FR3040918A1 - AIR CONDITIONING DEVICE FOR MOTOR VEHICLE - Google Patents

Abstract

The invention relates to an air conditioning device (1) for a motor vehicle, comprising an evaporator (4) and at least two bypass circuits (9, 9 ') of said evaporator allowing an air flow between an upstream zone of the evaporator (4) and an area located downstream of the evaporator (4), one or the other (9 ') of said bypass circuits, said balancing circuit, having a passage section at least locally scaled down.

Description

Air conditioning device for a motor vehicle

The present invention relates to an air conditioning device for a motor vehicle.

Motor vehicles are enclosed places of low volume, subject to changing and often harsh environments. It is therefore essential to regularly renew the air, and regulate the temperature.

For this purpose, air conditioning devices or air conditioners are used. These systems are designed so that heated or cooled air is blown inside the vehicle.

The air conditioning devices for a motor vehicle, in particular the HVAC (Heating, Ventilation and Air Conditioning) systems, generally comprise an air circuit between at least one inlet mouth and at least one outlet mouth, on which various means of air treatment are interposed. The air intake port is an outside air inlet and / or a recirculated air inlet. The air treatment means are in particular ventilation means for moving a flow of air through the circuit, heating and / or cooling means, such as an air-heating radiator and a heater. evaporator for cooling the air.

In particular, it has already been proposed air conditioning devices comprising a bypass flow allowing part of the air not to pass through the evaporator. The bypass flow notably results in an energy gain in the air conditioner. However, particularly when this flow is divided into two circuits, a flow imbalance can occur between each circuit which generates an undesired temperature difference output, up to several degrees. The invention aims to overcome at least in part the above disadvantages and proposes for this purpose an air conditioning device for a motor vehicle, comprising an evaporator and at least two bypass circuits of said evaporator allowing an air flow between an area located upstream of the evaporator and an area located downstream of the evaporator, one or the other of said bypass circuits, said balancing, having a passage section at least locally reduced.

Thus, according to the invention, one of the branch circuits is used to establish a balanced circulation between the two circuits. In other words, rather than having two branch circuits of maximum section given the congestion constraints imposed by the components of the air conditioner located nearby, one of the two circuits, namely that powered by the part of the flow with the highest throughput, offers a reduced section. In this way, the flow rates between the two circuits are balanced.

According to complementary features of the invention, which may be used separately or in combination: - said balancing circuit comprises at least one protuberance locally reducing said passage section, - said balancing circuit has at least locally a passage section 30% lower than the lowest passage section of the other bypass circuit, - the flow section of the balancing circuit is constant, - the air bypass circuits are arranged above the evaporator said device further comprises an air circulation element in the direction of the evaporator; said device is configured so that an air flow generated by said air circulation element has an imbalance; flow, said balancing circuit being positioned to compensate for said imbalance; the air circulating element comprises a centrifugal casing of nalisation of air, called volute, - the evaporator is wider than the volute, - the centrifugal envelope is arranged above the evaporator, - the air bypass circuits are preferably arranged next to the volute - the bypass circuits are located on either side of the volute, - the air circulation element comprises a motor actuating a wheel located inside the volute, - the branch circuits of respectively comprise a duct, - the duct of the balancing circuit is located under the motor of the air circulation element, - the other of said bypass ducts is located under an inlet zone of air of the device, - the duct of the balancing circuit comprises a shutter element, - said shutter element has a trapezoidal section, - said ducts are located on either side of the volute, - said device comprises in in addition to a single component, a degree of opening of the bypass circuits being controlled simultaneously by two distinct parts of said flap, - the two parts of the flap are interconnected by a common axis, - each of the two parts of the flap are respectively intended to cover one of said ducts of bypass, - said flap is of the butterfly, flag or drum type. Other advantages and features of the invention will appear on reading the following description, given solely by way of nonlimiting example, and with reference to the appended drawings in which: FIG. 1 schematically illustrates a side view of an air conditioning device according to the invention, - Figure 2 is a detail view of Figure 1, - Figure 3 is a partial view of the detail of Figure 2, illustrated according to the sectional plane AA of Figure 1, - Figures 4 and 5 show Figure 3 according to alternative embodiments of the device according to the invention.

