DE10306003B4 - Drive device for valves - Google Patents

Abstract

Drive device (21), in particular for a double safety solenoid valve,
with a first armature (37) which is linearly moveable along a predetermined direction of movement, which has a tube section (42) and to which a first magnetic coil (24) with a first magnetic circuit (22) is assigned,
with a second armature (45) which is linearly movable along the predetermined direction of movement and to which a second magnet coil (41) with a second magnetic circuit (23) is assigned and which is arranged within the tube section (42) of the first armature (37).

Description

driving means for valves

The The invention relates to a drive device, in particular for Use on gas valves, in particular gas valves with at least two coaxial valve seats.

For example from the DE 195 25 384 A1 a double shut-off and control valve is known which has two valve seats and two valve plates assigned to them. The valve seats and the valve plates are aligned coaxially to a common central axis and arranged one above the other in a common housing. A single magnetic circuit, to which a magnet armature is assigned and which extends into the magnetic circuit, is used for actuation, that is to say for the axial movement of the two valve plates. This armature is connected to one of the valve disks (the lower one). The second valve plate is connected to a thin-walled cup into which the first-mentioned armature extends. It consists of a non-magnetic material and is carried along by the solid armature when it opens the valve assigned to it.

at the two coaxially arranged valves are not of this type separately controllable.

Furthermore, from the DE-OS 1650534 a double seat valve with two superimposed valve seats and valve plates is known. Both valve plates are actuated by a common magnetic drive, for which purpose two armatures which are coaxially seated one another are provided. By specifically influencing the coil current, the individual valves can be addressed individually within limits. However, a truly independent control of both valves is not possible.

Next is from the DE 10114175 C1 a coaxial solenoid valve is known, which has two coaxially arranged valve closure members which are assigned to a common valve seat. The two valve closure members, which are arranged coaxially to a common axis, are assigned two magnetic circuits, which are also coaxial to the axis mentioned. The two magnetic circuits are, so to speak, stacked one above the other, the armature of the lower magnetic circuit being designed approximately as a hollow cylinder. It is connected to one of the valve closure members, which overlaps the other valve closure member like a bell. The upper magnetic circuit has an armature, which is connected by a rod to the inner valve closure member. This rod passes through the hollow cylindrical bottom anchor.

Between A space is formed between the two valve closure members. This may be used for leak tests not too big Have pressure loss. Therefore are in the lower hollow cylindrical Anchor seals are attached which make the rod gas tight against the anchor caulk. These seals cause some friction that overcome by the drives must become. Besides, they can in certain circumstances form a certain weak point.

From that starting from the object of the invention, a drive device to create that especially for Double seat valves coaxial design is suitable.

This Object is achieved with the drive device according to claim 1.

The has drive device according to the invention two largely independent magnetic circuits that can be controlled separately. Both magnetic circuits are one anchor each. The two magnetic circuits are, so to speak, one above the other arranged stacked, that is preferably coaxial to a common longitudinal axis. The anchor of the magnetic circuit which is further from the valve closure members, that is, further from the valve, has a tube section which engages over the armature of the other magnetic circuit. In the words of the claim, the second anchor is within this pipe section of the first anchor. This is the actuation two valve closure elements possible, which together create a gap, a so-called middle space, lock in. The first anchor, the pipe section of which overlaps the second anchor, forms a closed pot from the point of view of the second anchor seals the middle room gas-tight. So there can be any between the anchors and their transmission elements arranged seals are omitted. The second anchor can thus be in the first anchor with low friction axially freely movable his. Can if necessary anti-slip coatings on the inner wall of the pipe section the whole area or locally, for example in strips. By the omission of seals effective between the anchors is the use relatively weak closing springs as well as energy-saving magnetic drives possible. This comes aspirations to save space, material and energy.

The basic concept according to the invention allows a particularly simple production.

