Valve testing device and method for testing a solenoid valve

Abstract

The present invention relates to a valve testing device (10) and a method for testing a solenoid valve (14) by: applying a time-varying actual voltage (U) to at least one coil (12) of the solenoid valve (14) during a predetermined or self-defined testing time interval such that the at least one coil (12) of the solenoid valve (14) is energized during the testing time interval according to a predetermined target current profile such that an armature (16) of the solenoid valve (14) is adjusted at least temporarily during the testing time interval.Determining the time course of a voltage induced by means of the armature (16) which is at least temporarily adjusted during the test time interval, taking into account the time-varying actual voltage (U) applied to maintain the target current profile during the test time interval (Δ), and defining at least one physical quantity relating to a spring device (18) of the solenoid valve (14) and / or relating to a static and / or sliding friction of the armature (16), taking into account the determined time course of the voltage induced during the test time interval.

Description

[0001] The invention relates to a valve inspection device. The invention also relates to a method for inspecting a solenoid valve. Furthermore, the invention relates to a method for electrically adjusting a spring preload force of a spring device of a solenoid valve. State of the art

[0002] Solenoid valves for controlling a liquid and / or gaseous medium are known from the prior art, such as DE 10 2021 207 906 A1. Such a solenoid valve typically has at least one coil, by means of which a magnetic field can be generated when energized such that an armature of the respective solenoid valve, which is pushed or pulled by a spring device of the respective solenoid valve away from a first extreme position in the solenoid valve to a second extreme position in the solenoid valve, can be adjusted by means of the magnetic field against a spring force of the spring device. Disclosure of the invention

[0003] The present invention provides a valve inspection device having the features of claim 1, a method for inspecting a solenoid valve having the features of claim 6, and a method for electrically adjusting a spring preload force of a spring device of a solenoid valve having the features of claim 10. Advantages of the invention

[0004] The present invention provides advantageous possibilities for examining a solenoid valve with regard to its spring device and / or with regard to the static and / or sliding friction of its armature, without the need for a flow of a liquid and / or gaseous medium to be controlled by the respective solenoid valve to examine the respective solenoid valve. Therefore, the examination of the respective solenoid valve carried out when using the present invention is not associated with a consumption of the liquid and / or gaseous medium to be controlled by the respective solenoid valve. The present invention thus also creates possibilities for more cost-effective examination of the respective solenoid valve. Furthermore, the present invention makes it possible to examine the respective solenoid valve without the use of a pressure sensor and without the use of a quantity measuring element.Thus, the present invention also provides opportunities for faster and more precise testing of the respective solenoid valve compared to the prior art. As will also become clear from the following description, the present invention can be used for a variety of different solenoid valve types.

[0005] In an advantageous embodiment of the valve testing device, the armature, which is pushed or pulled by means of the spring device in the direction away from a first extreme position to a second extreme position, can be adjusted out of its first extreme position by means of the time-varying actual voltage applied during the testing time interval, wherein the electronic device is designed and / or programmed such that by means of the electronic device a first actual current intensity flowing through the at least one coil of the solenoid valve with a simultaneous temporal decrease of the induced voltage with an amount above a predetermined or fixed first threshold value during the testing time interval can be defined as the current intensity at which the armature leaves its first extreme position.Knowing the first actual current strength then allows conclusions to be drawn about a first force that is necessary to move the armature from its first extreme position.

[0006] Alternatively or additionally, the armature, which is pushed or pulled by means of the spring device in the direction away from the first extreme position to the second extreme position, can be adjusted out of its second extreme position by means of the time-varying actual voltage applied during the examination time interval, wherein in this case the electronic device is preferably designed and / or programmed such that by means of the electronic device a second actual current intensity flowing through the at least one coil of the solenoid valve with a simultaneous temporal increase of the induced voltage above a predetermined or fixed second threshold value during the examination time interval can be defined as the current intensity at which the armature leaves its second extreme position.In particular, the second actual current intensity represents a spring preload force of the spring device of the respective solenoid valve, by means of which the armature is pushed or pulled away from its first extreme position into its second extreme position.

[0007] In an advantageous development of the valve testing device, the electronic device is further designed and / or programmed such that at least one electrical signal can be output to a spring preload force adjustment device of the solenoid valve by means of the electronic device such that a spring preload force of the spring device of the solenoid valve can be varied by means of the spring preload force adjustment device controlled by the at least one electrical signal such that the first actual current strength can be set to a predetermined first target current value and / or the second actual current strength can be set to a predetermined second target current value. The development of the valve testing device described here thus enables electrical adjustment of the spring preload force of the respective solenoid valve, which can be carried out within a significantly reduced adjustment time compared to the prior art.

