Maintenance device for a thermal system in a motor vehicle.

Abstract

Maintenance method for a thermal system for a motor vehicle comprising: • a first assembly of components, • a second assembly of conduits for a heat transfer fluid, connecting the components of the first assembly, and • a third assembly comprising at least one solenoid valve, the thermal system having a first circuit in series connecting all the components of the first assembly when the solenoid valve(s) of the third assembly are all in a rest state, the maintenance method comprising: - a first step of implementing the first circulation, then - a second step of draining a heat transfer fluid circulating in the second assembly of conduits, then - a third step of filling the second assembly of conduits with a new heat transfer fluid.then a fourth stage of evacuating gas bubbles contained in the second set of ducts. Figure for the abbreviation: 2,

Description

Title of the invention: Device for maintaining a thermal system for a motor vehicle.

[0001] The invention relates to a method and device for maintaining a thermal system according to the invention.

[0002] To minimize the energy consumption of motor vehicles, in particular electric motor vehicles, cooling circuits are designed to recover the heat generated by one element of the circuit to heat another element of the circuit. More generally, a cooling circuit must allow different circulations of the coolant so as to adapt to different conditions of use of the vehicle, for example different heating needs of the passenger compartment, while minimizing the energy consumption of the vehicle. In addition, a cooling circuit must be designed to facilitate its maintenance, i.e. the periodic replacement of the coolant.

[0003] However, the maintenance of such cooling circuits can be complex.

[0004] The aim of the invention is to provide a maintenance method and device overcoming the above drawbacks and improving the methods and devices known from the prior art. In particular, the invention makes it possible to produce a method and a device which are reliable and efficient and which make it possible to simplify the maintenance of the cooling circuit.

[0005] To this end, the invention relates to a method for maintaining a thermal system for a motor vehicle, the thermal system comprising • a first set comprising components including - an electric motor, - a battery, - thermal resistance, - a cooler connected to an air conditioning circuit in the passenger compartment of the motor vehicle, - a radiator, • a second assembly comprising conduits for a heat transfer fluid, connecting the components of the first assembly, and a third assembly comprising at least one solenoid valve, and in particular at most three solenoid valves, connected to conduits of the second assembly, the thermal system implementing a first circulation of heat transfer fluid through said conduits in a first series circuit connecting together all the components of the first assembly when the solenoid valve(s) of the third assembly are all in the rest state, the maintenance process including - a first stage of implementation of the first circulation, then - a second stage of draining a heat transfer fluid circulating in the second set of conduits of the thermal system, then - a third stage of filling the second set of conduits of the thermal system with a new heat transfer fluid, then - a fourth stage of evacuation of gas bubbles contained in the second set of conduits of the thermal system.

[0006] In one embodiment, the first step comprises placing each solenoid valve of the third assembly in a resting state, the third assembly being made up - a single solenoid valve with at least seven ways, or - two solenoid valves, including a four-way solenoid valve and at least one three-way solenoid valve, or - three solenoid valves with at least three ways.

[0007] In one embodiment, the draining step comprises pressurizing air generating a forced evacuation of a heat transfer fluid remaining in the conduits of the second assembly, and / or the filling step comprises a pressurized injection of a new heat transfer fluid into the conduits of the second set, and / or the thermal system comprises at least one pump and the fourth step of evacuating gas bubbles contained in the thermal system comprises a circulation of the new heat transfer fluid by actuation of the at least one pump.

[0008] In one embodiment, at least one component of the first assembly comprises a bleed screw and the fourth step of evacuating gas bubbles contained in the thermal system comprises evacuating gas bubbles by opening the bleed screw.

[0009] In one embodiment, the thermal system comprises a single degassing jar, and / or the degassing jar is a circulating type jar and / or the degassing jar and the radiator are arranged on parallel circuit portions by said conduits, and / or an altitude of the degassing jar is higher than an altitude of each component of the first set.

[0010] The invention further relates to a device for maintaining a thermal system for a motor vehicle, the thermal system comprising • a first set comprising components including - an electric motor, - a battery, - thermal resistance, - a cooler connected to an air conditioning circuit in the passenger compartment of the motor vehicle, - a radiator, • a second assembly comprising conduits for a heat transfer fluid, connecting the components of the first assembly, and a third assembly comprising at least one solenoid valve, and in particular at most three solenoid valves, connected to conduits of the second assembly, the thermal system implementing a first circulation of heat transfer fluid through said conduits in a first series circuit connecting the components of the first set together when the solenoid valve(s) of the third set are all in the rest state, the device comprising hardware and / or software elements implementing the method according to the invention, in particular a tool equipped with a vacuum pump capable of sucking air present in the conduits of the second set.