Favorable The magnetic coils of the two magnetic circuits are turned in opposite directions poled, that is when activated, they preferably generate opposing directions Fields. This enables arrange the magnetic circuits at a very small axial distance from each other, without triggering one magnetic circuit the other Lets anchor pull. this makes possible the separate activation of the two valves even if, for example both magnetic circuits have a common outer magnetic yoke exhibit. In other embodiments can the inference elements of the two magnetic circuits can also be separated from one another.

are The magnetic circuits can be poled in opposite directions mutually facing end faces instead of two separate pole pieces a common pole piece exhibit. This reduces the overall height of the magnetic circuit without it functionality to restrict too much.

The first anchor has an upper portion that only the first Magnetic circuit is assigned and acts here as a conventional magnet armature. On However, part of the first anchor also extends into the second Magnetic circuit and acts as a flux guide for the second Anchor. In this configuration, the solenoids are the two Magnetic circuits are preferably of different dimensions. The Magnetic coil of the first magnetic circuit is preferably dimensioned so that that it can apply a force to the first anchor that is the sum of forces of return springs that are connected to both anchors. Such return springs can for example the closing springs of valve closure members that are connected to the anchors. Ultimately, the first anchor doesn't just have to be the force of its associated one Overcome the closing spring but also the counterforce for apply the second anchor, which is at least as large as the closing force the closing spring of the second armature or valve closure member.

The Pipe section preferably extends through the second magnetic circuit therethrough. It therefore goes at least on one pole piece of the second magnetic circuit past. The pipe section is preferably in a central zone designed so that the magnetic to be measured in the axial direction Resistance is significantly greater than the radial magnetic resistance in the area of the lower pole piece of the second Magnetic circuit. This weakens the second magnetic circuit, lengthways through the pipe section flowing Magnetic field negligible low. The one you want magnetic resistance can be due to a sufficiently small wall thickness in the Middle zone or reached by a suitable choice of materials if the first anchor and the pipe section are constructed in several parts are.

The axial length the interior enclosed by the pipe section is preferred larger than the length of the second anchor so that this when both anchors are at rest with its upper face in a desired Distance to the face of the cylindrical interior facing it of the second anchor or its pipe section. This desired distance represents represents the stroke that the second anchor can make when the first Anchor not moving. This stroke is preferably part of the total stroke, which the second anchor will perform can when the first anchor is raised.

The The first anchor can be constructed in different ways depending on your needs become. For example, it can be made in one piece as a forged or rolled part, as a turned part or in several pieces be constructed. In the latter case, the pipe section and the Anchor cohesive by gluing or welding or also form-fitting by flaring or similar Connection techniques to be connected. The seal can then take over an O-ring.

The Pipe section is preferably provided with an annular flow guide, that is in the area of the lower pole piece of the second magnetic circuit located. Its length is preferably greater than the sum of the thickness of the pole piece and the maximum stroke of the first anchor. It therefore remains in the area in every working position of the lower pole piece.

Preferably a tube passes through both magnetic circuits, this tube both Anchor picks up. At its top, facing away from any valve housing On the side, this pipe is closed by a flow guide that has no openings or the like. In this way the gas tightness the drive device ensured without moving seals.

In the drawing is an embodiment of the Invention illustrated. Show it

1 a double safety solenoid valve with a drive device comprising two magnetic circuits for separately actuating both valves in the closed position in a vertical section,

2 the double safety solenoid valve 1 in open position,

3 1 shows a modified embodiment of the drive device in a vertically sectioned illustration,

4 and 5 further embodiments of the drive device each in vertical section.

In 1 is a gas valve 1 illustrated in the form of a double shut-off and control valve, the two valves connected in series 2 . 3 in a common housing 4 are accommodated. The housing 4 has an entrance 5 and an exit 6 on, both through one in the housing 4 housed wall arrangement are separated from each other. There are two valve seats on this 8th . 9 formed, which are separated from each other, but are arranged approximately at the same height and concentrically to each other. The valve seats 8th . 9 are valve closure members 10 . 11 assigned, both of which are approximately bell-shaped. In the rest position they sit on the valve seats 8th . 9 on. Closing springs generate a corresponding closing force 12 . 14 , each between the housing 4 or parts connected to it and the respective valve closure member 10 . 11 support.

Between the valve closure members 10 . 11 is a middle room 15 trapped over one between the valve seats 8th . 9 existing passage 16 with a buffer space 17 communicated. At the bottom is a cover 18 locked of a regulator 19 wearing.

