Valve with electrodynamic actuator

Abstract

Valve (10) with an electrodynamic actuator (30), which is a magnetic arrangement for generating a magnetic field and has an actuator (56) that is movable relative to the magnet arrangement, wherein the actuator (56) is pivotably mounted and comprises an energizable air coil (54) which is arranged in the magnetic field and is rigidly coupled to a coil carrier (52) made of a non-magnetic material, and wherein sealing surfaces (76, 78) for sealing valve seats (72, 74) are arranged on two opposite sides of the actuator (56), wherein the actuator (56) is elongated, wherein one direction of the longitudinal extension of the actuator (56) extends substantially along the longitudinal extension of the coil, wherein the valve (10) has two valve seats (72,74) which are opposite each other, and wherein the valve (10) has a housing (12) consisting of several plastic housing parts (14, 16, 18) and a metallic casing (20), wherein the metallic casing (20) surrounds an upper region of the housing (12) in which the actuator (30) is arranged and at least partially surrounds a lower region of the housing (12) in which fluid channels (38, 40, 42) are arranged.

Description

[0001] The invention relates to a valve with an electrodynamic actuator.

[0002] In fluid power, valves with electromagnetic actuators are often used. In most of these actuators, an armature made of magnetic material is moved by a magnetic field generated by a coil.

[0003] In contrast, the magnetic field strength in electrodynamic drives depends on the volume of the permanent magnets used in the drive, whereby a reduction in the volume of the permanent magnets has a comparatively less significant impact on the magnetic field strength available in the drive than a reduction in the coil size in an electromagnetic actuator. Thus, comparatively high magnetic forces can be generated with an electrodynamic drive. An electrodynamic actuator is known, for example, from DE 10 2013 110 029 B4.

[0004] US 4 516 605 A discloses a valve which is controlled by a solenoid coil and which has two opposing valve seats.

[0005] US 2009 / 0 309 055 A1 discloses a valve with an actuator surrounded by an elastomer part.

[0006] Valves are known that seal valve seats with a diaphragm, which is pressed onto the respective valve seat by an actuator. However, the use of a diaphragm limits the maximum working pressure.

[0007] It is an object of the invention to provide a valve that enables a high magnetic force, a large stroke and a high working pressure.

[0008] This object is achieved according to the invention by a valve according to claim 1.

[0009] The invention is based on the fundamental idea that the Lorentz force can be used as a driving force for an actuator if the actuator's control element has a coil arranged in a magnetic field, which is supplied with current to deflect the actuator. This concept is implemented particularly effectively in the present invention by using an air-core coil as the coil, which is firmly coupled to a non-magnetic coil carrier. An air-core coil is known to be a wire wound multiple times around a non-soft magnetic material (usually air) without a soft magnetic core. The non-magnetic coil carrier should not be magnetizable and can be made of plastic, for example.

[0010] Since the distance between the air coil and the magnetic field is constant in the valve according to the invention, the force does not change due to a change in the stroke. This allows for large strokes with a relatively high force transmission, whereas with conventional solenoid valves, the available force decreases significantly with the stroke. This enables high working pressures, which ensures reliable sealing of the valve seats.

[0011] Since the valve seats are sealed directly by the sealing surfaces arranged on opposite sides of the actuator, a diaphragm is not necessary.

[0012] The fact that the valve has two opposing valve seats, particularly the fact that the valve seats are not in the same plane, enables a good seal between the valve seats. By pivoting the actuator, the opposing valve seats can each be sealed with one of the sealing surfaces located on opposite sides of the actuator. The actuator can be pressed onto the valve seats with relatively high pressure.

[0013] According to a preferred embodiment, the actuator is encased in an elastomer part. This allows impact noises to be dampened, making the valve particularly quiet during operation and largely eliminating switching noises. In this context, it is particularly noteworthy that the valve is particularly quiet because the Lorentz principle eliminates the metal-to-metal contact encountered in conventional solenoid valves.

[0014] The elastomer part can comprise two sealing sections arranged on the sealing surfaces of the actuator. This has the advantage of enabling particularly reliable sealing of the valve seats. Unevenness and manufacturing tolerances on a valve seat or on the sealing surfaces of the actuator can be compensated for by the sealing sections.

