WO2013093542A1

WO2013093542A1 - Thermal control system and method for a cabin of a vehicle

Info

Publication number: WO2013093542A1
Application number: PCT/IB2011/003252
Authority: WO
Inventors: Frédéric ROHI; Frédéric LAUDET
Original assignee: Renault Trucks SAS
Current assignee: Renault Trucks SAS
Priority date: 2011-12-20
Filing date: 2011-12-20
Publication date: 2013-06-27
Anticipated expiration: 2014-06-20

Abstract

Thermal control system and method for a cabin of a vehicle comprising a thermal unit providing an air flow,three air circuits each air circuit being capable of directing an air sub flow towards the cabin through at least one opening located respectively in a distinct first, second and third distribution areas in the cabin; an electronic control unit capable of automatically controlling the air flow temperature and the air flow rate, a distribution input device (32) for manually causing the system to implement a user defined air distribution - i.e. the respective rates of the air sub flows - which enables the user to customize the air distribution in place of a predetermined air distribution determined by the system; at least a storing input device (40) for causing the memorization of a current and preferred air distribution and at least a recall input device (40) for causing, when the user wishes to, the system to recall said memorized air distribution while the air flow temperature and the air flow rate are automatically controlled by the electronic control unit in a semi-automatic mode.

Description

THERMAL CONTROL SYSTEM AND METHOD

FOR A CABIN OF A VEHICLE

Field of the invention

The present invention relates to a thermal control system for a cabin of a vehicle, and a method for controlling the temperature of a cabin of a vehicle. Technological background

Vehicles have been provided with a thermal control system of their cabin for many years. Typically, an air flow is blown into the cabin, said air flow being heated when the outside temperature is low, especially in winter, and cooled when the outside temperature is high, especially in summer.

Such a system generally comprises at least three air circuits which direct an air sub flow towards openings arranged in distinct locations inside the vehicle cabin, for example to blow air towards the windscreen, the head, the torso and/or the feet of the cabin occupant.

A conventional thermal control system typically comprises an electronic control unit which is capable of automatically controlling some parameters of the air flow in order to reach a preset target temperature in the cabin - in a transient mode - and to maintain said target temperature in the cabin - in a permanent mode. Said parameters include the air flow temperature and the air flow rate.

These parameters are generally controlled by the electronic control unit in order to regulate the cabin temperature as effectively as possible. For example, in the transient mode, it may be preferred to reach the target temperature as quickly as possible, whereas in the permanent mode, it can be advantageous to minimize the required energy consumption.

Another parameter is the air distribution, i.e. the respective rates of the air sub flows in the air circuits. A predetermined air distribution is generally set by the vehicle manufacturer and input as a data of the system. Said predetermined air distribution aims at satisfying most users and at regulating efficiently the cabin temperature. However, this predetermined air distribution may not suit some users. By way of an example, some users do not like having air blown towards their face. An uncomfortable air distribution may be accepted by the cabin occupant in a transient mode, but however, it is generally hard to take in a permanent mode.

It therefore appears that, from several standpoints, there is room for improvement in thermal control systems and methods for vehicle cabins.

Summary

It is an object of the present invention to provide an improved thermal control system for a cabin of a vehicle which can overcome the drawbacks of the prior art systems.

More precisely, an object of the invention is to provide such a thermal control system which can improve the comfort of the cabin occupant without greatly impairing the efficiency of the temperature regulation.

According to a first aspect, the invention relates to a thermal control system for a cabin of a vehicle, said system comprising:

- a thermal unit capable of providing an air flow directed towards the cabin;

- at least a first, second and third air circuits, each air circuit being connected to at least one dedicated outlet provided on the thermal unit and being capable of directing an air sub flow - forming at least part of the air flow - towards the cabin through at least one opening, the openings of the first, second and third air circuits being located respectively in a distinct first, second and third distribution areas in the cabin;

- an electronic control unit capable of automatically controlling the air flow temperature and the air flow rate in order to reach or maintain a preset target temperature in the cabin;

- a distribution input device for manually causing the system to implement a user defined air distribution - i.e. the respective rates of the air sub flows in the air circuits - which is designed so that the actuation of said distribution input device enables the user to customize the air distribution in place of an air distribution determined by the system ;

- at least a storing input device for causing the memorization of a current and preferred air distribution ; - at least a recall device for causing, when the user wishes to, the system to recall said memorized air distribution while the air flow temperature and the air flow rate are automatically controlled by the electronic control unit, in a semi-automatic mode.

