FI87835C - Control dampers for ventilation duct systems - Google Patents

Description

The present invention relates to a damper for an air duct, comprising a generally annular or tubular body 5, a rotating shaft projecting through and rotatably supported thereon, and a control flap fixed to the rotary shaft inside the body.

Control dampers as described above usually comprise a pressed body part with tapered ends and associated seals to allow the control damper to be integrated into the air conditioning ductwork. The control flap itself is fitted inside the tubular body of the damper by inserting it from one end of the body into the body and connecting it to the axis of rotation 15 introduced through the side of the body. This connection can be done either by welding or by screw connections.

The manufacture of a conventional damper as described above is relatively complicated and requires special machines, in particular for producing a pressed body. In addition, the connection of such a pressed body with tapered ends to other parts of the air-conditioning duct: Y: requires the use of separate short-collar • pipe sections, if as is often the case. * ··. anlaita damper is connected to a part of the channel deformation ____: 25 or a corner part, which is also provided with a constriction. In addition, such a damper is practically impossible to retrofit to an already completed air conditioning ductwork. Quite often, in practice, the need for a damper is not detected until the installation of the air duct. ! After 30 measurements.

It is an object of the present invention to provide. a damper, which is structurally simpler than previously known and thus more cost-effective, and is particularly well suited for installation also in an already completed air conditioning duct 35.

2,87835

The above object is achieved by means of a control damper according to the invention, characterized in that the body part comprises a piece of metal collar provided at its ends with means for tightening the collar as a rim around the air-conditioning pipe with a notch cut into the control flap. Preferably, the collar comprises a seal on its control flap side surface of an elastic material, such as cellular rubber. Since the body part in the control damper according to the invention is an open collar-like part which is only tensioned around the air-conditioning duct, it is very well suited for installation in an air-conditioning duct already installed in place. For this purpose, it is only necessary to cut a narrower slot in the air duct, for example with an angle grinder or a hacksaw, for the introduction of the control damper of the damper. This notch to be cut should be so long in the transverse direction of the channel that an adjusting flap somewhat smaller than the inner diameter of the channel can be threaded into the channel. Thus, the inherent stiffness of the channel is not substantially impaired by var-20 zinc when the cut groove is supported around the tube by a tightenable collar. Since there is a seal on the inner surface of the collar, the groove cut in the tube can be sealed effectively. Since the collar and thus also the associated seal have some width, it is also able to cover and seal such an air conditioner - „* ·. a slot in the hub that is not nearly perpendicular to the axial direction of the channel. Thus, the installation of the control flap according to the invention does not require very high accuracy.

Preferably, the axis of rotation of the control valve is at least run. · Threaded in its part resting on the whole part, the body part being with an internal threaded sleeve, such as an internal threaded rivet, provided with an internal thread ____ at the shaft bushing point.

It is further preferred that a threaded nut, such as a wing nut, is threaded on the threaded portion of the shaft of rotation.

To lock in relation to the bushing. Such use of a threaded axis of rotation makes it possible to support the axis of rotation and thus also the control flap in the bushing. Since the rotary shaft is locked in position by means of a nut which is screwed onto it and pressed against the 5 bushings, the bushing is also obtained substantially tight when the threads of the rotary shaft are forced against the threads of the bushing by means of this tightening nut.

In the following, the damper according to the invention will be described in more detail with reference to the accompanying drawing, in which Fig. 1 shows the damper according to the invention seen from the front and Fig. 2 shows the damper according to Fig. 1 seen from the rear.

The exemplary embodiment of the control damper according to the invention shown in Figures 1 and 2 comprises a metal collar, such as a conventional steel packing pallet body part 1, bearing a plain and shaped generally welded to the threaded shaft 2 by means of a bushing 20 such as an internal threaded rivet 6 circular adjusting flap 3. Connected to the ends of the collar 1 are means 4 for tightening this collar as a rim around the air duct. In the embodiment shown, these means 4 comprise lugs 8 bent at the ends of the collar, into which holes have been made by stamping or drilling. One of these holes is riveted with an internal thread rivet 9 into which a nut 10 inserted through a hole in the second lug 8 is threaded. Of course, as these means for tightening the collar 30 as a rim around the tube, generally known, possibly adjustable clamping latches or the like could be used.

A seal 5 of elastic material, such as cellular rubber, is arranged on the inner surface of the collar 1 and thus on the surface facing the outer surface of the air conditioning duct. This seal 4 87835 substantially corresponds in width to the width of the collar 1. Thanks to this width, the slot for the control flap 3 in the air duct can also be made somewhat oblique without the risk of the seal 5 5 not sealing the slot. Most commonly, this slot is made by first drilling a hole in the channel, which will act as a passage point for the axis of rotation 2, and then at this hole a slot is cut in the channel, which may cover slightly less than half of the channel circumference. From such a slot, the inner diameter of the duct with a somewhat outer diameter of the smaller control flap 3 can be introduced into the air-conditioning duct.

