EP0658728A2 - Device for changing the volume of the air flow into a room - Google Patents

Abstract

For changing the volume of the airflow into a room, there is proposed a device with a flap (4) which is pivotable about a shaft (3). The flap (4) is equipped with a carrying arm (7) which is fitted with a displaceable weight (8). Whereas the flap (4) is pivotable through an acute angle phi , the carrying arm (7) with the weight (8) can pivot through an angle phi + phi 1. On the basis of the characteristic curve, the flap (4) opens and closes automatically, given appropriate differential pressures and acting flow forces. Depending on the angular position of the carrying arm (7) with respect to the flap (4) and depending on the position of the weight (8) with respect to the shaft (3), the flap (4) opens at a differential pressure DELTA pmax. Owing to the mass inertia, the flap (4) swings open, the pivoting movement of the carrying arm (7) additionally through the angle phi 1 accelerating the opening and preventing undesired states of equilibrium in intermediate positions of the flap (4). <IMAGE>

Description

The invention relates to a device for applying a variable air volume flow to a room, consisting of a flap pivotally mounted about an axis in a housing. A support arm is attached to this in the area of the axis, which is equipped with a displaceable weight or is connected to an adjustable spring.

From G 81 21 352.2 U1, such a device, designed as a pressure reducer for air ducts, is known, which is followed by a volume flow controller. So that the pressure reducer generates an approximately constant differential pressure even with variable volume flows, the area of the throttle valve is smaller than the assigned flow cross-section in the housing, a weight which is adjustable in its position relative to this being arranged on the throttle valve. The different effects of the flow forces on the surface sections of the throttle valve on both sides of the swivel axis, on the one hand, and the weight, on the other hand, are intended to produce return torques which lead to the generation of a differential pressure that is approximately constant even with variable volume flows. In addition, flapping and vibratory movements of the throttle valve are to be suppressed with this training.

For energetic reasons, it may be necessary to reduce them considerably in the partial load range when a room is exposed to variable volume flows. In many cases, the application limits of the different types of air diffusers are left. In order to expand the application limits, it is generally known to shut off either a part of the passages or partial lengths of linear passages by means of motor-operated closing flaps or slides, and thereby the unblocked remaining passages or partial lengths to be charged with a sufficiently large volume flow. While on the one hand the operating limit of an air outlet is determined by the minimally necessary momentum of the air at the outlet cross-section of the air outlet, on the other hand the application limit of an air outlet is determined by the fact that an excessively high momentum of the air at the outlet cross-section impairs comfort, by excessively high indoor air velocities, temperature differences and noise occur.

The invention is based on the object of designing a device of the type described in the introduction such that the air passages can be activated or deactivated individually or in groups, depending on the pressure prevailing in a duct system, completely or in particular in the case of linear passages, with different volumetric flows, in this way being complex , the outlet cross sections of the air passages changing individual devices are unnecessary.

To achieve this object, a device of the type mentioned in the preamble of claim 1 is assumed, which according to the invention has the features specified in its characterizing part.

Due to the additional pivotability of the support arm according to the invention by an acute angle φ ₁, the device assumes a switching function in that the flap is spontaneously automatically transferred to the closed or open position when the minimum or maximum duct pressure is exceeded or undershot, without being in an intermediate position remain. Based on its control characteristic, the flap is safely transferred to one of its two end positions depending on the duct pressure and held therein.

Individuals or a group of air passages, which are _preceded by a device according to the invention, are cut off spontaneously from the air supply when the valve _{falls below} a minimum pressure _.DELTA.pmin . If a maximum pressure Δ _pmax is _exceeded , the The flap, on the other hand, opens spontaneously, causing air to be applied to all air outlets, as a result of which the duct pressure drops.