In practice, the system can be operated in an automatic mode, where the electronic control unit automatically controls the parameters of the air flow to reach or maintain the preset target temperature in the cabin in the most efficient way. To that end, the electronic control unit controls:

- the air flow temperature, so that the thermal unit provides an appropriately heated or cooled air flow;

- the rate of the air flow provided by the thermal unit.

As regards the air distribution in said automatic mode, it is set according to programmed rules defined by the vehicle manufacturer. This programmed air distribution cannot be changed by the user, as it forms a set data of the system.

In case the air distribution set according to the programmed rules user is uncomfortable for the user, he/she can actuate the distribution input device, whereby he/she can manually choose a preferred air distribution. This air distribution not only concerns the locations from which air is blown into the cabin, but also the amount of air that is blown in each location. For example, the user can decide that less or no air is blown towards his/her face.

One significant advantage of the invention is that the transition between the automatic mode to a mode where the air distribution is manually set does not necessary result in the end of the automatic control of the other parameters, namely the air flow temperature and the air flow rate. The system may be then operated in a semi automatic mode, where said two parameters remain automatically controlled by the electronic control unit.

Another significant advantage of the invention is that there is provided a storing input device for causing the memorisation of the current air distribution and a recall input device for recalling said memorized air distribution while the air flow temperature and the air flow rate are automatically controlled by the electronic control unit, in a semi-automatic mode. In concrete terms, this makes it possible for the user to memorize the preferred air distribution that he has just manually set and, if needed, to later recall his/her preferred air distribution. For example, recalling the preferred air distribution can happen if the operation of the system has been switched back to the automatic mode, or if the air distribution has been manually changed, or at the next starting of the vehicle.

As regards air distribution, the user can therefore choose between a vehicle manufacturer scheme (automatic mode) or a preferred scheme that he has previously memorized, the automatic control of the other parameters remaining effective. This is particularly interesting for the user in the permanent mode. In transient mode, the driver may recall a preferred air distribution having a longer phase with a satisfying air distribution than a shorter phase with an uncomfortable air distribution.

The invention therefore makes it possible to reach easily a compromise between the user's comfort and the thermal control system efficiency.

Furthermore, by providing a recall input device, the invention improves safety. Indeed, after having stored once a preferred air distribution, the user, especially the driver, can choose again said preferred air distribution by actuating a single device instead of making many settings every time. Therefore, the invention makes it possible to reduce the time the driver needs to set his/her preferred air distribution, i.e. the time spent looking at the distribution input device while going on driving.

According to a second aspect, the invention relates to a method for controlling the temperature of a cabin of a vehicle, the method comprising:

distributing an air flow (F) towards the cabin (1) by mean of a thermal control system such as described hereinbefore, - memorizing a current air distribution upon a user request through a storing input device;

setting a semi-automatic mode where the previously memorized air distribution is recalled upon a user request through a recall input device and where the air flow temperature (T) and the air flow rate (Q) are automatically controlled by the electronic control unit.

In practice, the preferred air distribution that is memorized is the air distribution which the user has previously chosen and set, i.e. the preferred air distribution which will replace the air distribution determined by the system according to the programmed rules defined by the vehicle manufacturer. These and other features and advantages will become apparent upon reading the following description in view of the drawing attached hereto representing, a non-limiting example, one embodiment of a thermal control system according to the invention.

Brief description of the drawings

The following detailed description of one embodiment of the invention is better understood when read in conjunction with the appended drawings, it being however understood that the invention is not limited to the specific embodiment disclosed.

Figure 1 is a schematic and partial representation of a vehicle cabin including a thermal control system according to an embodiment of the invention, the system being operated in an automatic mode;

Figure 2 is a detailed view of the system of Figure 1 , the system being operated in a semi automatic mode;

Figure 3 is a schematic representation of an embodiment of a control board of the system according to the invention.