In the embodiment of the control damper according to the invention shown in the figures, the axis of rotation 2 is formed of a rod threaded along its entire length, the free end of which is turned substantially at right angles to the axial direction of the axis of rotation 2 to form a handle on this axis of rotation. A cover 11 of rubber or plastic is further fitted at this free end to facilitate rotation 20 of the axis of rotation. An advantage of the handle obtained in this way is that it also indicates a position in which the control flap is inside the channel, since the handle is arranged substantially parallel to the plane of the control flap. To lock the rotary shaft 2 in its desired position, there is a nut threaded on the rotary shaft 25, such as a wing nut 7, which can be tightened against the bushing 6, whereby the rotary shaft 2 can be locked in place. This lock does not have to be opened and thus loses the position information of the control flap even when the control damper is removed from the duct 30, for example for flushing the duct, because after opening the means 4 the collar 1 can be rotated to such a position that the Since the damper according to the invention can thus be simply removed from the duct, there is no need to place an additional cleaning hatch 5 87835 in the vicinity of the damper in the duct 35, as is normally the case.

The positioning of the axis of rotation and thus of the control valve is usually performed on the basis of differential pressure measurements. In order to perform such a differential pressure measurement as simply as possible, the damper according to the invention can be provided with measuring connections. These differential pressure measuring connections can be most simply placed on both sides of the bushing 1 in the collar 1. In this way, when the control flap 3 is slightly rotated away from the position perpendicular to the axial direction of the air supply duct, the measuring connections come to be located on different sides of the flap and thus enable the differential pressure measurement to be performed.

The axis of rotation of the damper according to the invention could also be realized by means of a hollow tube, to which the control flap 15 would be attached to a slot made at the end of this tube. In this way, the lower end of the axis of rotation would be divided into sections opening to different sides of the control flap. Now, by placing thin tubes inside the hollow axis of rotation, which would terminate in precisely these sections on different sides of the control valve, connections could be made in a simple manner for differential pressure measurements. These ends of the axis of rotation, which terminate on different sides of the control valve, could also be at least partially blocked in the axial direction and provided with one or more suitable holes on their sides, so that the pressures on the different sides of the control valve can be more reliably described. va. After all, it is known that the pressure in the air duct varies to some extent as it moves from its central axis towards the duct walls.

In contrast to the embodiment shown in the figures, the control flap 3 itself could also be made of a perforated sheet metal plate instead of the uniform sheet metal plate shown in the figures.

. ···. Such a solution might reduce the flow noise caused by the control. A very interesting possibility is also provided by a flap solution, in which a plate of perforated sheet metal is fastened to both sides of the axis of rotation 35, which is welded to each other at least in part of its circumference. In this way, the pressure reduction in the control valve would be effected in two stages, further enhancing the operation of the control valve and reducing the flow noises caused by it.

The damper according to the invention has been described above with the aid of only one exemplary embodiment and some of its further development forms. Thus, it is to be understood that various modifications may be made to the specifically described embodiment without, however, departing from the scope of the appended claims. Thus, for example, the axis of rotation 2, which is welded to the control flap 3 and terminates in the embodiment shown in the figures relatively close to the edge of the control flap 3, could also extend further 15, for example to the center of the control flap. Such a solution can be considered mainly when there is a need to stiffen the damper 3, as may be the case, for example, in the case of relatively large diameter damper flaps.

Claims (10)

A regulating damper for a ventilation duct system comprising a generally annular or tubular body part (1), a thrust shaft (2) projecting through its wall and rotatably stored therein (2) and a control flap (3) fixed to the rotary shaft (2). ), characterized in that the body part comprises a metal strip end (1), which at its ends is provided with means (4) for tensioning the strip in the form of a band around the ventilation pipe, at which a cutter for inserting the control flap ( 3). Control damper according to claim 1, characterized in that the strip (1) comprises, on the surface lying on the side of the control flap, a seal of elastic material, such as cellular rubber. Control damper according to claim 1, characterized in that the pivot shaft (2) is threaded at least at the part stored in the body part (1), whereby the body part (1) is at the point of entry of the shaft (2). seen with an insertion hole (6) with an inner thread, such as a rivet with an inner thread. Control damper according to claim 3, characterized in that on the threaded part of the rotary shaft (2) a nut (7), such as a wing nut, is rotated to read the shaft (2) in relation to the feedthrough (6). Control damper according to claim 1, characterized in that the body part comprises on both sides of the pivot shaft's bore for bounce differential measurement. Control damper according to claim 1, characterized in that the pivot shaft is tubular and that the control flap is fixed in a cutter made in the pivot shaft. 7. A damper as claimed in claim 6, characterized in that two tubes operating for pressure differential measurement are arranged inside the tubular pivot axis, which at their ends on the side of the control flap open p4 different sides of the control flap. 8. A regulating damper according to claim 7, characterized in that one or more heels are made on different sides of the control flap located on the tubular rotary shaft. Control damper according to claim 1, characterized in that the control flap is perforated. Control damper according to claim 1, characterized in that the control flap comprises two perforated plates, which are located on different sides of the rotary shaft and welded at their circumferences to each other.