As illustrated in Figures 1 to 3, an air conditioning device 1 according to the invention comprises an air circuit from at least one inlet mouth 2 through which is admitted air. The inlet mouth 2 is an outside air inlet and / or a recirculated air inlet. The air circuit comprises in particular an air circulation element such as an air blower 3, able to circulate the air coming from the inlet mouth 2, towards a heat treatment zone which comprises in particular an evaporator 4 and a radiator 5. The blower 3 is provided with a motor 3b which drives a wheel 3c located inside an envelope 3a. The envelope 3a is a centrifugal casing of air duct called volute.

In the illustrated configuration, also called centered architecture, the volute 3a is disposed above the evaporator 4, here centrally. Such a device is intended to be located at a central console of the motor vehicle equipped.

Advantageously, said volute 3a is placed on and / or in contact with the evaporator 4 or disposed near the evaporator 4. In this way, a high degree of compactness is obtained that is particularly sought after for air conditioners in centered architecture. The volute 3a is preferably narrower than the evaporator 4. The evaporator 4 is a heat exchanger. Its role is to absorb the heat flow from the air to be cooled. The evaporator 4 thus comprises a liquid refrigerant which is vaporized by the heat extracted from the air to be cooled. The radiator 5 is in turn a heat exchanger in which a hot heat transfer fluid sees its temperature decrease by yielding its heat to the air leaving the evaporator.

Different flaps 6, 7, 8 can direct the air in several directions. A first mixing flap 6 distributes the flow of air through the evaporator 4 to the radiator 5 (path shown in Figure 2 by the arrow a) and / or to a path that bypasses the radiator 5 (path illustrated in Figure 2 by the arrow b). A second flap 7, for example a drum flap, distributes the air between a central air outlet to the central console vents, or defrost outlets, and a lower air outlet in the direction of the driver's feet. A third flap 8 distributes the air between the central air outlet and an upper air outlet towards the windshield of the vehicle.

In addition, according to the invention, the air conditioning device comprises bypass circuits 9, 9 ', here two, allowing at least a portion of the air not to pass through the evaporator 4. The passage of the The air borrowing one 9 'of these branch circuits is shown in Figure 2 by the arrow c.

Advantageously, the air bypass circuits 9, 9 'are arranged above the evaporator 4, next to the volute 3a, for example, on either side of the volute 3a, which allows the device keep its compactness while allowing at least part of the flow to bypass the evaporator 4. Said branch circuits 9, 9 'may be laterally delimited by at least a portion of the wall of the volute to further promote compactness.

Moreover, as it appears better in FIG. 3, said bypass circuit 9 ', said balancing circuit, has a passage section that is at least locally reduced. In other words, it is partially obstructed while the other bypass duct 9 has a largest possible section taking into account the size of the components located nearby.

Here, said balancing circuit 9 'comprises a protuberance 20 locally reducing said passage section. According to another embodiment, the passage section of the bypass circuit 9 'may be constant along the path followed by the air flow.

To have a significant effect in the usual configurations of air conditioning device, said balancing circuit 9 'has at least locally a passage section 30% lower than the lowest passage section of the other branch circuit 9.

Such a balancing circuit 9 'will find its particular interest in air conditioning devices in which an air flow generated by said air circulation element has a flow imbalance, said balancing circuit 9' being positioned to compensate for said imbalance. More specifically, if the part of the air flow directed below the motor 3b at the outlet of the volute 3a has a greater flow than the portion of the air flow directed below the inlet mouth 2 then the circuit 9 'balancing will be that located under said engine 3b.

The bypass circuits 9, 9 'respectively comprise a bypass duct 9a and 9b, both of which are arranged above the evaporator 4, possibly in contact therewith, and on either side of the volute 3a, that is to say that the ducts 9a, 9b are aligned horizontally above the evaporator 4. It is thus possible to integrate the bypass circuits 9, 9 'in the air conditioning device 1, and this without reduction the volume of the volute 3a, which allows to maintain good aeraulic and acoustic performance. In addition, it is not necessary to move the volute 3a upwards to integrate the branch circuits 9, 9 '.

