Electromechanical valve and sorting manifold comprising plurality of stacks of such valves

Abstract

An electromechanical valve (10) includes a valve mechanism in a housing (20). The valve mechanism comprises a core (34) of magnetisable material surrounded by a coil (32) to be supplied with an excitation current, a stack of plates (36) of magnetic material fixed at a first end thereof, and a valve seat (38). And a stack of plates (34) provided in a space between the core (34) and the valve seat (38) such that when an excitation current is supplied to the coil (32), the valve is opened / closed by displacing the stack of plates (36) from the valve seat in response to the excitation current supplied to the coil (32), the stack of plates providing a return spring force when the stack of plates is attracted by the energized coil, and the valve is closed by displacing the stack of plates from the valve seat in response to the excitation current supplied to the coil (32). Wherein the core (34) is plate-shaped and has a thickness of less than 3 mm.

Description

Technical Field

[0001] The present disclosure relates generally to the field of valves, and more particularly to an electromechanical valve. The present disclosure also relates to an arrangement comprising such a valve. Background Art

[0002] In some applications, it is desirable to pack pneumatic valves with high density. One such application is the sorting of goods using airburst. Sorting using airburst is common in, but not limited to, sorting for quality and / or properties in applications where grain, seeds, and other relatively light items are sorted. This is commonly used in food, recycled items, and manufacturing, as well as mineral concentration.

[0003] Sorting is done by identifying which items to place in different paths and then separating them from the main stream. Feeding can be done through hoppers, conveyor belts, special chamber barrels, and other devices.

[0004] For example, in US2012152810, a sorting device for sorting parts by means of air blast is described. The sorting device comprises an air blast generator having a generator housing in which at least one reversibly deflectable diaphragm unit delimits a working chamber connected to an ejection opening. Activation of the diaphragm unit can cause the blast to be discharged from the working chamber through the ejection opening.

[0005] There is a continuing desire to improve the performance and robustness of valves used in various applications, such as in sorting equipment.Therefore, there is a need for an improved valve, particularly a valve suitable for sorting applications. Summary of the invention

[0006] It is an object of the present invention to overcome or at least partially reduce the disadvantages of existing valves and to provide a valve which can be used, for example, in sorting applications and as a sorting device.

[0007] Another object is to provide a compact valve which can be used in applications in which valves are stacked so that a plurality of valves can be packaged to form an assembly. Thereby, a plurality of valves can be placed adjacent to each other and detachably connected to each other. In order to obtain an efficient assembly of stacked valves, the valve preferably has a flat design as seen in the stacking direction.

[0008] These objects and / or other objects are at least partly achieved by an electromechanical valve according to the present invention as set out in the appended claims.

[0009] According to the present invention, an electromechanical valve is provided. The valve includes a valve mechanism located in a housing. The valve mechanism includes a core of a magnetizable material and a stack of plates of a magnetizable material, the core being surrounded by a coil to be supplied with an excitation current, and the stack of plates being fixed at its first end. The valve mechanism further includes a valve seat. The stack of plates is arranged in a space between the core and the valve seat so that when an excitation current is supplied to the coil, the valve is opened / closed by displacing the stack of plates from the valve seat in response to the excitation current supplied to the coil. When the stack of plates is attracted by the energized coil, the stack of plates provides a returning spring force, and the core is in the shape of a plate having a thickness of less than 3 mm. Thus, the valve can be made very thin, which is desired in many applications (e.g., sorting applications).

[0010] According to one embodiment, the core has an attraction portion facing the stack of plates, without a coil being wound around the attraction portion. Thus, the valve can be made thinner without reducing the performance of the valve. The attraction portion may form a protrusion from the flat core. According to some embodiments, the protrusion is a lip offset from the plane of the core. Thus, an even thinner valve can be provided.

[0011] According to some embodiments, the flat core has a rectangular cross-section.The thickness of the core may be less than 1 mm.

[0012] According to one embodiment, the valve seat has a slit-shaped seat opening. As a result, the performance of the valve can be improved and more air can pass through the valve in a short time. The slit-shaped seat opening can have a widened middle section. The opening time can thereby be shortened, because the air pressure is more easily equalized.

[0013] According to some embodiments, a plurality of outlets are provided in the housing. Also, at least two valve assemblies are provided in the housing, wherein each of the at least two valve assemblies is associated with a corresponding outlet. Since no wall is required between two adjacent air outlets, the size of the housing can be reduced, and the air outlets can be spaced closely together.