[0008] In a further advantageous embodiment of the valve testing device, the armature, which is pushed or pulled by means of the spring device in the direction away from the first extreme position to the second extreme position, can be excited by means of the time-varying actual voltage applied during the testing time interval, first to a first adjustment movement along a first adjustment direction, then briefly to a standstill between its first extreme position and its second extreme position and subsequently to a second adjustment movement along a second adjustment direction opposite to the first adjustment direction, wherein the electronic device is designed and / or programmed such that by means of the electronic device, based on a difference in the voltage induced by the armature being adjusted from its standstill to the second adjustment movement, the at least one physical quantity relating to the static friction of the armature,with respect to the sliding friction of the armature and / or with respect to a friction difference between the static friction of the armature and the sliding friction of the armature. Using the embodiment of the valve testing device described here, an automatic measurement / test of the guiding properties and / or friction coefficient anomalies of the respective solenoid valve can thus be carried out.

[0009] Carrying out a corresponding method for inspecting a solenoid valve also achieves the advantages described above. It is expressly noted that the method for inspecting a solenoid valve can be further developed according to the above-explained embodiments of the valve inspection device.

[0010] Furthermore, implementing a corresponding method for electrically adjusting a spring preload force of a spring device of a solenoid valve also provides the advantages explained above. Furthermore, it should be noted that the method for electrically adjusting a spring preload force of a spring device of a solenoid valve can also be further developed according to the above-explained embodiments of the valve testing device. Short description of the drawings

[0011] Further features and advantages of the present invention are explained below with reference to the figures. They show: Fig. 1 a to 1c coordinate systems for explaining a first embodiment of the method for examining a solenoid valve; Fig. 2a to 2f coordinate systems for explaining a second embodiment of the method for examining a solenoid valve; Fig. 3a and Fig. 3b Coordinate systems for explaining an embodiment of the method for electrically adjusting a spring preload force of a spring device of a solenoid valve; and Fig. 4 a schematic representation of an embodiment of the valve inspection device and a solenoid valve cooperating therewith. Embodiments of the invention

[0012] Fig. 1 a to 1c show coordinate systems for explaining a first embodiment of the method for examining a solenoid valve.

[0013] The method described below can be carried out with (almost) any solenoid valve which has at least one energizable coil, an armature which can be adjusted by means of a magnetic field generated by energizing the at least one coil, and a control device which moves the armature away from a first extreme position P C in the solenoid valve to a second extreme position P Oin the solenoid valve has a spring mechanism that pushes or pulls. The method described below is therefore not limited to any specific solenoid valve type.

[0014] In the coordinate system of the Fig. 1a, the abscissa is a time axis t (in seconds), while the ordinate represents current values ​​of a predefined temporal target current profile I0 (in amperes), which is to flow through the at least one coil of the solenoid valve during a test time interval Δ. To ensure that the at least one coil of the solenoid valve is energized during the test time interval Δ according to the predefined temporal target current profile I0, the current can be measured at high frequency and regulated to the target current profile I0 in a closed control loop using the voltage as a manipulated variable. This results in a time-varying actual voltage U being applied to the at least one coil of the solenoid valve during the test time interval Δ when executing the method described here. Also in the coordinate system of the Fig. In Figure 1b, the abscissa represents the time axis t (in seconds), while the ordinate indicates the actual voltage U (in volts) applied to at least one coil of the solenoid valve. The test time interval Δ can be a (fixed) predefined or user-defined time interval. For example, the specified temporal target current curve I0 can be repeated until a satisfactory test of the solenoid valve is completed.

[0015] The creation of the coordinate system of the Fig. The time-varying actual voltage U shown in Figure 1b at the at least one coil of the solenoid valve during the test time interval Δ causes the at least one coil of the solenoid valve to actually be energized during the test time interval Δ in precise compliance with the predetermined temporal target current intensity profile I0. The energization of the at least one coil of the solenoid valve during the test time interval Δ in accordance with the predetermined temporal target current intensity profile I0 causes a time-varying magnetic field within the solenoid valve, which interacts with the armature of the solenoid valve. The temporal target current intensity profile I0 is also predetermined such that the armature of the solenoid valve is adjusted at least temporarily during the test time interval Δ by means of the induced magnetic field.

