WO2022207733A1

WO2022207733A1 - Adjustable throttle element

Info

Publication number: WO2022207733A1
Application number: PCT/EP2022/058463
Authority: WO
Inventors: Michael Pittelkow
Original assignee: Samson Aktiengesellschaft
Priority date: 2021-03-31
Filing date: 2022-03-30
Publication date: 2022-10-06
Also published as: DE202021101739U1; EP4314611A1

Abstract

The invention relates to an adjustable throttle element (10), in particular for supplying air to or removing air from a pneumatic drive of an actuator valve. The invention is characterized by a throttle housing (12), which comprises an air feed channel (14), an air discharge channel (16), and a valve seat (18) that is formed in the flow channel between the air feed and air discharge channel (14, 16), and by a valve element (20), which has a valve section (22) that is designed to correspond to the valve seat (18), is adjustably mounted in the throttle housing (12), and can be moved between a completely open and completely closed position, wherein the valve element (22) has a passage bore (24), via which the air feed channel (14) is connected to a chamber (26) when the valve element (20) is closed, said air feed channel being fluidically connected to the air discharge channel (16) via the chamber (26). The passage bore (24) discharge region which opens into the chamber (26) is designed as a throttle channel (28), and the fluidically communicating connection between the chamber (26) and the air discharge channel (16) is designed as a thread-type throttle (30) which acts between the valve element (20) and the chamber (26).

Description

Adjustable throttle element

The invention relates to an adjustable throttle element, in particular for pressurizing and venting a pneumatic drive of a control valve according to claim 1.

It is known to use throttle elements for aerating or venting single-acting pneumatic drives. Such drives are used, for example, to actuate control valves. Positioners or solenoid valves are used to control these drives. To move a drive, a supply air source is released by means of a positioner or solenoid valve, for example, and the compressed air enters the pressure chamber of the drive. The pressure chamber expands against a spring preload and the valve member, which is coupled to a drive rod, changes the position in order to open or close the passage of a control valve for regulating process fluid. To move the valve element to its original position, the supply air source is closed and the compressed air in the pressure chamber of the drive is released to the atmosphere. Due to the spring preload of the pressure chamber, the compressed air escapes into the atmosphere and the valve member moves to its original position.

DE 2006 014476 B3 discloses a throttle element which is designed in the form of a threaded throttle. The throttling element consists of a sleeve provided with an internal thread and a rod screwed therein and provided with an external thread, the clearance between the flank tip of the two threads and the base of the two threads forming the throttling section.

Another adjustable throttle element is disclosed in DE 10 2007 000 143 A1. The throttle element is characterized in that a one-part or multi-part throttle body is inserted into a bore of a carrier and forms a throttle section. The throttle section runs between the bore wall and the outer wall of the throttle body and consists of at least one twisted throttle channel. The invention is based on the object of specifying an adjustable throttle element, in particular for pressurizing and venting a pneumatic drive of a control valve, which is able to precisely set not only large flow rates but also very small flow rates.

This object is solved by the features of claim 1.

Subclaims 2 to 16 form advantageous developments of the adjustable throttle element according to the invention.

The adjustable throttle element according to the invention, in particular for pressurizing and venting a pneumatic drive of a control valve, is characterized in that the throttle element has a throttle housing which comprises an air supply duct and an air discharge duct and a valve seat formed in the flow duct between the air supply and air discharge duct and in which a valve element, which has a valve member designed to correspond to the valve seat, is mounted adjustably and can be moved between a fully open and a fully closed position. Furthermore, the valve element has a through-bore via which, in the closed position of the valve element, the air supply duct is connected to a chamber and via the chamber to the air discharge duct in fluidic communication, with the outlet area of the through-bore opening into the chamber being designed as a throttle duct and the fluidly communicating Connection between the chamber and the air discharge channel is formed as an effective between the valve element and the chamber threaded throttle.

Merely for the sake of completeness, it is pointed out that the above formulation, namely that the fluidly communicating connection between the chamber and the air discharge duct is designed as a threaded throttle effective between the valve element and the chamber, is to be understood in such a way that the valve element and the chamber a thread in screwing engagement with each other. That is, the throttle section of the threaded throttle is formed by the play between the thread on the valve element side and the chamber side, i.e. the play between the tip of the flank of the two threads and the play between the base of the two threads.

