GB2336204A

GB2336204A - Heating or air-conditioning system

Info

Publication number: GB2336204A
Application number: GB9908183A
Authority: GB
Inventors: Klaus Arold
Original assignee: DaimlerChrysler AG
Current assignee: Daimler AG
Priority date: 1998-04-11
Filing date: 1999-04-09
Publication date: 1999-10-13
Anticipated expiration: 2019-04-09
Also published as: IT1307551B1; FR2777226A1; ITRM990214A1; GB2336204B; GB9908183D0; DE19816332C1

Abstract

A heating or air-conditioning system for ventilating a passenger cell of a vehicle, has an air-conditioning cabinet 10 with an air-flow heat exchanger 11 and an air-mixing chamber 13, 14 which has an air inflow orifice 16 for hot air flowing through the heat exchanger, a air inflow orifice 17 for cold air flowing round the heat exchanger 11 and outlet orifices 22, 24 for mixed air, of which at least one outflow orifice 24 is arranged at the bottom in the air-mixing chamber and at least one outflow orifice 22 is arranged at the top in the air-mixing chamber 13, 14, and with closing members 18, 19 controlling the orifice cross sections of the inflow orifices 16, 17. In order to achieve a temperature drop between the lower and the upper outflow orifices, the closing member 19 for the cold-air inflow orifice is in two parts, in such a way that an upper closing-member part 191 completely covers the upper region of extent and a lower closing-member part 192 the lower region of extent of the cold-air inflow orifice 17, and the two closing-member parts 191, 192 are controlled in such a way that, in any closing-member position, the lower closing-member part 192 covers a larger orifice cross section of the cold-air inflow orifice than the upper closing-member part 191.

Description

1 Heating or air-conditioning system 2336204 The invention relates to

heating or air-conditioning system for ventilating a passenger cell of a vehicle, with an air-conditioning cabinet which has an air-flow heat exchanger and at least one air-mixing chamber which has a hot air inflow orifice for hot air flowing through the heat exchanger, a cold air inflow orifice for cold air flowing round the heat exchanger and outflow orifices for the mixed air, of which at least one outflow orifice for ventilating the footwell andlor the rear compartment of the passenger cell is arranged at one side of the air- mixing chamber and at least one outflow orifice for ventilating the centre plane and/or the head area of the passenger cell is arranged at another side of the air-mixing chamber, and with closing members controlling the orifice cross sections of the inlet orifices.

In a known heating or air-conditioning system of this kind (US 5,016,704), the closing member for controlling the cold-air inlet orifice is designed as a pivotable air flap which, in one pivoting end position, completely covers the cold-air inlet orifice and, in its other pivoting end position, completely covers the air inlet surface of the heat exchanger, whilst at the same time opening the cold-air inflow orifice. By means of a suitable pivoting position of the air flap, the hot-air and cold-air streams flowing into the air-mixing chamber can be set in such a way that the mixed air in the distributor chamber has a desired temperature. This air is distributed, via the various mixed-air outlet orifices, to the footwell, the centre plane and the head area of the passenger cell, the air quantities for the individual zones being capable of being metered by means of adjusting flaps assigned to the mixed-air outlet orifices. All the zones of the passenger cell thereby receive air at the same temperature.

It is advantageous, for the passenger's comfort, to keep the temperature of the conditioned air flowing into the centre plane and into the head area lower than the temperature of the air flowing into the footwell. In order to achieve this, it has already been proposed in a heating or airconditioning system (earlier German patent application 198 04 287.6 not prior published) to provide an additional cold-air duct which opens out in an air duct leading away from the mixed-air outlet orifice for the centre plane and which can be controlled by means of an air flap. By the air flap being appropriately opened or closed, more or less cold air can be added to the mixed air 2 emerging from the mixed-air chamber and, consequently, the temperature of the air flowing into the centre plane can be lowered to a greater or lesser extent, as compared with the temperature of the footwell air.