Detailed description of the invention

In Figure 1 is schematically and partially shown a cabin 1 of a vehicle, said cabin 1 comprising a windscreen 2 and side windows 3.

The invention provides a thermal control system 4 for the cabin 1 , which makes it possible to bring and maintain the temperature in the cabin 1 to a target temperature Tt that is preset by the user, i.e. the cabin occupant, who is typically the vehicle driver.

The thermal control system 4 comprises a thermal unit 5 which typically includes a fan 6, a heater 7 and a cooler 8.

By means of the fan 6, outside air can be sucked in a channel 9, can enter the thermal unit 5 and pass through the heater 7 and the cooler 8. Therefore, the thermal unit 5 is capable of providing a heated or cooled air flow F which will be directed towards the cabin 1.

In practice, the heater 7 can be a radiator, and the cooler 8 can be an evaporator forming part of a refrigerant circuit of an air conditioning system. Such a refrigerant circuit typically carries a refrigerant in a loop through a compressor, a condenser, an expander and an evaporator capable of cooling an air flow directed towards the cabin.

The thermal control system 4 also comprises air circuits connected to the thermal unit 5 and designed to carry some of the air flow towards various locations in the cabin 1 and to blow it inside the cabin. More precisely, in the embodiment shown in Figure 1 , the system 4 comprises a first, a second and a third air circuits 11 , 12, 13. However, according to the invention, the number of circuits is not limited to three.

Each air circuit 11 , 12, 13 is connected to at least one dedicated outlet 14, 15, 16 provided on the thermal unit 5 and is capable of directing an air sub flow F1 , F2, F3 towards the cabin 1 through at least one opening 17, 18, 19. Each air sub flow forms at least part of the air flow. In other words, the rate Q1 , Q2, Q3 of each sub flow F1 , F2, F3 can range between 0% and 100% of the rate Q of the air flow F.

The openings 17, 18, 19 of the first, second and third air circuits 1 , 12, 13 are located respectively in a distinct first, second and third distribution areas 21 , 22, 23 in the cabin 1.

For example, the first distribution area 21 , in which are located the first openings 17 of the first air circuit 11 , can include the windscreen 2 and/or the head of the cabin occupant. In other words, the first distribution area 21 can be situated in the upper part of the cabin 1.

The second distribution area 22, in which are located the second openings 18 of the second air circuit 12, can include the torso of the cabin occupant and/or the front part of the side windows 3. In other words, the second distribution area 22 can be situated in the middle part of the cabin 1.

As regards the third distribution area 23, in which are located the third openings 19 of the third air circuit 13, it can include the feet of the cabin occupant and/or the area located along the lower part of the side doors. In other words, the third distribution area 23 can be situated in the lower part of the cabin 1.

The thermal control system 4 further comprises an electronic control unit 25 which is capable of automatically controlling the temperature T of the air flow F and the rate Q of the air flow F in order to reach or maintain a target temperature Tt in the cabin 1. The target temperature can be set by the user of the vehicle. To that end, the electronic control unit 25 may monitor the temperature of the outside air, of the air blown inside the cabin 1 through the openings 17, 18, 19, and/or of the ambient air in the cabin 1 , by means of appropriate sensors (not shown). In concrete terms, controlling the air flow temperature T can be achieved by controlling the heater 7 and the cooler 8, while controlling the air flow rate Q can be achieved by controlling the speed of fan 6.

Another parameter that can be set by the thermal control system 4 is the air distribution. The air distribution corresponds to the respective rates of the air sub flows in the air circuits. In other words, the air distribution not only includes the locations from where air is blown inside the cabin 1 , but also how much air is blown from each of said locations.

The air distribution can be set manually, as will be explained hereafter. Moreover, there is a programmed set of rules for automatically determining an optimized air distribution which forms a set data of the system 4, and which is generally given by the vehicle manufacturer so as to optimize the regulation of the cabin temperature and to suit most users.

In an implementation of the invention, each air circuit 11 , 12, 13 may be equipped with at least a flow controller 26, such as a flap, designed to adjust the rate Q1 , Q2, Q3 of the corresponding air sub flow F1 , F2, F3 according to air distribution determined by the system or defined by the user. The rate of one air sub flow is individually set to a chosen level among at least three levels, the sum of all air sub flow rates being equal to the air flow rate Q.