[0011] The invention further relates to a motor vehicle equipped with a maintenance device according to the invention.

[0012] [Fig.l] schematically represents a motor vehicle equipped with a device for maintaining a thermal circuit according to one embodiment of the invention.

[0013] [Fig.2] represents an implementation of a first circulation of heat transfer fluid for the maintenance of a thermal system according to a first embodiment of the invention.

[0014] [Fig. 3] represents several operating states of a four-way valve of a thermal system according to a second embodiment of the invention.

[0015] [Fig.4] represents an implementation of the first circulation of heat transfer fluid for the maintenance of a thermal system according to the second embodiment of the invention.

[0016] [Fig.5] represents an implementation of the first circulation of heat transfer fluid for the maintenance of a thermal system according to a third embodiment of the invention.

[0017] [Fig.6] is a flowchart of a maintenance method according to the invention.

[0018] [Fig.7] illustrates a step in implementing maintenance of a system thermal according to the invention.

[0019] Embodiments of a motor vehicle 100 equipped with a maintenance device 2 for a thermal system 1 are described below with reference to FIGS. 1 to 5. The motor vehicle 100 is a motor vehicle of any type, in particular a passenger vehicle or a utility vehicle.

[0020] In an embodiment more specifically described in this document, the motor vehicle 100 is an electric vehicle, and comprises a first assembly 10 comprising components including an electric motor 11, a battery 12, a cooler 13 connected to an air conditioning system of a passenger compartment of the motor vehicle 100, a thermal resistor 14, and a radiator 15.

[0021] In the remainder of the document, the term “cooler 13” designates a cooler connected to an air conditioning system of a passenger compartment of the motor vehicle 100.

[0022] In the remainder of the document, the term “motor 11” is used to designate the electric motor itself, as well as various components associated with the motor, and located close to the motor, such as for example current converters and a charger. In other words, the term “motor 11” encompasses a set of components dedicated to the operation of the motor 11, in particular the electric traction chain comprising one or more electric motors and inverters and / or one or more converters and / or one or more chargers.

[0023] In the remainder of the document, a maintenance device 2 of a thermal system 1 is defined, the thermal system 1 comprising the first assembly 10. The thermal system 1 takes charge of the thermal management of the engine 11, the battery 12, the cooler 13 (in particular by a heat exchange at the radiator 15), and the heating resistor 14.

[0024] The thermal system 1 further comprises a second assembly 20 comprising conduits and a third assembly 30 comprising at most three solenoid valves 31, 32, 33, 35, 36, 37 connected to conduits of the second assembly 20. The valves of the third assembly 30 are arranged so that, when they are all in the rest state, the thermal system 1 implements a first circulation 101 of heat transfer fluid in a first series circuit connecting the components of the first assembly 10 together.

[0025] The radiator 15 is a cooling radiator of the vehicle. Air passing through the radiator 15 makes it possible to cool the heat transfer liquid circulating in the conduits of the second assembly 20.

[0026] In the embodiments presented below, the thermal system 1 further comprises a first pump 41 and a second pump 42 making it possible to generate a circulation of heat transfer fluid in the conduits of the second set 20.

[0027] The third set 30 of at most three solenoid valves is made up - either a single solenoid valve 31 with at least seven ways, thus defining a first embodiment of the thermal system 1, shown in [Fig.2], - either two solenoid valves 32, 33, including a four-way solenoid valve 32 and a solenoid valve 33 with at least three ways, thus defining a second embodiment of the thermal system 1, shown in [Fig.4]„ - or three solenoid valves 35, 36, 37 with at least three ways, thus defining a third embodiment of the thermal system 1, shown in [Fig.5].

[0028] We first describe a thermal system 1 according to the first embodiment, making it possible to implement in particular a first circulation 101.

[0029] An implementation of the first circulation 101 according to the first embodiment of the thermal system 1 is illustrated by [Fig.2]. The first circulation 101, which creates a series circuit of conduits connecting all the components of the first assembly 10, is more particularly suitable for filling the thermal circuit 1 in the factory, as well as for a maintenance phase of the thermal circuit 1.

[0030] In the first embodiment, the first circulation 101 is advantageously obtained when the solenoid valve 31 (with at least 7 ways 311, 312, 313, 314, 315, 316, 317) is at rest, that is to say when the solenoid valve does not receive an activation order. In this case, - the channels 311 and 312 are connected to each other, creating a circuit connecting in series the battery 12 to the assembly constituted by the heating resistor 14 in series with the cooler 13, - tracks 313 and 316 are connected to each other, creating a series circuit connecting battery 12 to motor 11, - tracks 315 and 314 are connected to each other, creating a series circuit connecting between the engine 11 and the radiator 15.