In the case of a linear air outlet, this can be divided into two identical or unequal partial lengths by integrating the device according to the invention. In the normal area of application, the flap is in the _{open position} at Δ _pmin <Δ _p <Δ _pmax , so that both partial lengths of the linear air outlet are acted upon. If the pressure _drops below the pressure in the normal range of use at Δ _p <Δ _pmin , the flap pivots into the closed position, which increases the pressure in the duct and increases the jet pulse as a result of the partial loading of the linear air passage. The flap then remains in the closed position within the pressure limits Δ _pmin <Δ _p <Δ _pmax . If Δ _p > Δ _pmax during partial _loading , the flap pivots in the _{open position} , as a result of which the pressure drops again due to the total loading of the linear air passage and the jet pulse is consequently reduced. The flap then remains in the open position within the pressure limits Δ _pmin <Δ _p <Δ _pmax .

Based on the characteristic curve, the flap automatically moves from the open position to the closed position and from the closed position to the open position at corresponding differential pressures. Depending on the design, in particular with regard to the angle between the support arm and the flap as well as the position of the weight or the spring application point to the axis, the flap _swivels into the _open position at a differential _pressure Δ _pmax . The additional pivoting movement of the support arm by the angle φ ₁ accelerates the pivoting movement of the flap and prevents undesirable persistent states in intermediate flap positions.

According to one embodiment of the invention, the support arm articulated to the flap is pivotable about the axis of the flap or about an axis arranged at a distance from the axis of the flap.

Due to the pivoting of the support arm by a distance from the axis the axis of the flap passes through the line of action of force unchanged at the pivot point of the support arm and thus enables the support arm to be folded down by the angle φ ₁, but the line of action of force does not pass through the pivot point of the flap and thereby ensures an additional moment for moving the flap into its end positions.

According to a further embodiment of the invention, the axis about which the flap is pivotable divides it into a smaller and a larger flap section.

Due to the differential pressure, this subdivision results in a moment acting around the axis in the opening direction of rotation, which is opposed by a moment acting in the closing direction by forces resulting from the weight or the spring.

According to a further embodiment of the invention, an outer edge strip of the lower flap section is angled and is inclined at a larger angle to the direction of flow than the flap in the rest.

The angled flap section enables the impulse forces acting on the flap due to the flow to be exploited, which results in an increased torque in the opening direction.

In its closed position, the angled edge strip of the flap is preferably perpendicular to the direction of flow, so that the flap is angled in accordance with the effect of the impulse forces desired in its open position.

According to a further embodiment of the invention, a baffle narrowing the flow cross section is fastened in the housing, the arrangement of which allows the pivoting movement of the flap to be accelerated from the closed position.

The guide plate influences the flow and thus a phase shift of the characteristic curve, so that an angular acceleration of the flap is thereby achieved.

Finally, an embodiment of the invention provides that the flap is directly provided with an additional weight that acts exclusively in the closing direction and is also displaceable.

The arrangement of the additional weight makes it possible to change the level of the differential pressure from which the flap is pivoted from the closed to the open position without having to change the basic setting in the support arm area.

Fig. 1

eine Ausbildung, bei welcher ein an einer Klappe gelenkig befestigter Tragarm unmittelbar auf der Klappenachse schwenkbar ist;

Fig. 2

eine Ausbildung, bei welcher ein an einer Klappe gelenkig befestigter Tragarm um eine in einem Abstand zur Klappenachse angeordnete Achse schwenkbar ist;

Fig. 3

eine Ausbildung gemäß Fig. 2, wobei jedoch am Tragarm anstelle eines Gewichts eine Feder angreift.

In the drawing, three exemplary embodiments of a device according to the invention are shown schematically in a section. It shows:

Fig. 1

an embodiment in which a support arm articulated to a flap is pivotable directly on the flap axis;

Fig. 2

an embodiment in which a support arm articulated to a flap is pivotable about an axis arranged at a distance from the flap axis;

Fig. 3

2, but with a spring acting on the support arm instead of a weight.

The device consists of a broken-off housing 1 in the form of a channel with a rectangular cross section, to which a volume flow can be applied in the direction of an arrow 2.

In the housing 1, a flap 4 is pivotally mounted on an axis 3 passing through it. Axis 3 corresponds to the desired characteristic arranged off-center and divides the flap 4 into an upper smaller and a lower larger flap section.

