DE3244840A1 - Normally closed two-way needle valve with electromagnetic control - Google Patents

Description

NORMALLY CLOSED TWO-WAY NEEDLE VALVE WITH ELECTROMAGNETIC STEERING.

description

The present invention relates to a supply needle valve with direct or indirect electromagnetic control, which is normally closed, 'and in which the under Pressure standing flow can hit the valve itself radially, and zvi / ar with axial discharge or also axially with radial Indulgence.

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The typical property of this valve is that the valve gate is at a considerable distance from the corresponding valve Sealing seat can be removed even when magnets with very low power are used and when controlled Flow pressure around 400 bar, with the resulting pressure Possibility of passage openings with a diameter of one millimeter for versions with direct control and from 20 mm and more for versions with indirect control.

The valves of the above-mentioned type, which are known today, basically see a core which is movable in the axial direction before, which is attracted to a solid core, the entire complex being surrounded by a winding surrounded by electrical Electricity is passed through. The movable core has a needle lock, which serves to create a passage opening for the To block the flow, and an elastic spring, which acts by pressure, keeps the distance / wisrhen the moving and the featen core. With normally closed valves this spring is very weak as it only closes the needle valve has to hold in the corresponding sealing seat. However, once the needle valve is in its seat, if the pressure of the flow hits it, the force of the electromagnet must be such that it corresponds to the force of the spring as well as the force coming from the product has to overcome, i.e. the cross-section of the seal for the Pressure of the flow. It does happen, however, that the force with

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that the fixed core attracts the movable core, vice versa is proportional to the distance between them, and consequently the maximum tightening force between the two is achieved Cores when the moving core is very close to the solid core is located. From this it is clear that, if you want to achieve the appropriate clearance, you are on electromagnets having to resort to significant performance. The above proves to be a severe limitation on the Use of this type of solenoid valve for outputs of more than 15 l / min and with pressures of more than 250 bar, since the use of electromagnets of large dimensions enormous problems with very high power consumption of electricity and the bring the resulting overheating of the coils with it, as well as a large space requirement and unacceptable Costs. Another way of solving the problem is to provide a release stroke of the needle that is a few tenths of a millimeter is limited (so because of the very short distance between the movable and the fixed core, the force of attraction between the two cores is still strong enough). In this However, there are other significant disadvantages, such as high loading losses due to the narrowing of the discharge opening, but above all significant construction problems Reason for the very tight operating tolerances, with adjustments even having to be made piece by piece. An enormous one In any case, the big disadvantage is that very high performance cannot be achieved.

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The main purpose of the present invention is that Use of electromagnetic magnets with very low power too allow, with the possibility of release lifts of the Valve gate from the corresponding seat of considerable length (by 3-3.5 mm), even in the presence of considerable acting flow pressures (around 400 bar). This results in numerous advantages: The possibility of using the electromagnet the low energy consumption to keep it under tension for unlimited periods of time; small dimensions and reasonably low Costs; no excessive tolerances and therefore no difficulty in adapting the individual valves; the possibility fairly high performance without significant charging losses.

These and other advantages are all achieved by the object of the present invention valve, which is characterized by the fact that it contains:

A closure with a needle movable in the axial direction, also in relation to the movable core;

- Mutual stop elements, each on the needle valve and are arranged on the movable core and to that serve to intercept each other so that the movable core can pull the needle valve in motion with the position of the abovementioned stop elements in relation to one another is such that three movable cores intercept the closure can, if this is in close proximity to the end of the stroke triggered by the electromagnetic attraction force.

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tion of the solid core is located. The valve in question also provides elastic means which serve to control that force to deliver, which pushes the valve gate towards the corresponding seat of the discharge opening, as well as other elastic ones Means providing the force that lifts the valve gate relative to the movable core, that of thrust delivered to said second elastic means is greater than that delivered by said first elastic means Funds is delivered. In addition, there is the aforementioned needle valve movable within such a free space that it allows a considerable further upward displacement is when the movable core is already at the end of the stroke triggered by the electromagnetic attraction force has arrived.