[0015] The elastomer part preferably has a pear-shaped section and a tongue-shaped section, with the tongue-shaped section extending into the pear-shaped section and enclosing the actuator. The pear-shaped section of the elastomer part can be used to seal housing parts that can be joined together to form a valve housing. Because the tongue-shaped section encloses the actuator, the elastomer part is reliably attached to the actuator and cannot accidentally detach from it, even when the actuator moves.

[0016] According to one embodiment, the elastomer part has an assembly aid. The assembly aid is, for example, molded onto the elastomer part, in particular in the form of a bead on the pear-shaped section of the elastomer part. The assembly aid can, for example, be clamped between two housing parts during assembly, so that the pear-shaped section is fixed in a fixed position. At the same time, the assembly aid can serve to correctly position the elastomer part by aligning the assembly aid with a corresponding geometry on a housing part.

[0017] The actuator can have a toothing, whereby the coil carrier is firmly connected to the actuator by means of the toothing. In particular, the actuator can engage in the coil carrier by means of the toothing, so that the actuator and coil carrier can no longer be separated from each other without damage. The coil carrier and the actuator can thus advantageously be connected to each other without additional connecting means. The toothing can be molded onto the actuator.

[0018] The valve preferably has a housing, wherein the housing is formed at least partially from plastic and partially by a metallic casing. For example, the housing comprises several plastic parts, which can be manufactured by injection molding. Fasteners or fluid channels can be formed particularly easily in the plastic parts. The metallic casing serves both to shield the valve and as a magnetic guide plate. For this purpose, the metallic casing is particularly preferably formed from a magnetically conductive steel. Furthermore, the metallic casing improves heat dissipation.

[0019] The actuator is preferably pivotally mounted about an axis of rotation parallel to the main directions of the magnetic fields. Here, the Lorentz force is optimally utilized as the driving force for a pivoting movement. Such a design is particularly suitable for the alternating opening and closing of two oppositely arranged valve seats.

[0020] A particularly preferred embodiment is one in which a first half of the air-core coil is arranged in a first magnetic field with a first main direction, and the second half of the air-core coil is arranged in a second magnetic field with a second main direction opposite to the first main direction. In such a configuration, the different polarity (north / south pole) of adjacently arranged permanent magnets can be effectively utilized to make a large portion of the winding sections usable for generating the drive force. Since the current flows largely in opposite directions in the winding halves of the air-core coil, a Lorentz force acting in the same direction is generated in both cases, resulting in a large overall drive force.

[0021] Particularly advantageous is the use of an air-core coil that generally has the shape of an oval with a longitudinal axis, preferably the shape of two spaced-apart complementary semicircles with a linear center connecting the semicircles. The longitudinal axis divides the air-core coil into two halves, which are permeated by oppositely oriented magnetic fields. An oval shape of the air-core coil has the advantage that larger winding sections contribute to force generation than with a circular coil. This makes more force available in the direction of movement of the actuator. In principle, however, circular or rectangular coils can also be used.

[0022] According to a particularly advantageous aspect of the invention, a reset element is provided that exerts a preload on the actuator and forms at least part of an electrically conductive connection between a winding end of the air-core coil and an electrical terminal of the actuator. The reset element thus fulfills a dual function by, on the one hand, preloading the actuator into a specific switching or operating position and, on the other hand, eliminating the need for an otherwise required wire connection or the like.

[0023] Alternatively, contact can also be made via a wire connection. In this case, care must be taken to ensure the flexibility of the wire ends, as they move during the switching process. For this purpose, the wire ends can be coated with PTFE, for example.

[0024] A leaf spring or a coil spring, for example, is suitable as a return element. Several spring elements can also be combined to form a return element.

[0025] The magnet assembly and the actuator of the electrodynamic actuator according to the invention can be housed in an actuator housing that shields the magnetic fields of the magnet assembly. This prevents interference with neighboring electrical and / or magnetic devices.

[0026] According to a particular aspect of the invention, the electrodynamic actuator is provided with yoke plates made of a soft magnetic material that fulfill a dual function: On the one hand, they amplify the magnetic fields of the magnet assembly, and on the other hand, they shield the magnetic fields from the outside. The use of such yoke plates allows for the provision of a plastic actuator housing if stronger shielding is not necessary.

[0027] In a preferred embodiment, the yoke plates made of soft magnetic material with magnetic field amplification and shielding properties form the housing of the actuator.