[0014] According to one embodiment, the core is U-shaped with two legs. This results in a space-efficient realization of the core. According to some embodiments, the coil is wound only on one of the legs of the U-shaped core or on a part of one of the legs of the U-shaped core. This can save space.

[0015] The invention also extends to a manifold comprising a plurality of stacked valves according to the above.Thereby, an assembly usable in sorting applications can be provided which has a short distance between consecutive air outlets so that the blowers can be arranged at very close spacings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is described in more detail below by way of non-limiting examples and in conjunction with the accompanying drawings, in which:

[0017] - Figure 1 is a side view of an electromechanical valve that can be used as a sorting device.

[0018] - Figure 2 is a top view of the electromechanical valve.

[0019] - Figure 3 This is an exploded view of the electromechanical valve.

[0020] - Figure 4 This is a top view of the disassembled electromechanical valve.

[0021] - Figure 5a The diagram shows the state of the electromechanical valve when no excitation current is supplied. Figure 4 Details,

[0022] - Figure 5b showing details of the core in an electromechanical valve,

[0023] - Figure 6 is similar to Figure 5a A view of a circuit in which an excitation current is supplied to an electromechanical valve,

[0024] - Figure 7 The diagram shows the stacking of the boards.

[0025] - Figure 8 The valve seat is shown.

[0026] - Fig. 9 The diagram shows stacked electromechanical valves.

[0027] - Fig.10 illustrates a plurality of stacked valves in an offset configuration, and

[0028] - Figures 11a to 11c The different modes are illustrated. DETAILED DESCRIPTION

[0029] Various aspects of the present invention will now be described more fully. The same numbers refer to the same elements throughout the text. For ease of understanding and / or clarity, well-known functions or configurations are not necessarily described in detail. It should be further understood that the features can be combined in any suitable manner to meet different implementation requirements. Some elements can be omitted in some embodiments. Further, although the exemplary embodiments described herein are illustrated with a generally rectangular housing, other designs may also be used.

[0030] exist Figure 1, a view of the side of one embodiment of an electromechanical valve is shown. The valve may typically be designed as a pneumatic valve. However, other fluids than air may also be envisioned. In the following exemplary embodiments, it is assumed that air is used as the pressurized fluid. The valve 10 is provided in a housing 12. In the following description, the housing 12 is designed to have one inlet for pressurized air and one air outlet. However, it is also envisioned that multiple outlets may be provided in a single housing. In an embodiment with multiple outlets, each outlet may be controlled by a valve mechanism comprising a controllable electromagnet. In such an embodiment, the outlets may be stacked closer together.

[0031] exist Figure 1 In the embodiment, the housing 12 has an air inlet P, where pressurized air is supplied. The housing 12 further has an air outlet A. Figure 1 In the embodiment of the invention, the air inlet P and the air outlet A are located on the same surface. However, it is contemplated that other locations of the inlet P and the outlet A may also exist. The housing 12 may be provided with an electrical connector 14 for supplying power to the electromechanical valve. Further, a positioning plug 16 may be provided on the housing 12. The positioning plug may be formed as a protrusion formed in the housing 12. The plug 16 may be used to position the valve 10 in a certain arrangement or device.

[0032] The housing 12 may have a generally rectangular shape when viewed from the side. The size may be small, with a width W of less than 100 mm and typically less than 50 mm. Similarly, the height H may be less than 100 mm and typically less than 50 mm. The housing 12 may be made of a non-magnetic / non-magnetizable material (e.g., aluminum or a plastic material).

[0033] It should be understood that the position of the inlet P is not limited, but the position of the inlet P may depend on the intended use of the valve 10, and thus may be located at any suitable position depending on the field of use of the valve 10. Similarly, depending on the field of use of the valve 10, the outlet A may therefore be located at any suitable position.

[0034] exist Figure 2 , a top view of the valve 10 is shown. It can be seen that the valve 10 can be made very flat. The thickness T of the valve 10 can be only a few millimeters, for example, less than 10 mm or about 5 to 6 mm, or even less, such as 4 mm or less. In particular, the thickness T may be only a small part of the height H and / or width W of the valve. For example, the thickness T may be less than 1 / 5 of the height H and / or width W of the valve, or even less than 1 / 10 of the height H and / or width W of the valve 10. A surface with such dimensions may be referred to as a narrow surface.

[0035] According to some embodiments, some or all of the inlet P, outlet A, and electrical connector 14 may be disposed on the side that is narrower relative to the other sides. In the embodiment shown herein, the inlet P and outlet A are disposed on a common narrow surface. According to some embodiments, the electrical connector 14 may be disposed on a narrow surface opposite to the narrow surface providing the inlet P and / or outlet A.