Other features and advantages of the present invention will be more clear from the detailed description below some embodiments of the invention in question, given purely by way of example and not limitatively in the enclosed Drawings are shown of which

- Fig. 1 in a vertical axial section a form of implementation Figure 3 shows the direct control type valve in question;

- Fig. 2 and 3 show, also in vertical axial sections, two different forms of implementation of the valve in question, of the indirect control type.

The implementation form shown in Figure 1 is suitable

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especially for very small services around 2 1 per minute. the Indirect control implementations shown in Figures 2 and 3, although the same main body of the valve as shown in Figure 1, significantly higher performance (around 40 liters per minute) at pressures around 400 bar. The same components as in the basic solution in Figure 1 can be used to make a complete set \ / on normally closed electrovalves with indirect control to produce, with larger dimensions up to the achievement of performance values of 300 1 per minute. Limited on the solution shown in Figure 2, the inclusion of a Einu / EGventils is provided, which is able is to stop any Eluss coming out of the axial line.

In the text of the description and the claims, For the sake of simplicity of illustration, reference is made to valves which are spatially arranged as in the figures, respectively the terms "above" and "below" are used and reference is made to the position shown in the figures. It goes without saying that the valve can assume different positions during operation; for example, it can be inclined, horizontal or even rotated 180 ° be arranged.

With reference to Figure 1, (I) generally denotes a valve body in which there is an inflow channel (2) for the pressurized flow and a drainage channel (3)

are located.

The channel (3) comes from the bottom of a cavity (4), the at point (5) has a thread into which a body (6) is screwed is, which in turn has a cavity (7) which narrows to a bore (8) and then again expanded to a cavity (9), which extends into the Cavity (4) extends.

The cavity (7) widens in (10) and has in (11) a thread into which a small tube (12) made of stainless steel or other non-magnetic material is screwed, which has a threaded part (13) having. In the bore (8) a sleeve (14) is tightly sealed, which has an axial bore (15), which ends up in a small hole (16) on which the seat for the tip of the Nndelversrhlusses (17) is located. The sleeve (14) closes the cavity (7) on the Bore (8). In this way do you flow? through the canal (2) incoming flow through the cavity (7> and reaches the area (10), from here through the bore (16) and the bore (15) into the cavity (9) and finally passes through the drainage channel (3).

In the upper part of the cavity of the tube (12) is a solid one Core (21) made of ferromagnetic material, which is fixed to an electromagnetic coil (24), which the Tube (12) surrounds, is connected. Inside the tube (12) in the space between the upper surface of the sleeve (14) and

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the lower surface of the solid core (21) is located a core (28) that can move within said space, The movable core (28) has one along its axis incorporated cavity (29) in which a needle valve (17) moves in relation to the core (28). Of the Cavity (29) has a cross-sectional narrowing in the lower section a corresponding covenant (51). The closure (17) has a corresponding collar (18) on the upper part. Of the Bund (51) meets bundle (18) when it passes through the fixed core attracted moving core moved upward. The frets (18) and (51) thus describe the first on both sides Slings. Above the collar (18) a weak spring (19) acts in point (20) in the solid core (21) is mounted, which has a thread in point (13) and is provided with a seal (22). Is the solid core (21) once precisely set, it is blocked by a threaded ring (23) with an external thread. The electromagnetic one The coil (24) rests on top of the body (6) and is held against the same by a screw (25) screwed into the fixed core (21), said Screw presses on a washer (26), which in turn acts on the upper part of the spool (24). Below the collar (18) of the lock (17) acts a Compression spring (27) which is mounted in the movable core (28) and tends to push the shutter (17) upwards. The movable core sees a longitudinal bore (30) parallel to

