DE102014214112A1 - Method for controlling an electric valve - Google Patents

Abstract

The invention relates to a method (50) for controlling an electrical valve (1), wherein the valve (1) comprises a switching means (20) and a conducting means (18), wherein the switching means (20) cooperates with an actuating element (34). According to the invention, the method (50) has at least the following steps: triggering (70) of the actuating element (34) by means of a drive signal (52), determining (72) the current consumption of the actuating element (34) by means of a current measuring device and 74) of the voltage and / or the current of the drive signal (52) in determining a reduction in the current consumption of the actuating element (34).

Description

State of the art

The invention relates to a method for controlling an electric valve.

There are already known methods for driving electrical valves. Valves are also known which have a switching means and a conducting means, wherein the switching means cooperates with an actuating element.

Disclosure of the invention

The inventive method with the features of the main claim has the advantage that it is simple and inexpensive Implemented. The retrofitting of existing valves with the method is easily possible. Furthermore, the use of the method reduces the load on the components of the valve, in particular during switching operations.

The measures listed in the dependent claims, advantageous refinements and improvements of the main claim features.

It is particularly advantageous that the determination of the power consumption takes place over an interval. Advantageously, an interval corresponds to a period of time over which the measurements of the current consumption are made or a number of measurements. The determination of the current consumption over an interval enables an improved detection of a reduction of the current consumption. For example, fluctuations in the current profile can be easily compensated.

Furthermore, it is advantageous that the determined current consumption is interpolated. By means of the interpolation, possible fluctuations can be easily compensated and, in particular, a simple prediction of the future current consumption can be made.

It is to be regarded as advantageous that when determining a reduction, the current consumption of the actuating element, the voltage and / or current of the drive signal is reduced. By reducing the voltage and / or the current, the energy supplied to the actuator can be reduced. Furthermore, the forces that act when closing or opening the valve on the components of the valve are reduced.

An advantageous development of the invention is that the drive signal is pulse width modulated. The pulse width modulated control allows a simple change of the voltage and the current of the drive signal, for example by changing the pulse width, preferably by minimizing the pulse width.

It is particularly advantageous that the pulse-width modulated drive signal has a frequency which is in particular greater than 200 Hz. The frequency, greater than 200 Hz of the pulse-width-modulated drive signal, prevents a pulsating movement of the switching means.

It is advantageous that the actuating element has a coil. The current consumption of the coil is determined by means of a current measuring means. For example, the current measuring means is designed as a shunt resistor, which is in particular connected between the actuating element and a control line of the actuating element. By using the current measuring means is a simple, inexpensive and reliable detection of the current consumption of the coil.

Furthermore, it should be regarded as advantageous that the actuating element has a movable armature. The armature cooperates with the switching means. Preferably, the armature is connected to the switching means. The armature and the switching means are moved by means of the drive signal. By connecting the armature to the switching element, in particular via a valve stem, the switching element can be moved easily and quickly depending on the drive signal.

An advantageous development is that the change, in particular the reduction of the voltage and / or the current of the drive signal as soon as the armature moves takes place. By changing the drive signal upon detection of a change in the current profile, the energy that is transferred to the armature can be adjusted. It also prevents that too much kinetic energy is supplied to the anchor. Furthermore, it is advantageous that the forces acting on the armature, or the switching means when opening or closing the valve on the valve, are adjusted accordingly.

Valve with a control means for controlling the valve according to a method according to one or more of the preceding claims. The control means generates a drive signal.

Embodiments of the invention are illustrated in the figures and explained in more detail in the following description. Show it:

1 an electric valve,

2 an exemplary voltage waveform, current waveform on the actuator and a course of movement of the armature and

3 a flowchart of the method.