[0036] exist Figure 3 , an exploded view of the valve 10 is shown. The valve 10 comprises an air inlet P, an air outlet A and an electrical connector 14 mounted on a housing 12. In the present exemplary embodiment, the housing 12 is formed by a first cover 22 facing the pneumatic side where the air inlet P and the air outlet A are located. The housing 12 is further formed by a second cover 24 where the electrical connector is located. When the housing 12 is formed by multiple parts (such as in this exemplary embodiment), the different parts of the housing 12 (here the first cover 22 and the second cover 24) can be connected together. The different parts of the housing can be connected by some fastening means (such as screws 25) or other means (such as a snap-on connection).

[0037] A valve mechanism is arranged in the housing 12. The valve mechanism includes an electromagnet, a stack of plates and a valve seat. Furthermore, an electromagnet 30 is located in the housing 12. The electromagnet 30 is formed by a coil 32 wound around a core 34, and the core 34 includes a magnetizable material (for example, iron or cobalt); or a soft magnetic material. The core 34 can also include a magnetizable alloy (for example, FeCo). The electromagnet 30 cooperates with a stack 36 of multiple layers of magnetizable material to form a leaf spring. The stack 36 can be formed by laminated thin plates including magnetizable material (for example, iron or cobalt or the like). The stack 36 is located on the valve seat 38.

[0038] The stack 36 may be fastened using some suitable means 37, such as screws or rivets. The valve seat may be provided with a seal and may also be formed from a material having sealing properties, such as a plastic material or a reinforced plastic material, according to some embodiments.

[0039] By activating the electromagnet 30, a mechanism (such as the mechanism described in WO2015126304) is used to move the stack 36 between a first position of closing the valve and a second position of opening the valve. Furthermore, when an excitation current is supplied to the coil 32 around the core 34 to magnetize the core 34, the stack 36 cooperates with the magnetized core 34 (i.e., is attracted by the magnetized core 34) to open the outlet A. When no excitation current is supplied, the stack 36 returns to the initial position by its inherent spring force. In the present embodiment, the initial position is the position where the stack 36 abuts against the valve seat 38 to form a normally closed valve. In other words, when an excitation current is applied, the valve is opened to activate the valve. In an alternative embodiment, the valve can be designed to be normally closed so that the valve opens when no excitation current is provided.

[0040] Furthermore, in Figure 3 In the embodiment of the present invention, the valve seat 38 connects the pressurized interior of the housing with the air outlet A. By activating an electromagnet formed by a core 34 having a coil 32 wound thereon, when the stack 36 is lifted from its initial position by the magnetic force provided when the electromagnet is activated, the pressurized air in the housing is released to the air outlet A via the valve seat 38. When multiple air outlets A are provided in the same housing 12, each air outlet A can be controlled separately by a separate assembly of the electromagnet 30, the stack 36 of plates and the valve seat 38. Therefore, each air outlet A can be connected to such an assembly separately and thus controlled separately. Thereby, the housing can be made simpler and the outlets can be placed closer together, because, when multiple air outlets are provided, the housing wall can be removed. Thereby, when multiple individually controlled air outlets A are provided, a more compact design can be achieved.

[0041] exist Figure 4 , a top view of the valve 10 in a disassembled state is shown. In order to provide a very thin pneumatic valve with a thickness of only a few millimeters (e.g., less than 3 mm), the electromagnet 30 can have a core 34 of flat design and can be formed as a strip in the form of a plate with a thickness of only 0.2 to 3 mm. Typically, the core can be thinner than 1 mm. However, the strip forming the core 34 can be wider and have a width of at least 10 mm or wider (e.g., 30 to 50 mm). In particular, the width is much greater than the thickness, so that a thin core that can provide a large magnetic flow can be provided. For example, the width can be at least 5 times or 10 times the thickness of the plate-like core.

[0042] Figure 5a Shows Figure 4 Detail C. In order to provide a very thin pneumatic valve with a thickness of only a few millimeters, the electromagnet can have a core 34 of flat design and can be formed to be only 0.2 to 3 mm thick. The core 34 can generally have a generally rectangular cross-section and be thin so as to form a plate-like structure. The coil 32 is wound around at least a portion of the flat plate-like core.