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the cavity (29) which brings the region (10) in direct communication with a region (50) described between the lower surface of the fixed core (21) and the upper surface of the movable core (28). A radial bore (31) brings the bore (3Ό) with the cavity (29) in connection, in an area below the collar (18). Two seals (32) and (33) each ensure the perfect external seal and the perfect separation between the chamber (4) and the inflow line of the flow (2). If reference is now made to Figure 2, among the few variants, instead of the sleeve (14), one can find a controlled closure or piston (34) which moves with a good seal within the cavity (7). When this closure is in the three lower position * the connection between the line (2) and the cavity (9) is closed. If, on the other hand, the closure is lifted, the flow flows directly from the channel (2) into the chamber (9) and from there to the drainage channel (3). The closure (34) provides an axial bore (35) which ends at the top with a small hole (} f>) on which the seat is provided, into which the tip of the needle closure (17) slides. A second line (38) machined into the closure (34) parallel to the cW bore (35) brings the channel (2) directly into connection with the area (10). Said channel (38) has a constriction at point 137) with a diameter which is slightly below that of the small hole (36).

A ball of the appropriate diameter (39) is located in the cavity (9) and is supported by a drilled plate (40) held, which is why the flow from line (2) can flow into line (3) and not vice versa. Referring to Figure 3, it can be observed that this is in relation to the form of realization as shown in Figure 2 has two basic variants. The first variant provides a pin (44) in the same movable core (28) is attached and in contact with the upper surface of the collar (IB) in proportion to the movable core (28) limits the stroke of the shutter (17) upwards. The distance between the pin (44) and the collar (51) is much larger than the strength of the collar (18), so that the closure (17) the possibility of considerable Has axial displacements with respect to the movable core (28), that is to say, in other words, that the closure (17) there is the possibility of a further significant upward displacement after the movable core has been through the Excitation of the electromagnet has already been attracted to the solid core (21) (as will be better explained below). The spring (19) is replaced by an elastic spring (42), pressed between the lower surface of the solid Core (21) and the pin (44) which provides a weak force that pushes the movable core (28) straight down presses. Instead of the spring (27), an elastic spring (43) is provided, which lies in the movable core (28) and

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whose weak force is used to lift the closure (17) and to bring it into abutment against the pin (44). The collar (18) and the pin (44) describe the second mutual Slings. This variant can also be used in the form shown in Figure 1 Find.

The second variant, on the other hand, provides for use only on a valve of the type shown in Figure 2. The ball (39) is no longer present and a small ball (45) is intended to be inserted into the bore (35), which, when the flow wants to flow from the bore (35) to the bore (36), turns into inserts a corresponding seat which is:: nd »n: point at which the bore (36) opens into the bore (35), thus preventing the flow from flowing through. This ball (45) therefore works like a small one-way valve, which serves _{to prevent the flow through the bores (35) and (5C 1} ) in a direct upward direction. A stop element (46) is located Ln the bore (35) in order to hold the ball (45; when the flow is directed downwards or; .till). This element (46) is in any case not an obstacle to the passage of the flow. The use of this second variant is completely independent of the use of the first variant.

The valve in question operates in the manner described below.
With reference to the realization shown in Figure 1

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chungform takes place when the coil (24) is calm that the valve gate (17) is constantly in the closed position the bore (16) is held, thanks to the effect the spring (19) against the upper surface of the collar (18), and also (especially) by the downward thrust, the caused by the pressurized flow which, when it entered through line (2), the Cavity (10) and all other parts of the valve that are in communication with this cavity, fills, thanks the bores (30) and (31). The distance between the top surface of the moving core and the bottom surface of the solid core (approx. 3 mm) turns out to be a few tenths of a millimeter larger than the existing distance between the Bund (18) and the Bund (51). When the electromagnetic coil is energized (24), the movable core (28) in Tightened towards the solid core, initially only overcoming the weak force of the spring (27) as the closure (17) is subject to a downward pressing force caused by the pressure of the flow on the seal cross-section for the tip of the needle is generated. It therefore occurs that initially only the movable core (28) rises upwards (while he presses on the spring (27), since the needle lock remains pressed down), and then when the movable one Core (28) is located a short distance from the fixed core (21) and with the collar (51) on the collar (18) of the closure hits, it pulls the needle lock (17) with it