In 1 is an electric valve 1 , in particular a solenoid valve shown. The electric valve 1 can be used to control fluid flows, in particular gases or liquids. The electric valve 1 has a flow area 10 and a control area 30 ,

The flow area 10 includes a channel housing 12 , The channel housing points according 1 for example, an inlet channel 14 and a drain channel 16 on. The inlet channel 14 is with the drainage channel 16 of the duct housing 12 through a conducting agent 18 connected. The guiding agent 18 is designed in particular as a valve seat. The guiding agent 18 and the channel housing 12 are in particular formed in one piece. The guiding agent 18 has an opening through which a fluid can flow. The guiding agent 18 is made in particular of a material which has a very high sealing effect.

According to another embodiment, the conductive agent 18 made of a good sealing material and by means of joining with the channel housing 12 connected.

Further, within the duct housing 12 a switching means 20 arranged. The switching means 20 is opposite the duct housing 12 and the guiding agent 18 movable arranged. The switching means 20 according to 1 for example, the shape of a cone. The switching means 20 is dependent on its position relative to the conducting agent 18 with this together. The tip of the conical switching means 20 points in the direction of the conductive agent 18 , The guiding agent 18 has a correspondingly corresponding shape.

The switching means 20 is with a valve stem 22 connected. In particular, the switching means 20 and the valve stem 22 formed in one piece.

The duct housing 12 has a first recess 24 on. The recess 24 is, for example, circular. In the recess 24 is the movable valve stem 22 arranged. The valve stem 22 is through the recess 24 guided. Further, in or on the recess is a seal 26 arranged. The seal 26 prevents leakage, the channel housing 12 flowing through the medium, through the recess 24 , The shape of the seal 26 is due to the shape of the recess 24 adjusted so that the best possible sealing takes place. For example, the seal 26 a circular recess 24 designed as a ring.

Depending on the position of the switching means 20 to the lead 18 can the electric valve 1 be traversed by a fluid or the flow through the fluid is blocked. According to 1 has the switching means 20 a distance to the conducting means 18 on. Thus, the switching means closes 20 not the opening of the conductive agent 18 , The fluid may pass through the opening of the conductive agent 18 through and at the switching means 20 flow past. The electric valve 1 is flowed through. Is the switching means 20 at the conducting agent 18 on, so locks the switching means 20 the opening of the conductive agent 18 , The fluid may be the electrical valve 1 do not flow through. The electric valve 1 is locked.

Furthermore, depending on the distance of the switching means 20 to the lead 18 that the electric valve 1 flowing fluid quantity are defined. The amount of fluid may also be across the cross-section, or the size of the opening in the conducting means 18 be managed. However, this is a one-time adjustment in the manufacture of the valve 1 ,

According to a further embodiment, the electric valve 1 any number of inlet channels or drainage channels. Accordingly, the electric valve 1 any number of switching means and conducting means.

The tax area 30 of the valve 1 has a control housing 32 on. The control housing 32 is on the channel housing 12 arranged, in particular connected to this, advantageously by means of joining.

Next is in the tax area 30 an actuator 34 arranged. The actuator 34 acts on the switching means 20 , In particular, the switching means 20 over the valve stem 22 through the actuator 34 emotional.

The actuator 34 includes an anchor 36 and a coil 38 , The anchor 36 is within a leadership 40 movably arranged, in particular displaceable. According to 1 can the anchor 36 within the leadership 40 to be moved up and down. The leadership 40 is for example circular or square. The leadership 40 and / or the control housing 32 have attacks 48 on. The attacks 48 limit the movement of the anchor 36 longitudinal. An attack can also be made by the conducting agent 18 that with the switching means 20 works together, be formed. The anchor 36 has a corresponding shape. The anchor 36 has elements 42 which are repelled or attracted by a magnetic field. For example, at the anchor 36 magnets 42 arranged. For a circular anchor 36 are the magnets 42 for example, revolving around the anchor 36 arranged.

