The invention relates to a drive device, the
especially for use on gas valves, in particular
Gas valves with at least two coaxial
Valve seats, is set up.
For example, from DE 195 25 384 A1
Double shut-off and control valve known, the two
Has valve seats and two valve plates assigned to them. The
Valve seats and the valve plates are coaxial to one
aligned central axis and in a common
Housing arranged one above the other. For actuation, d. H. to
Axial movement of the two valve plates, serves only one
Magnetic circuit to which a magnet armature is assigned, the
extends into the magnetic circuit. This magnet armature is
with one of the valve plates (namely the lower one)
connected. The second valve plate is with a thin wall
Bowl connected, in which the first anchor mentioned
extends. It consists of a non-magnetic material
and is taken away by the massive anchor when it is
the valve assigned to it opens.
In this design, the two are arranged coaxially
Valves cannot be controlled separately.
Furthermore, from DE-OS 16 50 534
Double seat valve with two valve seats and
Valve plates known. Heide valve plates are made by one
actuated common magnetic drive forth, two of which are coaxial
nested anchors are provided. Through targeted
The individual valves can influence the coil current
can be addressed individually within limits. A really
however, independent control of both valves is not
Furthermore, from DE 101 14 175 C1
Known coaxial solenoid valve, the two coaxially arranged to each other
Has valve closure members that are common
Valve seat are assigned. The two
Valve closure members arranged coaxially to a common axis
are assigned to two magnetic circuits, which are also
are coaxial to the axis mentioned. The two magnetic circuits
are, so to speak, stacked one on top of the other, with the anchor
of the lower magnetic circuit approximately as a hollow cylinder
is trained. It is with one of the valve closure members
connected that the other valve closure member like one
Bell reaches over. The upper magnetic circuit has an armature
on that through a rod with the inside
Valve closure member is connected. This rod penetrates the
hollow cylindrical bottom anchor.
There is a between the two valve closure members
Gap formed. This may be with
Leakage tests do not show excessive pressure loss. That is why
seals in the lower hollow cylindrical anchor
attached that the rod gas-tight against the anchor
caulk. These seals cause some friction that
must be overcome by the drives. You can also
they may form a certain weak point.
Based on this, it is an object of the invention to
To create a drive device, in particular for
Double seat valves coaxial design is suitable.
This object is achieved with the drive device according to claim 1:
The drive device according to the invention has two largely independent magnetic circuits which can be controlled separately from one another. An anchor is assigned to both magnetic circuits. The two magnetic circuits are to a certain extent stacked one above the other, ie preferably coaxially to a common longitudinal axis. The armature of the magnetic circuit, which lies further away from the valve closure members, ie from the valve, has a tube section which overlaps the armature of the other magnetic circuit. In the words of the patent claim, the second anchor is arranged within this tube section of the first anchor. This enables the actuation of two valve closure members which enclose an intermediate space, a so-called central space. From the point of view of the second anchor, the first anchor, the pipe section of which overlaps the second anchor, forms a closed pot which closes the middle space in a gas-tight manner. It is therefore possible to dispense with any seals arranged between the armatures and their force transmission members. The second armature can thus be mounted in the first armature with low friction in an axially freely movable manner. If necessary, anti-slip coatings can be applied to the inner wall of the pipe section over the entire surface or locally, e.g. B. be installed in strips. By eliminating seals between the armatures, relatively weak closing springs and energy-saving magnetic drives can be used. This complies with efforts to save space, materials and energy.
The basic concept according to the invention enables one
particularly simple manufacture.
The magnetic coils of the two are advantageously
Magnetic circuits poled in opposite directions, d. H. they generate at
Control preferably fields facing each other.
This enables the magnetic circuits to be very small
Axial spacing to be arranged without the control
of a magnetic circuit attract the other armature
leaves. This enables the two to be controlled separately
Valves even if, for example, both magnetic circuits
a common external magnetic yoke
exhibit. In other embodiments, the
Inference members of the two magnetic circuits also from one another
Are the magnetic circuits poled in opposite directions?
Magnetic circuits on the facing end faces
Place two separate pole pieces also a common one
Have pole piece. This reduces the overall height of the
Magnetic circuit without restricting its functionality too much.
The first anchor has an upper section that
is only assigned to the first magnetic circuit and here as one
conventional magnetic armature works. Part of the first anchor
however, it also extends into the second magnetic circuit
and acts as a flow guide for the second
Anchor. In this configuration, the solenoids are the
two magnetic circuits preferably different strengths
dimensioned. The solenoid of the first magnetic circuit is
preferably dimensioned so that they are on the first
Anchors can exert a force that is the sum of the forces
of return springs that with both anchors
are connected. Such return springs can for example
Closing springs of valve closure members with the
Anchors are connected. Ultimately, the first anchor
not only the force of the closing spring assigned to it
but also overcome the counterforce for the second anchor
apply, which is at least as large as that
Closing force of the closing spring of the second armature or
The pipe section preferably extends through
through the second magnetic circuit. So at least he goes
past a pole piece of the second magnetic circuit.