at the top and releases the sealing seat of the bore (16). The opening of the bore (16) from the side of the closure (17) takes place only when the movable core is very close to the fixed core (the attraction force between the two cores (28) and (21) is therefore very strong) , in addition, the collar (51) hits the collar (18) with a certain kinetic force. Thus, various conditions are created through which it is possible to lift the closure (17), even if it is subject to a considerable flow force that keeps it in the closed position, with the help of a coil of not very high power. As soon as the closure (17) has lifted from the seat on the bore (16), the inflow line (2) of the flow is connected to the outflow line (3) and the closure (1.7) is at this point over its entire surface from the Flow, i.e. it is in perfect hydrostatic equilibrium and the spring (27), which ensures a higher pressure than that of the spring (19), overcomes the latter and the needle is lifted out of its sealing seat and lifted until the spring (27 ) is completely relaxed. In this situation, the opening for the flow to pass through the guide (16) is the maximum and the flow itself can flow through without the tip of the closure (17) preventing the flow from flowing out of the line (2) into the line (3 ) with special needs.
If you now refer to Figure 2, it appears as

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only variant that the shutter or controlled piston (34) With the magnet calmed, the pressure from the line (2) through the constriction (37) and the bore (38) is subject to the inflowed flow, so it turns out to be against the through the bore (8) formed sealing seat pressed, with, u / ie above said, the needle valve (17) under perfect sealing in the bore (36) is inserted, thanks to the action of the spring (19), which at the same time the closure (17) and the keeps moving core (28) pressed down. In this situation is the flow coming through line (2) perfectly blocked.

If the coil (24) is excited, then in the same way, which was described above for the realization form as in Figure 1 that the closure (17) completely from the Bore (36) is released and consequently there is a negative pressure in the chamber (10) and the entire interior of the valve forms, since the higher charging losses due to the narrowing (37) (of a smaller diameter than the bore (36)) a considerable Form pressure difference between the line (2) and the chamber (10). Thanks to the cross-sectional difference between the sealing seat on the piping and the cavity (7) on which if the closure (34) moves tightly, the latter proves to be subjected to a force that would cause it to be lifted off causes from the sealing seat (8). At this point the flow opening for the flow of the turns out to be Line (2) to line (3) as very significant and the charging

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Losses or passive resistances depend solely and exclusively on the proportions of the line (Z), the hole (8) and the lines following (9).

The ball (39) remains on the drilled plate (40) and does not offer any resistance to the passage of the current. If necessary, the said ball can block the flow of flow in the reverse direction. With reference to the first variant in the realization form from Figure 3, the operation of the valve differs from the above-mentioned operation only by the following:

When the valve has settled down, the shutter (17) turns into The closed position of the bore (36) held, thanks the action of the spring (42) that holds the movable core (28) pushes down, which in turn presses through the pin (44) on the collar (18) of the closure (17), the tip of which protrudes from the core (28). When the coil (24) is energized and the filed core (21) shifts, in a first phase only the movable core upwards (while the closure (17) is pressed against the bore (36) by the pressure of the flow remains) and compresses the spring (43) as well as the spring (42) (which offer a weak resistance).

Then, as well as the closure (17) due to the stop of the collar (51) against the collar (18) from the seat on the bore (36) has lifted, the spring (43) lifts the lock

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(17) in relation to the movable nucleus even more (which the spring (19) does not oppose, e.g. in the realization forms in Figures 1 and 2) and brings it in the stop against the pin (44), so that the passage through the hole (36) is released to the maximum. Thanks to this variant, the position of the Closure (17) is clearly delimited in this last phase by the pin (44) and also not the need consists of balancing the pressures of the springs (42) and (43) with one another, since they act independently of one another. You get basically greater precision and reliability in operation compared to those shown in Figures 1 and 2 Realization forms.

