (I C1 ): At this current intensity, the armature (16) leaves the second limit position (P C ).

9. The method according to any one of claims 6 to 8, wherein: By means of the spring device (18), the first limit position (P O ) towards the second extreme position (P C ) is stimulated by means of a time-varying actual voltage (U) applied during the inspection time interval (Δ) to first perform a first displacement movement along a first displacement direction and then to a first extreme position (P O ) and the second limit position (P C ), then performs a second displacement movement in a second displacement direction opposite to the first displacement direction, and according to a voltage (U) induced by the armature (16) which is displaced from the stationary state of the armature to the second displacement movement ind ) to determine at least one physical quantity regarding the static friction of the armature (16), regarding the sliding friction of the armature (16) and / or regarding the friction difference between the static friction and the sliding friction of the armature (16).

10. A method for electrically adjusting a spring preload of a spring device (18) of a solenoid valve (14), comprising the following steps: At least once the method according to claim 7 or 8 is carried out to determine a first current actual current intensity (I O1 ), at the first actual current intensity, the solenoid valve (14) is moved away from the first limit position (P O ) towards the second extreme position (P C ) direction, the armature (16) is pressed or pulled away from the first limit position (P O ), and / or determining the current second actual current intensity (I C1 ), at the second actual current intensity, the armature (16) of the solenoid valve (14) leaves the second limit position (P C );and Outputting at least one electrical signal (24) to a spring preload adjusting device (26) of the solenoid valve (14), so that the spring preload of the spring device (18) of the solenoid valve (14) is changed by means of the spring preload adjusting device (26) controlled by the at least one electrical signal (24) so ​​that the first actual current intensity (I O1 ) is set to a predetermined first desired current intensity value and / or the second actual current intensity (I C1 ) is set to a predetermined second desired current intensity value.

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