Patent Application
20140001387
The invention relates to a drive device for a valve and to a valve for controlling a gas flow and/or a liquid flow.
Conventionally, valves with a shut-off body rod are known which include a shut-off body, such as a piston, a ball, etc., being mounted on one end of this rod. If the shut-off body rod is moved back and forth in a translational motion, the valve can be either opened or closed. Such valves are used, for example, for controlling gas flows or liquid flows in a pipe, etc.
The pneumatic cylinder 110 comprises a piston 111 that is mounted on one end of a pneumatic cylinder piston rod 112, two air inlet holes 113, and two damping elements 114. The two air inlet holes 113 are arranged one above the other in
The valve block 120 has a valve block piston rod 121, a valve tappet 122, a valve seat 123, a medium inlet opening 124, a medium outlet opening 125, and a compression spring 126.
The valve block piston rod 121 is coupled with the pneumatic cylinder piston rod 112 such that a translational motion of the pneumatic cylinder piston rod 112 also causes a translational motion of the valve block piston rod 121. For this purpose, the compression spring 126 is installed in the valve block 120 such that, in the uncompressed state, that is, when the pneumatic cylinder 110 is not charged with compressed air 115, the valve tappet 122 contacts the valve seat 123 and thus closes the medium outlet opening 125 and thus the valve 100. If the pneumatic cylinder 110 is charged with compressed air 115 through the air inlet hole 113, then the valve tappet 122 is lifted from the valve seat 123 and thus the valve 100 opens. Therefore, a medium 130 flowing into the medium inlet opening 124 (e.g., gas and/or liquid) can flow via the medium outlet opening 125 into the reservoir 140 arranged underneath. As soon as the reservoir 140 is sufficiently filled with the medium 130, the valve 100 can be closed again.
The pneumatic cylinder 110 is thus a single-acting cylinder that is actuated by compressed air 115 in one direction and is actuated in the second direction by the compression spring 126 in the uncompressed state.
Disadvantages in such a pneumatically actuated valve 100 are that the switching time is relatively long at approx. 0.1 to 0.3 seconds, loss of compressed air and thus energy occurs continuously with each switching cycle, and only two end positions E1, E2 are possible. Controlled movement of the valve tappet is not possible between the two end positions E1, E2, that is, a medium-dependent stroke-time cycle cannot be adjusted and regulated, because the piston of the pneumatic cylinder 110 moves between the two end positions E1, E2 at an arbitrary speed.
It is also disadvantageous for a pneumatic drive for a valve that leaks can result at different points in the compressed air supply. Because such leaks are usually not detected immediately or only with difficulty, this can lead to a permanent loss of compressed air and energy.
Special stroke magnets are known from DE 41 28 983 A1, DE 10 2007 034 768 B3, DE 10 2007 053 005 A1, and DE 20 2007 015 492 U1. With such stroke magnets or magnetic cylinders, the force-stroke characteristic curve is generally strongly degressive or strongly progressive, so that the axial force rises or falls significantly over the stroke displacement. The range of the stroke in which a significant axial force can be used is very limited and short. For this reason, such stroke magnets are less suitable for valves with a shut-off body rod as described above.
Therefore, the objective of the invention is to provide a drive device for a valve and a valve for controlling a gas flow and/or liquid flow that can eliminate the disadvantages of the prior art mentioned above and have, with reference to the valve, freely programmable end positions, a freely selectable and controllable motion profile, a highest possible force output (large stroke displacement and high shut-off body rod force for minimal installation space requirements), short switching times, reduced energy consumption, low maintenance requirements, and long service life.
The objective is met by a drive device for a valve according to the invention that comprises a housing for holding a coil and a drive rod. The coil is stationary with respect to the housing. A pole shoe and a magnetized, permanently magnetic or magnetizable, soft-magnetic element are mounted on the drive rod such that the drive rod can be moved with a translational motion relative to the coil by a magnetic force. Here, the drive rod can be coupled with a shut-off body of the valve that can move with a translational motion such that a translation motion of the drive rod causes a translational motion of the shut-off body for opening and closing the valve.
Additional advantageous constructions of the drive device are disclosed in the dependent claims.
Advantageously, the housing is equipped for holding a metal part that is mounted on the housing and surrounds the coil and another coil arranged alongside, wherein the coils are mounted on the metal part and each of these coils has at least one winding, with the directions of these windings being opposite each other. Here, the pole shoe, another pole shoe, and the element that is magnetized and permanently magnetic or magnetizable and soft-magnetic in the axial direction of the drive rod is mounted on the drive rod such that the drive rod can be moved with a translational motion into and along the coils by means of magnetic force.