For example, each rate Q1 , Q2, Q3 can be set to one of the following levels : 0%, 50%, 100% of the air flow rate Q, while Q1+Q2+Q3=Q. One given sub flow rate can be individually chosen, but if the air flow rate Q remains unchanged, then the rate of the other sub flows will be impacted accordingly.

Of course, the invention is not limited to three levels for the sub flow rates. It can for example be envisaged to provide five possible levels (such as 0%, low rate, medium rate, high rate, 100%).

In order for the user to operate the system 4, said system 4 is provided with a control board 27, as shown in Figure 3, which is operationally connected to the electronic control unit 25.

On the control board 27 are provided means for manually setting some parameters of the system 4, the air flow F and the air sub flows F1 , F2, F3. Such means include one or several human/machine interface input devices.

First of all, there are provided means for setting the target temperature Tt in the cabin 1 , which can typically comprise one "-" key 28 and one "+" key 29.

Besides, the control board 27 comprises means for setting the air flow rate Q. These means can comprise a rotating button 30. Turning the button 30 clockwise can typically result in increasing the air flow rate Q. In addition, there may be provided a display of the current air flow rate Q, by means of illuminated points 31 , the number of which is all the more great as the air flow rate Q is high.

Furthermore, the system 4 comprises a distribution input device 32 for manually setting the air distribution. In the embodiment shown in Figure 3, the distribution input device 32 is arranged on the control board 27 and comprises, for each air circuit 11 , 12, 13, means for setting the corresponding air sub flow rate Q1 , Q2, Q3. In practice, each air circuit 1 , 12, 13 can be represented by a drawing 33, 34, 35 of the corresponding first, second and third distribution areas 21 , 22, 23 in the cabin 1. Close to each drawing 33, 34, 35 are one "-" key 36 and one "+" key 37. However, other embodiments of the distribution input device are possible.

The thermal control system 4 can thus be operated in a manual mode, where the user can choose manually each parameter, no automatic regulation being made on the air flow rate Q, and the air distribution.

Alternatively, the thermal control system 4 can be operated in an automatic mode, as illustrated in Figure 1 , in order to reach or maintain in the cabin 1 the target temperature Tt that the user has previously set, for example by means of keys 28 and 29. The operation of said automatic mode can be achieved by means of an automatic mode actuator which can typically comprise a key 38 arranged on the control board 27.

Then, the air distribution is set by the system according to the programmed rules typically set by the vehicle manufacturer and being a set data of the system that the user cannot change. The electronic control unit 25 sets the flow controllers 26 of the air circuits 11 , 12, 13 in accordance with said programmed rules. Besides, the air flow temperature T and the air flow rate Q are automatically controlled by the electronic control unit 25 in order to reach or maintain the target temperature Tt in the cabin 1 in the most efficient way.

According to the invention, the thermal control system 4 can alternatively be operated in a semi automatic mode, as illustrated in Figure 2.

In the semi automatic mode, the air distribution is manually set by the user as a preferred air distribution, in place of said air distribution according to the programmed rules, but the air flow temperature T and the air flow rate Q remain automatically controlled by the electronic control unit 25.

In practice, when the system 4 is in automatic mode, the user can actuate the distribution input device 32 in order to change the air distribution to a preferred air distribution which is more comfortable for him/her than the air distribution according to the programmed rules given by the vehicle manufacturer. The electronic control unit 25 sets the flow controllers 26 of the air circuits 11 , 12, 13 in accordance with said preferred air distribution. The system 4 is designed so that the distribution input device 32 takes precedence over the automatic mode input device 38 as regards air distribution, without resulting in the end of the automatic control of the air flow temperature T and of the air flow rate Q by the electronic control unit 25. Therefore, the efficiency of the thermal control system 4 is not greatly impaired. As shown in Figure 2, for example, the user may choose to stop air entry from the openings 18, i.e. towards his/her torso.

An important aspect of the invention lies in the fact that the current and preferred air distribution can be memorized and recalled.

To that end, the system 4 comprises a storing input device for causing the memorisation of the current and preferred air distribution, and a recall input device for causing, when the user wishes to, the system to recall said memorized air distribution while the air flow temperature T and the air flow rate Q are automatically controlled by the electronic control unit 25 in a semi-automatic mode.

