Device for control of air flow rates to the instrument panel air outlets of a vehicle heating or air conditioning unit

A device for control of the air flow rates into the instrument panel air outlets of a vehicle heating or air conditioning unit is described that is provided with a casing, with damper doors for both instrument panel side air outlets in the casing parts and at least one damper door for the instrument panel central air outlet in the casing part, whereby the damper doors are pivotably supported on one common shaft. Exactly one closing position is assigned to the damper doors in the first casing part, whereas several closing positions are assigned to the damper door in the second casing part continuously over a pivoting range of the shaft, whereby the closing position of the damper doors is arranged in the pivoting range of the damper door. This device enables separation and independent control of the air flow rates.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application Serial Number 102005047253.2-16, filed Oct. 1, 2005, the entire disclosure of which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a device for the control of the air flow rates into the instrument panel air outlets of a vehicle heating or air conditioning unit that achieves improvement of the separation and control of the air flow.

BACKGROUND OF THE INVENTION

In many configurations of air conditioning units, the air flow rates into the side outlets of the instrument panel are defined for the window ventilation mode, the floor/window intermediate mode and the floor ventilation mode. This air is used to prevent the side windows from fogging or icing up and to deliver some warm air between the cold window and the passengers in order to enhance the temperature comfort. In most cases, the air conditioning unit is equipped with one or several damper doors at the openings for the side regions and the central region of the instrument panel. Thereby, the flow path to the central region of the instrument panel must be configured closable by use of the appropriate damper door while the flow path to the side openings of the instrument panel keeps opened. Frequently, the outlet of air into the side regions of the instrument panel is ensured by that at the instrument panel side outlet damper doors, there are holes and/or regions that cannot be closed at all. It is disadvantageous of these designs that, with the exception that the hole sizes at the outlet damper doors are dimensionable, they do not allow the air flow rate into the side regions of the instrument panel to be controlled. The air flow rate can only be tuned for one ventilation mode, for example, the floor mode. For other modes such as the window mode or the floor/window intermediate mode, there is no possibility at all to adapt the air flow rate exiting through the side openings of the instrument panel.

Devices for control of several different air flow rates are disclosed in the following documents.

In DE 100 48 529 A1, the different air flow rates are set by means of at least two damper doors mounted on a shaft. By rotating only one shaft, the damper doors mounted on said shaft can be moved. The single damper doors include means for adjustable, opposite-sense setting of several air flow rates to different air guiding channels. As an advantageous embodiment, it is recommended that the at least two damper doors mounted on the shaft should be oriented at an angle of 60° to each other. In this way, by simple means, the possibility is raised to provide several air guiding channels with the desired air flow rates using one single mechanical component. A disadvantage of this embodiment is that no independent control of the air flow rates through one or several damper doors is possible when one of these damper doors is closed.

In DE 101 35 330 A1, a drive mechanism for damper doors is described that serve to control the flow through air guiding channels of a vehicle heating or air conditioning unit. Several damper doors, preferably three, are operated by means of a common drive. One of the damper doors is only moved over part of the opening or closing motion of the other damper doors but held in a closing position for the remaining part of the pivoting motion. A common drive is provided with at least one gear wheel which engages with segment gears of both damper doors, whereby a segment gear the next to last tooth of which is omitted is assigned to one of the damper doors so that the toothing can get out of gear. At the same time, a lever connected with the segment gear engages with the gate ensuring continued holding of the damper door in the closing position. An offset pair of teeth located outside the toothing plane ensures defined re-engagement of the separated gears. The advantage of such a design is that it enables to move different damper doors on one shaft and hold, however some of them in the closing position independent of the other ones. Disadvantageous are the material and cost efforts for such an expensive realization.

It is the objective of the present invention to establish an instrument panel damper door device in the casing of a vehicle heating or air conditioning unit while maintaining the advantages of the art, such that separation and independent control of the air flow rates is achieved with means that are plain in design.

SUMMARY OF THE INVENTION

Consistent and consonant with the present invention, an instrument panel damper door device in the casing of a vehicle heating or air conditioning unit wherein separation and independent control of the air flow rates is achieved with means that are plain in design, has surprisingly been discovered.

In one embodiment of the invention, an instrument panel damper door device for control of air flow rates into instrument panel air outlets of a vehicle heating and air conditioning unit comprises: a casing with a first damper door for a first instrument panel air outlet in a first casing part and a second damper door for an instrument panel central air outlet in a second casing part, whereby the first damper door and the second damper door are pivotably supported on a common shaft, wherein one closing position is assigned to the first damper door and a plurality of closing positions are assigned to the second damper door over a pivoting range of the shaft, and wherein the closing position of the first damper door is arranged in the pivoting range of the shaft.

The problem of the invention is solved by the features described above.

