Thermal regulation device for a vehicle gearbox.

Abstract

Thermal regulation device for a vehicle gearbox. The invention relates to a thermal regulation device (10) for a gearbox of a motor vehicle, the thermal regulation device (10) comprising a casing (11) intended to at least partially enclose an external housing (3) of such a gearbox to facilitate the warm-up of the gearbox, particularly when starting such a motor vehicle, or the cooling of the gearbox, an air supply duct (20) comprising a first air inlet (21) and a second air inlet (22), a first opening and closing means (31) for the first inlet (21) and a second opening and closing means (32) for the second inlet (22). Illustration: Fig. 2

Description

Title of the invention: Thermal regulation device for a vehicle gearbox. Technical field of the invention

[0001] The invention relates to a thermal regulation device for a motor vehicle gearbox. The invention further relates to an arrangement comprising an engine, a gearbox, and such a thermal regulation device. The invention further relates to a method of operating such an arrangement. The invention further relates to a motor vehicle comprising such an arrangement or such a thermal regulation device. Prior art

[0002] A motor vehicle includes a powertrain. Such a powertrain includes at least one internal combustion engine and / or at least one electric motor and at least one gearbox. Such a gearbox is generally arranged between the engine(s) and at least one drive shaft for transmitting torque to at least one means in contact with the ground, such as a wheel. Such a gearbox generally includes gears meshing with each other and uses oil for its lubrication. Such a lubricating oil includes an operating temperature range within which its lubricating properties are optimal.

[0003] However, when starting one or more engines, particularly in cold weather, the gearbox oil only reaches its optimal operating temperature range after a certain period of time. Furthermore, particularly in hot weather and / or at high engine speeds and / or high gearbox speeds, the gearbox oil exceeds its optimal operating temperature range.

[0004] More specifically, at temperatures below this range, the oil is viscous, which reduces the gearbox's efficiency, leading to increased vehicle consumption of electricity and / or fuel. Conversely, at temperatures above this range, the oil film between meshing gears is not sufficiently thick, resulting in premature gear wear. Eventually, such wear leads to abnormal noises from the gearbox, malfunctions, or even gear breakage, ultimately resulting in gearbox deterioration and rendering it unusable.

[0005] Such a situation is not acceptable. Presentation of the invention

[0006] The present invention aims to provide a thermal regulation device for a gearbox that overcomes the above drawbacks. In particular, the invention makes it possible to reach the optimal operating temperature range of the oil more quickly during engine start-up and to prevent this temperature range from being exceeded during engine and / or gearbox acceleration, and / or in hot weather. Summary of the invention

[0007] To achieve this objective, the invention relates to a thermal regulation device for a gearbox of a motor vehicle, the thermal regulation device comprising: - a casing designed to at least partially enclose the external casing of such a gearbox to facilitate the gearbox's temperature rise, particularly when starting such a motor vehicle, or the gearbox's cooling, - an air supply duct comprising a first air inlet and a second air inlet, - a first means of closing and opening for the first admission and a second means of closing and opening for the second admission.

[0008] The first and second means of closing and opening may include at least one pivoting flap and / or at least one sliding curtain.

[0009] The first and second means of closing and opening may be common.

[0010] The thermal regulation device may include a control means configured to control the first and second means of closing and opening the first and second inlets.

[0011] The invention further relates to an arrangement comprising a thermal regulation device as defined above, the arrangement comprising an exchanger arranged opposite one of the first and second air inlets.

[0012] The invention further relates to an arrangement as defined above for a vehicle, the arrangement comprising an engine including a liquid cooling system, a gearbox including lubricating oil, the gearbox including an external casing, the body being arranged relative to the external casing so as to create a circulation space for an airflow between the body and the external casing, the airflow coming from the air supply duct.

[0013] The air supply duct can be arranged so as to capture air substantially longitudinally, in particular at the level of a front face of such a vehicle.