In practice, after the user has manually set the air distribution that better suits him/her, said preferred air distribution, which is the current air distribution, can be memorized and recalled later when needed. Furthermore the preferred air distribution may be memorized and/or recalled at any time from the automatic, the semi-automatic or the manual mode.

According to an implementation of the invention, the storing input device can comprise a key which can be actuated by a user in order to causing the memorization of the preferred air distribution. The recall input device can also comprise a key which can be actuated by a user in order to cause the system to recall a memorized air distribution. A key is a device which is very easy to actuate, especially for a user that keeps driving while setting the parameters of the system 4.

In a particularly advantageous implementation of the invention, the storing input device and the recall input device can be one and the same device.

As illustrated in Figure 3, the thermal control system 4 may comprise a key 40 acting as both the storing input device and the recall input device. In the whole specification, the term "key" can mean a button that can be pressed by a user, or a zone on a touch screen.

It may be envisaged that the system be designed so that briefly pressing the key 40 leads to recalling the memorized air distribution from and pressing the key 40 or a longer time leads to memorizing the preferred air distribution.

Thus, after manually choosing the air distribution that suits him/her, if the user presses the key 40 during a few seconds (for example 3 seconds), said current preferred air distribution is memorized. From that moment, the system 4 will use this memorized air distribution when the user briefly presses the same key 40, whatever the previously set air distribution.

The storing input device may also be capable of causing the memorization of another preferred air distribution in the place of the previously memorized air distribution. In other words, if the current air distribution is different from the memorized air distribution, pressing the key 40 during a few seconds results in memorizing the current air distribution as the new memorized air distribution. With this implementation, the system 4 can be provided with a single key 40 for memorizing an air distribution, recalling it, and also memorizing a new air distribution. Of course, the invention is not limited to memorize and to recall only one preferred air distribution. According to a further implementation of the invention the system 4 is capable of memorizing and recalling different preferred air distributions. It can be envisaged to provide one or several storing input devices and one or several recall input devices managed in order to memorize and to recall different preferred air distributions corresponding for example to different weather conditions or seasons or corresponding to the preferred air distributions of different drivers,

Preferably, the automatic mode input device 38 can be designed so that the actuation of said automatic mode input device 38 sets the air distribution back to the an air distribution determined according to the programmed rules. Of course, the user can recall his/her preferred air distribution by actuating the recall input device, if said preferred air distribution has been previously memorized.

Then, thanks to the invention, moving from the automatic air distribution mode to a preferred air distribution and vice versa is very quick and easy.

In an embodiment of the invention, as shown in Figure 3, the system 4 can comprise a display 41 able to show the current air distribution, i.e. not only the locations from which air is blown inside the cabin 1 , and the location from which no air is blown, but also the respective rates Q1 , Q2, Q3 of the air sub flows F1 , F2, F3 in the air circuits 11 , 12, 13. This display 41 is able to show this current air distribution whether it is the air distribution according to the programmed rules or a manually set air distribution (memorized or not). Various means can be used to indicate on the display 41 the value of one given sub flow rate, such as a sliding cursor, a more or less bright arrow, etc.

The display 41 may also show the target temperature (Tt) which has been set by means of keys 28 or 29. By providing such a thermal control system including a storing input device and a recall input device for the air distribution, possibly as a single additional key, the invention offers many advantages:

- a preferred air distribution can be chosen while the automatic regulation is maintained on the air flow temperature and rate;

- said preferred air distribution can be stored and recalled while the automatic regulation is maintained on the air flow temperature T and rate Q. This customization of the system is particularly positive for the driver in terms of comfort, perceived quality and brand image;

- the safety is improved since the user only has to press a key instead of doing multiple actions.

In a different embodiment of the invention, when the memorized air distribution is recalled the air flow temperature T and the air flow rate Q could be set manually instead of being automatically controlled by the electronic control unit 25.

Of course, the invention is not restricted to the embodiment described above by way of a non-limiting example, but on the contrary it encompasses all embodiments thereof.