The inventive design, namely the provision of the valve seat/valve member as a first throttle stage, the throttle channel acting as a fixed throttle as a second throttle stage and a third throttle stage designed as a threaded throttle, proves to be particularly advantageous because now Using the throttle element, very large flow rates as well as very small flow rates can be set precisely:

It is now possible to realize very large flow rates via the first throttle stage, i.e. the valve seat element that has the valve seat and the corresponding valve seat formed in the throttle housing, since in the open position the supply air can reach the pneumatic drive of the control valve almost unhindered. This means that the drive can be filled at the maximum speed. The process time of the control valve is at its maximum.

In the closed position, it is no longer possible for the supply air to flow via the first throttle stage, but the second throttle stage designed as a fixed throttle, i.e. the through hole in the valve element and its outlet area designed as a throttle channel, allows a greatly reduced proportion of the supply air to flow into the Flow or through-flow direction S viewed downstream chamber escape. This reduced compressed air then reaches the third throttle stage designed as a threaded throttle and from there to the air outlet duct. A fine adjustment is possible via a corresponding setting of the third throttle stage, i.e. setting the engaged thread length, i.e. a minimum speed in the process of the pneumatic drive can be set.

It is also advantageous that—since the component valve element is the only adjustment element—it is now possible, by moving a single component, namely the valve element, to be able to precisely adjust very large flow rates as well as very small flow rates.

In order to ensure a sufficient throttling effect of the second throttling stage, the throttling channel has a throttling opening with a diameter d<0.15 mm. The diameter d is preferably selected in such a way that the following applies to it:

0.1mm < diameter d < 0.15mm.

In order to avoid clogging of the throttle opening as far as possible or to be as insensitive as possible to contamination of the supply air, the valve element has a filter element upstream of the entry area to the through bore, viewed in the flow or through-flow direction S. The air supply duct and the air discharge duct are preferably arranged offset to one another, ie not in alignment, with the valve seat element being arranged in the throttle housing in an orthogonally aligned manner in relation to the ducts.

A particularly preferred embodiment of the adjustable throttle element provides that the valve element is mounted in the throttle housing in a rotationally fixed and linearly displaceable manner, and that an adjusting sleeve, which is aligned with the valve element and is arranged downstream of the valve element in the direction of flow or flow direction S, is arranged in the throttle housing, so that the chamber between the valve element and the adjustment sleeve is formed. The adjusting sleeve is fixed and rotatable in the housing in the axial direction, the adjusting sleeve having an internal thread and the valve element having a correspondingly formed external thread, via which the adjusting sleeve and valve element components are in engagement with one another in the form of a threaded throttle. The advantage of this configuration is that the valve element can now be moved in a simple manner by rotating the adjusting sleeve.

In order to prevent compressed air from escaping undesirably through the gap between the throttle housing and the adjustment sleeve to the atmosphere, a seal is arranged in the throttle housing, via which the adjustment sleeve is mounted in the throttle housing in a fluid-tight manner.

Preferably, the adjustment sleeve has a drive that is easily accessible on the outside of the housing and by means of which a rotation of the adjustment sleeve and thus an adjustment of the valve element is made possible. The drive is particularly preferably designed in the form of a slot, so that the adjustment sleeve can be adjusted by means of a simple screwdriver, i.e. without special tools/handling equipment.

A further preferred embodiment of the adjustable throttle element is characterized in that the adjusting sleeve has a circumferential latching surface on the outside and that a spring-loaded latching element is arranged in the throttle housing, the latching element having a counter-contour designed to complement the latching surface, via which the latching element can be connected to the latching surface of the Adjusting sleeve is engaged. This ensures in an advantageous manner that an unintentional adjustment of the adjustment sleeve and thus the throttle setting is prevented.

According to a further preferred embodiment, the valve element has a multi-part design and comprises a first valve element component which has the filter element, a first valve element component which has the external thread Second valve element component having a threaded throttle and a third valve element component having the throttle channel. The multi-part configuration proves to be advantageous, since this enables a structurally simple configuration of the valve element.

The first and the second valve element component are preferably connected to one another via a screw connection. For this purpose, according to a specific embodiment, the first valve element component has an external thread and the second valve element component has a corresponding internal thread, via which the first and second valve element components can be screwed together.

A particularly advantageous embodiment provides that the valve seat is designed to extend, starting from the first valve element component, towards the second valve element component. In other words, the valve member complementary to the valve seat extends over two components, namely the first valve element component and the second valve element component. The advantage of this configuration is that, with a compact design, a sealing seat between the valve seat and the valve member is made possible over a long linear travel, and thus a large adjustment travel of the threaded throttle is also made available for fine adjustment. To prevent compressed air from escaping undesirably, a seal is arranged in the contact area in the form of an annular gap between the first and second valve element components.

