Rocking valve

Abstract

Rocker valve (10) comprising a valve top (16) and a valve bottom (14) in which two valve seats (26, 28) and an additional fluid opening (44) positioned between the valve seats are formed, a diaphragm (12) which is clamped at its edge between the valve top (16) and the valve bottom (14), and a rocker arm (22) pivotably mounted on the valve bottom (14) via a pivot axis (24), which is connected to the diaphragm (12) and, by pivoting, alternately presses the diaphragm (12) against one of the valve seats (26, 28), wherein the diaphragm (12) has an arc-shaped form in plan view, the longitudinal ends (50) of which have closing sections which come into contact with the associated valve seats (26, 28), and an arc-shaped central section (52) which lies above the additional fluid opening (44), wherein the additional fluid opening (44) is laterally outside in plan view. one of the valve seats (26,28) connecting area and the pivot axis (24) projecting into the area connecting the valve seats (26, 28) when viewed from above.

Description

[0001] The invention relates to a rocker valve.

[0002] Rocker and solenoid valves for fluidic switching have been used in industrial and laboratory analytical process engineering for decades. Typically, their fluid connections – both hose barbs and UNF fittings – are arranged side-by-side in one plane.

[0003] To allow for the space-saving arrangement of multiple valves, the connection ports are often slightly tilted relative to each other. The central, usually bone-shaped, diaphragm lies between the valve head and lower body and is pressed against the respective seats by a rocker arm mounted above them. This cost-effective solution has become particularly established in the field of miniature and proportional valves.

[0004] The angled connection nozzles lead to unfavorable hose routing in compact valve blocks, make it difficult for the lines to exit completely vertically, and thus cause assembly effort and space problems in densely packed analytical instruments.

[0005] The present invention is intended to avoid these disadvantages.

[0006] To solve this problem, a rocker valve with a valve top and a valve bottom is provided according to the invention, in which two valve seats and an additional fluid opening positioned between the valve seats are formed; an arc-shaped diaphragm is clamped at the edge between the two valve parts, connected to a rocker pivotably mounted on the valve bottom and is alternately pressed against the valve seats by its movement, the pivot axis projecting into the area defined by the valve seats in a top view.

[0007] The pivot axis being set deep into the seat area reduces the necessary rotation angle of the rocker arm, which lowers the diaphragm load, increases sealing reliability, speeds up the switching behavior and at the same time allows for a flatter valve design.

[0008] The present invention addresses the disadvantages of the prior art by introducing an arc-shaped diaphragm whose lateral indentation creates space for a lower-positioned rocker arm and simultaneously enables an off-center central fluid port. The lowered pivot axis reduces the required rotation angle of the rocker arm, resulting in less diaphragm deformation, improved sealing, and faster, more energy-efficient switching behavior. The offset position of the additional central fluid port provides the structural space to align all connection ports parallel and perpendicular downwards, allowing the valve seats to be positioned closer together and the connection ports to be arranged without disruptive angles.Overall, the invention thus realizes a compact, easy-to-assemble valve architecture that significantly improves both the mechanical service life of the diaphragm and the flow performance and the ability to be integrated into tightly packed fluidic systems.

[0009] Furthermore, the classic bone-shaped diaphragm limited the positioning depth of the rocker arm's pivot axis: in this design, it had to be positioned high above the valve seats to avoid collisions with the diaphragm. This increased the rocker arm's angular deflection, heightened the relative movement between the diaphragm and seats, promoted material fatigue, made sealing more difficult with varying manufacturing tolerances, and slowed down the switching process. At the same time, the high pivot point favored flow-unfavorable channel geometries, which restricted flow and increased pressure losses.

[0010] According to one embodiment, the membrane surrounds the pivot axis at least in the area of ​​its connection to the rocker by having the pivot axis project into a lateral, concave indentation of the arc-shaped membrane, which also implies that it is completely arranged within it.

[0011] The indentation creates additional installation space for a lower position of the pivot axis, shortens the kinetic lever of the rocker, reduces forces in the diaphragm and allows for a closer arrangement of several valves because the overall height decreases.

[0012] In one variant, it is provided that a virtual plane, in which the two valve seats are located, intersects the pivot axis, with ideally the central axis of the pivot axis lying in this plane.

[0013] Due to this position of the central axis, the diaphragm has no transverse movement component when it comes into contact with the valve seat.

[0014] Furthermore, the rocker arm can have a bearing projection for receiving the pivot axis of the rocker arm, which extends from above the valve seats to a lateral indentation of the diaphragm, formed by a concave edge section of the arc-shaped diaphragm.

[0015] The bearing projection can thus be formed stably without increasing the overall height.