The device for the control of the air flow rates into the instrument panel outlets of a vehicle heating or air conditioning unit comprises a casing with damper doors for both instrument panel side outlets and at least one damper door for the instrument panel central outlet. All damper doors are pivotably supported on a common shaft, that is, they can be moved simultaneously by rotating said shaft, which is preferably positioned central between the damper door wings. One closing position is assigned to the side damper doors over a defined pivoting range of the shaft. Several closing positions, however, are as signed to the central damper door, that is the closing position is continuously maintained over the defined pivoting range of the shaft. The one closing position of the side damper doors is established within the pivoting range of the common shaft wherein the central damper door remains closed. Preferably, the pivoting range of the shaft is configured to extend over an angle from 0° to 38°.

Concerning the shape of its inner walls, the casing part in the region of the side damper doors differs from the casing part in the region of the central damper door. Thus at least one inner wall of the casing part, for example the lower one, is configured as a planar surface parallel to the outer edge of the damper door in the pivoting range of a side damper door.

On the other hand, in the pivoting range of the central damper door, the casing part along the lower inner wall is preferably configured as a concave cylinder element. Preferably, the single damper doors are configured as pairs of damper door wings positioned opposite to each other on the shaft. In another advantageous embodiment of the invention, the damper doors on the common shaft are oriented in phase, at an angle of 0° to each other.

Preferably, in the casing part that comprises the pivoting range of the side damper doors, the upper and lower inner walls are planar surfaces parallel to each other.

In the central casing part, the pivoting range of the central damper door, preferably two concave cylinder segments oppose each other, whereby one segment is established on the upper inner wall and the other segment is established on the lower inner wall. The concave cylinder segments can be formed by projections on the inner walls. In a preferred embodiment, the cylinder segment on the upper inner wall is formed by two nose-like projections, while in another embodiment the cylinder segment located opposite starts at the lower edge of the lower inner wall and is then formed by only one nose-like projection.

In an alternative embodiment the cylinder segments opposite to each other are not formed by projections on the casing wall but by a recess in form of a cylindrical widening of the casing.

The common shaft preferably extends longitudinally axially through the entire casing of the device. Preferably, three damper doors in all are moved at the common shaft, whereby, preferably again, two damper doors are provided for both instrument panel side air outlets and one damper door is provided for the instrument panel central air outlet.

The invention enables one to adjust the instrument panel damper doors by means of the common shaft such that the air exits to the instrument panel sides, while the central outlet remains closed. The central outlet remains closed, because the outer edges of the central outlet damper door bear against the inner walls of the casing still sealing. Both side damper doors, however, do not bear against the inner walls of the casing. On the contrary, they form open cross-sections between the outer longitudinal edges of the damper door and the inner casing walls with the area of the open cross-sections dependent on the damper door angle positions.

Preferably in the region of the instrument panel central outlet damper door, at the upper and lower inner casing walls, the casing has two concave-bent surfaces opposite to each other that together form a circular cylinder segment, whereby both damper door wings take up the radius of the circular cylinder segment. Hence the central opening damper door moves into the circular cylinder segment in such a way that no open cross-section for an air flow outlet from the central opening of the instrument panel is available, because the longitudinal edges of the damper door wings bear against the wall of the circular cylinder segment in sealing manner.

At the side openings of the instrument panel, however, the casing is not configured cylindrical but preferably, has planar inner surfaces opposite to each other running parallel. When the damper doors are open, the air can flow through the channel to the side of the instrument panel. Thus the air flow rate can be controlled by the damper door angle position using the shaft. The cylindrical-shaped segment in the casing region of the central instrument panel preferably should cover a pivoting range from 0° to 38°, wherein the damper door bears against the cylindrical part of the inner wall of the casing sealing with its outer edges, hence holding the instrument panel central air outlet closed yet.

The invention allows for the instrument panel central outlet closed to independently control the air flow rates to the instrument panel sides by setting the damper door angles. So the different settings of the air flow to the instrument panel sides for the window mode, the floor/window intermediate mode and the floor mode are achievable.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The device1has two instrument panel side air outlets1.1toFIG. 1aand an instrument panel central air outlet1.2toFIG. 1b. The outlets1.1,1.2are substantially aligned in a common plane.

The device1for the control of the air flow rates into the instrument panel air outlets of a vehicle heating or air conditioning unit comprises, at its instrument panel side air outlets1.1toFIG. 1a,the part2.1of the casing2with a damper door3.1each for either instrument panel side air outlet1.1. Both damper doors3.1are pivotably supported on a common central shaft4which extends longitudinally axially through the entire casing2. The shaft4is preferably placed approximately in the centre of the casing part2.1. On both sides of the shaft4, the shaft4is provided with damper door wings5.1and6.1which have outer longitudinal edges7.1and8.1, forming what is known in the art as a butterfly damper door.

In the device1of the invention the casing part2.1has planar inner surfaces in the pivoting region of the damper doors3.1. Preferably, in the pivoting region of the damper door3.1, the part2.1of the casing2is configured such that the lower inner wall9.1and the upper inner wall10.1are parallel planar surfaces in three-dimensional space. The upper inner wall10.1is wider than the lower inner wall9.1, therefore projecting in direction of the passenger compartment longer than the lower inner wall9.1. The continuous line inFIG. 1adefines a damper door angle position14of the damper door3.1which is also the closing position as in this position14the outer longitudinal edges7.1,8.1bear against the inner walls9.1,10.1in sealing manner. Being pivoted within the pivoting range13the damper door3.1can move into position15which is identified by the dotted line. ToFIG. 1a,position15shows the side damper doors3.1in an open position. In this case, in position15, the outer longitudinal edges7.1,8.1of the side damper doors3.1do not bear against the inner walls9.1,10.1.FIG. 1aindicated that the position14is the only possible closing position of the side damper doors within the pivoting range13.