The drive device can produce a stroke of the drive rod from the length of the coil in the longitudinal direction of the drive rod minus the thickness of the pole shoe in the longitudinal direction of the drive rod.
In addition, the drive device can also comprise another permanently magnetic or soft-magnetic element that is arranged at a predefined distance from the pole shoe and permanently magnetic or soft-magnetic element on the drive rod and another soft-magnetic element that surrounds the additional permanently magnetic or soft-magnetic element.
The housing is preferably constructed so that it is sealed against the ingress of liquid and/or gas from the outside.
It is possible that the permanently magnetic or soft-magnetic element, the two pole shoes, and the additional permanently magnetic or soft-magnetic element are arranged on the drive rod with axis symmetry relative to the drive rod.
Furthermore, the drive device can have a measurement device for measuring a translational motion performed by the drive rod in the housing, wherein the measurement device is arranged on the end of the drive rod facing away from a coupling with the shut-off body.
It is also advantageous if the housing is also constructed for holding a control device for connecting to a bus line by means of which the control device can receive data for controlling and/or regulating the drive device.
The previously mentioned problem is also solved by a valve for controlling a gas flow and/or liquid flow that has a shut-off body that can be moved with a translational motion and is coupled with a drive rod of the previously described drive device such that a translational motion of the drive rod causes a translational motion of the shut-off body for opening and closing the valve.
The construction of the drive device as described above makes possible both freely programmable end positions and a controlled movement profile of a valve equipped with the drive device. Here, the movement profile can be specified by an operator as a function of the type of medium (e.g., glass or liquid) and can be preset in the controller or control device.
In addition, due to the previously described construction of the drive device that reliably protects sensitive components of the drive device from harmful environmental influences, namely, for example, disinfecting and cleaning agents, moisture, dust, and shocks. This is very advantageous because the disinfecting and cleaning agents are generally aggressive acids or bases, so that the drive device and the valve are exposed to very adverse environmental conditions. In addition, the drive device and the valve can also operate reliably at high environmental temperatures. This results overall in a long service life for the drive device and the valve.
Furthermore, the previously described drive device can manage completely without lubricants and it exhibits no friction and no wear, so that environmental contaminants can be completely ruled out.
In addition, in the drive device, associated control electronics can also be integrated by means of the control device, so that any individual drive device can be driven individually by means of a bus line. This increases the dynamic response of the switching process and the accuracy and also reduces the energy consumption of the drive device.
As an additional advantage of the previously described construction of the drive device, the wiring complexity can be minimized, because it is possible to use electronic bus systems, for example, CANopen, Ethernet, EtherCAD, Profibus, etc.
In addition, a large stroke displacement and a large piston rod force are achieved by means of the previously described drive device for minimal installation space requirements. That is, a valve equipped with the drive device has a high force output.
The invention is described in more detail below using embodiments with reference to the accompanying drawings. Shown are:
Identical reference symbols are used for elements that are identical or have an identical action. The illustrated embodiments merely represent examples how the drive device according to the invention and the valve according to the invention could be equipped. They do not represent a conclusive restriction of the invention.
In a first embodiment of the invention,
The drive device 10 has a housing 11 in which are housed a control device 12 for controlling a drive force generated by the drive device 10, a measuring device 13a, 13b, a drive rod 14, a first to fourth pole shoe 15a, 15b, 15c, 15d, a first to third permanently magnetic element 16a, 16b, 16c, a first to fourth coil 17a, 17b, 17c, 17d with electric connection lines 17e, a coil carrier 18, a metal part 19, another permanently magnetic element 20, a soft-magnetic element 21, and a first and second bearing 22a, 22b for supporting the drive rod 14 in and on the housing 11. A first and second electrical line 23a, 23b are inserted into the housing 11. The drive device 10 can be provided with electrical energy via these lines and can be connected to a controller of a higher level system that is not shown here.
The housing 11 is divided in
In the first housing space 11a, the control device 12 and the measuring device 13a, 13b are held. On one side of the first housing space 11a that corresponds to the outer wall 11d of the housing 11, the first and second electrical lines 23a, 23b project with one of their ends, that is, partially, into the first housing space 11a. On the side of the first housing space 11a opposite the outer wall 11d of the housing 11 or on the side of the housing intermediate wall 11e, the drive rod 14 projects with one of its two ends, that is, partially, into the first housing space 11a. In addition, the electrical connection lines 17e lead through the housing intermediate wall 11e in order to connect the coils 17a, 17b, 17c, 17d to the control device 12.