It also becomes clear that this first variant is also in the same way in the form of implementation as in the figure 1 can be attached.

Referring to the second variant in the realization form as in Figure 3 it is observed that this is used for reciprocation the possible use of the valve in question compared to the implementation forms in Figure 2. Assuming to remove the ball (39) when the flow is flowing from the line (3) to the line (2), it works this variant is in fact as follows: when the spool (24) is still, the closure (34) is closed by the pressure of the in the chamber (9) entering flow is raised itself and the passage of the flow from the channel (3) into the channel (2) is

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secured, while on the other hand, if the coil (24) is energized, this pass is in no way secured and the operation of the valve is uncertain as it will feel the force of gravity acting on the moving elements of the valve (especially on the closure (34)) and consequently also the spatial arrangement when installing the valve self.

In contrast, the form of realization as in Figure 3, except that they operate as a normally closed directional control valve with indirect control as described above and normally where the channel (2) receives flow directed in the direction of the channel (3), with certainty the opening of the Passage for the flow in a straight direction from channel (3) to channel (2), with both excited and calmed Coil (24) and in any installation position. So if the river is directed from channel (3) to channel (2), the cavity (9) is under pressure and, since the ball (45) the passage the flow through the bore (36) is prevented, the chamber (10), however, has a pressure equal to zero, since it over the Line (38) is in communication with the channel (2). Therefore, the stronger pressure is applied to the lower surface of the shutter (34) the lifting of the closure itself and the opening of the passage for the flow of channel (3) after Channel (2). If, on the other hand, the direction of wear runs from channel (2) to channel (3), the valve behaves like a normal closed directional control valve and the lock (34) blocks

the pass for the flow.

There must be the unification of the components and the pronounced Simplicity and interchangeability of the components themselves between the presented solutions are emphasized. In fact, only the body (6), which is interchangeable with the closure (34), changes. Furthermore, other forms of realization can be used be provided with indirect control, in which the hydraulic and electrical components (25), (26), (23), (21), (22), (19), (24), (17), (27), (42), (43), (47) in the upper part of the valve are the same are while ever only the lower part of the valve turns out differently depending on the desired performance. As explained above, it also turns out that that it is possible through the valve in question, even with coils of not very high power, a considerable distance of the closure (17) from the corresponding sealing seat, also in relation to a high pressure and in the presence of a flow of significant pressures.

Claims (10)