[0016] The valve body can have a fluid chamber enclosed by the diaphragm, which, in plan view, has an arc-shaped form with a lateral indentation into which the bearing projection extends. The valve body itself can also, in plan view, have an arc-shaped form with a lateral indentation into which the bearing projection extends.

[0017] This geometry saves on housing material, reduces weight and allows for a compact outer contour that integrates better into module blocks.

[0018] Advantageously, the valve body has a plate-shaped section with an arc-shaped form in top view, on the side of which facing the diaphragm the valve seats are formed.

[0019] The plate shape simplifies manufacturing processes such as milling or injection molding in the area of ​​the valve seat and the clamping edge for the diaphragm.

[0020] On the side of the plate-shaped section facing away from the membrane, connecting nozzles may be molded on, protruding from the section.

[0021] Direct molding greatly simplifies manufacturing and reduces the number of parts.

[0022] The connecting spigots can run parallel to each other and are preferably arranged perpendicular to the underside of the plate-shaped section.

[0023] Instead of connecting stubs, it is also possible to use flanged connections, i.e., a back plate with connections is screwed on. UNF / threaded connections are also conceivable instead of flanged connections.

[0024] This layout guides all hoses vertically downwards, avoids kinks, simplifies hose routing and allows valve block mounting without disruptive angular offsets.

[0025] The valve body can each have a channel leading to the valve seat and surrounded by the seat, with both channels lying parallel to the central axis of the additional fluid opening.

[0026] The parallel channel design reduces flow deflections, lowers pressure losses, ensures uniform flow distribution and improves metering accuracy during fast switching cycles.

[0027] It is also optionally provided that the channels and the central axis of the additional fluid opening run perpendicular to the underside of the plate-shaped section,

[0028] This allows all fluidic connections to be bundled in a straight line, creating compact, stackable valve blocks; at the same time, the straight flow minimizes dead volumes.

[0029] Viewed from above, the membrane can have circular disk-shaped longitudinal ends that are connected to each other by an arc-shaped bridge.

[0030] The disc ends optimize the sealing surface at the valve seats and the fluid chamber section around the valve seat, while the elastic bridge acts as a joint-like zone, distributing stresses and extending the service life of the elastomer, as well as sealing the remaining section of the fluid chamber below the diaphragm and in the area of ​​the additional fluid opening.

[0031] If the valve seats are located centrally in the circular disc-shaped longitudinal ends, a homogeneous surface pressure is created over the entire seat, leakage risks are minimized and wear appears uniform, which extends the maintenance intervals.

[0032] The additional fluid opening can be arranged on an imaginary central axis between the circular disk-shaped longitudinal ends.

[0033] This design ensures symmetry of the fluid chamber.

[0034] Advantageously, the edge of the valve base runs laterally from and along the outer edge of the diaphragm in top view, preferably parallel to it.

[0035] The tight outer contour avoids unnecessary material, meaning the housing material is used efficiently.

[0036] The diaphragm and / or valve base can be designed to be axially symmetrical in top view.

[0037] The symmetry simplifies component orientation and allows for mirror-image multiple arrangements.

[0038] Finally, the diaphragm and valve base can optionally form a fluid chamber together.

[0039] The flow-optimized, arc-shaped chamber reduces pressure losses, prevents air entrapment, and enables high flow rates, making the rocker valve ideally suited for demanding applications in laboratory analysis, medical technology, and precision dosing. The arc-shaped design of the fluid chamber also significantly improves its cleanability.

[0040] Further features and advantages of the invention will become apparent from the following description and from the following drawings, to which reference is made. The drawings show: Fig. 1 a longitudinal sectional view through a rocker valve according to the invention in a section plane in which the central axes of two valve seats lie, Fig. 2 a perspective top view of the rocker valve according to Fig. 1 with valve top removed, Fig. 3 a bottom view of the rocker valve according to Fig. 1, Fig. 4 a top view of the upper side of the valve body according to Fig. 1, and Fig. 5 a sectional view along line BB in Fig. 3.

[0041] In Fig. Figure 1 shows a rocker valve, but the actuator for the rocker valve is omitted. This actuator can be of any design, for example with an electromagnetically driven lifting or hinged armature, or as a pneumatic or hydraulic actuator.

[0042] In the illustrated embodiment, the rocker valve 10 is designed as a diaphragm valve, with a diaphragm 12 that is clamped at the edge between a valve lower part 14 and a plate-shaped valve upper part 16.

[0043] The membrane 12 has on its upper side sleeve-shaped, molded extensions 18 into which projections 20 on the underside of a rocker 22 extend in order to create a permanent attachment between the respective rocker arm and the sleeve-shaped extension 18.