[0031] Thus, this configuration of the solenoid valve 31 makes it possible to drain and fill the conduits of the second assembly 20, without having to activate the solenoid valve 31. Then, by simply setting the speed of the water pumps arranged on the circuit, the first circulation 101 can be used to expel all the air bubbles blocked in the circuit. These treatments will be developed further in the document.

[0032] In the second embodiment of the thermal system 1, the set of solenoid valves 3 is made up of two solenoid valves 32, 33 including at least one four-way solenoid valve 32 and at least one three-way solenoid valve 33.

[0033] [Fig. 3] represents an operating diagram of the four-way solenoid valve 32 of a thermal system according to the second embodiment of the invention, in which: - a first track 321 is connected by a conduit to battery 12, - a second channel 322 is connected to the first pump 41, - a third channel 323 is connected to the cooler 13, and - a fourth channel 324 is connected to the second pump 42.

[0034] Furthermore, [Fig. 3] describes three configurations 325, 326, 327 implemented by the four-way solenoid valve 32, each configuration being obtained by connecting at least two channels taken from the four channels 321, 322, 323, 324 of the solenoid valve 32: - the first configuration 325 connects the battery 12 to the first pump 41, - the second configuration 326 connects the cooler 13 to the first pump 41 and the battery to the second pump 42, - the third configuration 327 connects the battery 12 to the second pump 42.

[0035] A solenoid valve with at least three ways 33 and the three configurations 325, 326, 327, 328 described for the solenoid valve 32 make it possible to implement the first circulation 101.

[0036] In the second embodiment, the first circulation 101 is advantageously obtained when - the solenoid valve 32 is in the third configuration 327, that is to say the solenoid valve 32 connects the battery 12 to the second pump 42, and - solenoid valve 33 connects engine 11 to the radiator.

[0037] Thus, all the components of the component set 10 are connected together in series.

[0038] In the third embodiment of the thermal system 1, the set of solenoid valves 3 consists of three solenoid valves 35, 36, 37 with at least three ways.

[0039] In the third embodiment, the first circulation 101 is advantageously obtained when - the solenoid valve 35 connects the battery 12 to the second pump 42, and - solenoid valve 36 connects engine 11 to the radiator.

[0040] In the remainder of the document, the term "jar" or "degassing jar" is used to name an expansion tank, also called a "feeder". A jar of a thermal system is pressurized and is used to create sufficient pressure at the inlet of each water pump of the thermal system so as not to generate cavitation in the water pump. Indeed, if the pressure at a pump is too low, a cavitation phenomenon may appear, that is to say a boiling of the heat transfer fluid at the level of the blades of the pump, which damages the blades of the pump.

[0041] Advantageously, the degassing jar 50 may be a circulating type jar, that is to say the jar 50 comprises a first inlet nozzle for the heat transfer liquid placed in its upper part, and a second outlet nozzle for the liquid placed at its lowest point.

[0042] In a preferred embodiment, the thermal system 1 comprises a single degassing jar 50, which facilitates maintenance operations of the thermal system 1.

[0043] Furthermore, the position of the jar 50 on the circuit of the thermal system can be chosen to promote rapid and simple degassing of the circuit, in particular by creating a circuit connecting in series all the components of the first assembly. Advantageously, the jar 50 can be arranged on a circuit loop 70 in parallel with the component offering the greatest resistance to the passage of the heat transfer fluid, such as the radiator 15. air bubbles are then pushed towards jar 50, jar 50 allowing separation of the liquid and gas phases.

[0044] Furthermore, an altitude of the degassing jar 50 is preferably greater than an altitude of each component of the first set 10 of components.

[0045] The thermal system may further comprise a non-return valve 71 to prevent the heat transfer fluid from moving in the opposite direction to a desired direction of movement. Such a phenomenon may occur in particular due to negative pressures in a conduit upstream of a pump.

[0046] In an advantageous embodiment, the maintenance device 2 comprises - thermal system 1, and - a controller 90 which determines a transition between a driving mode and a maintenance mode of the motor vehicle 100.

[0047] In other words, the controller 90 makes it possible in particular to initiate a maintenance phase of the thermal system 1.

[0048] The maintenance device 2 advantageously comprises a connection means 91 to a tool 60, used during a maintenance phase of the motor vehicle 100. The connection means 91 can be located at the level of the jar 50, as illustrated by [Fig.7]. The tool 60 is equipped with a vacuum pump capable of sucking the air present in the conduits of the assembly 20. Furthermore, the tool 60 allows the conduits to be filled with a new heat transfer fluid.

[0049] In an advantageous embodiment, the maintenance device 2 further comprises the means for implementing a maintenance method according to the invention. In particular, the maintenance device 2 comprises a processing unit 80 comprising a microprocessor 81, a memory 78 and communication interfaces 79.