[0016] The adjustment 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 a voltage U induced in at least one coil of the solenoid valve during the test time interval Δ ind In particular, acceleration / deceleration of the armature in the induced magnetic field leads to magnetic induction (motion induction). In the coordinate system of the Fig. 1c, the abscissa shows a respective current value of the specified temporal target current curve I0 (in amperes) and the ordinate shows a voltage U induced in the at least one coil at the respective current values. ind (in volts). In the method described here, a time course of the voltage U induced by the at least temporarily adjusted armature during the test time interval Δ indThis can be easily carried out by knowing the time-varying actual voltage U applied to maintain the desired current intensity I0 during the test time interval Δ (U ind (t) = U(t) -R * I0(t)). The induced voltage U ind can therefore be calculated comparatively accurately and relatively reliably.

[0017] As can be seen from the coordinate system of the Fig. 1c, a variety of variables and properties characterizing the respective solenoid valve can be determined from the voltage U induced during the test time interval Δ indThe quality and reproducibility of the signal curve, and thus the quality of the characteristic variables, can be improved by appropriate filtering of the measured values. Furthermore, before starting the test—i.e., before applying the target current curve I0—the magnetic circuit can be brought to a defined saturation state, since the initial state often influences the result.

[0018] In the method described here, at least one physical quantity is determined with respect to the spring device of the solenoid valve and / or with respect to a static and / or sliding friction of its armature, taking into account the specific temporal course of the voltage U induced during the test time interval Δ indIn particular, a spring preload force of the spring device of the solenoid valve, a spring force exerted on the armature of the solenoid valve by means of the spring device due to the spring preload force and / or a current intensity to be conducted through the at least one coil of the solenoid valve to overcome the spring force of the spring device can be determined taking into account the voltage U induced during the test time interval Δ ind can be determined relatively accurately and comparatively reliably.

[0019] The method described here is carried out to investigate a solenoid valve whose spring device moves the armature of the solenoid valve in a direction away from the (first) extreme position P C to the (second) extreme position P O pushes or pulls (cf. Fig. 2e). For example only, the extreme position P CA "closed" position of the armature is understood to mean that the armature is pressed / pulled by the spring device against a seat of the solenoid valve in such a way that the solenoid valve is in its closed state. Accordingly, in the example described here, the extreme position P O an "open" position of the armature in which the armature strikes a stroke stop of the solenoid valve with maximum stroke of the armature relative to the seat of the solenoid valve, so that the solenoid valve is in its fully open state.

[0020] As indicated by the arrow A1 in the coordinate system of the Fig. 1c, the temporal target current intensity curve I0 is specified in such a way that the armature is moved from the extreme position P during a sub-interval Δ1 of the test time interval Δ by means of the applied time-varying actual voltage U C out to the extreme position P Ois adjusted. For this purpose, the temporal target current curve I0 is specified in such a way that its current values ​​during the sub-interval Δ1 start from a minimum current value I min , preferably with a constant gradient, up to a maximum current value I max It may be possible to take into account that in an initial time interval Δ i of the subinterval Δ1 at this temporal target current curve I0 fluctuations in the induced voltage U ind occur, which can be used to evaluate the induced voltage U ind are not taken into account. The values ​​in the initial time interval Δ i of the subinterval Δ1 at this temporal target current intensity curve I0 occurring fluctuations in the induced voltage U indHowever, they contain additional variables (especially those characterizing a magnetic circuit of the solenoid valve) that can be used to verify the correct execution of the measurement (even if they are not discussed in detail here). A value measured during the subinterval Δ1 and possibly after the initial time interval Δ i Actual current I flowing through at least one coil of the solenoid valve Cl with a simultaneous temporal increase of the induced voltage U ind above a given or specified threshold can be reliably determined as the current I Cl be determined at which the anchor reaches its extreme position P C Optionally, a time interval Δ1 and possibly after the initial time interval Δ i Actual current I flowing through at least one coil of the solenoid valve Oa with a simultaneous temporal decrease of the induced voltage U indwith an amount above a predetermined or fixed (further) threshold value as the current I Oa be determined at which the anchor in its extreme position P O arrives.