[0043] In addition, if Figure 5aAs can be seen in the figure, the flat core 34 can be formed with a protrusion formed by a lip 35 located in the end facing the stack 36. The lip 35 can be offset from the plane of the flat plate-like core by a curved portion. The curved portion can be, for example, S-shaped. Therefore, the stack 36 can be located below the lip 35, so that the size of the valve 10 can be further reduced. Furthermore, in such an embodiment, the coil is not wound around the core at the position where the lip 35 is formed. The protrusion forms the attraction portion of the core 34. In other words, the protrusion is a part of the core 34, and the stack 36 cooperates with it to open / close the valve. In an alternative embodiment, the protrusion from the flat core 34 can be formed as an extension from the flat plate-like core 34. The protrusion can then be formed to be thinner than the rest of the core and located at the top, as in Figure 5a In other words, the protrusion is located at the maximum distance from the valve seat so as to increase the space between the valve seat 38 and the attraction portion of the core 34. Figure 5a In the embodiment of the present invention, the valve is not activated and no excitation current is applied to the coil. Then, the stack 36 rests on the valve seat 38.

[0044] According to some embodiments, core 34 is generally U-shaped. Figure 5a The embodiment of FIG. 3 shows such a U-shaped core 34. The core 34 has two legs. Figure 5a As shown, an upper leg 34a on which a coil 32 is wound, and a lower leg 34b. By providing the coil 32 on only one of the legs 34a, 34b, space can be saved and the valve 10 can be made thinner. The lower leg 34b can have a stack 36 and a valve seat 38 fixed to the lower leg 34b. The two legs 34a, 34b can be connected in a suitable manner by a magnetizable material (e.g., a material containing iron). According to some embodiments, the U-shaped core is formed as an integral element.

[0045] When the core 34 is U-shaped, the stack 36 and the valve seat 38 may be located between the end portions of the legs 34a, 34b. Therefore, when an excitation current is applied to the coil 32 and the core is magnetized, the magnetic flow in the U-shaped core may be closed via the stack 36. Figure 5a Such an embodiment is illustrated.

[0046] exist Figure 5b In FIG. 3 , a portion of the core 34 is shown. Figure 5b In the embodiment, only the upper leg 34a is shown, and a connecting element 34c is provided at the rear of the upper leg 34a to connect to the lower leg. Figure 5b As shown, the lip 35 is offset from the main plane of the upper leg 34 via a curved portion 34 d on the core 34 .

[0047] exist Figure 65 , a view similar to that of FIG. 5 is shown. Here an excitation current is applied so that the electromagnet is activated. Then, the stack 36 comprising magnetic material is attracted by the core 34 of the electromagnet so as to Figure 5a The valve in this exemplary embodiment is then opened and air is output via outlet A. At the same time, since the coil can be located near the air path through the valve 10, air cooling of the coil can be achieved by the air flowing through the valve 10.

[0048] exist Figure 7 , a detailed view of a plate 39 of a stack 36 is shown. The plate 39 can have a generally rectangular design. The portion facing away from the core can be provided with fastening holes for fixing the stack to the valve housing or core 34. The top plate 39a facing the core and lifted by the core can be different from the other plates 39. The top plate 39a can be shaped to hold the other plates together. In addition, the top plate 39a can be made of another material, in particular a non-magnetizable material. The top plate 39a can also be provided with a cutout 41 for adjusting the spring force of the stack 36. The cutout 41 can be separated by a bridging portion 42. In addition, the thickness of the top plate 39a can be different from that of the other plates 39 of the stack 36.

[0049] exist Figure 8 In FIG, a valve seat 38 is shown. The valve seat may have at least one outlet passage 46 operatively connected to the air outlet A. Figure 8 In the embodiment of the invention, multiple outlet channels are formed in the valve seat 38, as the valve seat 38 has four outlet channels 46. The valve seat 38 has a seat opening 47 suitable for use with the stack 36. The seat opening 47 forms an inlet channel to the valve. Thus, when the stack 36 abuts against the seat opening 47, the air connection between the pressurized air from the air inlet P inside the valve 10 and the air outlet A via the outlet channel 46 is closed. When the stack 36 is lifted from its rest position, see Figure 6 , air can flow through the valve 10 from the air inlet P via the seat opening 47 via the outlet channel 46 to the air outlet A.

[0050] In order to increase the air flow, the seat opening 47 may be slit-shaped with an elongated shape. Typically, the seat opening 47 may be elongated in the same direction as the plates in the stack 36. By making the seat opening 47 slit-shaped, a higher air flow can be achieved with a relatively small lift height of the stack 36 compared to using a circular seat opening. Further, a widened portion 49 may be formed in the middle portion of the slit-shaped seat opening 47. Therefore, when an excitation current is applied, air begins to flow rapidly in the valve 10. This helps lift the stack because the pressure is quickly balanced. As a result, the time from no air flow in the valve to full air flow in the valve can be shortened.