The valve closure members 10 . 11 is a drive device 21 assigned to which two magnetic circuits 22 . 23 belong. These are arranged coaxially to a central axis a, which is also the central axis of the valve closure members 10 . 11 is.

The first magnetic circuit 22 has a first magnetic coil 24 with a bobbin 25 , for example made of plastic. At the two ends of the coil 24 are concentric to the central axis a ring and disk-shaped pole pieces 26 . 27 arranged. The lower pole piece 27 has an opening through a tube 28 is reached. The latter extends through a housing cover 29 of the housing 4 and is on this by means of a seal 31 kept sealed. At the top is the pipe 28 through a river guide 32 hermetically sealed. For example, while the tube is a thin-walled stainless steel tube, there is the flow guide 32 preferably made of a soft magnetic material. It has an approximately cylindrical outer circumference, which is provided with a step. The tube sits in this 28 , 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.

The flow guide has on its top 32 one shoulder 33 on, on the pole piece 26 sitting. The pole piece can have an opening with an internal thread, which has an external thread of a cylindrical thread through the pole piece 26 extending bolt is screwed. The threaded connection 34 is in 1 designated.

The pole piece 26 is supported on the outside by a magnetic yoke 35 from, which is designed as a tube and on the outside of the housing cover 29 stands. While the inference member 35 thus the pipe is subjected to pressure 28 stressed on train, causing the seal 31 from the inside on the housing cover 29 is pressed.

The river guide 32 has a flat, cylindrical recess arranged concentrically to the central axis a, the upper flat end face of which 36 a stop surface for a first anchor 37 forms. This slides with its cylindrical outer surface 38 with little play in the tube 28 , The anchor 37 is thus axially movable. At its upper end it has a peg-like extension, which with little play in the recess of the flow guide 32 fits. On this cylindrical extension, a small cylindrical pin can also be unshaped, which in a corresponding recess in the flow guide 32 fits. The end face of the cylindrical extension carries an anti-adhesive disc 39 that stick the anchor 37 on the river guide 32 prevented when the coil 24 is de-excited.

To achieve a desired force characteristic, it is in the flow guide 32 provided recess from an edge 41 surrounded, which tapers towards its free edge.

From the anchor 37 extends a pipe section 42 concentric through the tube 28 down to the interior of the case 4 , Here it is with the bell-shaped valve closure member 10 connected. The connection allows a certain angular play. It is marked by an outside on the pipe section 42 seated snap ring 43 and through one at the bottom of the pipe section 42 trained ring shoulder. For sealing purposes, there is a sealing element, for example in the form of an O-ring 44 intended.

The pipe 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 on the cylindrical inner wall of the pipe section 42 slide. There can be a non-stick coating on the anchor and / or on the inner wall of the pipe section 42 be provided.

The anchor 45 belongs to the second magnetic circuit 23 that like the first magnetic circuit in the yoke 35 coaxial to the central axis a is ordered. To the second magnetic circuit 23 include an upper pole piece, which is designed as a flat perforated disc and with its outer cylindrical edge on the inside of the yoke 35 and with its inner peripheral surface on the pipe 28 is applied. Between the pole pieces 27 . 45 can be a spacer in the form of a non-magnetic ring 48 be provided.

To the second magnetic circuit 23 also includes a coil 49 that with their bobbin 51 on the tube 28 sitting. The housing cover 29 also forms a lower pole piece on which the coil 49 and the magnetic yoke 35 sit.

To the magnetic circuit 23 also includes a lower section 52 of the first anchor 37 , The section 52 is a cylindrical, preferably solid section of the armature 37 in all operating positions below the pole piece 27 stands. To distinguish it from the magnetic circuit 22 part of the anchor 37 is in 1 a dotted line is entered. It lies approximately at the top of the pole piece 45 when the anchor 37 is at rest. In this state, the pipe section continues 42 around the middle of the coil 49 to the lower face 53 of the anchor 37 on. On the opposite end face of the anchor 45 is a non-stick disc 54 made of a non-magnetic material, such as plastic, brass or aluminum.