The pipe section is preferably in a central zone
designed so that the one to be measured in the axial direction
magnetic resistance is significantly greater than radial
magnetic resistance in the area of the lower pole piece of the
second magnetic circuit. This will be the second
Magnetic circuit weakening, flowing longitudinally through the pipe section
Magnetic field negligible. The one you want
magnetic resistance can be achieved by a sufficiently low
Wall thickness in the central zone or by a suitable one
Material choice can be achieved when the first anchor and the
Pipe section are constructed in several parts.
The axial length of the pipe section
enclosed interior is preferably greater than the length of the
second anchor so that when both anchors are in
Rest position, with its upper face in
a desired distance from the face facing him
of the cylindrical interior of the second armature or its
Pipe section lies. This desired distance represents the
Represents the stroke that the second anchor can perform when the
first anchor not moving. This stroke is preferably a
Part of the total stroke that the second anchor can perform
when the first anchor is raised.
The first anchor can be different depending on your preference
Be built up way. For example, it can be in one piece
as a forged or rolled part, as a turned part or also
be constructed in several pieces. In the latter case, the
Pipe section and the anchor cohesively by gluing or
Welding or form-fitting by flanging or
Similar joining techniques must be connected. The
Sealing can then take over an O-ring.
The pipe section is preferably with a
provided annular flow guide, which is in the area of
lower pole piece of the second magnetic circuit. His
Length is preferably greater than the sum of the thickness
of the pole piece and the maximum stroke of the first anchor. It
remains in the work area in any working position
lower pole piece.
A tube preferably passes through both magnetic circuits,
this tube receiving both anchors. At its top,
is facing away from a possible valve housing
this pipe is closed by a flow guide that
has no openings or the like. In this way
is the gas tightness of the drive device without moving
In the drawing, an embodiment of the
Invention illustrated. Show it:
Fig. 1 a double safety solenoid valve with two magnetic circuits comprising drive means for the separate control of both valves in the closed position in vertical sectional representation,
Fig. 2 shows the dual safety solenoid valve according to Fig. 1 in the open position,
Fig. 3 shows a modified embodiment of the drive means in vertical sectional representation,
Fig. 4 u. 5 further embodiments of the drive device each in vertical section.
In Fig. 1, a gas valve 1 is illustrated in the form of a double shut-off and control valve, the two series-connected valves 2 , 3 are housed in a common housing 4 . The housing 4 has an input 5 and an output 6 , both of which are separated from one another by a wall arrangement accommodated in the housing 4 . On this two valve seats 8 , 9 are formed, which are separated from one another, but are arranged approximately at the same height and concentrically to one another. Valve closure members 10 , 11 are assigned to valve seats 8 , 9 , both of which are each approximately bell-shaped. In the rest position, they sit on the valve seats 8 , 9 . A corresponding closing force is generated by closing springs 12 , 14 , which are each supported between the housing 4 or parts connected to it and the respective valve closure member 10 , 11 .
A central space 15 is enclosed between the valve closure members 10 , 11 and communicates with a buffer space 17 via a passage 16 between the valve seats 8 , 9 . At the bottom it is closed by a cover 18 which carries a regulator 19 . A drive device 21 , to which two magnetic circuits 22 , 23 belong, is assigned to the valve closure members 10 , 11 . These are arranged coaxially to a central axis a, which is also the central axis of the valve closure members 10 , 11 .
The first magnetic circuit 22 has a first magnetic coil 24 with a coil body 25 , for example made of plastic. At the two front ends of the coil 24 , annular and disk-shaped pole pieces 26 , 27 are arranged concentrically with the central axis a. The lower pole piece 27 has an opening through which a tube 28 passes. The latter extends through a housing cover 29 of the housing 4 and is kept sealed thereon by means of a seal 31 . The tube 28 is hermetically sealed at its top by a flow guide 32 . For example, while the tube is a thin-walled stainless steel tube, the flux guide 32 is preferably made of a soft magnetic material. It has an approximately cylindrical outer circumference, which is provided with a step. The tube 28 sits in this. The connection can be made by a flare connection, not shown, a welded connection, an adhesive connection or a similar mechanically firm and gas-tight connection.