[0014] The heat exchanger can be connected to the liquid cooling system and the first The air supply duct intake can be arranged to capture heated air that has passed through the exchanger.

[0015] The second inlet of the air supply duct can be arranged so as to capture fresh air at the same level or substantially at the same level as the exchanger in the longitudinal direction, in particular below or above or to the right or left of the exchanger.

[0016] The invention further relates to a method of operating an arrangement as defined above, the method comprising measuring the temperature of the engine coolant and measuring the temperature of the gearbox oil, then a comparison of the gearbox oil temperature to a maximum gearbox temperature so that If the gearbox oil temperature is higher than the maximum gearbox temperature, then the opening of the second closing and opening means and the closing of the first closing and opening means.

[0017] If the gearbox oil temperature is lower than the maximum gearbox temperature, then - if the coolant temperature is lower than the gearbox temperature, then the first and second closing and opening mechanisms should be placed in the closed position. - if the temperature of the coolant is higher than the temperature of the gearbox, then the first closing and opening means is put in the open position and the second closing and opening means is put in the closed position.

[0018] The invention further relates to a motor vehicle comprising an arrangement as defined above, or a thermal regulation device as defined above. Presentation of the figures

[0019] These objects, features and advantages of the present invention will be described in detail in the following description of an embodiment of a thermal regulation device and an execution method of operating an arrangement, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0020] Fig. 1 is a schematic view of a motor vehicle according to one embodiment of the invention.

[0021] Fig. 2 is a partial schematic cross-sectional view of the vehicle according to the mode of realization of the invention.

[0022] Fig. 3 is a partial perspective view of the vehicle according to the embodiment of the invention.

[0023] Fig. 4 is a schematic view of an exchanger, a gearbox and a thermal regulation device according to the embodiment of the invention, the first and second inlets being blocked.

[0024] Fig. 5 is a schematic view of the heat exchanger, gearbox and thermal regulation device according to the embodiment of the invention, the first inlet being open and the second inlet being blocked.

[0025] Fig. 6 is a schematic view of the heat exchanger, gearbox and thermal regulation device according to the embodiment of the invention, the first inlet being blocked and the second inlet being open.

[0026] The [Fig.7] is a logic diagram of a method of operation of an arrangement comprising a thermal regulation device. Detailed description

[0027] The direction in which a vehicle, particularly a motor vehicle, moves in a straight line is defined as the longitudinal direction X. By convention, the direction perpendicular to the longitudinal direction, located in a plane parallel to the ground, is called the transverse direction Y. The third direction, perpendicular to the other two, is called the vertical direction Z. Thus, a right-handed coordinate system XYZ is used in which X is the longitudinal direction in the front-to-back direction of the vehicle, i.e., directed towards the rear, Y is the transverse direction directed to the right, and Z is the vertical direction directed upwards. The forward direction corresponds to the direction in which the vehicle usually moves in the longitudinal direction and is opposite to the backward direction.

[0028] As illustrated in [Fig. 1], a motor vehicle 1 comprises a GM powertrain. Such a powertrain comprises at least one engine 8. The engine 8 is, for example, an internal combustion engine, an electric motor, or a hybrid motor. The vehicle 1 or the powertrain comprises a transmission 2. The transmission 2 comprises an external casing 3.

[0029] Preferably, the motor vehicle 1 comprises a front face 5. At least one heat exchanger 6, in particular of the radiator type, is arranged at this front face 5. The heat exchanger is, for example, of the air / liquid type, a coolant for the engine(s) 8 being able to flow through the radiator 6 in order to be cooled. Alternatively, several heat exchangers or radiators, for example superimposed or substantially superimposed, are arranged at the front face. The engine 8 comprises at least one cooling system 7 or cooling circuit. dissement, in particular to cool the engine. System 7 includes at least heat exchanger 6.