[0044] The two-armed rocker 22 can be pivoted about a pivot axis 24 by means of the drive. One or more return springs can act on the rocker 22 or the respective drive to cause a return movement.

[0045] Below the extensions 18 and the projections 20, two valve seats 26, 28 are formed in the valve base 14, around which a fluid chamber 30 is formed by a recess in the valve base 14.

[0046] The fluid chamber 30 is closed at the top by the membrane 12.

[0047] The valve seats 26, 28 are assigned to fluid channels 32, 34, which in the present embodiment, which is not to be understood as restrictive, are defined by connecting nozzles 36, 38.

[0048] The connecting nozzles 36, 38 are integrally formed on the underside of an otherwise plate-shaped section 40 of the valve base 14.

[0049] The central axes of the connecting nozzles 36, 38 run perpendicular to the plane of the plate-shaped section 40 of the valve base 14 and thus parallel to each other.

[0050] In the Fig. As shown in the side view 1, a further connection 42 is provided between the connection spigots 36, 38, which is also formed on the plate-shaped section 40 and runs parallel to the other connection spigots 36, 38.

[0051] This connecting piece 42 ends in a Fig. 3 additional fluid opening 44 shown, which is permanently open to the fluid chamber 30.

[0052] Fig. 1 is a sectional view along line AA in Fig. 3.

[0053] As the Fig. 3 and Fig. As shown in Figure 4, the fluid opening 44, viewed from below or from above, lies laterally outside a region connecting the valve seats 26, 28, which would form the shortest path between the valve seats 26, 28. The additional fluid opening 44 is preferably spaced uniformly from the valve seats 26, 28, i.e., in a median plane or central axis that is perpendicular to a line connecting the central axes of the valve seats 26, 28 and lies exactly between the valve seats 26, 28.

[0054] Membrane 12, which is in Fig. 2, which can be seen after the valve top 16 has been removed, has an arc-shaped form with two disc-shaped longitudinal ends 50, the center of which is aligned with the central axes of the valve seats 26, 28, and an arc-shaped central section 52 connecting these longitudinal ends 50, which acts as an arc-shaped bridge between the disc-shaped longitudinal ends 50 and connects them together.

[0055] The fluid chamber 30 is adapted to the shape of the diaphragm 12 and thus also has two circular disk-shaped circular disk sections 60 centered on the respective valve seats 26, 28, as well as an arc-shaped section 62 connecting the circular disk sections 60, see Fig. 4.

[0056] The valve base 14 can optionally have, viewed from above, a rim 64 that runs laterally from and along the outer edge of the diaphragm 12, for example parallel to this edge of the diaphragm 12, in order to save installation space and material.

[0057] The diaphragm 12 and the valve base 14 are, viewed from above or below, each axially symmetrical about a central axis, through which the central axis of the pivot axis 24 also runs in top or bottom view, see Fig. 4.

[0058] The arc-shaped form of the diaphragm 12 and the valve base 14 creates a lateral indentation 70 in both the diaphragm 12 and the valve base 14. This indentation 70 is formed by a concave edge section of the diaphragm 12 and the valve base 14 and lies between the circular disk-shaped longitudinal ends 50. This indentation 70, designed as a cutout, allows the pivot axis 24 to be adjusted vertically with respect to Fig. 1. to be displaced towards the valve lower part 14 so that the pivot axis 24 comes close to a plane formed by the valve seats 26, 28. The central axis of the pivot axis 24 can preferably also lie in the virtual plane defined by the valve seats 26, 28.

[0059] The rocker 22 has a downward-projecting bearing projection 72 (see Fig. 1 and Fig. 2), which accommodates the pivot axis 24.

[0060] In side view according to Fig. Figure 1 shows that this bearing projection 72 extends from above the valve seats 26, 28 into the lateral indentation 70.

[0061] In the Fig. 2 and Fig. Figure 4 also shows that the membrane 12 surrounds the pivot axis 24 when viewed from above, specifically in the area of ​​the bearing projection 72 (i.e., in the area where the pivot axis 24 sits on the rocker 22).

[0062] The pivot axis 24 is mounted, among other things, on the valve top 16, for example on a projecting wall 76 (see Fig. 3) The wall 76 carries a tubular bearing 78 into which the pivot axis 24 is inserted. On the opposite side, the pivot axis is supported in a recess 80 in the valve lower part 14 and valve upper part 16.

[0063] Due to the special design of the diaphragm 12 and the lower valve body 14, the pivot axis 24 can be positioned closer to the diaphragm 12 and thus also closer to the valve seats 26, 28 thanks to the laterally offset additional fluid opening 44. The offset of the additional fluid opening 44 to the valve seats 26, 28 results in a very compact design.

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