In the second housing space 11b are housed the first to fourth pole shoe 15a, 15b, 15c, 15d, the first to third permanently magnetic element 16a, 16b, 16c, the first to fourth coil 17a, 17b, 17c, 17d on the coil carrier 18, and the metal part 19. In contrast, the drive rod 14 leads completely through the second housing space 11b. Here, the drive rod 14 is supported in the housing intermediate wall 11e by means of the first bearing 22a so that it can be moved with a translational motion, while it projects into the third housing space 11c through an opening in the housing intermediate wall 11e without a support.
In the third housing space 11c are housed the additional permanently magnetic element 20 and the soft-magnetic element 21. In contrast, the drive rod 14 also leads completely through the third housing space 11c. Here, the drive rod 14 is supported in the outer wall 11g of the housing 11 bordering the valve block 30 by means of the second bearing 22b so that it can move with a translational motion.
Due to the translational support of the drive rod 14 by the first and second bearing 22a, 22b, the drive rod 14 can be raised and lowered or moved back and forth by a stroke H as shown in
The coil carrier 18 is constructed in
On the side of the coils 17a, 17b, 17c, 17d facing away from the coil carrier 18 there is the metal part 19 around the coils 17a, 17b, 17c, 17d. In other words, the metal part 19 is also constructed as a pipe in
Between the coil carrier 18 and the assembly made from pole shoes 15a, 15b, 15c, 15d and permanently magnetic elements 16a, 16b, 16c on the drive rod 14 there is a spacing such that the drive rod 14 can move with a translational motion by the stroke H with the assembly made from pole shoes 15a, 15b, 15c, 15d and permanently magnetic elements 16a, 16b, 16c relative to the stationary coil carrier 18. If the pole shoes 15a, 15b, 15c, 15d have a larger outer extent than the permanently magnetic or soft-magnetic elements 16a, 16b, 16c, as shown in
The metal part 19, the series of coils 17a, 17b, 17c, 17d arranged one next to the other, and the coil carrier 18 are adapted in their length or height to the length of the second housing space 11b. In other words, the metal part 19 and the coil carrier 18 are, in
The first to third permanently magnetic elements 16a, 16b, 16c are each magnetized in the axial direction, that is, in the axial direction of the drive rod 14, the vertical direction in
The measuring device 13a, 13b comprises a solid measure 13a that is formed of two grooves in the drive rod 14 and a detecting device 13b for detecting the position or location of the solid measure 13b. For this purpose, the detecting device 13b is arranged in
If an electrical voltage is applied to the coils 17a, 17b, 17c, 17d so that the coils 17a, 17b, 17c, 17d carry an electrical current, a magnetic field forms around the windings of each coil 17a, 17b, 17c, 17d, and due to this magnetic field, the arrangement made from pole shoes 15a, 15b, 15c, 15d and permanently magnetic elements 16a, 16b, 16c is pulled upward in
In the third housing space 11c, the additional permanently magnetic element 20 is also mounted, for example, plugged onto the drive rod 14. The additional permanently magnetic element 20 is magnetized in the axial direction. The soft magnetic element 21 has a ring-shaped construction in
The valve block 30 in
The shut-off body rod 32 is coupled to the drive rod 14 of the drive device 10 such that a translational motion of the drive rod 14 also causes a translational motion of the shut-off body rod 32. In the valve block 30, the drive rod 14 and the shut-off body rod 32 of the valve 1 are coupled by means of a passage hole in a wall of the valve block housing in which the drive rod 14 contacts the shut-off body rod 32 and they are fastened to each other. In addition, the compression spring 37 is installed in the valve block 30 such that, in the non-compressed state, that is, when no current is flowing in the coils 17a, 17b, 17c, 17d, the shut-off body 33 contacts the valve seat 34 and thus the medium outlet opening 36 and thus the valve 1 closes. Conversely, if a current is flowing in the coils 17a, 17b, 17c, 17d, then the shut-off body 33 is lifted from the valve seat 34 and thus the valve 1 opens at least partially or even completely. The opening of the valve 1 is thus dependent on the intensity of the current flowing in the coils 17a, 17b, 17c, 17d. Therefore, a medium 40 (e.g., gas and/or liquid) flowing into the medium inlet opening 35 can flow via the medium outlet opening 36 into the reservoir 50 arranged underneath. As soon as the reservoir 50 is filled sufficiently with the medium 40, the valve 1 can be closed again.