[0030] The vehicle 1 includes an engine compartment 9. The engine compartment 9 generally accommodates at least the engine(s) 8 and the gearbox 2. Advantageously, as illustrated in [Fig. 1], the engine compartment 9 is located at the front of the vehicle. Thus, the radiator 6, located near the front end 5 of the vehicle, is close to the engine 8 and the gearbox 2.

[0031] Vehicle 1 includes an arrangement 4. Vehicle 1 or arrangement 4 includes a thermal regulation device 10 for the vehicle's gearbox 2.

[0032] More specifically, as illustrated in [Fig. 2], the thermal regulation device 10 comprises a shell 11. The shell or casing 11 encloses, at least partially, the outer casing 3 of the gearbox 2 to facilitate the gearbox's temperature rise. This is particularly relevant when starting the vehicle. Preferably, the shell 11 does not come into full contact with the outer casing 3 of the gearbox 2. Preferably, the shell 11 comprises an insulating material. For example, the shell 11 is covered, on the side facing the outer casing 3 and / or on the opposite side, with an insulating material, for example, rock wool.

[0033] Conversely, the casing 11 facilitates the cooling of the gearbox 2. This is particularly the case once the gearbox has reached a high temperature, for example in very hot weather and / or following high stresses on the gearbox, in particular at high rotational speeds of the engine(s) 8.

[0034] As illustrated in [Fig.2], the thermal regulation device 10 further includes an air supply duct 20. The air supply duct 20 includes a first air inlet, or inlet, or inlet 21, and a second air inlet, or inlet, or inlet 22.

[0035] Advantageously, the air inlet duct 20 is, for example, a tube. For instance, the cross-section of the duct 20 is circular, or substantially circular, particularly so as to obtain airflow within the duct with low pressure losses. Alternatively, as schematically illustrated in [Fig. 3], the cross-section of the duct is square or rectangular. An airflow F enters the duct 20 and passes between the outer casing 3 of the gearbox 2 and the housing 11, in other words, into a space E for the circulation of the flow F. Note that this space E extends in front of, and / or below, and / or above the outer casing 3, or even behind this casing 3.

[0036] The inlets 21, 22 preferably each have a non-constant cross-section, so as to capture more air. Preferably, the air capture cross-section is along a plane The vertical and transverse area at the front of the device has a greater area than the area of ​​a cross-section along a vertical and transverse plane at a junction 12 arranged between the duct 20 and the shell 11 (see [Fig. 2]). Such a reduction in cross-section may potentially allow for an acceleration of the airflow F.

[0037] For example, the intakes 21, 22 are made of polypropylene (PP). For example, the intake duct, pipe, or sleeve 20 is made of polypropylene and / or Ethylene-Propylene-Diene Monomer (EPDM). Preferably, the gearbox is rigidly fixed to the engine, while the engine is fixed to the vehicle body via vibration-damping means. Furthermore, the housing 11 is preferably fixed directly to the outer casing 3 of the gearbox. Thus, movement is possible between the housing attached to the gearbox and the air intake duct, for example, fixed to the body. Thanks to the EPDM material in particular, such movement is tolerated, where applicable, by the duct 20 without risk of cracking and / or breakage of the duct and / or at the junction between the duct 20 and the housing 11.

[0038] For example, a partition or wall 23 divides a main inlet of the duct 20 into two inlets 21, 22. In the case of air inlet below (or above) the radiator 6, the partition 23 preferably extends in a longitudinal and transverse plane XY, as illustrated in figures 2, 4, 5 and 6. Alternatively, in the case of air inlet to the right or left of the radiator, the partition separating the first air inlet from the second air inlet preferably extends in a longitudinal and vertical plane XZ (variant not illustrated).

[0039] The thermal regulation device 10 further includes a first closing and opening means 31 for the first inlet 21. The thermal regulation device 10 further includes a second closing and opening means 32 for the second inlet 22.

[0040] For example, the first closing and opening means 31 and / or the second closing and opening means 32 comprises at least one pivoting flap and / or at least one sliding curtain.