The pipe section 42 points directly to the face 53 a tapered wall, which is followed by a thin-walled pipe section that forms a central zone. The wall here is so thin that axial magnetic flux in the pipe section 42 that like the anchor 37 consists of a soft magnetic material, takes on a negligible value. To the middle zone 55 in turn a tubular section closes 56 whose radial thickness is so great that both to the anchor 45 as well as the housing cover serving as a pole piece 29 only a small air gap remains.

The cylindrical anchor 45 is provided on its underside with a short extension, the connection with the bell-shaped closed valve closure member allowing clearance 11 connected is. A tubular extension of the valve closure member serves for the connection 11 in which the extension of the anchor engages.

The drive device described so far 21 works as follows:
Both coils are at rest 24 . 49 de-energized. The closing springs 12 . 14 press the valve closure members 10 . 11 on the valve seats 8th . 9 , the anchor 37 . 45 in their lowest position. Between the face 53 and the non-stick disc 54 there is a distance of a few millimeters, which is an axial stroke of the armature 45 allows. Now becomes the lower coil 49 when it is energized, a magnetic flux is generated from the upper pole piece 45 through the lower section 52 of the first anchor 37 and the one between the face 53 and the anchor 45 formed air gap goes. From here, the river continues through the lateral surface 46 of the anchor 45 and the section 56 in the radial direction into the pole piece 29 to find out about the inference link 35 close. This will make the anchor 45 in 1 moved upwards, that is from the anchor 37 dressed. The valve closure member 11 thus opens. The opening width is somewhat limited, but the middle room can 15 with the exit 6 be brought into fluid communication.

Will the coil 49 de-energized, the anchor falls 45 and the valve closure member 11 closes again.

Now the coil 24 excited a field builds up around her, the flow of which from the pole piece 26 over the river guide 32 and the one with the anchor 37 formed air gap through the armature in the pole piece 27 flows and over the yoke 35 closes. On the anchor 37 Then, as a result of the air gap field, forces occur that axially upwards, that is, on the flow guide 32 to move. Between the anchor 37 and the anchor 45 However, there is no magnetic coupling, so that the armature 45 rests. The pipe section 42 is magnetically passive in this case and only acts as a force transmission element for transmitting the movement of the armature 37 on the valve closure member 10 , The lower section 52 and the pipe section 42 thus have a double function - on the one hand they serve to mechanically connect the anchor 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 forms 42 with the section 52 of the anchor 37 a hermetic seal for the central area 15 ,

If both valves are to be opened, the in 2 illustrated state reached. They are both coils 24 . 49 preferably energized in opposite directions. This makes both anchors 37 . 45 transferred to their highest possible position. The stroke of the lower anchor 45 is now larger than the face 53 is due to the movement of the anchor 37 been shifted upwards. Both anchors 37 . 45 can therefore go through a full stroke and both valve closure members 10 . 11 fully open.

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. In the 3 The illustrated embodiment differs from the previous embodiments in the design of the tube 28 and the first anchor 37 with its pipe section 42 , The pipe 28 is made up of several parts here. At the river guide 32 a thin-walled stainless steel tube closes 57 with the flow guide 32 is connected gastight via a flare connection. An O-ring can be provided for sealing. The stainless steel tube 57 is at its lower end with a piece of pipe 58 connected from a soft magnetic material that has a thicker wall. This piece of pipe serves as a flow guide and extends through the pole piece 27 , Below the pole piece 27 a stainless steel pipe closes again 59 to the pipe section 58 and extends through the second magnetic circuit 23 up to the flow guide and housing cover 29 ,

Sealing the stainless steel pipe 59 on the housing cover 29 takes place here via an O-ring 61 ,

The anchor 37 and its pipe section 42 are also not formed in one piece but by assembling an essentially cylindrical piece with a stainless steel tube 61 manufactured. This overlaps at least part of the section 52 and is attached in a flare. An O-ring seals the stainless steel tube 61 here against the anchor. The connection point is preferably below the pole piece 45 arranged. However, as illustrated, it can also be arranged above the same.