[0021] By means of the arrow A2 in the coordinate system of the Fig. 1c shows that in a further sub-interval Δ2 of the test time interval Δ the armature is moved from the extreme position P by means of the applied time-varying actual voltage U O out to the extreme position P C The sub-interval Δ2 can be positioned either before or after the sub-interval Δ1. Specifically, the temporal target current intensity curve I0 is specified such that its current values ​​during the sub-interval Δ2 are based on the maximum current value I max , preferably with a constant gradient, up to the minimum current value I mir, decrease. It may also be possible to take into account that in a final time interval Δ e of the subinterval Δ2 at this temporal target current I0 also strong fluctuations in the induced voltage U ind occur, which can be used to evaluate the induced voltage U ind are not to be considered. A change during the subinterval Δ2 and possibly before the end time interval Δ e Actual current I flowing through at least one coil of the solenoid valve Ol with a simultaneous temporal decrease of the induced voltage with an amount above a given or fixed (further) threshold value is then referred to as the current I Ol at which the anchor reaches its extreme position P O Optionally, a time interval can also be set during the subinterval Δ2 and possibly before the end time interval Δ e Actual current I flowing through at least one coil of the solenoid valveCa with a simultaneous temporal increase of the induced voltage U ind above a predetermined or fixed (further) threshold value than the current I Ca be determined at which the anchor in its extreme position P C arrives.

[0022] The actual currents I determined in this way Ca , I Cl , I Oa and I Ol are parameters that characterize the solenoid valve and vary with the spring preload of its spring mechanism. The method described here is therefore a discrete measurement method, by means of which the actual currents I can be determined within a relatively short measurement and evaluation time, for example, within a maximum measurement and evaluation time of 1 second. Ca , I Cl , I Oa and I Ol and use this to determine the corresponding spring preload force of the spring device. The actual currents I Ca , I Cl, I Oa and I Ol , where the anchor has a respective extreme position P C or P O leaves or enters the valve can also be reliably determined using the measuring method described here, without the need to pass a liquid and / or gaseous medium through the respective solenoid valve under investigation. This eliminates the otherwise necessary consumption of the respective liquid and / or gaseous medium when carrying out the method described here. Likewise, no pressure gauge or flow meter is required to carry out the method described here. By eliminating such measuring devices, increased accuracy in determining the actual currents I Ca , I Cl , I Oa and I Ol and possibly the spring preload force of the spring device.

[0023] Fig. 2a to 2f show coordinate systems for explaining a second embodiment of the method for examining a solenoid valve.

[0024] As can be seen from the coordinate systems in the Fig. 2a and Fig. 2b, in the method described here, the time-varying actual voltage U is also applied to the at least one coil of the respective solenoid valve under investigation during the investigation time interval Δ in such a way that the at least one coil is energized during the investigation time interval Δ according to the predetermined temporal target current intensity profile I0. In this way, the armature of the solenoid valve is adjusted at least temporarily during the investigation time interval Δ, whereby a temporal profile of the voltage U induced by the at least temporarily adjusted armature during the investigation time interval Δ ind can be determined. In the coordinate system of the Fig. 2a, the abscissa represents the time axis t (in seconds), while the ordinate represents the current values ​​of the specified time-dependent current curve I0 (in amperes). Also in the coordinate system of the Fig. 2b, the abscissa is the time axis t (in seconds), while the ordinate indicates the actual voltage U (in volts) applied to at least one coil of the solenoid valve. The abscissas of the coordinate systems of the Fig. 2c and Fig. 2d shows the respective current values ​​of the specified temporal target current curve I0 (in amperes). The voltage U induced during the test time interval Δ ind is in the coordinate systems of the Fig. 2c and Fig. 2d by means of the ordinates (in volts), where the coordinate system of the Fig. 2d an enlarged section of the coordinate system of the Fig. 2c shows.

[0025] Also to carry out the method described here, a solenoid valve is used, the spring device of which moves the armature of the solenoid valve in a direction away from the extreme position P C to the extreme position P O pushes or pulls, whereby only as an example under the extreme position P C a “closed” position of the anchor and below the extreme position P O an “open” position of the anchor.

[0026] In contrast to the previously described embodiment, the method of Fig. 2a to 2f, the armature is stimulated to a variety of different movement sequences by means of the time-varying actual voltage U applied during the test time interval Δ. As indicated by the arrows A 10 in Fig. 2c and Fig. 2d, the armature is first actuated by the applied actual voltage U during a sub-interval Δ 10of the examination time interval Δ to a first adjustment movement along a first adjustment direction. In particular, the temporal target current intensity profile I0 is specified such that its current values ​​during the sub-interval Δ 10 start from the minimum current value I min , preferably with a constant gradient, up to a first intermediate current value I1. This can be seen from the coordinate systems of the Fig. 2c and Fig. 2d, that the anchor during the subinterval Δ 10 at the actual current I Cl from its extreme position P C is adjusted out.