On its upper side, the flux guide piece 32 has a shoulder 33 on which the pole piece 26 sits. The pole piece can have an opening with an internal thread that is screwed to an external thread of a cylindrical pin that extends through the pole piece 26 . The threaded connection is designated 34 in FIG. 1.
The pole piece 26 is supported on the outside on a magnetic yoke member 35 , which is designed as a tube and is on the outside of the housing cover 29 . While the yoke member 35 is thus subjected to pressure, the tube 28 is subjected to tension, as a result of which the seal 31 is pressed against the housing cover 29 from the inside.
The flow guide piece 32 has a flat, cylindrical recess arranged concentrically to the central axis a, the upper flat end face 36 of which forms a stop surface for a first anchor 37 . With its cylindrical outer surface 38, this slides with little play in the tube 28 . The armature 37 is thus axially movable. At its upper end it has a peg-like extension which fits into the recess of the flow guide piece 32 with little play. A small cylindrical spigot can also be unshaped on this cylindrical extension, which fits into a corresponding recess in the flow guide piece 32 . The end face of the cylindrical extension carries an anti-adhesive disc 39 which prevents the armature 37 from sticking to the flow guide piece 32 when the coil 24 is de-energized.
To achieve a desired force characteristic, the recess provided in the flow guide 32 is surrounded by an edge 41 which tapers towards its free edge.
A pipe section 42 extends from the armature 37 concentrically through the pipe 28 into the interior of the housing 4 . Here it is connected to the bell-shaped valve closure member 10 . The connection allows a certain angular play. It is formed by a snap ring 43 seated on the outside of the pipe section 42 and by an annular shoulder formed at the bottom of the pipe section 42 . A sealing element, for example in the form of an O-ring 44, is provided for sealing.
The tube section 42 encloses a cylindrical interior in which a second anchor 45 is arranged to be longitudinally displaceable. Its cylindrical outer peripheral surface 46 can slide on the cylindrical inner wall of the tube section 42 . A non-stick coating can be provided on the armature and / or on the inner wall of the tube section 42 .
The armature 45 belongs to the second magnetic circuit 23 which , like the first magnetic circuit, is arranged in the yoke 35 coaxially to the central axis a. The second magnetic circuit 23 includes an upper pole piece 47 , which is designed as a flat perforated disk and rests with its outer cylindrical edge on the inside of the yoke member 35 and with its inner circumferential surface on the tube 28 . A spacer in the form of a non-magnetic ring 48 can be provided between the pole pieces 27 , 45 .
The second magnetic circuit 23 also includes a coil 49 , which sits with its coil body 51 on the tube 28 . The housing cover 29 also forms a lower pole piece on which the coil 49 and the magnetic yoke 35 sit.
A lower section 52 of the first armature 37 also belongs to the magnetic circuit 23 . The section 52 is a cylindrical, preferably solid section of the armature 37 , which is below the pole piece 27 in all operating positions. A dotted line is drawn in FIG. 1 to delimit the part of the armature 37 belonging to the magnetic circuit 22 . It lies approximately at the top of the pole piece 45 when the armature 37 is at rest. In this state, the tube section 42 attaches to the lower end face 53 of the armature 37 at approximately the middle height of the coil 49 . On the opposite end face of the armature 45 , an anti-adhesive disc 54 made of a non-magnetic material, for example plastic, brass or aluminum, is attached.
The pipe section 42 has a tapered wall immediately adjacent to the end face 53 , which is followed by a thin-walled pipe section which forms a central zone. The wall is so thin here that axial magnetic flux in the tube section 42 , which like the armature 37 consists of a soft magnetic material, assumes a negligible value. The central zone 55 is in turn followed by a tubular section 56 , the radial thickness of which is so great that only a small air gap remains both to the armature 45 and to the housing cover 29 serving as a pole piece.
The cylindrical armature 45 is provided on its underside with a short extension, which is connected to the bell-shaped closed valve closure member 11 via a connection allowing play. A tubular extension of the valve closure member 11 , into which the extension of the armature engages, serves for the connection.
The drive device 21 described so far operates as follows:
In the idle state, both coils 24 , 49 are without current. The closing springs 12 , 14 press the valve closure members 10 , 11 onto the valve seats 8 , 9 , the armatures 37 , 45 being in their lowest position. There is a distance of a few millimeters between the end face 53 and the anti-adhesive disc 54 , which permits an axial stroke of the armature 45 . If current is now supplied to the lower coil 49 , a magnetic flux occurs, which flows from the upper pole piece 45 through the lower section 52 of the first armature 37 and the air gap formed between the end face 53 and the armature 45 . From here, the flow continues through the lateral surface 46 of the armature 45 and the section 56 in the radial direction into the pole piece 29 in order to close via the yoke 35 . As a result, the armature 45 is moved upward in FIG. 1, ie attracted by the armature 37 . The valve closure member 11 thus opens. The opening width is somewhat limited, however, the middle space 15 can be brought into fluid connection with the outlet 6 .