According to the invention, the device1further comprises the casing part2.2toFIG. 1bwith a damper door3.2for the instrument panel central air outlet. The damper door3.2is also pivotably supported on the common central shaft4which extends longitudinally axially through the entire casing2, and hence is located between both damper doors3.1.

According to the invention, the inner walls9.2and10.2of the casing part2.2, which are placed opposite to each other, are not configured continuously planar. In side view, toFIG. 1b, part of the lower inner wall9.2is configured as concave circular-arc segment11, and part of the upper inner wall10.2is configured as concave circular-arc segment12. The concave circular-arc segments11and12located opposite to each other define, together with the surfaces longitudinally adjacent within the casing part2.2, a shape that can be considered a segment of a circular cylinder.

The circular-arc segments, or cylinder segments11and12are arranged on the casing inner walls9.2and10.2in such a way that the damper door wings5.2and6.2of the damper door3.2correspond to the radius of the above-mentioned circular cylinder within the pivoting range13. Hence the damper door3.2with its outer longitudinal edges7.2and8.2bears against the cylindrical-shaped region of the inner casing wall in sealing manner, whereby this region is formed by the concave cylinder segments11and12opposite to each other.

So the central damper door3.2closes the path of the air flow into the central part of the instrument panel within the pivoting range13. As the damper door angle positions14and15toFIG. 1bare inside the pivoting range13, both positions as well as all positions in between are closing positions.

The function of the device1becomes apparent by coherent consideration ofFIGS. 1aand1b.

The side damper doors3.1are open in the damper door angle position15dotted shown inFIG. 1a.Preferably in phase, that is at the equivalent damper door angle position15on the common shaft4, the instrument panel central damper door3.2, also dotted inFIG. 1b,within the pivoting range13still bears with its outer edges7.2and8.2against the cylindrical-shaped inner wall of the casing part2.2in sealing manner. In contrast to the damper doors3.1for the instrument panel side air outlets, the central damper door3.2is still at closing position when at position15of the dotted line.

In an embodiment of the invention the concave cylinder segments11and12are formed by projections on the inner walls9.2and10.2.

Preferably, the concave circular-arc segment or the cylinder segment12is formed by two nose-like projections16and17at the upper inner wall10.2of the casing. Also in the casing part2.2, the upper inner wall10.2is wider than the lower inner wall9.2and therefore is longer than the lower inner wall9.2projects in direction of the passenger compartment. The lower circular-arc segment or the cylinder segment11preferably starts at the lower edge18limiting the lower inner wall9.2in direction of the passenger compartment and is then formed by only one nose-like projection19.

In another advantageous embodiment of the invention the cylindrical-shaped segment which is formed by both opposite concave cylinder segments11and12in the casing part2.2images a pivoting range13from 0° to 38°, wherein the central damper door3.2with its outer longitudinal edges7.2and8.2still bears against the cylindrical-shaped inner wall of the casing part2.2and hence is at closing position.

Within the pivoting range the air flow rate which is to pass through the instrument panel side outlets is controlled by the size of the open cross-sections between the outer longitudinal edges7.1, or8.1, respectively, and the inner walls9.1, or10.1of the casing part2.1.

In another advantageous embodiment of the device1for control of the air flow rates, there are defined damper door angle positions of the damper doors3.1for the following ventilation modes:for the window mode,for the floor/window intermediate mode, andfor the floor mode.

As all three settings are within the pivoting range, in which the instrument panel central outlet is still closed, this embodiment establishes an independent control of the air flow rates flowing to the instrument panel sides.

Nomenclature

1device1.1instrument panel side air outlets1.2instrument panel central air outlet2casing2.1casing part of the damper doors for the instrument panel side air outlets2.2casing part of the damper door for the instrument panel central air outlet3.1instrument panel side damper doors3.2instrument panel central damper door4shaft for all damper doors5.1damper door wing for side damper door5.2damper door wing for central damper door6.1damper door wing for side damper door6.2damper door wing for central damper door7.1lower longitudinal edge of a side damper door3.17.2lower longitudinal edge of the central damper door3.28.1upper longitudinal edge of a side damper door3.18.2upper longitudinal edge of the central damper door3.29.1lower inner wall of the casing part2.19.2lower inner wall of the casing part2.210.1upper inner wall of the casing part2.110.2upper inner wall of the casing part2.211cylinder segment12cylinder segment13pivoting range of the damper doors3.1and3.2at closing position of3.214closing position of3.115open position of damper door3.116nose-like projection at the upper inner wall10.217nose-like projection at the upper inner wall10.218edge at the lower inner wall9.219nose-like projection at the lower inner wall9.2