Gas-tight butterfly valve

Abstract

Gas-tight butterfly valve (1) with a cuboid housing and two rectangular flaps (10, 10') which can be moved along a travel path (26) from an open to a closed position, in which the flaps (10, 10') are pressed gas-tight onto a flap seat (15), wherein the flaps (10, 10') are pivotally mounted on one side, a spindle drive (20) is provided with which the damper blades (10, 10') can be moved, and a link (25) is provided which specifies the travel path (26), characterized by that the damper blades (10, 10') comprise sealing elements running around the edges on their underside, which ensure a tight fit of the damper blades (10, 10') in the closed position on sealing seat frame struts of a rectangular sealing seat frame (6), and that in the closed position, the outer longitudinal edges of the flap leaves (10, 10') which are in a horizontal position in this position each cooperate with the flap seat (15, 15'), which comprises a support in the form of the upper sides of longitudinal struts (9, 9') of the sealing seat frame (6) and a wedge-shaped projection (16) which is fixed to an inner side of a housing side wall (3) and extends along this, wherein the outer longitudinal edges of the damper blades run with their upper side against the inclined surface of the respective projection (16) during the final movement of the damper blades (10, 10') into their horizontal closed position and are driven a little way along the inclined surface by the spindle drive (20), so that the circumferential sealing elements on the underside of the damper blades (10, 10') are pressed together by the outward horizontal movement of the damper blades (10, 10') in order to create a gas-tight seal along the outer edge of the damper blades.