If the coil 49 is de-energized, the armature 45 drops and the valve closure member 11 closes again.
If the coil 24 is now excited, a field is built up around it, the flow of which flows from the pole piece 26 via the flux guide piece 32 and the air gap formed with the armature 37 through the armature into the pole piece 27 and closes via the yoke 35 . As a result of the air gap field, forces then appear on the armature 37 which move it axially upward, ie towards the flow guide piece 32 . However, there is no magnetic coupling between the armature 37 and the armature 45 , so that the armature 45 is at rest. In this case, the tube section 42 is magnetically passive and acts only as a force transmission element for transmitting the movement of the armature 37 to the valve closure element 10 . The lower section 52 and the pipe section 42 thus have a double function - they serve on the one hand for the mechanical connection of the armature 37 with the valve closure member 10 and on the other hand as flux guiding elements for the second magnetic circuit 23 . In addition, the pipe section 42 forms a hermetic seal for the central space 15 with the section 52 of the armature 37 .
If both valves are to be opened, the state illustrated in FIG. 2 is reached. Both coils 24 , 49 are preferably energized in opposite directions. As a result, both anchors 37 , 45 are moved into their highest possible position. The stroke of the lower armature 45 is now greater than the end face 53 has been displaced upward as a result of the movement of the armature 37 . Both anchors 37 , 45 can thus go through a full stroke and both valve closure members 10 , 11 fully open.
Fig. 3 illustrates a modified embodiment of the invention. Unless otherwise expressly described below, reference is made to the above description using the same reference numerals. The embodiment illustrated in FIG. 3 differs from the previous execution farms in the design of the tube 28 and the first anchor 37 with its tube section 42 . The tube 28 is constructed here in several parts. To the flux conductor 32 is a thin-walled stainless steel tube 57 connects, which is gas-tightly connected with the flux guide 32 via a flare. An O-ring can be provided for sealing. The stainless steel tube 57 is connected at its lower end to a tube piece 58 made of a soft magnetic material which has a thicker wall. This piece of pipe serves as a flow guide piece and extends through the pole piece 27 . Below the pole piece 27 , a stainless steel tube 59 again connects to the tube piece 58 and extends through the second magnetic circuit 23 to the flux guide piece and housing cover 29 .
The stainless steel tube 59 is sealed to the housing cover 29 on the outside by an O-ring 61 .
The armature 37 and its tube section 42 are likewise not formed in one piece but are manufactured by assembling an essentially cylindrical piece with a stainless steel tube 61 . This overlaps at least a part of section 52 and is fastened in a flanging groove. An O-ring seals the stainless steel tube 61 against the anchor. The connection point is preferably arranged below the pole piece 45 . However, as illustrated, it can also be arranged above the same.
In this embodiment, the magnetic yoke 35 is divided into two individual yokes 35 a, 35 b. Due to this extensive separation of the magnetic circuits 22 , 23 , the polarity of the coils is of little importance here. Spacer 48 is preferably non-magnetic.
The particular advantage of this embodiment lies in the simple construction of the first anchor 37 as a built part. Instead of stainless steel tubes, other materials (brass tube, etc.) can also be used if necessary.
Another embodiment illustrated in FIG. 4 differs from the embodiments described above in the design of the tube 28 . At its lower end, this has a sleeve 62 consisting of soft magnetic material, which acts as a flow guide. For the rest, reference is made to the description that has been given in connection with the embodiments illustrated in FIGS. 1 and 2.
The further embodiment illustrated in FIG. 5 is a combination of the embodiment according to FIG. 1 and FIG. 3. The tube section 42 of the armature 37 is here composed of a soft magnetic ring 63 and a stainless steel tube section which forms the central zone 55 . The connection between the anchor 37 , the stainless steel tube section 34 and the ring 33 can be made by gluing, welding or flanging.
A magnetic drive device 21 for a gas valve 1 has two magnetic circuits 22 , 23 , each of which has its own armature 37 , 46 . One of the two armatures has a tube section 42 which extends through the other magnetic circuit and receives the other armature. Part of the first armature and its tube section magnetically belong to the other magnetic circuit and conduct the flux required for moving the other armature without moving the first armature itself. The peculiarity of this drive is that no seals are required between the two anchors, and yet a central space enclosed between two valves actuated by the anchors and coaxial to one another is hermetically sealed.