For the function described above, the drive device 10 shown in
In
The previously described drive device 10 is a permanently magnetically excited magnetic cylinder that is used for driving the valve block 30 instead of the described pneumatic cylinder of the prior art. The magnetic cylinder can be controlled and regulated in a simple way with the help of common servo boosters. Through the use of permanently magnetic elements 16a, 16b, 16c, the efficiency of the drive device 10 is high and thus its required installation volume is small. Furthermore, the stroke H in which the axial force of the permanently magnetic elements 16a, 16b, 16c can be used is also long and the axial force profile over the stroke H is essentially constant.
The control device 12 and the measuring device 13a, 13b are indeed separated by the previously described arrangement into two different housing spaces 11a, 11b from the coils 17a, 17b, 17c, 17d on the coil carrier 18 and the metal part 19, but these form one drive unit because they are all housed compactly in a single housing 11. Through suitable sealing of the passages of the electrical lines 23a, 23b and the drive rod 14 through the outer walls 11d and 11g of the housing 11, the drive unit or the whole drive device 10 can be protected from the ingress of gas and/or liquid from the outside. Thus, the drive unit or the whole drive device 10 can be protected from harmful environmental effects.
In the previously described first embodiment, typical switching cycles for the valve 1 are dependent on the required output power. The switching cycles equal, for example, up to ca. 100 strokes per minute. Here, preferably a freely programmable stroke displacement of 0 mm to 25 mm can be realized. Driving voltages can be low voltages of 24 or 48 volts or the like. This produces a thermal loss power of approx. 50 watts.
Typical environmental temperatures can be up to +90° C. As the protection class for protecting against contact with the voltage-carrying parts and against ingress of moisture, preferably the pressurized-jet water-tight protection class is selected.
According to a second embodiment of the invention, in the drive device 10 of the valve 1 of
According to a third embodiment of the invention, in the drive device 10 of the valve 1 of
All of the constructions of the drive device 10, the valve 1, and the system 60 described above in connection with the first to third embodiment can be used individually or in combination. In particular, the following modifications are conceivable for all embodiments.
The dimensions of the parts shown in
The housing 11 can be made from corrosion-resistant stainless steel, advantageously austenitic stainless steel, or plastic, advantageously corrosion-resistant plastic. The drive rod 14 can be made from a paramagnetic or diamagnetic material, such as austenitic stainless steel or a non-ferrous metal. The pole shoes 22 can have a cylindrical shape and can be made from a soft-magnetic steel. The permanently magnetic elements 16a, 16b, 16c and the other permanently magnetic element 20 can be made from hard ferrite, SmCo (rare earths), or NdFeB. The metal part 19 can have a solid or plated construction as a pipe made from a soft-magnetic material, for example, iron. The coil carrier 18 is, in the simplest case, a pipe made from plastic.
The coils 17a, 17b, 17c, 17d can also be connected electrically to the control device 12 with more than one connection wire.
The bearings 22a, 22b can be, for example, linear roller bearings or anti-friction bearings.
The assembly including the drive rod 14, the pole shoes 15a, 15b, 15c, 15d, and the permanently magnetic elements 16a, 16b, 16c must have a non-rotationally symmetric shape. In such a case, an anti-rotational device is also useful, in order to protect the drive rod 14, the pole shoes 15a, 15b, 15c, 15d, and the permanently magnetic elements 16a, 16b, 16c from rotation.
In the coil arrangement on the coil carrier 18, temperature sensors or switches can also be embedded with whose help the assembly in the second housing space 11b is monitored and protected against overheating.
The at least one winding of the coils 17a, 17b, 17c, 17d has a single-phase construction that can be operated with a very simple control device 12. According to the required axial force, fewer than four or also additional coils can be added on the coil carrier 18 and connected in series, as well as fewer than three additional permanently magnetic elements 16a, 16b, 16c or magnetizable soft-magnetic elements and four pole shoes can be added on the drive rod 14. The number of coils on the coil carrier 18 and the permanently magnetic or soft-magnetic elements and the pole shoes on the drive rod 14 is oriented only according to the stroke required for the shut-off body 33 of the valve block 30 for opening the valve 1.
The shut-off body 33 can be a piston, a ball, a needle, etc. Thus, the system formed from the drive device 10 and valve block 30 can have a modular construction and can be adapted and matched to the required axial force range.
For the dimensional body 13a, the grooves can be cylindrical, all-around grooves with a groove width of preferably approx. 0.5 to 2.0 mm. The detecting device 13b can scan the grooves with an induction or magneto-resistive method, preferably with a non-contact method, by a suitable scanning head.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102011006071.5 | Mar 2011 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2012/054199 | 3/12/2012 | WO | 00 | 9/16/2013 |