The flap 4 shown in the closed position and oriented at an angle of 45 ° to the horizontal can be pivoted through an angle φ of approximately 45 ° into the horizontal open position indicated by dash-dotted lines. A lower edge strip 5 of the flap 4 is angled 45 ° downward so that it is oriented at right angles to the horizontal in the closed position of the flap 4.

A baffle 6, which slightly narrows the flow cross section of the housing 1, is arranged in relation to the closed position of the flap 4 in the flow direction behind the edge strip 5 such that the flow cross section is released only after the flap 4 has been partially pivoted to initiate the opening process.

According to the embodiment shown in FIG. 1, a support arm 7 is articulated on the outflow side of the flap 4 and, like the flap 4, can be pivoted about the axis 3 in synchronism with it via an angle φ. The equipped with a displaceable weight 8 support arm 7 is hinged to the flap 4, that the support arm 7 is independent of the flap 4 additionally pivotable by an acute angle φ ₁. The pivoting range of the support arm 7 thus extends over a total angle φ + φ ₁.

An additional weight 9 is also slidably associated with the lower larger flap section, which, in deviation from the weight 8, exerts only a closing force on the flap 4, while the weight 8 has a closing or opening effect on the flap 4 depending on the position of the support arm 7. The weights 8 and 9, which are displaceable in relation to the axis 3, are arranged out of phase by the angle φ ₀ in accordance with the desired characteristic curve.

When the flap 4 is open, the flow cross section of the housing 1 is released, so that those arranged in the flow direction behind the device are not air outlets shown are sufficiently supplied with air. Due to the shape of the flap 4 and the interaction of the phase-shifted weights 8 and 9, the flap 4 is spontaneously completely opened when a Δ _{pmax is} exceeded and remains in the open position until a Δ _{pmin is undershot} . When Δ _pmin is _undershot , flap 4 is also spontaneously transferred to the closed position and held therein until Δ _{pmax is} exceeded.

1 differs essentially in that the support arm 7 'is pivotable about an axis 10 which is associated with the lower flap section at a distance from the axis 3. In this exemplary embodiment, the functions of the weights 8 and 9 from the exemplary embodiment according to FIG. 1 are taken over by the weight 8 alone.

In the embodiment shown in FIG. 3, one end of a pretensioned tension spring 12 is connected to a fixed point 11 of the housing 1, the other end of which acts on the support arm 7 ″ at a connection point 13. The fixed point 11 and the connection point 13 define with the axis 10, about which the support arm 7 '' can be pivoted, in both end positions of the flap 4 an acute-angled triangle, so that the tension spring 12 under increased prestress via a dead center position of the support arm 7 '' pivoted in the opening or closing direction of the flap 4.

Claims (7)

Device for loading a room with a variable volume flow, consisting of a flap pivotally mounted about an axis in a housing, to which a support arm is attached in the region of the axis, which is equipped with a displaceable weight or is connected to an adjustable spring, characterized that the support arm (7) in addition to an acute angle φ, by which the flap (4) can be pivoted between the two end positions defining the closed or open position, can be pivoted by an acute angle φ ₁. Device according to claim 1, characterized in that the support arm (7) articulated on the flap (4) is arranged around the axis (3) of the flap (4) or around a distance from the axis (3) of the flap (4) Axis (10) is pivotable. Device according to claim 1 or 2, characterized in that the axis (3) about which the flap (4) is pivotable divides it into a smaller and a larger flap section. Device according to one of claims 1 to 3, characterized in that an outer edge strip (5) of the larger flap section is angled and is inclined at a larger angle to the direction of flow than the flap (4) in the rest. Device according to one of claims 1 to 4, characterized in that in the closed position of the flap (4) the angled edge strip (5) points perpendicular to the direction of flow. Device according to one of claims 1 to 5, characterized in that a baffle plate (6) narrowing the flow cross section is fastened in the housing (1), the arrangement of which allows the pivoting movement of the flap (4) to be accelerated from the closed position. Device according to one of claims 1 to 6, characterized in that the flap (4) is directly provided with an additional weight (9) which acts exclusively in the closing direction and is also displaceable.

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