The present invention seeks, in a heating or airconditioning system of the type mentioned in the introduction, to implement, at little technical outlay, a reduction in temperature of the air flowing into the centre plane and/or into the head area of the passenger cell, as compared with the air entering the footwell, and thereby to lower the production costs of the system.

According to the present invention there is provided a heating or airconditioning system for ventilating a passenger cell of a vehicle, with an airconditioning cabinet which has an air-flow heat exchanger and at least one air-mixing chamber which has a hot air inflow orifice for hot air flowing through the heat exchanger, a cold air inflow orifice for cold air flowing round the heat exchanger and outflow orifices for the mixed air, of which at least one outflow orifice for ventilating the footwell and/or the rear compartment of the passenger cell is arranged at one side of the air-mixing chamber and at least one outflow orifice for ventilating the centre plane and/or the head area of the passenger cell is arranged at another side of the airmixing chamber, and with closing members controlling the orifice cross sections of the inlet orifices, wherein the cold-air inflow orifice extends both over the region of the upper and over the region of the lower mixed-air outlet orifices, the closing member for the cold-air inflow orifice is in two parts, in such a way that an upper closingmember part can completely cover the upper region of extent and a lower closingmember part the lower region of extent of the cold-air inflow orifice, and the two closing-member parts are controlled in such a way that, in any closing-member position, the lower closing-member part covers a larger orifice cross section of the cold-air inflow orifice than the upper closing-member part.

The heating or air-conditioning system according to the invention has the advantage that, by virtue of the fact that the closing member for the cold-air inlet orifice of the air-mixing chamber is subdivided and the closing-member parts are controlled in such a way that the lower closingmember part always covers a larger orifice cross section of the cold-air inlet orifice than the upper closingmember part, always less cold air enters the lower region of the air-mixing chamber, in which region 3 the outlet orifice for the footwell is arranged, than the upper region of the air-mixing chamber, in which region the outlet orifice for the centre plane andlor the head area is arranged. Consequently, temperature stratification is established in the air-mixing chamber, with a temperature drop from the air outlet orifice for the footwell towards the outlet orifice for the centre plane andlor the head area, so that the centre plane and/or the head area arelis always supplied, directly from the air-mixing chamber, with air at a lower temperature than is the footwell. Additional devices, such as a cold-air duct with a control flap, may be dispensed with, so that the production costs are reduced due to these components being omitted.

According to advantageous embodiments of the invention, the two closingmember parts may in each case be driven by a separate actuating element or be rigidly synchronized with or mechanically coupled to one another. In the first case, temperature stratification in the air-mixing chamber can be set individually, and, in the second case, air stratification is predetermined as a consequence of the overall concept.

Advantageous embodiments of the heating or air-conditioning system according to the invention, together with expedient designs of the invention, may be gathered from the other claims.

According to a preferred embodiment of the invention, there is arranged between the two closing-member parts a partition which subdivides the cold-air inflow orifice, is continued into the air-mixing chamber as far as the rear wall of the latter located opposite the cold-air inflow orifice and separates the upper and lower mixed-air outlet orifices from one another. Preferably, the partition subdivides the air-mixing chamber only in the region of the two closing-flap parts, not completely. This design measure makes it possible, at little technical outlay, to achieve very good air stratification in the air-mixing chamber between the lower and the upper air outlet orifices for the footwell and the centre plane andlor head area.

The invention is described in more detail below with reference to an embodiment illustrated in the drawing. In the diagrammatically illustrated drawing:

Figure 1 shows a horizontal cross section through an air-conditioning cabinet of a heating or air-conditioning system, Figure 2 shows a section along the line II-II in Figure 1.