Furthermore, the location element 34 a coil 38 on. The sink 38 is energized. The energization generates a magnetic flux and a magnetic field. The magentic field becomes the element 42 of the anchor 38 attracted or repelled. The mobile in the lead 40 arranged anchor 36 thus becomes dependent on the current supply to the coil 38 attracted or repelled. Due to the attraction or repulsion due to the magnetic field, a relative movement of the armature 36 opposite the coil 38 reached. The sink 38 is on the control box 32 fixed. The switching means 200 and the anchor 36 are over the valve stem 22 firmly connected. The movement of the anchor 38 has a movement of the switching means 20 result. Thus, the switching means 20 depending on the current supply of the coil 38 within the leadership 40 moved, or moved.

The tax area 30 also has a spring 46 , in particular a return spring. The feather 46 moves the anchor to a defined position. Preferably, the force of the spring acts 46 the force through the magnetic field of the coil 38 opposite. Is the coil 38 not energized and thus exerts no magnetic force on the anchor 36 off, that's the anchor 36 through the spring 46 moved to a defined position. The feather 46 is according to 1 exemplary within the leadership 40 arranged. Further, it is exemplified as a ring spring, which the valve stem 22 surrounds. The spring pushes the anchor from the channel housing 12 path. Also pushes the spring 46 the anchor 36 from the coil 38 path. A point of attack for the spring 46 forms the channel housing 12 , Another anchor point is the anchor 36 .The feather 46 is through the leadership 40 guided.

According to a further embodiment, the actuating element 34 a return ring 44 on. The return ring 44 is at the coils 38 arranged and guides the magnetic flux.

In accordance with a further embodiment, the coils can be used for amplifying or better guiding the magnetic flux 38 be wound on flux guide elements. The flux guide elements are aligned radially in the direction of the armature and guide the magnetic flux to the elements 42 of the anchor 36 ,

According to another embodiment, the coil is around the guide 40 wound. For example, the guide 40 designed so that an optimal magnetic flux from the coils 38 to the anchor 36 is possible. It is also possible that several coils 38 for the lead 40 be wrapped. Several coils 38 allow a gradual movement of the anchor 36 , Exemplary is in 1 another coil 38a shown. Depending on whether the coil 38 or 38a energized becomes the anchor 36 moved, or moved. When driving the coil 38 with a drive signal becomes the anchor 36 in a first position, or moved down. When driving the coil 38 with a drive signal becomes the anchor 36 in a second position, or moved upwards.

The method according to the invention is not limited to the electric valve described above 1 , The method can be used in any electrical valves, in particular valves with an actuator, preferably in valves with an actuator with a coil and an armature.

The inventive method 50 serves for the advantageous control of an electric valve 1 , in particular a solenoid valve 1 , The change of the state of the valve 1 or the position of the switching means 20 opposite the conducting agent 18 takes place by acting on the control element 34 with a drive signal 52 , The sink 38 of the actuating element 34 is with the drive signal 52 applied. The sink 38 converts the electrical drive signal into a magnetic flux, or magnetic field, which translates into a magnetic force on the armature 36 leads. Is the force of the magnetic field through the coil 38 greater than, for example, the inertial force, the force of the spring 46 and the force through the fluid together, the anchor begins 36 in the direction of the coil 38 to move. With reverse polarization, the armature moves 36 according to the coil 38 away, the anchor is repelled.

In 2 are the current course 54 and the voltage curve 56 of the actuating element 34 , in particular the coil 38 shown. Also, the course of movement of the anchor 36 exemplified. At the time t1, the drive signal becomes 52 to the actuator 34 , or the coil 38 created. Until time t2, the current increases 54 at. At time t2, the force through the magnetic field is sufficient for the inertial force of the armature 36 and the counterforce of the spring 46 to overcome. If the force due to the magnetic field is sufficiently large, the armature begins 36 to move. The anchor 36 is according to 2 attracted and moves down. The switching means 20 moves to the conducting agent 18 to. The valve 1 will be closed. A flow through the valve 1 will be blocked.

In 2 is the course of the movement 60 of the anchor 36 exemplified. Once the anchor 36 Moves, a voltage in the coil 38 induced. The induced voltage affects the current flow in the coil 38 counter, reducing the current drawn by the coil 38 is reduced. A corresponding reduction of the current profile 54 is in 2 shown from t2.