[0027] During a subsequent subinterval Δ 11 of the test time interval Δ, the armature is brought to a standstill. For this purpose, the current values ​​of the target current curve I0 during the sub-interval Δ 11 kept constant.

[0028] After the subinterval Δ 11 The armature is controlled by the time-varying actual voltage during a subsequent sub-interval Δ 12 of the examination time interval Δ to a second adjustment movement along a second adjustment direction opposite to the first adjustment direction. The current values ​​of the temporal target current curve I0 decrease during the sub-interval Δ 12 starting from the first intermediate current value I1, preferably with a gradient of a constant magnitude, to a second intermediate current value I2. However, the armature remains stationary even after the start of the sub-interval Δ 12 still in its standstill, as indicated by arrows A 11 in the Fig. 2c and Fig. 2d is displayed. Only at an actual current I release1 a static friction of the armature is overcome and the armature is set into the reproduced second adjustment movement.

[0029] Afterwards, the anchor can be used during another sub-interval Δ 13 of the examination time interval Δ. Preferably, the specified temporal target current intensity curve I0 during the sub-interval Δ 13 constant current values. The arrows A 13 enter into the Fig. 2c and Fig. 2d the standstill of the anchor again.

[0030] In a subinterval Δ 14 of the test time interval Δ, the armature is then stimulated again to its first adjustment movement along the first adjustment direction. The current values ​​of the temporal target current curve I0 decrease during the sub-interval Δ 14 starting from the second intermediate current value I2, preferably with a constant gradient, up to the maximum current value I max As shown by arrows A 14displayed, the static friction of the armature at an actual current I release2 overcome and the armature comes to the actual current I Oa in its extreme position P O to.

[0031] To better understand the multitude of different movements of the anchor, the coordinate system of the Fig. 2e the abscissa the current values ​​of the temporal target current curve I0 (in amperes) and the ordinate a stroke h of the armature in relation to its extreme position P C (in micrometers) again.

[0032] In the coordinate system of the Fig. 2f, the abscissa shows the current values ​​of the temporal target current curve I0 (in amperes) and the ordinate the respective induced voltage U ind (in volts). In the coordinate system of the Fig. 2f shows graphs g1 to g5, which represent various solenoid valves with different static and sliding friction. As can be seen from a comparison of graphs g1 to g5, the behavior of the armature of the respective solenoid valve during the direction reversal between the subintervals Δ 10 to Δ 12 or when reversing the direction between the subintervals Δ 12 to Δ 14 depends on the respective static and sliding friction of the respective armature. The current difference between the first intermediate current value I1 and the respective actual current I release1 , or between the second intermediate current value I2 and the respective actual current I release2is a measure of static friction. If the respective armature exhibits a significant difference between its static friction and its sliding friction, the armature makes a "jump" after overcoming the static friction, which is expressed as an "overshoot" in the curve of the induced voltage U ind Therefore, when carrying out the method described here, a difference in the voltage U induced by the armature being moved from its standstill to the second adjustment movement can be used to determine the indthe at least one physical quantity relating to the static friction of the armature, the sliding friction of the armature, and / or a friction difference between the static friction of the armature and the sliding friction of the armature is determined with a relatively high degree of accuracy. The difference occurs between the current level upon reversal of the current gradient and the current level at which a movement of the armature in the opposite direction is detected (ie, I1 - I release1 or I2 - I release2 , see Fig. 2a and Fig. 2d).

[0033] The method described here thus enables a quick check of the guiding properties and / or friction coefficient anomalies for the respective solenoid valve. By appropriately selecting the first intermediate current value I1 and / or the second intermediate current value I2, the friction situation at various points along the guide of the respective armature can be examined. In this way, the entire guiding area of ​​the respective armature can be scanned with any desired resolution with regard to its static and / or sliding friction properties.

[0034] All of the methods described here enable both the characterization of the spring device and / or the friction properties, as well as further processing of the spring device and / or the friction properties for predictive friction models. The characterization can also be performed on an installed solenoid valve after its electrical contact has been made. This also enables use in the aftermarket to monitor the function of the respective solenoid valve. The measurement data obtained using the methods described here can then be stored in a control unit of the respective solenoid valve to determine correction values. This eliminates the need for complex characteristic curve measurements during production to detect discontinuities or "errors" in a characteristic curve of the respective solenoid valve.

