GB1559327A

GB1559327A - Heater unit for air-conditioner in automobile vehicles

Info

Publication number: GB1559327A
Application number: GB17824/76A
Authority: GB
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1975-04-30
Filing date: 1976-04-30
Publication date: 1980-01-16
Also published as: FR2309360A1; FR2309360B1

Description

(54) HEATER UNIT FOR AIR-CONDITIONER IN AUTOMOBILE VEHICLES (71) We, HONDA GIKEN KOGYO KABUSHIKI KAISHA, a body Corporate existing under the laws of Japan, of 27-8 Jingumae 6-Chome, Shibuya-Ku, Tokyo-To, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a heater unit which is intended for use in an airconditioner for an automotive vehicle.

In general, it is desirable for reasons of comfort for the air supplied to the lower parts of the interior of the vehicle to be warmer than the air supplied to the upper parts of the vehicle interior. However, the difference in temperature should not be excessive. The invention is intended to make it possible to keep this difference in temperature to an acceptable value.

According to the present invention, a heater unit for an automotive vehicle air conditioner comprises: an air inlet; a first adjustable valve which divides a flow of air entering the air inlet between an air entry of a heat exchanger and a first bypass passage, in proportions dependent on the adjustment of the first valve; the heat exchanger being adapted to heat air supplied to the air entry thereof, and to deliver such heated air to a heated air passage; a second bypass passage leading from the air entry of the heat exchanger to the heated air passage; a second valve which is adjustable to control the flow of air through the second bypass passage; a merging zone into which the first bypass passage and the heated air passage both lead; and a third adjustable valve which is adapted to control the flow of air from the merging zone to first and second outlets, the third valve including a valve member which has a flow-dividing edge, the first outlet being positioned to receive air which passes on one side of the flow-dividing edge, while the second outlet is positioned to receive air which passes on the other side of the flow-dividing edge; the first bypass passage and the heated air passage opening into the merging zone in directions which are generally at right angles to one another and to the said flow-d*iding edge; the valve member of the third valve being movable to shift the flow-dividing edge to produce variations in opposite senses in the cross-sectional areas available for flow past the flow-dividing edge to the first and second outlets respectively; and the first bypass passage, the heated air passage, the second outlet, and the first outlet leading into or out of the merging zone at positions arranged in that order around the merging zone, as viewed along a direction parallel to the flow-dividing edge.

The invention may be carried into practice in various ways, but one specific embodiment will now be described, by way of example, with reference to the accompanying drawings, of which Figure 1 is a schematic diagram showing the general layout of an air conditioning system for automotive vehicles; and Figure 2 is a side elevational view in crosssection showing a heater unit embodying the present invention, which is to be incorporated in the air conditioning system of Figure 1.

Referring now to Figure 1, an airconditioning system for automotive vehicles generally comprises a housing 1 having an inlet opening 2 for external air, an inlet opening 3 for internal air within the vehicle cabin, outlet openings 4 for directing air to the upper parts of the vehicle cabin, and an outlet opening 5 for directing air to the lower parts of the vehicle cabin. Within the housing, there are provided a change-over damper 6, a blower 7, a refrigerant evaporator 8, and a heater unit 9.

Figure 2 illustrates the detailed construction of one form of the heater unit 9 to be installed in the above-described air conditioning device. As show in the drawing, this heater unit is constructed with a housing 10, which has a lateral inlet opening 11 for air which has been cooled by passing through the refrigerant evaporator 8. The housing 10 contains a first valve 12 in the form of a flap attached to a pivot shaft 22; the valve 12 divides the cool air flow entering the housing through the opening 11 into a first portion which flows into a bypass passage 13, and a second portion which flows downwards to the entry 15 of a heat exchanger 14 situated below the valve 12. The heat exchanger 14 is supplied with a hot fluid, normally the engine cooling water, so that the air passing through the heat exchanger is heated.The heater unit also has a second bypass 25 at one side of the heat exchanger 14, leading from the space (indicated at 28) through which air flows into the heat exchanger to a passageway 16 which carries the heated air leaving the heat exchanger 14. A second valve 26 for controlling the air flow is provided in the second bypass 25. In the illustrated embodiment, the valve 26 is formed integrally with the first valve 12 in such a way that, when the first valve 12 is rotated clockwise by the shaft 22, to close the entrance 27 to the first bypass 13, the valve 26 closes the second bypass 25.

Thus, valves 12 and 26 are so constructed that, when the maximum possible heating of the vehicle interior is required, the whole of the air entering the opening 11 may be directed through the heat exchanger 14.