The air-conditioning cabinet 10, illustrated diagrammatically in a 4 sectional top view in Figure 1, of a heating or air-conditioning system is connected on the entry side, in a known way, to a blower which is not illustrated here. The airconditioning cabinet 10 receives an air-flow heat exchanger 11 which is preceded by an evaporator 12, as seen in the air-flow direction, in the version as an air-conditioning system. A heating medium flows in a known way through the heat exchanger 11, for which purpose the cooling water of the internal combustion engine of a vehicle is normally used. Two air-mixing chambers 13, 14 arranged next to one another and separated by a partition 15 are designed in the airconditioning cabinet 10 downstream of the heat exchanger 11 in the airflow direction, the said air-mixing chambers serving for supplying air respectively to the right-hand and left-hand sides of the passenger cell of the vehicle. The air-mixing chambers 13, 14 are designed identically and are equipped with the same elements for air control, so that reference is made below only to the air-mixing chamber 13, although the same remarks also apply to the air-mixing chamber 14.

The air-mixing chamber 13 has a hot-air inflow orifice 16, which is arranged downstream of the heat exchanger 11 and which is picked up directly at the air outlet surface 111 of the heat exchanger 11, and a cold-air inflow orifice 17, which is arranged laterally of the heat exchanger 11 and via which cold air coming directly from the evaporator 12 and flowing round the heat exchanger 11 can flow into the airmixing chamber 13. Each inflow orifice 16, 17 is provided with a closing member 18, 19 for controlling the orifice cross section of the inflow orifice 16, 17. In the embodiment of Figure 1, the closing member 18 of the hot-air inflow orifice 16 is designed as a construction-space-saving shutter 20 having a multiplicity of narrow pivoting slats which are arranged next to one another and which, in their entirety, can cover the hot-air inflow orifice 16. The closing member 19 for the cold-air inflow orifice 17 is described in more detail below. For ventilating the passenger cell with conditioned air, the air-mixing chamber 13 has a plurality of outflow orifices which are continued in air outflow connection pieces for the connection of air ducts leading into various regions of the passenger cell. Thus, the outflow orifice 22 arranged at the top in the air-mixing chamber 13 and having the connection piece 23 adjoining it (Figure 2) serves for supplying air to the centre plane and/or the head area of the passenger cell, specifically for the right-hand half of the passenger cell, whilst the outflow orifice 24 arranged at the bottom in the air-mixing chamber 13 and having an associated connection piece 25 serves for ventilating the footwell and/or the rear compartment on the right-hand side of the passenger cell. The air-mixing chamber 14 has corresponding outflow orifices and connection pieces for ventilating the left-hand side of the passenger cell.

The two air inflow orifices 16, 17 are designed with a large area and extend both over the region of the upper outflow orifice 22 and over the region of the lower outflow orifice 24. The closing members 18, 19 for controlling the air inlet cross section of the inflow orifices 16, 17 are designed with a correspondingly large area. In order to achieve temperature stratification in the air-mixing chamber 13, with a temperature drop from the bottom upwards, that is to say from the region of the lower outflow orifice 24 towards the upper outflow orifice 22, the closing member 19 is designed in two parts, in such a way that an upper closing-member part 191 can completely cover the upper region of extent and a lower closing-member part 192 the lower region of extent of the cold-air inflow orifice 17. The two closing-member parts 191, 192 are controlled in such a way that, in any closing-member position, the lower closing-member part 192 covers a larger orifice cross section of the coldair inflow orifice 17 than the upper closing-member part 191. In the embodiment illustrated, the two closing-member parts 191, 192 are designed as air flaps 26, 27 which are seated on a common pivoting shaft 28 mounted pivotably in the air-conditioning cabinet 10. In this case, the two air flaps 26, 27 are rotated relative to one another through a fixed pivot angle a and are rigidly connected to one another via the pivoting shaft 28. Consequently, as illustrated in Figure 1, during the opening movement of the closing member 19, the upper air flap 26 always leads the lower air flap 27 by the amount of this constant pivot angle a, so that, in any pivoting position, the lower air flap 27 always covers a larger orifice cross section of the cold-air inflow orifice 17 than the upper air flap 26. In Figure 1, the closed position of the closing member 19 is illustrated by unbroken lines and a pivo ting position of the closing member 19 during the opening movement is illustrated by dashed lines. In this pivoting position, the upper air flap 26 opens the orifice cross section a of the cold-air inflow orifice and the lower air flap 27 opens the orifice cross section b of the cold-air inflow orifice 17. Consequently, in any pivoting position, more cold air flows in in the upper region of 6 extent of the cold-air inflow orifice 17 than in the lower region of extent of the cold-air inflow orifice 17, and the desired temperature stratification, with the temperature drop from the bottom upwards, is established.