[0028] Further features and advantages of the invention will become apparent from the following description and the accompanying drawings, to which reference is made. In the drawings: - Fig. 1 a valve according to the invention, - Fig. 2 a view of the valve according to the invention from below, - Fig. 3 an exploded view of the valve according to the invention, - Fig. 4 a longitudinal section through the valve along the line AA Fig. 1, - Fig. 5 shows another longitudinal section through the valve along the line BB Fig. 1, - the Fig. 6a to 6c different views of an actuator - the Fig. 7a and Fig. 7b various sectional views of an actuator, - Fig. 8 a section through a valve housing and - Fig. 9 a casing of the valve housing.

[0029] Fig. 1 shows a valve 10 according to the invention, which has a housing 12. The housing 12 is composed of several plastic housing parts 14, 16, 18 and a metallic casing 20. The metallic casing 20 comprises two nested casing parts 22, 24, which are at least partially fitted over the plastic housing parts 14, 16. Another plastic housing part 18 forms a cover that closes the housing 12. In an assembled state, all housing parts 14, 16, 18, 20 form a uniform surface.

[0030] The shell parts 22, 24 of the metallic sheath 20 are preferably made of a magnetically conductive steel. They each have tabs 26 that widen in a direction away from their own shell part 22, 24 and engage in corresponding recesses 28 of the other shell part 22, 24 to secure the shell parts 22, 24 to one another.

[0031] In an upper area of ​​the housing 12, in which an actuator 30 is also arranged, the casing 20 serves to shield against magnetic fields. This prevents interference with neighboring electrical and / or magnetic devices. The actuator 30 is in the Fig. 3 to 5. Furthermore, the sheath 20 serves as a magnetic guide plate, which can direct magnetic fields in a desired direction. The sheath also serves to dissipate heat.

[0032] In a lower region of the housing 12, the casing 20 is designed to save material and primarily serves a fastening function. In particular, extensions 32, 34 of the casing 20 extend into a lower region of the housing 12. The extensions 32, 34 increase the surface area of ​​the casing 20, thus improving heat exchange between the casing 20 and the environment.

[0033] Fig. Figure 2 shows the valve 10 in a bottom view. A fluid plate 36 is molded onto the plastic housing parts 14, 16. Fluid channels 38, 40, 42 are formed in the fluid plate 36. Fluid lines can be connected to the fluid channels 38, 40, 42. Furthermore, stiffening ribs and through holes are formed in the fluid plate 36, which serve to secure the fluid plate 36.

[0034] Fig. 3 shows an exploded view of the valve 10 according to the invention from the Fig. 1 and Fig. 2.

[0035] The housing parts 14, 16 have fastening areas 44, 46 with which the housing parts 14, 16 engage in the metallic casing 20, in particular in the extensions 32, 34 of the casing 20. For example, the housing parts 14, 16 are connected to the casing 20 by clamping. For this purpose, elevations 48, for example in the form of webs, are provided in the fastening areas 44, 46. The height of the elevations 48 is selected such that a sufficient clamping force is achieved between the housing parts 14, 16 and the casing 20, thus ensuring a secure hold of the casing 20 on the housing parts 14, 16.

[0036] Recesses 50, particularly grooves, are arranged directly adjacent to the elevations 48. Any material abrasion that may occur when the casing 20 is placed on the plastic housing parts 14, 16 can collect in the recesses 50.

[0037] The electrodynamic actuator 30 is arranged in the housing 12. The actuator 30 comprises a coil carrier 52 made of a non-magnetic material with an air coil 54, which is Fig. 4 and Fig. 5 is visible, and an actuator 56 firmly connected to the coil carrier 52. In addition, the actuator 30 comprises two return springs 58 and two contacts 60, which connect the coil ends to a positive pole and a negative pole, respectively.

[0038] The air-core coil 54 is fixedly connected to the coil support 52, meaning that the coil support 52 and the air-core coil 54 always move together. The air-core coil 54 comprises a plurality of windings around a non-soft magnetic core (air or another non-magnetic material). The windings give the air-core coil 54 an overall substantially oval shape with a longitudinal axis perpendicular to the center axis of the air-core coil. In the illustrated embodiment, the air-core coil 54 has the shape of two spaced-apart complementary semicircles with a straight center connecting the semicircles.