[0035] Fig. 3a and Fig. 3b show coordinate systems for explaining an embodiment of the method for electrically adjusting a spring preload force of a spring device of a solenoid valve.

[0036] The method described below can be carried out with (almost) any solenoid valve which has at least one energizable coil, an armature which can be adjusted by means of a magnetic field generated by energizing the at least one coil, a control device which moves the armature away from a first extreme position P C in the solenoid valve to a second extreme position P oa pushing or pulling spring device in the solenoid valve and a spring preload force adjustment device that can be controlled by at least one electrical signal. The controllable spring preload force adjustment device can, for example, be an electrically adjustable screw of the solenoid valve. However, the feasibility of the method described below is not limited to a specific design of the controllable spring preload force adjustment device.

[0037] In the procedure described here, the current actual current I Cl of the solenoid valve, at which the armature of the solenoid valve reaches its first extreme position P C leaves, and / or the current actual current I Ol of the solenoid valve, at which the armature of the solenoid valve reaches its second extreme position P O The values ​​used to determine the current I Cl and I OlThe procedural steps to be carried out are described in the procedure of the Fig. 1 a to 1c. The actual currents I Ca and I Oa be co-determined.

[0038] After determining at least one of the actual currents I Cl , I Ca , I Ol and / or I Oa At least one electrical signal is output to the spring preload force adjustment device of the solenoid valve, whereby the spring preload force of the spring device of the solenoid valve is varied by means of the spring preload force adjustment device controlled by the at least one electrical signal. The variation of the spring preload force of the spring device is preferably carried out by continuously determining at least one of the actual current intensities I Cl , I Ca , I Ol and / or I Oa continued until at least one of the actual currents I Cl , I Ca , IOl and / or I Oa is set to a specified target current value. This allows electrical adjustment of the spring preload force of the solenoid valve's spring mechanism to a preferred value, e.g., to compensate for manufacturing variations in the spring preload force.

[0039] In contrast to a conventional spring preload adjustment process, in which the spring preload force of the spring device is varied until a desired pneumatic or hydraulic flow is achieved at the respective solenoid valve, the method described here can be carried out much more quickly. The time required to carry out the method described here depends solely on how frequently at least one of the actual currents I Cl , I Ca , I Ol and / or I Oamust be measured until the respective target value is reached. Since the effect of actuating the respective spring preload force adjustment device, such as turning an electrically adjustable screw of the solenoid valve on the spring preload force (due to a thread increase of the respective screw), is usually known, it is generally expected that fewer than 10 measurements are necessary to reach at least one respective target value. In addition, no flow of a liquid and / or gaseous medium through the respective solenoid valve is necessary to detect an actual pneumatic or hydraulic flow.

[0040] In the coordinate systems of the Fig. 3a and Fig. 3b, the abscissas show a respective current value of the specified temporal target current curve I0 (in amperes) and the ordinates a voltage U induced in the at least one coil at the respective current values ind (in volts), where the coordinate system of the Fig. 3b an enlarged section of the coordinate system of the Fig. 3a. In addition, graphs g0, g 45° , g 90° , g 135° , g 180° and g 225° into the coordinate systems of the Fig. 3a and Fig. 3b, which shows an initial situation before performing a screw rotation (g o ), an effect of a screw rotation of 45° (g 45° ) after the initial situation, an effect of a screw rotation of 90° (g 90° ) after the initial situation, an effect of a screw rotation of 135° (g 135° ) after the initial situation, an effect of a screw rotation of 180° (g 180°) after the initial situation and an effect of a screw rotation of 225° (g 225° ) depending on the initial situation. This allows the spring preload of the spring device to be quickly and reliably adjusted to a preferred value.

[0041] Fig. 4 shows a schematic representation of an embodiment of the valve inspection device and a solenoid valve cooperating therewith.

[0042] The Fig. The valve testing device 10 schematically illustrated in Figure 4 has an electronic device 10a, by means of which a time-varying actual voltage U can be applied to at least one coil 12 of the solenoid valve 14 during a predetermined or self-determined testing time interval such that the at least one coil 12 can be energized during the testing time interval according to a predetermined temporal target current intensity profile. In this way, an armature 16 of the solenoid valve 14 can be adjusted at least temporarily during the testing time interval.In addition, the electronic device 10a can be used to determine a time profile of a voltage induced by the at least temporarily adjusted armature 16 during the examination time interval, taking into account the time-varying actual voltage U applied to maintain the desired current intensity profile during the examination time interval. Furthermore, the electronic device 10a is designed and / or programmed such that, by taking into account the determined time profile of the voltage induced during the examination time interval, at least one physical variable relating to a spring device 18 of the solenoid valve 14 and / or to a static and / or sliding friction of the armature 16 can be determined by the electronic device 10a.