Claims

1. A thermal control system for a cabin (1) of a vehicle, said system (4) comprising:

- a thermal unit (5) capable of providing an air flow (F) directed towards the cabin (1);

at least a first, second and third air circuits (11 , 12, 13), each air circuit being connected to at least one dedicated outlet (14, 15, 16) provided on the thermal unit (5) and being capable of directing an air sub flow (F1, F2, F3) - forming at least part of the air flow (F) - towards the cabin (1) through at least one opening (17, 18, 19), the openings of the first, second and third air circuits (11 , 12, 13) being located respectively in a distinct first, second and third distribution areas (21 , 22, 23) in the cabin (1);

an electronic control unit (25) capable of automatically controlling the air flow temperature (T) and the air flow rate (Q) in order to reach or maintain a target temperature (Tt) in the cabin (1);

a distribution input device (32) for manually causing the system to implement a user defined air distribution - i.e. the respective rates (Q1 , Q2, Q3) of the air sub flows (F1 , F2, F3) in the air circuits (1 1 , 12, 13) - which is designed so that the actuation of said distribution input device (32) enables the user to customize the air distribution in place of an air distribution determined by the system (4) ;

characterized in that the system (4) further comprises :

at least a storing input device (40) for causing the memorisation of a current and preferred air distribution ;

at least a recall input device (40) for causing, when the user wishes to, the system to recall said memorized air distribution while the air flow temperature (T) and the air flow rate (Q) are automatically controlled by the electronic control unit (25) in a semi-automatic mode.

2. The system according to claim 1 , characterized in that the storing input device (40) is capable of causing the memorization of another preferred air distribution in the place of the previously memorized air distribution.

3. The system according to claim 1 or claim 2, characterized in that the storing input device comprises a key (40) which can be actuated by a user in order to cause the memorization of the preferred air distribution.

4. The system according to any one of claims 1 to 3, characterized in that the recall input device comprises a key (40) which can be actuated by a user in order to cause the system to recall a memorized air distribution.

5. The system according to any one of claims 1 to 4, characterized in that the storing input device (40) and the recall input device (40) are one and the same device.

6. The system according to claims 3, 4 and 5, characterized in that it is designed so that briefly pressing the key (40) leads to recalling the memorized air distribution and pressing the key (40) for a longer time leads to memorizing the preferred air distribution.

7. The system according to any one of claims 1 to 6, characterized in that it is capable of memorizing and recalling different preferred air distributions.

8. The system according to claim 7, characterized in that it comprises one or several storing input devices and one or several recall input devices managed in order to memorize and to recall different preferred air distributions.

9. The system according to any one of claims 1 to 8, characterized in that it comprises a display (41) able to show the current air distribution.

10. The system according to any one of claims 1 to 9, characterized in that it comprises an automatic input device (38) which is designed so that the actuation of said automatic input device (38) causes the system to set the air distribution according to programmed rules.

11. The system according to any one of claims 1 to 10, characterized in that each air circuit (11 , 12, 13) is equipped with at least a flow controller (26) designed to adjust the rate (Q1 , Q2, Q3) of the corresponding air sub flow (F1 , F2, F3) according to the air distribution determined by the system or defined by the user, the rate of one air sub flow being individually set to a chosen level among at least three levels, the sum of all air sub flow rates (Q1 , Q2, Q3) being equal to the air flow rate (Q).

12. The system according to any one of claims 1 to 1 , characterized in that the first distribution area (21) includes the windscreen (2) and/or the head of the cabin occupant.

13. The system according to any one of claims 1 to 12, characterized in that the second distribution area (22) includes the torso of the cabin occupant and/or the front part of the side windows (3).

14. The system according to any one of claims 1 to 13, characterized in that the third distribution area (23) includes the feet of the cabin occupant and/or the area located along the lower part of the side doors.

15. A method for controlling the temperature of a cabin (1) of a vehicle, characterized in that the method comprises:

distributing an air flow (F) towards the cabin (1) by mean of a thermal control system according to any one of claims 1 to 14 ;

- memorizing a current air distribution upon a user request through a storing input device ;

setting a semi-automatic mode where the previously memorized air distribution is recalled upon a user request through a recall input device and where the air flow temperature (T) and the air flow rate (Q) are automatically controlled by the electronic control unit (25).