[0039] For reasons of clarity, further parts of the actuator 30, for example permanent magnets 62 and reinforcement plates 64, in particular yoke plates, are shown in Fig. 3 not shown. In Fig. However, in Figure 5 the actuator 30 is shown in full.

[0040] The air-core coil 54 can be electrically energized via the springs 58. For better contact, a contact tab 66 is arranged at each coil wire end. A coil wire end can be placed on a contact tab 66 for fastening, and the contact tab 66 can then be pressed closed and welded. The contact tabs 66 are electrically conductive and are preferably made of a metallic material. Each spring 58 is placed on one end of a contact tab 66.

[0041] The coil body 52, in particular the actuator 56, can be biased by the springs 58 into a position in which a valve seat is sealed when the valve 10 is de-energized.

[0042] When direct current is applied to the air coil 54 via the contacts 60, a Lorentz force acts on the air coil 54. This causes the actuator 56 to pivot, closing the second valve seat. As soon as the current is switched off, the Lorentz force disappears, and a return element in the form of springs 58 pushes the actuator 56 back to its original state.

[0043] The coil carrier 52 is pivotally mounted in the housing parts 14, 16 by means of a bolt 68.

[0044] The housing parts 14, 16 have complementary projections or grooves that interlock when the housing parts 14, 16 are assembled. The bolt 68 is enclosed between the housing parts 14, 16 and rotatably mounted. Two pins 70, each inserted into coaxially arranged bores in the housing parts 14, 16, secure the connection between the two housing parts 14, 16.

[0045] In Fig. 4 is a longitudinal sectional view along the line AA of Fig. 1 shown.

[0046] At the ends of the fluid channels 38, 40 located inside the valve 10, in particular inside the housing parts 14, 16, a valve seat 72, 74 is arranged, wherein the valve seats 72, 74 are opposite one another.

[0047] The course of the fluid channels 38, 40, 42 corresponds at least approximately to a circular path, especially in the area of ​​a deflection. This achieves particularly good flow. A rectangular deflection would be easier to manufacture, but it would have a negative impact on the flow.

[0048] The valve seats 72, 74 can each be closed by sealing surfaces 76, 78 arranged on opposite sides of the actuator 56 when the air coil 54 is energized.

[0049] The actuator 56 is elongated, with a direction of the longitudinal extent of the actuator 56 extending substantially along the longitudinal extent of the coil. The actuator 56 preferably has a metallic core 80.

[0050] The metallic core 80 of the actuator 56 is at least partially encased by an elastomer part 82. The elastomer part 82 is composed of a pear-shaped section 84 and a tongue-shaped section 86. This is particularly well suited to the Fig. 5 or Fig. 7a. Instead of a pear shape, other geometries are also conceivable. For example, the elastomer part 82 can also consist of an O-shaped section and a tongue-shaped section.

[0051] The sealing surfaces 76, 78 of the actuator 56 are covered by the elastomer part 82, in particular by the tongue-shaped section 86. This allows for a particularly reliable sealing of the valve seats 72, 74. In particular, the elastomer part 82 comprises two sealing sections 96, 98, which are arranged on the sealing surfaces 76, 78 of the actuator 56. The sealing sections 96, 98 can be thickened portions of the elastomer part 82 in the tongue-shaped section 86; in particular, the sealing sections 96, 98 are formed integrally with the elastomer part 82.

[0052] The pear-shaped portion 84 of the elastomer part 82 serves to seal the housing parts 14, 16. For this purpose, the elastomer part 82, in particular the pear-shaped portion 84 of the elastomer part 82, is clamped between the housing parts 14, 16.

[0053] The pear-shaped section 84 forms a closed contour that surrounds the actuator 56, in particular the sealing surfaces 76, 78 of the actuator. The pear-shaped section 84 is arranged at least partially concentrically around the sealing surfaces 76, 78, as shown, for example, in Fig. 5. To simplify the positioning or assembly of the elastomer part 82, an assembly aid 88 is provided, which is molded onto the elastomer part 82, particularly in the form of a bead. This ensures a reliable seal between the two housing parts 14, 16.

[0054] In Fig. 5 is a longitudinal sectional view along line BB of Fig. 1 shown.

[0055] In this view, the permanent magnets 62 and the reinforcement plates 64, which serve to strengthen the magnetic field, are visible.