[0043] The solenoid valve 14 examined by the valve examination device 10 is preferably a current-controlled solenoid valve. For example, the solenoid valve 14 can be a proportional valve. Specifically, in the example of the Fig. 4 the solenoid valve 14 is an HGI, ie a pneumatic valve, which can dose hydrogen into a fuel cell as a proportional valve in a closed control loop. This can be Fig. 4 schematically shown solenoid valve 14 can therefore also be referred to as a hydrogen dosing valve.

[0044] By means of the spring device 18 of the solenoid valve 14, the armature 16 is pushed or pulled away from a first extreme position in the solenoid valve 14 to a second extreme position in the solenoid valve 14. For example only, Fig.4, the armature 16 is pressed / pulled by the spring device 18 against a 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 with mechanical contact with the seat 20. However, against a spring force of the spring device 18, the armature can be adjusted from its second extreme position such that the armature strikes a stop 22 in its first extreme position and the solenoid valve is in its fully open state.

[0045] The electronic device 10a can optionally be designed / programmed to execute at least one of the methods explained above. For example, the electronic device 10 can be used to determine a first actual current flowing through the at least one coil 12 of the solenoid valve 14, at which the armature 16 leaves its first extreme position, and / or a second actual current flowing through the at least one coil 12, at which the armature 16 leaves its second extreme position.As an optional development, the electronic device 10a can additionally be designed / programmed to output at least one electrical signal 24 to a spring preload force adjustment device 26 of the solenoid valve 14 such that a spring preload force of the spring device 18 is varied by means of the spring preload force adjustment device 26 controlled by the at least one electrical signal 24 such that the first actual current strength is set to a predetermined first target current strength value and / or the second actual current strength is set to a predetermined second target current strength value. The spring preload force adjustment device 26 can, for example, be an adjustment screw 26 for the spring preload force of the spring device 18. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 207 906 A1

[0002]