The duct of the balancing circuit 9 'comprises a closure element 22 to reduce at least locally its section and here forming said protrusion 20. In Figure 3, it is positioned substantially halfway said channel 9b. It may be from a wall of the engine 3b or a side cheek of the evaporator 4.

In Figures 3 and 4, said closure member 22 has a trapezoidal section and the resulting passage section of the bypass channel 9b forming the balancing circuit 9 'is trapezoidal also at this level. In FIG. 3, the closure element 22 extends over the height of the bypass channel 9b defining the balancing circuit 9 'while in FIG. 4 it extends over its width. In FIG. 5, said shutter element 22 has a cross section, extending here over the width of the bypass channel 9b defining the balancing circuit 9 '.

Said closure element 22 is advantageously fixed. In other words, once set up during the assembly of the air conditioning device, it is immobile and its positioning does not have to be ordered. The passage section left free is configured from the outset to compensate imbalances predicted or measured on devices of identical configuration but without the passage section restriction according to the invention.

This being so, to adapt the amount of air passing through the evaporator and that passing through the bypass channels 9a, 9b, their degree of opening can be controlled simultaneously by two separate parts of a bypass louver 10. This is, for example, a butterfly flap (Figure 2). The flap 10 may also be a flag-type flap, in which the axis of the flap is located at the lower or upper end of the flap 10. A flag flap allows a gain in section in the bypass ducts 9a, 9b. Part 10 can also be a drum type component, such as the second part 7.

Said flap 10 is unique and common for said bypass channels 9a, 9b. In other words, the flow balancing in each of the bypass channels is provided by said shutter member 22 and not by the shutter. Said flap comprises, for example, an axis 10 extending on either side of the volute 3a, substantially over the width of the evaporator 4 to connect each of the parts of the flap 10 respectively associated with each of the bypass channels 9a , 9b.

Claims (15)

An air conditioning device (1) for a motor vehicle, comprising an evaporator (4) and at least two bypass circuits (9, 9 ') of said evaporator allowing an air circulation between an area situated upstream of the evaporator ( 4) and an area located downstream of the evaporator (4), one or the other (9 ') of said bypass circuits, said balancing, having a passage section at least locally reduced. 2. Device according to claim 1 wherein said balancing circuit (9 ') comprises at least one protuberance locally reducing said passage section. 3. Device according to claim 1 wherein said balancing circuit (9 ') has at least locally a passage section 30% lower than the lower passage section of the other branch circuit. 4. Device according to claim 3 wherein the passage section of the balancing circuit (9 ') is constant. 5. Device according to any one of the preceding claims wherein the air bypass circuits (9, 9 ') are arranged above the evaporator (4). 6. Device according to any one of the preceding claims further comprising an air circulating element (3) in the direction of the evaporator (4). 7. Device according to claim 6 configured for a flow of air generated by said air circulation element (3) has a flow imbalance, said balancing circuit (9 ') being positioned to compensate said imbalance. 8. An air conditioning device (1) according to any one of claims 6 or 7, characterized in that the air circulating element (3) comprises a centrifugal envelope (3a) of air ducting, called volute. 9. An air conditioning device (1) according to claim 8, characterized in that the centrifugal casing (3a) is disposed above the evaporator (4). 10. An air conditioning device (1) according to one of claims 8 or 9, characterized in that the air bypass circuits (9, 9 ') respectively comprise a conduit (9a, 9b). 11. An air conditioning device (1) according to claim 10 wherein the duct (9b) of the balancing circuit (9 ') comprises a closure element. 12. An air conditioning device (1) according to claim 11 wherein said closure member has a trapezoidal section. 13. An air conditioning device (1) according to any one of claims 10 to 12 wherein said ducts are located on either side of the volute (3a). 14. An air conditioning device (1) according to any one of the preceding claims further comprising a single flap (10), a degree of opening of the bypass circuits (9, 9 ') being controlled simultaneously by two separate parts. said flap (10). 15. Device (1) according to claim 14, characterized in that the two parts of the flap (10) are interconnected by a common axis.