The third valve element component is preferably designed as a stone throttle which is arranged in the through bore in the second valve element component and has an internal bore with a diameter d<0.15 mm, in particular a diameter d=0.12 mm. As initial tests have shown, the use of a stone choke with an internal bore diameter of d= 0.12 mm in conjunction with the downstream third throttling stage is sufficient to ensure a sufficient throttling effect, so that smaller bore diameters in the stone choke used in production would be many times more expensive and would tend to get dirty or stick despite the provision of a corresponding filter element in the inlet area of the valve element, can be dispensed with. It is thus ensured in an advantageous manner that, in addition to a cost-effective configuration of the adjustable throttle element, the throttle element is also insensitive to contamination in the supply air.

The stone throttle is preferably connected to the second valve element component in a non-positive and/or material connection. The invention is also based on the object of providing an actuating device for a process engineering plant according to the type specified in the preamble of claim 17, in which, in addition to rapid venting of the pneumatic drive, fine adjustment of the pneumatic drive is also made possible.

This object is achieved by the characterizing features of claim 17 in conjunction with its preamble features.

In a known manner, the control device includes a control valve with a movably arranged valve member for regulating a process fluid, a pneumatic drive for moving the valve member, and a throttle element for pressurizing and venting the pneumatic drive.

According to the invention, it is now provided that the throttle element is designed according to one of claims 1 to 16.

All statements regarding the throttle element according to the invention can be transferred analogously to the actuating device according to the invention, so that the aforementioned advantages can be achieved with it.

Further advantages and application possibilities of the present invention result from the following description in connection with the exemplary embodiments illustrated in the drawings.

In the description, in the claims and in the drawing, the terms used in the list of reference numbers given below and associated reference numbers are used. In the drawing means:

1 shows a plan view of an adjustable throttle element according to the invention;

FIG. 2 shows a sectional representation of the throttle element from FIG. 1 according to AA in a view obliquely from the front; FIG. FIG. 3 shows a side view of section AA from FIG. 2 in an enlarged representation, with the valve element being in the closed position and with the threaded throttle being set to the smallest throttle distance;

Fig. 4 is an enlarged view of section A-A of Fig. 2 with the door closed

Valve element position, with a greater throttling distance being set compared to FIG. 3, and

5 shows a sectional representation of the throttle element from FIG. 1 according to B-B in a view obliquely from above.

1 and FIG. 2 show an adjustable throttle element, denoted overall by the reference numeral 10, for pressurizing and venting a pneumatic drive of a control valve.

As can be seen from Fig. 3 and Fig. 4, the throttle element 10 comprises a throttle housing 12 with an air supply duct 14 and an air discharge duct 16 arranged offset thereto, as well as a valve seat 18 formed in the flow duct between the air supply duct 14 and the air discharge duct 16, see Fig. 4. On the representation of a z. B. switchable via a solenoid valve, to be connected to the air supply duct 14 supply air and to be connected to the air discharge duct 16 pneumatic drive of the control valve was omitted here for reasons of clarity.

As Fig. 3 and Fig. 4 further show, the throttle element 10 also comprises a valve element 20 aligned orthogonally to the two channels 14, 16. The valve element 20 is non-rotatable and, viewed in the direction of extension of the valve element 20, adjustable, i.e. linearly movable, im Mounted throttle housing 12 and has a valve member 22 designed to correspond to the valve seat 18 . That is, the valve element 20 can be moved between the fully closed position shown in FIG. 3 by a corresponding linear displacement movement, in this case according to FIG. 3 or FIG. 4 by a displacement movement directed to the right, into a fully open position.

In the present case, the anti-twist device is realized by a tongue 21 formed on the valve element 20 and a corresponding groove 13 introduced in the throttle housing 12 .

The valve seat 18 formed in the throttle housing 12 and the valve member 22 of the valve element 20 interacting therewith form a first throttle stage, by means of which very large throughflows are to be realized, since in the open position the supply air can pass almost unhindered via the air supply duct 14 into the air discharge duct 16 and from there into the pneumatic drive of the control valve. This means that in the open position, the downstream pneumatic drive can be filled at maximum speed and the travel time of the control valve is maximum. Any intermediate positions of the valve element 20 and thus of the valve member 22 relative to the valve seat 18 with reduced flow rates can also be set.