Claims

[1] 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 examination time interval (Δ) in such a way that the at least one coil (12) of the solenoid valve (14) can be energized during the examination time interval (Δ) according to a predetermined temporal desired current intensity profile (I0) in such a way that an armature (16) of the solenoid valve (14) can be adjusted at least temporarily during the examination time interval (Δ); wherein, by means of the electronic device (10), taking into account the time-varying actual voltage (U) applied to maintain the temporal target current intensity profile (I0) during the examination time interval (Δ), a time profile of a voltage (U ind ) can be determined, characterized by , that the electronic device (10a) is additionally designed and / or programmed in such a way that, by means of the electronic device (10a), taking into account the specific time course of the voltage (U ind ) at least one physical variable can be determined with respect to a spring device (18) of the solenoid valve (14) and / or with respect to a static and / or sliding friction of the armature (16). [2] Valve inspection device (10) according to claim 1, wherein the spring means (18) is moved in the direction away from a first extreme position (P O ) to a second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ) from its first extreme position (P O ), and wherein the electronic device (10a) is designed and / or programmed such that by means of the electronic device (10a) a first actual current intensity (I Ol ) with a simultaneous temporal decrease of the induced voltage (U ind ) with an amount above a predetermined or fixed first threshold value during the examination time interval (Δ) as the current intensity (I Ol ) can be determined, at which the armature (16) reaches its first extreme position (PO ) leaves. [3] Valve inspection device (10) according to claim 1 or 2, wherein the spring device (18) is moved in the direction away from the first extreme position (P O ) to the second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ) from its second extreme position (P C ), and wherein the electronic device (10a) is designed and / or programmed such that by means of the electronic device (10a) a second actual current intensity (I Cl ) with a simultaneous temporal increase of the induced voltage (U ind ) above a predetermined or fixed second threshold during the examination time interval (Δ) as the current intensity (I Cl) can be determined, at which the armature (16) reaches its second extreme position (P C ) leaves. [4] Valve testing 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 force adjusting device (26) of the solenoid valve (14) by means of the electronic device (10a) in such a way that a spring preload force of the spring device (18) of the solenoid valve (14) can be varied by means of the spring preload force adjusting device (26) controlled by the at least one electrical signal (24) in such a way that the first actual current intensity (I Ol ) to a predetermined first target current value and / or the second actual current (I Cl ) can be set to a predetermined second target current value. [5] Valve inspection device (10) according to one of the preceding claims, wherein the spring device (18) is arranged in a direction away from the first extreme position (P O ) to the second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ), first to a first adjustment movement along a first adjustment direction, then between its first extreme position (P O ) and its second extreme position (P C) can be briefly excited to a standstill and subsequently to a second adjustment movement along a second adjustment direction opposite to the first adjustment direction, and wherein the electronic device (10a) is designed and / or programmed such that by means of the electronic device (10a) on the basis of a difference between the voltage (U ind ) the at least one physical variable can be determined with respect to the static friction of the armature (16), with respect to the sliding friction of the armature (16) and / or with respect to a friction difference between the static friction of the armature (16) and the sliding friction of the armature (16). [6] Method for examining a solenoid valve (14) comprising the steps: Applying a time-varying actual voltage (U) to at least one coil (12) of the solenoid valve (14) during a predetermined or self-determined examination time interval (Δ) such that the at least one coil (12) of the solenoid valve (14) is energized during the examination time interval (Δ) according to a predetermined temporal desired current intensity profile (I0) such that an armature (16) of the solenoid valve (14) is adjusted at least temporarily during the examination time interval (Δ); and Determining a time profile of a voltage (U ind ) taking into account the time-varying actual voltage (U) applied to maintain the desired current intensity profile (I0) during the test time interval (Δ); characterized by the step: Determining at least one physical variable with respect to a spring device (18) of the solenoid valve (14) and / or with respect to a static and / or sliding friction of the armature (16) taking into account the determined temporal course of the voltage (U ind ). [7] Method according to claim 6, wherein the spring device (18) is moved in a direction away from a first extreme position (P O ) to a second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ) from its first extreme position (P O ), and wherein a first actual current intensity (I Ol ) with a simultaneous temporal decrease of the induced voltage (U ind) with an amount above a predetermined or fixed first threshold value during the examination time interval (Δ) as the current intensity (I Ol ) is determined, at which the armature (16) reaches its first extreme position (P O ) leaves. [8] Method according to claim 6 or 7, wherein the spring device (18) is moved in the direction away from the first extreme position (P O ) to the second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ) from its second extreme position (P C ) is adjusted out, and a second actual current intensity (I Cl ) with a simultaneous temporal increase of the induced voltage (U ind) above a predetermined or fixed second threshold during the examination time interval (Δ) as the current intensity (I Cl ) is determined, at which the armature (16) reaches its second extreme position (P C ) leaves. [9] Method according to one of claims 6 to 8, wherein the spring device (18) moves the spring element (18) in a direction away from the first extreme position (P O ) to the second extreme position (P C ) pressed or pulled armature (16) by means of the time-varying actual voltage (U) applied during the test time interval (Δ), first to a first adjustment movement along a first adjustment direction, then between its first extreme position (P O ) and its second extreme position (P C) is briefly excited to a standstill and then to a second adjustment movement along a second adjustment direction opposite to the first adjustment direction, and wherein on the basis of a difference between the voltage (U ind ) the at least one physical variable is determined with respect to the static friction of the armature (16), with respect to the sliding friction of the armature (16) and / or with respect to a friction difference between the static friction of the armature (16) and the sliding friction of the armature (16). [10] Method for electrically adjusting a spring preload force of a spring device (18) of a solenoid valve (14) comprising the steps: at least once carrying out the method according to claim 7 or 8 for determining the current first actual current intensity (I Ol), in which the armature (16) of the solenoid valve (14), which is guided by means of the spring device (18) in the direction away from a first extreme position (P O ) to a second extreme position (P C ) is pushed or pulled, its first extreme position (P O ) and / or the current second actual current (I Cl ), at which the armature (16) of the solenoid valve (14) reaches its second extreme position (P C ) leaves; and Outputting at least one electrical signal (24) to a spring preload force adjusting device (26) of the solenoid valve (14) such that the spring preload force of the spring device (18) of the solenoid valve (14) is varied by means of the spring preload force adjusting device (26) controlled by the at least one electrical signal (24) such that the first actual current intensity (I Ol ) to a predetermined first target current value and / or the second actual current (I Cl) to a predefined second target current value.

Images