Conversely, when the maximum possible cooling of the vehicle interior is required, the whole of the air entering the opening 11 may be routed through the bypass passage 13. In intermediate positions of the valves 12 and 26, a major portion of the cool air which passes below the first valve 12 after entering the housing 10 is introduced into the heat exchanger 14, but a part of this cool air is allowed by the valve 26 to pass through the bypass 25. The cool air flow through the bypass 25 then merges and mixes with the heated air flow from the heat exchanger 14 in the lower part of the housing to reduce the temperature of the heated air current to an appropriate level.

The passageway 16 is of such a configuration that the heated air which has been discharged downwardly from the heat exchanger 14 is turned to flow upwards. At its upper end, the passageway 16 debouches into the bypass passage 13; thus, the space above and to the right (as seen in Figure 2) of this debouchment will normally carry both an air flow which has been heated by passage through the heat exchanger 14, and an air flow which has arrived directly from the inlet opening 11. Some mixing of these air flows will take place, and therefore this space can be termed a merging zone. The flow direction of the heated air arriving in the merging zone is generally perpendicular to the flow direction of the unheated air arriving in the merging zone.

From the merging zone, a continuation of the bypass passage 13 leads to the outlet openings 4 leading to the upper parts of the vehicle interior, while a further passage 18, separated from the heated air passageway 16 by a partition 17, leads downwards from the merging zone to various outlet openings 20 and 21; the opening 20 supplies air to a passage leading to the area of the windscreen of the vehicle, to perform a defrosting or demisting function, while the openings 21 supply air to the lower parts of the vehicle interior, and therefore correspond to the opening 5 of Figure 1.

A third valve 19, comprising a flap attached to a pivot shaft 23, is provided in the merging zone, to control the distribution of the air flows between the outlet openings 4 on the one hand, and the outlet passage 18 leading to the openings 20 and 21 on the other hand. Although some mixing of the heated and unheated air flows will take place in the merging zone, the air flows will still be to some extent stratified when they reach the valve 19, with the uppermost part of the flow comprising unheated air, and the lowermost part of the flow comprising heated air.Since the free edge of the flap of the valve 19 extends horizontally across the merging zone, a major part of the unheated air will be routed to the upper part of the vehicle interior, through the openings 4, while a major part of the heated air will be routed to the windscreen area and to the lower part of the vehicle interior, through the passage 18.

The third valve 19 is interlinked with the above-mentioned first and second valves 12 and 26 and closes the entrance to the downwardly directed outlet passageway 18 when the valves 12 and 26 are positioned for the maximum possible cooling, as described above. Within the downwardly directed passageway 18, there is provided a valve 21a mounted on a pivot shaft 24, which valve controls the heated air flow to the outlet openings 21. The abovementioned valves 12, 26, 19 and 21a can be controlled either manually or automatically by rotation of the respective pivot shafts 22, 23, and 24.

Since the air heated in the heat exchanger 14, together with the air passing through the second bypass 25, has to flow up much of the length of the passage 16 before reaching the merging zone, it will become mixed, so that its temperature is reasonably uniform across the cross-section of the passage 16, by the time it reaches the merging zone, even if the heating effect of the heat exchanger 14 is non-uniform. As mentioned above, a major part of this heated air flow passes into the passage 18, while a major part of the unhe ated air flow passes to the openings 4.However, some mixing of the heated and unheated air flows will take place before these flows reach the second valve 19, and therefore the flows into which the valve 19 divides the air stream will not be as widely divergent in temperature (after mixing of each flow to achieve a uniform temperature) as are the flows in the passages 13 and 16. By lessening the temperature difference, this arrangement ensures a reasonably comfortable temperature distribution in the vehicle interior.

Furthermore, when the maximum possible cooling effect is required, the entrance 15 of the heat exchanger 14 is closed by the first valve 12, so that even if a warm water valve is opened by mistake and the heat exchanger 14 is brought to an operative state, heating of the cool air current can be kept to the minimum possible extent, because the cool air current simply passes over the top of the valve 12. Furthermore, since most of the adjustments of the heater unit can be carried out by the valves 12,26, and 19, interconnection of the heater unit with a control system is relatively easy.