[0041] By "pivoting flap," we mean, for example, a closing / opening plate of an inlet extending in a plane, an axis being arranged at the level of, or even in, this plane so as to allow the plate to pivot around the axis. In other words, by "pivoting flap," we mean, for example, an opening and closing means known in particular as a "butterfly flap." Figure 2 schematically illustrates such pivoting flaps 31, 32. A double arrow illustrates the transition from the closed position (flap shown in solid line) of the corresponding inlet to the open position (flap shown in dashed line) of the corresponding inlet. In this case, the flaps 31, 32 are separate, independent of each other.

[0042] By "sliding curtain," we mean, for example, a closing / opening plate extending in a plane and sliding to open or close an inlet, along a direction contained in or parallel to that plane. For example, as schematically illustrated in Figures 4, 5, and 6, the closing and opening means 31, 32 are of the sliding curtain type. For example, the curtains 31, 32 slide, or translate, by means of two opposing guides or slides, for example, two grooves or U-shaped channels, for example, like a guillotine. In the cases illustrated in Figures 4 to 6, the movements occur in a plane parallel to the YZ plane.

[0043] Preferably, the first and second opening and closing means 31, 32 are common, linked, or even form a single part 33. This is particularly the case for the means 31, 32 illustrated in Figures 4 to 6, which translate simultaneously along the vertical direction, for example. In this case, an action on the means 31 moves the means 32 and vice versa. However, for example, opening one of the two inlets does not necessarily open the other inlet. Similarly, for example, closing one of the two inlets does not necessarily close the other inlet.

[0044] More specifically, as illustrated in [Fig. 4], the curtain 33 is in the closed position. The curtain 33 then closes the first and second inlets 21, 22 respectively.

[0045] In [Fig. 5], the curtain 33 is shifted downwards. In this case, the first inlet 21 is open. This position has no effect on the inlet 22, which remains closed. Indeed, the inlet 22 is obstructed by an upper portion of the curtain 33, for example.

[0046] In [Fig. 6], the curtain 33 is offset, translated upwards. In this case, the second inlet 22 is open. This position has no effect on the inlet 21, which remains closed. Indeed, the inlet 21 is obstructed by a lower portion of the curtain 33, for example.

[0047] Advantageously, the thermal regulation device 10 of the gearbox includes a first control means 13. For example, the control means 13 is configured to actuate the first and second opening and closing means 31, 32 of the first and second inlets 21, 22. Preferably, the first control means 13 includes a temperature measurement means, for example of the probe type, for measuring the temperature of the outer casing 3, for example on an inner wall of the casing, and / or the temperature of the oil present within the gearbox 2. For example, a second control means 14 includes a means for measuring the temperature of the coolant within the cooling system 7 of the engine 8. The second control means 14, for example of the probe type, is also configured to actuate the first and second opening and closing means 31, 32 of the first and second inlets 21, 22.

[0048] The arrangement 4 includes the engine 8. As a reminder, the engine 8 includes the liquid cooling system 7, preferably of the type with coolant circulating through it. The system 7 preferably includes a pump to circulate the coolant if necessary.

[0049] The cooling circuit or system 7 may be a high temperature circuit, in the sense that the nominal temperature of the coolant is for example between 80°C and 110°C.

[0050] According to one embodiment, the circuit or system 7 includes an opening / closing means 15 for allowing or preventing the circulation of the coolant within the circuit. For example, this means is of the thermostat type, capable of opening, or closing, the circuit respectively, depending on the temperature of the fluid present in, or flowing through, the circuit.

[0051] The cooling circuit or system 7 may be a low temperature circuit, in the sense that the nominal temperature of the coolant is for example between 40 and 60°C.