A reduction of the power consumption can be determined by a current measuring means, in particular by a shunt resistor. The current measuring means is advantageous in one of the drive lines, by which the drive signal to the actuator 34 flows arranged. The current measuring means is thus traversed by the drive signal. If a reduction is detected, then the voltage of the drive signal 52 lowered. In 2 is an example of a corresponding voltage curve 58 with a lowered tension 58 the drive signal 52 shown. The lowered tension 58 the drive signal 52 is opposite to the regular tension 56 minimized. By minimizing the voltage becomes that of the coil 38 lowered energy supplied, reducing the magnetic force and therefore the force on the anchor 36 is lowered. The reduction of the voltage is up to a defined, in particular constant, value, but can also be adjusted depending on the situation.

At time t3, the anchor reaches 36 a stop 48 the leadership 40 or the switching means 20 touches the conducting agent 18 of the valve 1 , The anchor 36 can not be moved further. In the following, the magnetic force is used around the armature 36 to hold in the position. Again, a reduced voltage is sufficient to achieve a sufficient force through the magnetic field, for example, the force of the spring 46 or counteracts the force by the fluid and the switching means 20 holds in a defined position. The reduced voltage must therefore not be increased. Will the switching means 20 held in a position, after an initial increase in the course of the current 54 a saturation.

Should the valve 1 For example, work particularly energy-saving, so the voltage when touching the switching means 20 at the conducting agent 18 be lowered again. The switching means 1 only has to hold in position, so no additional energy is needed for the movement. Such a further reduced voltage curve 62 is in 2 shown. Should the valve 1 on the other hand work particularly reliable, the voltage at touch of the switching means 20 at the conducting agent 18 be increased, reducing the force on the switching means 20 is increased.

Finally, at the time t4, the drive signal 52 off. By switching off, no magnetic force is applied to the armature 36 exercised. The spring force by the spring 46 moves the anchor 36 in the starting position, in particular, according to 1 the anchor moves up. A corresponding movement of the anchor 60 , or the switching means 20 is in 2 from the time t4 by means of the curve 60 shown.

By minimizing the voltage 56 , after detection of a movement of the anchor 36 that can be the anchor 36 supplied energy can be lowered. Thus, in the anchor 36 stored kinetic energy reduced. The anchor 36 stored kinetic energy is when the anchor hits 38 at the stop 48 or when touching the conductive agent 18 through the switching means 20 abruptly dismantled. Furthermore, it comes when hitting the anchor 36 at the stop 48 or with touching the conductive agent 18 through the switching means 20 to a noise, especially a click. The noise can be due to the use of the method 50 be minimized because the speed at which the impact or the touch occurs is minimized. Furthermore, the forces acting on the components of the valve 1 act less, which can be used in particular easier to process materials for the components. Furthermore, the energy needed to hold the valve 1 needed will also be lowered.

From the time t1, the actuator is 34 with a drive signal 52 applied. Between times t2 and t3, the armature moves 36 of the valve 1 , The movement of the anchor 36 occurs due to the application of the actuating element 34 with a drive signal 52 , Between times t3 and t4 becomes the anchor 36 held in a defined position. Again, the actuator is 34 with a drive signal 52 applied. From the time t4 is the actuator 34 no longer with the control signal 52 applied. The anchor 36 is determined by the force of the spring 46 moved back to its original position.

In 3 is the procedure of the method according to the invention 50 shown. In a first step, the control takes place 70 of the actuating element 34 by means of a drive signal 52 , The drive signal is by means of a control means, which with the control element 34 is electrically connected to the actuator 34 applied. Preference is given to the beginning of the application of the drive signal 52 the current consumption of the control element 34 recorded or determined. For this purpose, in particular a current measuring means is used. The current measuring means can be designed in particular as a shunt resistor and voltage meter. The result of the current measuring means is supplied to the control means. The control means determines the drive signal from the signal of the current measuring means 52 , The current consumption is determined continuously or in cyclic repetitions. The current consumption is preferably carried out over an interval. By determining the current consumption over a defined interval, an erroneous assessment, for example due to fluctuations in the current profile, is ruled out. The interval is defined according to the invention over a period of time or a number of measurements.