WHAT WE CLAIM IS: 1. A heater unit for an automotive vehicle air-conditioner, which unit comprises: an air inlet; a first adjustable valve which divides a flow of air entering the air inlet between an air entry of a heat exchanger and a first bypass passage, in proportions dependent on the adjustment of the first valve; the heat exchanger being adapted to heat air supplied to the air entry thereof, and to deliver such heated air to a heated air passage; a second bypass passage leading from the air entry of the heat exchanger to the heated air passage; a second valve which is adjustable to control the flow of air through the second bypass passage; a merging zone into which the first bypass passage and the heated air passage both lead; and a third adjustable valve which is adapted to control the flow of air from the merging zone to first and second outlets, the third valve including a valve member which has a flow-dividing edge, the first outlet being positioned to receive air which passes on one side of the flow-dividing edge, while the second outlet is positioned to receive air which passes on the other side of the flow-dividing edge; the first bypass passage and the heated air passage opening into the merging zone in directions which are generally at right angles to one another and to the said flow-dividing edge; the valve member of the third valve being movable to shift the flow-dividing edge to produce variations in opposite senses in the cross-sectional areas available for flow past the flow-dividing edge to the first and second outlets respectively; and the first bypass pas sage, the heated air passage, the second outlet, and the first outlet leading into or out of the merging zone at positions arranged in that order around the merging zone, as viewed along a direction parallel to the flowdividing edge.

2. A heater unit as claimed in Claim 1, in which the first and second valves are so interlinked that, when the first valve is adjusted to close off flow communication from the air inlet of the heater unit to the first bypass passage, the second valve is adjusted to close off flow through the second bypass passage.

3. A heater unit as claimed in Claim 1 or Claim 2, in which the first and third valves are so interlinked that, when the first valve is adjusted to close off flow communication from the air inlet of the heater unit to the air entry of the heat exchanger, the valve member of the third valve is positioned to close off flow communication between the merging zone and the second outlet.

4. A heater unit as claimed in any of the preceding claims wherein the said valves comprise pivotal flaps.

5. A heater unit as claimed in any of the preceding claims, in which the first bypass passage is positioned above the heat exchanger and the heated air passage, and the first outlet is positioned above the second outlet.

6. An automotive vehicle provided with an air-conditioning system including a heater unit as claimed in any of the preceding claims, the first outlet of the heater unit being connected to a discharge opening arranged to discharge air into the upper part of the interior of the vehicle, while the second outlet of the heater unit is connected to a discharge opening arranged to discharge air into the lower part of the interior of the vehicle.

7. A heater unit for an automotive vehicle air conditioner, the heater unit being substantially as herein described, with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. ated air flow passes to the openings 4. However, some mixing of the heated and unheated air flows will take place before these flows reach the second valve 19, and therefore the flows into which the valve 19 divides the air stream will not be as widely divergent in temperature (after mixing of each flow to achieve a uniform temperature) as are the flows in the passages 13 and 16. By lessening the temperature difference, this arrangement ensures a reasonably comfortable temperature distribution in the vehicle interior. Furthermore, when the maximum possible cooling effect is required, the entrance 15 of the heat exchanger 14 is closed by the first valve 12, so that even if a warm water valve is opened by mistake and the heat exchanger 14 is brought to an operative state, heating of the cool air current can be kept to the minimum possible extent, because the cool air current simply passes over the top of the valve 12. Furthermore, since most of the adjustments of the heater unit can be carried out by the valves 12,26, and 19, interconnection of the heater unit with a control system is relatively easy. WHAT WE CLAIM IS:

1. A heater unit for an automotive vehicle air-conditioner, which unit comprises: an air inlet; a first adjustable valve which divides a flow of air entering the air inlet between an air entry of a heat exchanger and a first bypass passage, in proportions dependent on the adjustment of the first valve; the heat exchanger being adapted to heat air supplied to the air entry thereof, and to deliver such heated air to a heated air passage; a second bypass passage leading from the air entry of the heat exchanger to the heated air passage; a second valve which is adjustable to control the flow of air through the second bypass passage; a merging zone into which the first bypass passage and the heated air passage both lead; and a third adjustable valve which is adapted to control the flow of air from the merging zone to first and second outlets, the third valve including a valve member which has a flow-dividing edge, the first outlet being positioned to receive air which passes on one side of the flow-dividing edge, while the second outlet is positioned to receive air which passes on the other side of the flow-dividing edge; the first bypass passage and the heated air passage opening into the merging zone in directions which are generally at right angles to one another and to the said flow-dividing edge; the valve member of the third valve being movable to shift the flow-dividing edge to produce variations in opposite senses in the cross-sectional areas available for flow past the flow-dividing edge to the first and second outlets respectively; and the first bypass pas sage, the heated air passage, the second outlet, and the first outlet leading into or out of the merging zone at positions arranged in that order around the merging zone, as viewed along a direction parallel to the flowdividing edge.