Description

The present invention relates to a gas-tight butterfly valve.Shut-off flaps are a fitting for flow control, for example in a ventilation system. Gas-tight variants of a butterfly valve are used, for example, when shutting off ventilation systems of safety areas (enclosures).DE 10 2015 111 908 A1 discloses a gas-tight shut-off flap which comprises two flap leaves which comprise a planar component with which an opening can be closed, wherein the flap leaves can be rotated and displaced by an axis whose ends engage in a groove. The two flap leaves are each flexibly connected to one another at one end of the planar component in a joint region and are movable by a drive element made of a material with shape memory property, which is fastened to the joint region or the planar components.DE 10 2007 013 665 A1 discloses a mixing flap for the air streams of a climate control branch, which mixing flap comprises two flap leaves, one of which is mounted asymmetrically. On the asymmetrically mounted flap leaf, a joint is arranged which engages in one end of the other flap leaf. By means of a flow-inlet-side arrangement of the joint in the open position of the mixing flap, the inflowing air is directed outwards in the direction of a surrounding housing in order to mix different air flows by means of reduced pressure which arises behind the mixing flap.DE 31 48 709 A1 discloses a butterfly valve pivotably mounted at one end, the pivoting movement of which between an open and closed position is effected by an electric motor drive.From WO 2003 / 100 302 A1 a shut-off valve is known. This comprises a housing connected pressure-tightly to a pipeline and a closure body movable between open and closed positions.There is a need for a gas-tight shut-off flap with a highly effective sealing performance that can be detected from outside the flap housing, with a cost-effective construction and a low dead weight of the flap.It is the object of the present invention to provide a gas-tight shut-off flap with a highly effective sealing performance detectable from outside the flap housing with a cost-large construction and a low dead weight.This object is achieved according to the invention by the features of claim 1.Due to the linear drive (which is designed according to the claims as a spindle drive) for the flap leaf of the shut-off flap according to the invention in conjunction with a link control, a sealing performance which is safe even under the action of stress is achieved with a cost-effective construction.Preferably, two synchronously running spindles are provided, on each of which a spindle nut is connected to the flap blade by means of a joint guide in order to move the flap blade and, in its closed position, press it onto a sealing seat via two contact pressure points. In addition, the link on both sides of the flap blade comprises two identical link guides in which the flap blade is guided via sliding pins or roller bearings which additionally press the flap blade onto the sealing seat via two further pressing points in the closed position. Thus, in this preferred embodiment, a total of four pressing points secure the flap leaf in its closed position.In favor of a particularly effective drive power and a high sealing quality, the pivotably mounted side of the flap blade can be driven by the linear drive. Preferably, the flap blade is pivotable through approximately 90 degrees.In order to optimize the sealing function provided by the flap sheet in the closed position, it is provided that a projection is provided above the flap seat, which projection is arranged such that the flap sheet comes to lie between the flap seat and the projection in the closed position.The flaps according to the invention can also be provided with two flap blades which are configured, controlled and driven in an identical (symmetrical) manner. For this purpose, it is advantageously provided that the flap comprises, in a mirror-image arrangement, a further flap blade which is mounted pivotably on the same side as the flap blade mentioned above and can be moved with the same linear drive as this under the control of a link for presetting the travel path which corresponds to the link of the flap blade mentioned first.Further details and advantages of the invention will now be explained in more detail with reference to an exemplary embodiment shown in the drawings.The following are shown: FIG. 1 is a schematic representation of an embodiment of the gas-tight flap according to the invention with two flap leaves in the closed position, FIG. 2 is a side view of the flap of FIG. 1, with a wall element of the flap housing removed on one side for clarity of illustration, FIG. 3 shows a schematic illustration of the sealing seat frame for the two flap leaves of the flap of FIG. 1 which are in the open position here and for their slotted guide and actuation, FIG. 4 is a side view of the arrangement of FIG. 3; and FIG. 5 shows a schematic detailed view of an embodiment variant of the flap seat of the flap according to the invention.The gas-tight flap 1 shown in FIG. 1 comprises a rectangular housing 2 with four side walls, of which only three side walls 3, 4 and 5 are shown, while the fourth side wall is disassembled. At its upper and lower sides (inflow and outflow sides), the housing 2 is open. Inserted into the underside of the housing 2 is a supporting sealing seat frame 6 for two rectangular flap leaves 10 and 10' and for guiding and driving them. Webs 7 and 7' protrude from two mutually opposite sides of the sealing seat frame 6 (on the 2 opposite side walls, arranged perpendicularly to the linear drive and leading above the sealing seat of the flap leaf), which webs extend as far as the side walls 3 and 4 and define slotted guides 25, 25a and 25', 25a' for defining a travel path 26 of the flap leaves 10 and 10', as explained in more detail below.The sealing seat frame 6 comprises two central struts which are spaced apart from one another on both sides of its longitudinal central axis running parallel to the latter and of which only the strut 8 is visible in FIG. 3, which struts serve as a support for a respective inner longitudinal edge of the two flap leaves 10 and 10' in the closed position, wherein the upper sides of the outer longitudinal struts 9 and 9' of the sealing seat frame 6 form supports for the outer longitudinal edges of the two flap leaves 10 and 10' in the closed position. These supports form part of a flap seat 15, which will be explained in more detail below. The other two mutually opposite side struts 12, 13 of the sealing seat frame 6 form supports for the narrow sides of the flap leaves 10 and 10' which are in the closed position. Advantageously, the flap leaves 10 and 10' comprise circumferential sealing elements on their underside, which ensure a tight fit of the flap leaves 10 and 10' in the closed position on the sealing seat frame struts. In addition, compressive forces acting on the longitudinal edges of the flap leaves 10 and 10' in the closed position contribute to a tight fit of the flap leaves 10 and 10' on the sealing seat frame struts.The two central struts (of which only the strut 8 is visible in FIG. 3) of the sealing seat frame 6 support spindle bearings of a motor-operated spindle drive 20 for the two flap leaves 10 and 10'. The spindle drive 20 comprises two spindles 21 and 22 which engage with their lower ends in the spindle bearings, extend perpendicularly upwards therefrom and engage with their upper ends in abutments which are accommodated in a rail-like, elongate housing 23 which is fixed to the inner side of the side wall 5 and the opposite side wall which is not mounted in FIG. 1 and extends parallel and in opposition to the central struts of the sealing seat frame. Nuts 24 and 24a are seated as drive transmission elements on the threaded spindles 21 and 22, which nuts are connected via joints to the inner longitudinal edges of the flap leaves 10 and 10' (see FIG. 3).As a result of the upward and downward movement of the nuts 24 and 24a along the spindles 21 and 22, the longitudinal edges of the flap leaves 10 and 10' undergo a lifting movement in the vertical direction, which is converted by the end-side guidance from the outer longitudinal edges of the flap leaves 10 and 10' in the slide members 25, 25a and 25', 25a' for defining the travel path 26 of the flap leaves from their open position shown in FIGS. 3 and 4 into the closed position shown in FIG. 1. The guiding of the flap blades 10 and 10' in the slotted guides 25, 25a and 25', 25a' is effected by sliding bolts or roller bearings which are fixed in the mutually opposite ends of the outer edge of each flap blade and project from there into the slotted guides.In the closed position, the outer longitudinal edges of the flap leaves 10 and 10' which are in a horizontal position in this position cooperate in each case with the flap seat 15, 15' which comprises the support in the form of the upper sides of the longitudinal struts 9 and 9' of the rectangular sealing seat frame 6 and a wedge-shaped projection 16 which is fixed on the inside of the housing side wall 3 and extends along the latter (see FIG. 5). Due to the fact that the outer flap-blade longitudinal edges during the final movement of the cap blades 10 and 10' into their horizontal open position run with their upper side against the inclined surface of the respective projection and are driven along the same by the spindle drive, the seals on the lower side of the flap blades are compressed in favor of a gas-tight seal along the flap-blade outer edge by the outward horizontal movement of the flap blades 10 and 10'.The seals on the underside of the flap leaves are also compressed by the spindle drive in this last phase of its drive activity over the entire length of the two central sealing seat frame struts (only the strut 8 is shown in FIG. 3 ) by the downward force of application of the spindle drive via the inner edges of the flap leaves. As a result of the compression at their inner and outer longitudinal edges of the sealing seat frame 6, the seals on the narrow sides of the sealing seat frame 6 are also subjected to a compression, so that along the entire contour of the flap leaves 10, 10', these provide a gas-tight seal.The slotted guides 25 and 25', 25a and 25a' for providing the travel path 26 of the flap leaves 10 and 10' pivotable about 90 degrees have a special arc shape which brings about the following:the initiation of the horizontal movement of the flap leaves in the first third of the travel path 26 along the slotted links is promoted by a gradient of the travel path 26 in the slotted link 25,the flap leaves are moved in the middle third of the travel path 26 along the slide links into a quasi-parallel position with respect to the flap seat 15 and they can be moved without contact of the flap leaves with their respective flap seat 15, andthe flap leaves are pressed perpendicularly onto the flap seat 15 in the last third of the travel path 26 along the slide links out of a quasi-parallel position with respect to the flap seat 15.List of reference characters1 Gas-tight flap 2 housing 3 side wall 4 side wall 5 side wall 6 sealing seat frame 7, 7' web 8 central strut 9, 9' longitudinal strut 10, 10' flap leaf 11, 11' sliding bolt 12 side strut 13 side strut 15 flap seat 16 projection 20 linear drive 21 spindle 22 spindle 23 housing 24 nut 24a nut 25, 25' slotted link 25a, 25a' slotted link 26 travel path