Advantageously, an interpolation of the determined current consumption can be carried out in order to prevent a misjudgment.

According to a further embodiment, the determination of the reduction of the current consumption takes place by the change of the sign of the slope of the current curve. The determination can also be made by detecting the vertex of the current profile by means of the derivative. Also by means of the formation of the derivative can be concluded on reaching the point of failure or on a reduction in power consumption.

Is used in the investigation 72 If a reduction is determined, a change takes place 74 the drive signal 52 , The voltage of the drive signal 52 is changed, especially reduced.

For a continuous drive signal 52 the amplitude of the voltage is lowered.

In a pulse width modulated drive signal 52 the pulse width is reduced. Due to the low pulse width and the smoothing of the drive signal 52 through the inductance of the coil 38 it comes to a reduction of the resulting voltage of the drive signal 52 at the coil 38 ,

According to a further embodiment, the valve 1 several coils 38 . 38a on whose magnetic force counteracts each other. According to the loading of the coils 38 . 38a with a drive signal 52 takes the anchor 36 a position. In particular, here could be a spring 46 omitted.

To a lapping currents at the coils 38 To prevent the frequency of the pulse width modulation is advantageously selected greater than 200 Hz, in particular between 200 Hz and 1 kHz.

Claims (11)

Procedure ( 50 ) for controlling an electric valve ( 1 ), whereby the valve ( 1 ) a switching means ( 20 ) and a conducting agent ( 18 ), wherein the switching means ( 20 ) with an actuating element ( 34 ), characterized in that the method ( 50 ) comprises at least the following steps: 70 ) of the actuating element ( 34 ) by means of a drive signal ( 52 ), • Detection ( 72 ) the current consumption of the actuating element ( 34 ), by means of a current measuring instrument and • Amendment ( 74 ) the voltage and / or the current of the drive signal ( 52 ) in determining a reduction in the current consumption of the actuating element ( 34 ). Procedure ( 50 ) for controlling an electric valve ( 1 ) according to the preceding claim, characterized in that the determination ( 72 ) of the power consumption over an interval, wherein in particular an interval corresponds to a period or a number of measurements. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of the preceding claims, characterized in that the determined current consumption is interpolated. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of the preceding claims, characterized in that in the determination ( 72 ) a reduction, the current consumption of the actuating element ( 34 ), the voltage and / or current of the drive signal ( 52 ) is reduced. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of the preceding claims, characterized in that the drive signal ( 52 ) is pulse width modulated. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to the preceding claim, characterized in that the change of the pulse width modulated drive signal ( 52 ), by changing, in particular minimizing the pulse width occurs. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to claim 6, characterized in that the pulse width modulated drive signal ( 52 ) has a frequency greater than 200 Hz and preferably less than 1 kHz. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of the preceding claims, characterized in that the actuating element ( 34 ) a coil ( 38 ), wherein the current consumption of the coil ( 38 ) is determined by the current measuring means. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of the preceding claims, characterized in that the actuating element ( 34 ) an anchor ( 36 ) and the armature ( 36 ) with the switching means ( 20 ), in particular connected to it, wherein the armature ( 36 ) and the switching means ( 20 ) by means of the drive signal ( 52 ) is moved. Procedure ( 50 ) for controlling an electric valve ( 1 ) according to one of preceding claims, characterized in that the change ( 74 ), in particular the reduction of the voltage and / or the current of the drive signal ( 52 ) as soon as the anchor ( 36 ) is moved. Valve ( 1 ) with a control means for controlling the valve ( 1 ) according to a method ( 50 ) according to one or more of the preceding claims.

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