[0052] The arrangement 4 further includes the gearbox 2 containing lubricating oil. As a reminder, the gearbox 2 includes the outer casing 3. More specifically, as illustrated in [Fig. 2], the housing 11 is arranged relative to the outer casing 3 so as to create the circulation space E for the airflow F between the housing 11 and the outer casing 3. The airflow F originates from the air intake duct 20. Advantageously, the air intake duct 20 is arranged and oriented so as to capture air substantially longitudinally. In other words, the air inlets 21, 22 extend so as to capture air in a YZ plane. Preferably, the air intake occurs at the front face 5 of the vehicle so as to take advantage of the airflow created by the vehicle's movement, if applicable.

[0053] The arrangement 4 further includes the heat exchanger 6 connected to the liquid cooling system 7. The first inlet 21 of the air supply duct 20 is arranged, oriented, and positioned so as to capture heated air that has passed through the heat exchanger 6. Preferably, the first inlet 21 is therefore arranged just behind the radiator 6.

[0054] The second inlet 22 of the supply duct 20 is preferably arranged to draw in fresh air at the same level or substantially at the same level as the heat exchanger 6 in the longitudinal direction. In Figures 2, 4, 5, and 6, the second inlet 22 is below the radiator 6. Alternatively, the second inlet 22 is below, above, to the right, or to the left of the heat exchanger 6. Optionally, the second inlet 22 is offset in front of or behind the radiator. For example, this offset in the longitudinal direction relative to the radiator, or group of radiators, is less than 30 cm, or even less than 10 cm.

[0055] An execution method of an operating method of the arrangement 4 will now be described in relation to [Fig.7].

[0056] After a step 100 of starting the vehicle, the successive, possibly simultaneous, steps 101 and 102 of measuring a temperature Tbv of the gearbox and a temperature Tco of the engine coolant 8 are carried out.

[0057] If the transmission temperature Tbv is lower than a maximum transmission temperature Tbv max, a temperature comparison step 104 is performed such that if the coolant temperature Tco is lower than the transmission temperature Tbv, the two inlets 21, 22 are closed, or remain closed, as illustrated in [Fig. 4]. This situation is thus obtained if a first condition 103 is not met, namely that the transmission temperature Tbv is not higher than a maximum transmission temperature Tbv max, and if a second condition 104 is not met, namely that the transmission temperature Tbv is not lower than the coolant temperature Tco. This situation is encountered in particular during a cold start of the vehicle.In this case, there is indeed no point in trying to recover heat from the radiator since the coolant is not hot. In other words, the first means 31 should remain closed, that is, prevent air from entering space E from the radiator. Furthermore, particularly when driving immediately after a cold start, the second means 32 should also remain closed to prevent air from the front of the vehicle, generated by its movement, from entering space E. This would cool the casing 3 and consequently the gearbox, whereas the goal is to warm it up. Thus, with means 31 and 32 closed, the first and second intakes 21 and 22 are also closed, as shown in step 105 and in [Fig. 4].The casing 11 encloses and isolates the gearbox from any heat exchange in space E, thus contributing to the gearbox heating solely through its lubricating oil. In other words, the creation of airflow around the gearbox is prevented, isolating it from the air-cooling system, so that it heats up through heat exchange with the engine oil and / or through its own heat losses from operation. As a reminder, the coolant temperature is preferably measured with a temperature probe and is taken on the radiator via the second control means 14.

[0058] In the case of a high-temperature cooling circuit 7, preferably, the opening / closing means 15 simultaneously prevents the circulation of the coolant so as to contribute to rapidly heating the coolant The system is cooled by losses from the engine, thus warming the engine and gearbox. The opening / closing mechanism can be a thermostatic valve.