In order to improve this air stratification, a partition 29 subdividing the cold-air inflow orifice 17 horizontally is arranged between the upper air flap 26 and the lower air flap 27, the said partition being continued in the air-mixing chamber 13 as far as its wall 131 opposite the cold-air inflow orifice 17. The partition 29, which passes through only part of the air-mixing chamber 13 and reaches as far as the side wall 132 of the air-mixing chamber 13, in which side wall the two outflow orifices 22, 24 for the mixed air are arranged, therefore blocks the direct air path between the two mixed-air outflow orifices 22, 24, so that, in a mixedair setting, the hotter air is below the partition 29 and the colder air above the partition 29 and they can be intermixed only by flowing round the partition.

The invention is not restricted to the embodiment described. Thus, the two air flaps 26, 27 do not have to be rigidly connected to one another via a common driven pivoting shaft 28, but, instead, each air flap 26, 27 may be assigned an independent actuating drive, the actuating drives being controlled either synchronously or individually. Also the system may be adapted for a heating system using ambient air instead of the air cooling climate control system of the preferred embodiment.

7

Claims

1. A heating or air-conditioning system for ventilating a passenger cell of a vehicle, with an air-conditioning cabinet which has an air-flow heat exchanger and at least one air-mixing chamber which has a hot air inflow orifice for hot air flowing through the heat exchanger, a cold air inflow orifice for cold air flowing round the heat exchanger and outflow orifices for the mixed air, of which at least one outflow orifice for ventilating the footwell andlor the rear compartment of the passenger cell is arranged at one side of.the air-mixing chamber and at least one outflow orifice for ventilating the centre plane and/or the head area of the passenger cell is arranged at another side of the air-mixing chamber, and with closing members controlling the orifice cross sections of the inlet orifices, wherein the cold-air inflow orifice extends both over the region of the upper and over the region of the lower mixed- air outlet orifices, the closing member for the cold-air inflow orifice is in two parts, in such a way that an upper closing-member part can completely cover the upper region of extent and a lower closing-member part the lower region of extent of the cold- air inflow orifice, and the two closing-member parts are controlled in such a way that, in any closing-member position, the lower closing-member part covers a larger orifice cross section of the cold-air inflow orifice than the upper closing-member part.

2. A system according to Claim 1, wherein there is arranged between the two closing-member parts a partition which subdivides the cold-air inflow orifice, is continued into the air-mixing chamber as far as its rear wall opposite the cold-air inflow orifice and separates the upper and lower mixed-air outflow orifices from one another.

3. A system according to Clahn 2, wherein the partition subdivides the airmixing chamber completely.

4. A system according to Claim 1, 2 or 3, wherein the two closing member parts are synchronized with one another in such a way that the difference in the degree of coverage of the upper and lower regions of extent of the cold-air inflow 8 orifice by the closing-member parts is consistent in any closing-member position.

5. A system according to Claim 4, wherein the two closing-member parts comprise air flaps pivotable about the same pivoting shaft, and the two air flaps are rotated relative to one another through a pivot angle (a) and are fixedly connected to one another.

6. A system according to Claim 5, wherein the two air flaps are arranged fixedly in terms of rotation on a pivoting shaft mounted pivotably in the air conditioning cabinet.

7. A heating or air-conditioning system for ventilating a passenger cell of a vehicle, substantially as described herein with reference to and as illustrated in the accompanying drawings.