[0051] By using a valve as described above a sorting device can be obtained. In many applications, it is desirable to stack a number of valves close together. The valve 10 described herein is particularly suitable for such applications. Fig. 9 A plurality of valves 10 are shown stacked together to form a manifold 50 for sorting items (eg, grains). The sorting device formed by the manifold 50 can also be used to sort other items by means of air blast.

[0052] Manifolds 50 are combined to form a manifold arrangement 60 having a plurality of stacked valves arranged in parallel. By providing a small offset between the parallel stacked valves, the incremental distance between consecutive valves can be reduced. For example, if the valves are 6 mm thick, three parallel lines of stacked valves 10 are arranged with an offset spacing of 2 mm. In this arrangement, the distance between 2 valves will only be 2 mm. Fig.10 Such a manifold arrangement 60 is shown. Furthermore, a greater number of air passages can be achieved within a certain distance using multiple rows of offset valves. 3 rows of 6 mm valves can achieve a resolution of 2 mm of air opening, 6 rows for 1 mm, and so on.

[0053] The use of valves as described herein enables stacking of valves with narrow spacing. In addition, the design enables relatively high air flow relative to the small size of the valve. In other words, the flow capacity of the valve can be higher than other types of valves relative to the size of the valve. The service life of the valve is long, and the valve can withstand multiple cycles without losing its good characteristics. Further, the response time of the valve is also very short compared to other types of valves. This enables, for example, higher frequencies to be achieved in sorting applications, so that sorting can be faster. Fast response time and high air flow capacity are also useful in other applications. In blowing applications, spraying applications and dispensing applications, pressure will gradually accumulate during the opening of the valve, so that a fast activation time can achieve improved results and accuracy. This is very important in sorting and precision spraying (e.g., inkjet) and similar applications using air explosions. Different ink patterns formed by air explosions are illustrated in Figure 11. Fig.11a The desired "perfect" ink dot is illustrated. Fig.11b shows the ink dot formed as pressure builds up slowly. Fig.11c The results of using a faster valve are shown.

Claims

1. An electromechanical valve (10), comprising a valve mechanism in a housing (20), the valve mechanism comprising: a core (34) of magnetizable material, said core (34) being surrounded by a coil (32) to be supplied with an excitation current, - a stack (36) of plates of a magnetizable material, said stack of plates being fixed at a first end thereof, - a valve seat (38), wherein The stack of plates (34) is arranged in the space between the core (34) and the valve seat (38) so that when an excitation current is supplied to the coil, the valve is opened / closed by shifting the stack of plates (36) from the valve seat in response to the excitation current supplied to the coil (32), and when the stack of plates is attracted by the energized coil, the stack of plates provides a returning spring force, wherein the core (34) is in the shape of a plate having a thickness of less than 3 mm.

2. An electromechanical valve (10) according to claim 1, wherein the core has an attraction portion facing the stack (36) of plates, no coil being wound around the attraction portion.

3. An electromechanical valve (10) according to claim 2, wherein the attraction portion forms a protrusion from the core.

4. An electromechanical valve (10) according to claim 3, wherein the protrusion is a lip (35) offset from the plane of the core.

5. An electromechanical valve (10) according to any one of claims 1 to 4, wherein the thickness of the core is less than 1 mm.

6. The electromechanical valve (10) according to any one of claims 1 to 5, wherein the valve seat (38) has a slit-shaped seat opening (47).

7. The electromechanical valve (10) according to any one of claims 6, wherein the slit-shaped seat opening (47) has a widened middle section (49).

8. An electromechanical valve (10) according to any one of claims 1 to 7, wherein a plurality of outlets are arranged in the housing (12), and wherein at least two valve assemblies are provided, wherein each of the at least two valve assemblies is associated with a respective outlet.

9. An electromechanical valve (10) according to any one of claims 1 to 8, wherein the core (34) is U-shaped with two legs (34a, 34b).

10. An electromechanical valve (10) according to claim 9, wherein the coil is wound only on one of the legs (34a) of the U-shaped core (34) or on a portion of one of the legs (34a) of the U-shaped core (34).

11. An electromechanical valve (10) according to any one of claims 1 to 10, wherein the core (34) has a cross-section having a width which is at least 5 times greater than the thickness of the core.

12. A sorting manifold comprising a plurality of stacked valves according to any one of claims 1 to 11.

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