PATENT CLAIMS ΓΙ. 7 Normally closed two-way needle valve with electromagnetic control worn type comprising an axially movable core, which is used by a to be attracted to an electromagnetically activated solid core characterized in that it contains: - One also in relation to the movable nucleus in iixialer Direction of movable needle lock (17); - Elements to stop on both sides, arranged accordingly on the closure (17) and on the movable core and serving to intercept one another, so that the movable Core can pull the closure (17) along, the position of the abovementioned stop elements relative to one another being such that the moving core can intercept the shutter (17) when it is a short distance from the end of the electromagnetic Activation triggered stroke is located in the direction of the solid core; 32U840 - Three said closure (17) finally being designed in this way is that when the valve is calmed down, its tip protrudes from the movable core so far that a perfect Sealing on the seat of the closure is guaranteed. 2. Valve according to claim 1, characterized in that it contains as follows: - Elastic means (19) which provide the force that the Pushes the shutter (17) towards the corresponding seat of the discharge opening (16) and (36); - elastic means (27) providing the force that raises the shutter (17) in relation to the movable core, the thrust delivered to the elastic means (27) being greater than that delivered by the elastic means (19), and wherein, moreover, said shutter (17) is movable in such a free space as to give it a considerable further upward displacement is possible after the movable core has been activated by the electromagnetic activation Has reached the end of the stroke in the direction of the solid core. 3. Valve according to claim 1, characterized in that - said shutter (17) is movable within a cavity (29) which extends along the axis of the movable one Core (28) is located, wherein the flow located in said cavity is subject to the same pressure as the Flow surrounding the movable core (28); - the elements mentioned for the two-sided stop on each .3 · because it is described by a covenant (18) which is contained in the upper part of the closure (17) is located, and by a corresponding collar (51), provided at a narrowing of the Cross-section in the cavity (29), the distance between said collars (18) and (51) from each other when the and the non-energized valve is less than the distance between the lower surface of the solid core (21) and the upper surface of the movable core (28). ■ 4. Valve according to claim 1, characterized in that it is made of stainless steel or of non-magnetic Material existing tube (12) which receives the movable as well as the fixed core, said tube on the Valve body (6) is attached and in the upper part has a thread inside to regulate the distance between to enable the fixed and the movable core. 5. Valve according to claim 1, characterized in that that it provides various forms of implementation with direct and indirect control, in which the hydraulic and the electrical components are the same and only the fixed body (6) changes with a movable one Closure (34 is interchangeable. 6. Valve according to claim 1, characterized in that there are various forms of implementation with indirect control provides, in which the hydraulic and electrical components (25), (26), (23), (21), (12), (22), (19), (24), (17), <27), (42), (43), (44) of the upper part of the valve die ■ ί- are the same and, depending on the desired flow rate, only the remaining lower part of the valve is changed. 7. Valve according to claim 1, characterized in that there is the possible use of a one-way valve (39) provides, which blocks the flow of the flow in the opposite direction than in the intended. 8. Valve according to claim 1, characterized in that it contains as follows: - Second mutual abutment means arranged respectively on the shutter (17) and on the movable core and serve to intercept each other so that the movable core closes the closure (17) when the valve is calmed. pushes against the corresponding seat of the discharge opening (16) and (36); elastic means (42) designed to provide a certain force which adjusts the closure in relation to the movable one Core lifts: - said shutter (17) in relation to the movable one The core is movable within a free space which is described by the first and the second stop means is so that it is allowed a substantial further upward displacement after the movable core is through the electromagnetic activation was attracted to the solid core. 9. Valve according to claim 8, characterized in that: BAD ORIGJNAL - said closure (17) within a cavity (29), which extends along the axis of the movable core (28) is movable, the liquid located in said cavity being exposed to the borrowed pressure like the liquid surrounding the movable core (28); - the upper part of the closure (17) contains a collar (18); - the cavity (29) provides a narrowing in cross section, which forms a collar (51) whose distance from the collar (18) is less than when the valve is closed and not energized is the distance between the bottom surface of the solid core (21) and the top surface of the collar (18), the Pin (4) and the collar (51) are of greater strength than the strength of the collar (18), and said collars (18) and (51) said first two-sided stop means and said collar (18) and said pin (A4) forming said second mutual stop means. 10. Valve according to claim 1 of the type with indirect control with a radially extending and normally as an inflow used channel (2) and an axially extending and normally used as a drain channel (3) containing a controlled closure (34), which serves to open the connection between the channels (2) and (3) in the lowered position to be closed, characterized in that it contains the following: - An axial bore machined into the closure (34) (35), which serves to connect the drainage channel (3) with an axial . € · To connect the bore (36) on which the seat is provided, into which the tip of the shutter (17) penetrates; - A line (38) incorporated in the closure (34), which serves to connect the channel (2) with the movable core (28) To bring surrounding area in direct connection, said line (38) having a constriction (37) of lesser Has diameter than the diameter of the bore (36); - A small automatic one-way valve in the form of a ball (45) which is mounted in the bore (35) and the connection between the bore (35) and the bore (36) only closes when the flow tends to move from the bore (35) to run through to the bore (36).