[0059] If the coolant temperature Tco is higher than the gearbox temperature Tbv, the first inlet 21 is opened and the second inlet 22 is closed, or the second opening and closing means 32 is held in the closed position, as illustrated in [Fig. 5] and by step 107 of [Fig. 7]. In this case, preferably the cooling system 7 is operating, i.e., the coolant circulation has been initiated, for example by means of a pump and / or a thermostat-type opening / closing means 15 arranged within the cooling circuit 7. This is particularly the case after a few tens of seconds of operation of the internal combustion engine, if applicable, for example around one minute of operation.Thus, since the coolant circulates within the radiator 6, the heat from the coolant is exchanged at the radiator and transferred to the cooling air flowing through the radiator core 6. The air passing through the radiator is then heated, and the opening of the means 31 allows some of the air passing through the radiator to be recovered, particularly when the vehicle is moving forward. In this case, in addition to the losses generated by the gearbox, the hot air arriving through the open intake 21 helps to heat the space E around the gearbox. As a result, the gearbox, and especially its lubricating oil, reaches its optimal operating temperature range more quickly. The thermal control device 10 then operates in gearbox heating mode.

[0060] Simultaneously, the temperature of the lubricating oil of the gearbox 2 is measured, for example at the bottom of the gearbox, via the first control means 13.

[0061] If the transmission oil temperature Tbv is at least equal to the maximum temperature Tbv max, for example 100 degrees Celsius, the second inlet 22 is opened and the first inlet 21 is closed, or held closed, as illustrated in [Fig. 6], and by step 106 of [Fig. 7]. This allows the transmission oil to be cooled by a cooling airflow F through the space E. The thermal control device 10 then operates in transmission cooling mode.

[0062] Indeed, when the gearbox 2 has reached a high temperature, it is necessary to remain within the optimal operating temperature range and not exceed it. For example, the optimal temperature range for the gearbox casing and / or for the gearbox lubricating oil is 70 to 90 degrees Celsius. By optimal operating range of the oil, we mean a temperature range temperatures in which the oil has optimal, or even maximum, lubricating power. Thus, by opening the second means 32, the air coming from the front 5 of the vehicle due to the vehicle's movement rushes into the second intake 22 and creates a flow around the gearbox in space E. The gearbox, in particular its external casing 3, is thus cooled, which helps to cool the internal lubricating oil of the gearbox and keep it within the optimal temperature range for its operation.

[0063] In the case of a control system with temperature measurement, the control of means 31, 32 is, for example, independent of the vehicle speed. As a reminder, control is preferably based on the oil temperature and / or the temperature of the gearbox (for example, its external casing), and / or the temperature of the coolant of the engine(s) connected to the gearbox.

[0064] In summary, the solution relates to a thermal envelope for a gearbox allowing active blowing on the external casing of the gearbox.

[0065] In particular, the solution is suitable for a gearbox coupled to an electric motor in order to improve gearbox efficiency, notably by reducing the gearbox warm-up time, particularly for the WLTP homologation cycle (Worldwide Harmonised Light Vehicles Test Procedure), which is generally around 30 minutes. As a reminder, reducing the gearbox warm-up time reduces friction within it.

[0066] Note that the solution can be used for a gearbox coupled to a hybrid engine or adapted to a reduction gear or a manual gear-shifting gearbox.

[0067] Advantageously, the thermal envelope or shell 11 around the gearbox is arranged essentially on the front face and / or under the gearbox.

[0068] At start-up, particularly in cold weather, the housing 11 creates an insulated enclosure and facilitates the transmission's temperature rise. For example, the housing is made of polyamide, possibly sealed, and insulated on at least one side. Thus, a volume of air heats up rapidly between the housing 11 and the outer casing 3, especially when the vehicle is not moving and / or when the intakes 21, 22 are closed. The small volume of rapidly heated air in space E promotes the transmission's temperature rise, which quickly improves its efficiency and reduces electrical and / or fuel consumption. Indeed, the lower end of the transmission's optimal temperature range is reached quickly. In other words, the disadvantages of low-temperature oil, particularly in terms of viscosity, are short-lived.To maximize this temperature increase, as soon as the coolant circulates in the . radiator 6, heat is taken from the radiator by opening the first means 31 so as to allow air to pass into the first intake 21 after passing through the radiator to supply heated air to the space E around the gearbox.