In this embodiment, the magnetic yoke is also 35 into two individual inference elements 35a . 35b divided. This extensive separation of the magnetic circuits 22 . 23 the polarity of the coils is of little importance here. The spacer, ring 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 in 4 The illustrated embodiment differs from the previously described embodiments in the design of the tube 28 , This has a soft magnetic material cuff at its lower end 62 that acts as a flow guide. For the rest, reference is made to the description in connection with the in 1 and 2 illustrated embodiments has been given.

The further one in 5 Illustrated embodiment is a combination of the embodiment according to 1 and after 3 , The pipe section 42 of the anchor 37 is here through a soft magnetic ring 63 and a stainless steel pipe section 64 composed of the middle zone 55 forms. The connection between the anchor 37 , the stainless steel pipe section 64 and the ring 63 can be made by gluing, welding or flanging.

A magnetic drive device 21 for a gas valve 1 has two magnetic circuits 22 . 23 on, each with its own anchor 37 . 46 exhibit. One of the two anchors has a pipe 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.

Claims (18)

Drive device ( 21 ), in particular for a double safety solenoid valve, with a first armature that is linearly movable along a predetermined direction of movement ( 37 ) which has a pipe section ( 42 ) and a first magnetic coil ( 24 ) with a first magnetic circuit ( 22 ) is assigned, with a second armature that is linearly movable along the predetermined direction of movement ( 45 ) which has a second solenoid ( 41 ) with a second magnetic circuit ( 23 ) is assigned and that within the pipe section ( 42 ) of the first anchor ( 37 ) is arranged. Drive device according to claim 1, characterized in that the first and second magnetic circuits ( 22 . 23 ) are arranged coaxially to each other. Drive device according to claim 1, characterized in that the magnetic coil ( 22 . 23 ) of the two magnetic circuits ( 22 . 23 ) are polarized in opposite directions. Drive device according to claim 1, characterized in that both magnetic circuits ( 22 . 23 ) one external magnetic return element ( 35 ) on both ends of each coil ( 23 . 41 ) with a pole piece ( 26 . 27 ) is magnetically connected. Drive device according to claim 1, characterized in that the armature ( 37 ) of the first Ma network ( 22 ) a section ( 52 ) which is assigned to the second magnetic circuit. Drive device according to claim 5, characterized in that the section ( 52 ) of the first anchor ( 37 ) the second magnetic circuit in all working positions ( 23 ) protrudes. Drive device according to claim 5, characterized in that the section ( 52 ) of the first anchor ( 37 ) a pole piece for the second anchor ( 45 ) is. Drive device according to claim 1, characterized in that the pipe section ( 42 ) through the second magnetic circuit ( 23 ) extends through. Drive device according to claim 4, characterized in that the pipe section ( 42 ) on both pole pieces of the second magnetic circuit ( 23 ) extends past. Drive device according to claim 1, characterized in that the pipe section ( 42 ) in a central zone ( 55 ) in all positions that the first anchor ( 37 ) in a neutral range, has a magnetic resistance in the longitudinal direction that is greater than the radial magnetic resistance of an end zone, which is caused by a radial magnetic field of the second magnetic circuit ( 23 ) is enforced. Drive device according to claim 10, characterized in that the neutral region between the two pole pieces of the second magnetic circuit ( 23 ) lies. Drive device according to claim 1, characterized in that the first anchor ( 37 ) and the pipe section ( 42 ) are connected in one piece. Drive device according to claim 1, characterized in that the first anchor ( 37 ) and the pipe section ( 42 ) are integrally connected. Drive device according to claim 1, characterized in that the first anchor ( 37 ) and the pipe section ( 42 ) are positively connected. Drive device according to claim 1, characterized in that the magnetic circuits ( 22 . 23 ) are penetrated by a tube that both anchors ( 37 . 45 ) gas-tight towards the outside. Drive device according to claim 15, characterized in that the tube contains at least one annular flow guide. Drive device according to claim 16, characterized in that the flux guide piece the pole of the first magnetic circuit ( 22 ) through which the first anchor ( 37 ) extends through. Drive device according to claim 15, characterized in that the tube at the end of a flow guide ( 32 ) which is connected to the first magnetic circuit ( 22 ) heard.