For fine adjustment of the flow rate, the throttle element 10 has a second and third throttle stage, which are described in more detail below.

As can also be seen from Fig. 3 and Fig. 4, the valve element 20 is designed as a hollow part, in other words the valve element 20 has a through hole 24, via which, in the closed position of the valve element 20, the air supply duct 14 with an in Flow or through-flow direction S considered the valve element 20 downstream chamber 26 is fluidly connected. The outlet area of the through hole 24 that opens into the chamber 26 is designed as a throttle channel 28 acting as a fixed throttle and has a throttle opening with a diameter d=0.12 mm and forms the second throttle stage.

Chamber 26 is in turn operatively connected to air discharge duct 16 via a further fluidically communicating connection. This is designed as an adjustable threaded throttle 30 and thus forms the third throttle stage.

The threaded throttle 30 forming the third throttle stage is formed between an adjusting sleeve 32 arranged in the throttle housing 12 and the valve element 20, see Fig. 3 and Fig. 4. For this purpose, the adjusting sleeve 32 is mounted axially fixed and rotatable in the throttle housing 12 and projects over a Internal thread with a trained on the valve member 20 corresponding external thread in screwing engagement.

The adjusting sleeve 32 is sealed off from the throttle housing 12 by a seal 34, in the present case in the form of an O ring, so that no supply air can escape into the atmosphere.

If the valve element 20 is now - as shown in Fig. 3 and Fig. 4 - in the closed position, ie no flow through the first throttle stage, only a greatly reduced proportion of the supply air in the Chamber 26 and from there via the threaded throttle 30, so the third throttle stage, reach the air outlet duct 16. By means of a corresponding rotary movement of the adjustment sleeve 32 and the resulting linear movement of the valve element 20, the thread engagement length between the valve element 20 and the adjustment sleeve 32 and thus the effective throttling distance of the threaded throttle 30 can be set in a targeted or very precise manner for fine adjustment of the smallest flow rates.

As can be seen in particular from FIGS. 1 and 2 , the adjustment sleeve 32 has a drive that is easily accessible on the outside of the housing, here in the form of a twisting slot 38 . Thus, the rotary movement of the adjusting sleeve 32 and thus a linear movement of the valve element 20 can be carried out in a simple manner using a screwdriver.

In order to prevent an unintentional adjustment of the adjustment sleeve 32 and thus of the selected throttle position, the adjustment sleeve 32 has a circumferential latching surface 40 on the outside, and a spring-loaded latching element 42 is arranged in the throttle housing 12 and has a counter-contour designed to complement the latching surface 40, which latching surface 40 of the adjustment sleeve 32 is engaged, see Fig. 5.

In the present case, as can also be seen from FIGS. 3 and 4, the valve element 20 has a multi-part design and comprises a first valve element component 20-1 having the filter element 36, a second valve element component 20-2 carrying the external thread of the threaded throttle 30, and a throttle channel 28 having and thus forming the third throttle stage third valve element component 20-3.

In the present case, the first and first valve element components 20-1 and 20-2 are firmly connected to one another by means of a screw connection. For this purpose, the first valve element component 20-1 has an external thread and the second valve element component 20-2 has an internal thread designed to correspond thereto, so that the two components can be firmly screwed together. As Fig. 3 and Fig.

4, the first and second valve element components 20-1, 20-2 are sealed by a seal, here in the form of an O-ring 44, so that no supply air can get into the through hole 24 via the gap between the two components .

The third valve element component 20-3 is--as FIG. 3 and FIG. 4 also show--arranged in the valve element component 20-2 and connected to it in a materially bonded manner. Here is the third valve element component 20-3 is designed as a stone throttle having an internal bore with a diameter of d=0.12 mm.

Reference List

10 throttle element

12 throttle body

13 slots

14 air supply channel

16 air discharge duct

18 valve seat

20 valve element

20-1 first valve element component

20-2 second valve element component

20-3 third valve element component

21 tongue

22 valve member

24 through hole

26 chamber

28 throttle channel

30 thread choke

32 adjustment sleeve

34 O-ring seal

36 filter element

38 slot

40 rest area

42 locking element

44 O-ring seal

S flow direction

Claims

P at entclaims

1. Adjustable throttle element (10), in particular for pressurizing and venting a pneumatic drive of a control valve, characterized by a throttle housing (12) with an air supply duct (14) and an air discharge duct (16) and a flow duct between the air supply and air discharge duct (14 , 16) formed valve seat (18), and a valve element (20) which has a valve member (22) formed to correspond to the valve seat (18) and which is adjustably mounted in the throttle housing (12) and can be moved between a fully open and a fully closed position is, wherein the valve element (22) has a through hole (24) via which, in the closed position of the valve element (20), the air supply duct (14) with a chamber (26) and via the chamber (26) with the air discharge duct (16) is fluidically connected, wherein in the chamber (26) opening out outlet region of the through hole (24) as a throttle channel (28) is formed un d the fluidically communicating connection between the chamber (26) and the air discharge duct (16) is designed as a threaded throttle (30) effective between the valve element (20) and the chamber (26).