[0069] Once the gearbox has reached a warm temperature, for example, from a measured value as described previously, fresh air is introduced between the housing 11 and the outer casing 3 of the gearbox via the intake opening 22 of the fresh air supply duct 20. The opening of the means 32 allows fresh air to circulate in space E and prevents the outer casing 3 and the oil inside the gearbox from reaching excessively high temperatures. By thus limiting the maximum oil temperature, temperatures at which the oil film between the gears is too thin are avoided. In other words, the reliability of the gearbox is ensured at high temperatures, particularly at high engine speeds, for example, when driving on the motorway. As a reminder, this air intake is achieved by drawing air preferably from the front, for example, in front of or at the radiator 6.

[0070] Preferably the opening and closing means 32 of the air supply duct 20 is controlled according to the temperature of the oil in the gearbox 3 so as to promote a lowering of the oil temperature (in case of significant stress on the gearbox, in particular when driving on the motorway and / or in high outside temperatures) or to promote a rise in the oil temperature (in case of cold start, in particular in cold weather, for example in negative outside temperatures).

[0071] Thanks to this solution, the gearbox oil and its structure can be maintained within an optimal temperature range, for example, between 60 or 70 degrees Celsius and 90 degrees Celsius. This results in improved performance of the gearbox, which is thus enclosed and, if necessary, equipped with a ventilated external casing. The solution therefore reduces heat loss from the gearbox when cold while ensuring its reliability when hot.

[0072] Furthermore, by avoiding excessively high temperatures, for example on the order of 100 degrees Celsius, any degradation of the mechanical strength of the gears and / or bearings of the gearbox is prevented. By reducing the operating time below the temperature range, for example below 60 degrees Celsius, the efficiency of the gearbox is improved.

[0073] Thus, the solution helps to reduce the consumption of the powertrain during the start-up phase, particularly during a homologation cycle (WLTP as mentioned previously), while ensuring excellent mechanical performance of the gearbox components once the start-up phase is over and / or during high stresses, particularly during high-speed driving.

[0074] Advantageously, the geometric shapes of the inlets 21, 22 and / or the duct 20 and / or the housing 11, particularly with respect to the outer casing 3 for the housing 11, are determined so as to maximize airflow for cooling and to insulate the outer casing for heating the gearbox. For example, the housing 11 follows, or substantially follows, the shape of the outer casing 3, particularly under the gearbox, leaving a gap extending perpendicularly from the outer casing of, for example, 2 to 3 cm. In other words, the air circulation space E or air stagnation space includes an air gap, for example, of the order of 2 to 3 cm thick, around the outer casing.

[0075] The thermal regulation device thus allows the gearbox oil to reach its optimal operating temperature range quickly, particularly when starting the engine(s), especially in cold weather. Conversely, particularly in hot weather and / or at high engine speed(s) and / or high gearbox speed, the gearbox oil remains within the optimal operating temperature range without exceeding it. Therefore, the gearbox equipped with the regulation device operates for very short periods with viscous oil, which would result in reduced gearbox efficiency and increased vehicle energy and / or fuel consumption. Furthermore, the oil film between the meshing gears remains sufficiently thick, preventing premature gear wear at high engine speeds and / or high ambient temperatures.This eliminates wear and tear that could cause abnormal noises from the gearbox, malfunctions, or even gear breakage leading to gearbox deterioration.

[0076] For example, the solution is suitable for use in vehicles in cold countries where engines, particularly internal combustion engines, are preheated before starting, for example, to raise the engine temperature from -20 degrees Celsius to -5 degrees Celsius. For example, an electric heating element connected to the electrical grid where the vehicle is located heats the coolant, notably by "thermosiphoning," meaning that heating the coolant causes it to circulate in the cooling system. In this case, after the coolant has been preheated before the vehicle moves, the means 15 is opened to allow the coolant to circulate through a water pump and thus through the radiator.The closing and then opening of the first intake 21 then allows the gearbox to be warmed up quickly, for example during the first minute of vehicle use, or even the first few minutes.