Claims

Gas-tight shut-off flap (1) having a cuboidal housing and two rectangular flap leaves (10, 10') which can be moved along a travel path (26) from an open position into a closed position in which the flap leaves (10, 10') are pressed in a gas-tight manner onto a flap seat (15), the flap leaves (10, 10') being mounted pivotably on one side, a spindle drive (20) is provided with which the flap leaves (10, 10') can be moved, and a link (25) is provided which presets the travel path (26), characterized in that the flap leaves (10, 10') comprise sealing elements which run on the edge on their underside and ensure a tight fit of the flap leaves (10, 10') which are in the closed position onto sealing seat frame struts of a rectangular sealing seat frame (6), and that in the closed position the outer longitudinal edges of the flap leaves (10, 10') which are in the horizontal position in this position cooperate in each case with the flap seat (15, 15'), which comprises a support in the form of the upper sides of longitudinal struts (9, 9') of the sealing seat frame (6) and a wedge-shaped projection (16) which is fixed to an inner side of a housing side wall (3) and extends along the latter, wherein the outer flap leaf longitudinal edges during the final movement of the flap leaves (10, 10') into their horizontal closed position run with their upper side against the inclined surface of the respective projection (16) and are driven forwards a certain amount along the inclined surface by the spindle drive (20), so that the encircling sealing elements on the lower side of the flap leaves (10, 10') are compressed along the outer edge of the flap leaves by the outward horizontal movement of the flap leaves (10, 10') in favor of a gas-tight seal.Butterfly valve (1) according to one of the preceding claims, characterized in that the flap leaf (10) is pivotable through approximately 90 degrees.Shut-off flap (1) according to one of the preceding claims, characterized in that the initiation of the horizontal movement of the respective flap leaf (10) in the first third of the travel path (26) along the slotted link (25) is promoted by a gradient of the travel path (26) in the slotted link (25).Butterfly valve (1) according to one of the preceding claims, characterized in that the respective flap leaf (10) is moved in the middle third of the travel path (26) along the slotted link (25) into a quasi-parallel position with respect to the flap seat (15) and can be moved without contact of the flap leaf (10) with the flap seat (15).Butterfly valve (1) according to one of the preceding claims, characterized in that the respective flap leaf (10) is pressed perpendicularly onto the flap seat (15) in the last third of the travel path (26) along the slotted link (25) out of a quasi-parallel position with respect to the flap seat (15).

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