2. Adjustable throttle element (10) according to claim 1, characterized in that the throttle channel (28) has a throttle opening with a diameter (d) <0.15 mm.

3. Adjustable throttle element (10) according to claim 1 or 2, characterized in that the valve element (20) viewed in the direction of flow (S) has a filter element (36) upstream of the entry area to the through bore (24).

4. Adjustable throttle element (10) according to any one of claims 1 to 3, characterized in that the air supply duct (14) and air discharge duct (16) are offset from one another are arranged and that the valve element (20) is arranged orthogonally aligned in relation to the channels (14, 16) in the throttle body (12).

5. Adjustable throttle element (10) according to claim 4, characterized in that the valve element (20) is rotatably and axially displaceably mounted in the throttle housing (12) and that in the throttle housing (12) is aligned with the valve element (20) and aligned in the direction of flow ( S) the adjusting sleeve (32) is arranged downstream of the valve element (20), so that the chamber (26) is formed between the valve element (20) and the adjusting sleeve (32), the adjusting sleeve (32) being fixed and rotatable in the throttle housing in the axial direction (12), and wherein the adjusting sleeve (32) has an internal thread and the valve element (20) has an external thread designed to correspond thereto, via which the adjusting sleeve (32) and valve element (20) in the form of a threaded throttle (30) engage with one another .

6. Adjustable throttle element (10) according to claim 5, characterized in that the adjusting sleeve (32) is mounted fluid-tight in the throttle housing (12) via a seal (34) acting between the throttle housing (12) and the adjusting sleeve (32).

7. Adjustable throttle element (10) according to claim 5, characterized in that the adjusting sleeve (32) has a housing outside accessible drive.

8. Adjustable throttle element (12) according to claim 7, characterized in that the drive is designed in the form of a slot (38).

9. Adjustable throttle element (10) according to claim 5, characterized in that the adjusting sleeve (32) has a peripheral latching surface (40) on the outside and that a spring-loaded latching element (42) is arranged in the throttle housing (12), the latching element (42) has a counter-contour designed to complement the latching surface (40) and is in engagement with the adjusting sleeve (32) via the latching surface (40).

10. Adjustable throttle element (10) according to claim 5, characterized in that the valve element (20) is designed in several parts and a first valve element component (20-1) having the filter element (36), a the external thread of the threaded throttle (30) having the second valve element component (20-2) and the throttle channel (28) having the third valve element component (20-3).

11. Adjustable throttle element (10) according to claim 10, characterized in that the first and the second valve element component (20-1, 20-2) are connected to one another via a screw connection.

12. Adjustable throttle element (10) according to claim 11, characterized in that the first valve element component (20-1) has an external thread and the second valve element component (20-2) has a correspondingly formed internal thread, via the first and second valve element component (20- 1, 20-2) can be screwed together.

13. Adjustable throttle element (10) according to claim 12, characterized in that the valve member (22) is designed to extend from the first valve element component (20-1) to the second valve element component (20-2), with the annular gap-shaped contact area between the first and second Valve element component (20-1, 20-2) a seal (44) is arranged.

14. Adjustable throttle element (10) according to claim 10, characterized in that the third valve element component (20-3) is designed as a stone throttle having an internal bore with a diameter (d) <0.15 mm.

15. Adjustable throttle element (10) according to claim 14, characterized in that the stone throttle is arranged in the through bore (24) in the second valve element component (20-2).

16. Adjustable throttle element (10) according to claim 15, characterized in that the stone throttle and non-positive and / or materially connected to the second valve element component (20-2).

17. Actuating device for a process engineering plant, comprising a control valve with a movably arranged valve member for regulating a process fluid, a pneumatic drive for moving the valve member and a throttle element (10) for aerating and venting the pneumatic drive, characterized in that the throttle element ( 10) is formed according to any one of claims 1 to 16.