[0077] As a side note, the solution therefore achieves the desired objective of improving the reliability of a motor vehicle gearbox and has the advantage of being adaptable for a other motorized vehicle, for example a motorcycle, a snowmobile, a tractor, a construction vehicle or even a train.

Claims

Demands

1. An arrangement (4) comprising a thermal regulation device (10) for a gearbox (2) of a motor vehicle (1), the thermal regulation device (10) comprising: - a shell (11) intended to at least partially enclose an external casing (3) of such a gearbox (2) to facilitate the temperature rise of the gearbox (2), in particular when starting such a motor vehicle (1), or the cooling of the gearbox (2), - an air supply duct (20) comprising a first air inlet (21) and a second air inlet (22), - a first closing and opening means (31) for the first inlet (21) and a second closing and opening means (32) for the second inlet (22), the arrangement (4) comprising a heat exchanger (6) arranged opposite one of the first and second air inlets (21, 22),the arrangement (4) comprising an engine (8) including a liquid cooling system (7), a gearbox (2) including lubricating oil, the gearbox (2) including an external casing (3), the shell (11) being arranged relative to the external casing (3) so as to create a circulation space (E) for an airflow (F) between the shell (11) and the external casing (3), the airflow (F) originating from the air supply duct (20).

2. Arrangement (4) according to the preceding claim, characterized in that the first and second closing and opening means (31, 32) comprise at least one pivoting flap and / or at least one sliding curtain.

3. Arrangement (4) according to any one of the preceding claims, characterized in that the first and second closing and opening means (31, 32) are common.

4. Arrangement (4) according to any one of the preceding claims, characterized in that the thermal regulation device (10) includes a control means (13) configured to drive the first and second closing and opening means (31, 32) of the first and second inlets (21, 22).

5. Arrangement (4) according to any one of the preceding claims, characterized in that the air supply duct (20) is arranged so that to capture air substantially longitudinally, particularly at the level of a front face (5) of such a vehicle (1).

6. Arrangement (4) according to any one of the preceding claims, characterized in that the exchanger (6) is connected to the liquid cooling system (7) and in that the first inlet (21) of the air supply duct (20) is arranged so as to capture heated air having passed through the exchanger (6).

7. Arrangement (4) according to the preceding claim, characterized in that the second inlet (22) of the air supply duct (20) is arranged so as to capture fresh air at the same level or substantially at the same level as the exchanger (6) in the longitudinal direction, in particular below or above or to the right or left of the exchanger (6).

8. A method of operating an arrangement (4) according to any one of the preceding claims, characterized in that it comprises a measurement (102) of a temperature (Tco) of the engine coolant (8) and a measurement (101) of a temperature (Tbv) of the gearbox oil (2), then a comparison of the temperature (Tbv) of the gearbox oil to a maximum temperature (Tbv max) of the gearbox such that if the temperature (Tbv) of the gearbox oil is greater than the maximum temperature (Tbv max) of the gearbox, then the opening of the second closing and opening means (32) and the closing of the first closing and opening means (31) are set to the closed position.

9. A method of operating an arrangement (4) according to the preceding claim, characterized in that if the temperature (Tbv) of the gearbox oil is less than the maximum temperature (Tbv max) of the gearbox, then - if the temperature (Tco) of the coolant is less than the temperature (Tbv) of the gearbox, then the first and second closing and opening means (31, 32) are placed in the closed position, - if the temperature (Tco) of the coolant is greater than the temperature (Tbv) of the gearbox, then the first closing and opening means (31) is placed in the open position and the second closing and opening means (32) is placed in the closed position.

10. A motor vehicle (1), characterized in that it comprises a arrangement (4) according to any one of claims 1 to 7.

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