[0056] The actuator 56 is held in the coil carrier 52 by two webs 90. To ensure secure attachment, several teeth 92 are formed on the webs 90, by means of which the actuator 56 can engage in the coil carrier 52. Preferably, the actuator 56 is made of metal and the coil carrier 52 is made of plastic. This allows the teeth 92 to penetrate at least partially into the material of the coil carrier 52. The teeth 92 can be pointed or rounded.

[0057] The coil carrier 52 is pivotally mounted in the housing 12 about the rotational axis 95 via the bolts 68. Thus, the coil carrier 52 can be pivoted to seal the valve seats 72, 74 when the air coil 54 is appropriately energized. The rotational axis 95 is advantageously located below the shoulder of the elastomer part 82 on the actuator 56. As a result, this shoulder does not move during a pivoting movement of the coil carrier 52, because the pear-shaped section 84 should always lie rigidly between the housing parts 14, 16 to ensure optimal sealing.

[0058] In the Fig. 6a to 6c, the actuator 56 is shown together with the elastomer part 82 in different views. Fig. 7a and Fig. 7b each show a section through the actuator 56 with the elastomer part 82.

[0059] The elastomer part 82 is geometrically optimized below the attachment point of the tongue-shaped section 86 to the pear-shaped section 84, i.e., at the point of movement, to prevent cracking. In particular, an indentation 96 is provided in this area. The contour of the indentation 96 can be elliptical.

[0060] Due to its pear-shaped shape, the elastomer part 82 is expanded in the area of ​​the sealing surfaces 76, 78. This allows a fluid to flow unhindered through a fluid channel 38, 40 when the corresponding valve seat 72, 74 is open.

[0061] Fig. 8 shows a sectional view of the connection of the two housing parts 14, 16 by means of the pins 70.

[0062] In Fig. 9 shows the arrangement of the permanent magnets 62 and the reinforcing plate 64 on the casing 20.

[0063] The valve 10 preferably has a plurality of permanent magnets 62. Their magnetic fields can be used most effectively if the permanent magnets 62 are arranged such that their longitudinal axes run parallel to the longitudinal axis of the air coil 54.

[0064] In addition, the permanent magnets 62 should be arranged so that opposite permanent magnets 62 always have opposite poles.

Claims

[1] Valve (10) with an electrodynamic actuator (30), which has a magnet arrangement for generating a magnetic field and an actuator (56) movable relative to the magnet arrangement, wherein the actuator (56) is pivotally mounted and comprises an energizable air coil (54) which is arranged in the magnetic field and is fixedly coupled to a coil carrier (52) made of a non-magnetic material, and wherein sealing surfaces (76, 78) for sealing valve seats (72, 74) are arranged on two opposite sides of the actuator (56), wherein the actuator (56) is elongated, wherein a direction of the longitudinal extent of the actuator (56) extends substantially along the coil longitudinal extent, wherein the valve (10) has two valve seats (72,74) which are opposite one another, and wherein the valve (10) has a housing (12) consisting of a plurality of plastic housing parts (14, 16, 18) and a metallic casing (20), wherein the metallic casing (20) surrounds an upper region of the housing (12) in which the actuator (30) is arranged, and at least partially surrounds a lower region of the housing (12) in which fluid channels (38, 40, 42) are arranged. [2] Valve (10) according to claim 1, characterized by that the actuator is encased in an elastomer part (82). [3] Valve (10) according to claim 2, characterized by that the elastomer part (82) comprises two sealing sections (96, 98) which are arranged on the sealing surfaces (76, 78) of the actuator (56). [4] Valve (10) according to one of claims 2 to 3, characterized bythat the elastomer part (82) has a pear-shaped section (84) and a tongue-shaped section (86), wherein the tongue-shaped section (86) projects into the pear-shaped (84) section and encloses the actuator (56). [5] Valve (10) according to one of claims 2 to 4, characterized by that the elastomer part (82) has an assembly aid (88). [6] Valve (10) according to one of the preceding claims, characterized by that the actuator (56) has a toothing (94), wherein the coil carrier (52) is firmly connected to the actuator (56) by means of the toothing (94). [7] Valve (10) according to one of the preceding claims, characterized by that the valve (10) has a housing (12), wherein the housing (12) is formed at least partially from plastic and partially by a metallic casing (20). [8] Valve (10) according to one of the preceding claims, characterized bythat the actuator (56) is pivotally mounted about an axis of rotation (95) parallel to the main directions of the magnetic fields.

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