[0050] The maintenance device 2 and particularly the microprocessor 81, mainly comprises the following modules which cooperate with each other: - a module 811 for implementing the first circulation, this module being able to cooperate with the controller 90, the solenoid valves of the third set 30, the first and second pumps 41, 42, - a module 812 for draining a heat transfer fluid circulating in the set of conduits 20 of the thermal system, this module being able to cooperate with the connection means 91 and the tool 60, - a module 813 for filling the set of conduits of the thermal system, this module being able to cooperate with the connection means 91 and the tool 60, - a module 814 for evacuating gas bubbles contained in the set of conduits 20, this module being able to cooperate with the first and second pumps 41, 42.

[0051] The motor vehicle 100, in particular the maintenance device 2, preferably comprises all the hardware and / or software elements configured so as to implement the method defined in the subject of the invention or the method described below.

[0052] With reference to [Fig.6], a method of maintaining the thermal system 1 previously described is described; comprising: - a first stage El of implementation of the first circulation 101, then - a second step E2 of draining a heat transfer fluid circulating in the set of conduits 20 of the thermal system 1, then - a third step E3 of filling the set of conduits 20 of the thermal system 1 with a new heat transfer fluid, then - a fourth step E4 of evacuating gas bubbles contained in the set of conduits 20 of the thermal system 1.

[0053] The first step E1 comprises receiving a maintenance order for the thermal system 1, the order possibly coming from the controller 90.

[0054] Following receipt of a maintenance order, the solenoid valves of the thermal system 1 are configured so as to allow implementation of the first circulation 101 of heat transfer fluid. For this, the solenoid valves of the third assembly 30 are controlled to implement a circuit connecting the components of the first assembly 10 in series. Advantageously, the thermal system 1 is designed so that the circulation 101 is implemented when the solenoid valves are in the rest state.

[0055] In other words, the first step E1 comprises placing at least one solenoid valve of the third assembly 30 in a resting state, the third assembly 30 being made up - a single solenoid valve 31 with at least seven ways, or - two solenoid valves 32, 33, including a four-way solenoid valve 32, and a solenoid valve 33 with at least three ways, or - three solenoid valves 35, 36, 37 with at least three ways.

[0056] Then we continue with step E2 of draining the heat transfer fluid contained in the thermal system 1. After opening the cap of the expansion tank, the drain plugs and advantageously disconnecting certain pipes constituting the assembly 20, the heat transfer fluid flows naturally out of the assembly of pipes 20, and out of the components that it passes through, such as for example the battery 12, by gravitational effect. The heat transfer fluid is thus completely or partially automatically replaced by air.

[0057] Once the thermal system 1 has been drained by flow under atmospheric pressure, a tool 60 for pressurizing the conduits with air can be used to evacuate the heat transfer fluid remaining in the circuit. For this purpose, the tool 60 is connected to the jar 50, as illustrated in [Fig.7].

[0058] The draining step E2 comprises pressurizing the heat transfer circuit with air, generating a pressure higher than atmospheric pressure in the conduits of the second assembly 20. For this purpose, using an air pump, the tool 60 evacuates the remaining heat transfer fluid which is present in the conduits of the assembly 20. The tool 60 thus creates an air pressure in the conduits of the assembly 20, in particular the pressure inside the conduits which is between 1.5 and 3 bar, preferably 2 bar.

[0059] Then we continue with step E3 of filling the conduits with a new heat transfer fluid, after having replaced or repositioned each of the drain plugs. The filling step E3 comprises a depression of the circuit by the air pump, then a pressurized injection of a new heat transfer fluid into the conduits of the second assembly 20. The tool 60 is thus able to create an air depression in the conduits of the assembly 20, in particular the pressure inside the conduits is 900 millibar.

[0060] For this purpose, the conduits of the assembly 20 are connected to a reserve of heat transfer fluid forming part of the tool 60, the reserve of fluid being at atmospheric pressure. The heat transfer fluid will be sucked into the conduits of the assembly 20, due to the depression previously created in the conduits. Thus, a pressure balancing phenomenon makes it possible to fill the conduits of the assembly 20 with a new heat transfer fluid. However, the filling - although facilitated by the tool 60 - is not perfect, because a large quantity of air may remain in the conduits and / or the components of the thermal system 1.

[0061] In the degassing step E4, a circulation of heat transfer fluid is activated in all the conduits of the assembly 20. In other words, the first circulation 101 is implemented, in particular by actuating the pumps 41, 42 of the thermal system 1. Advantageously, the implementation of the first circulation 101 makes it possible to move residual air pockets to the degassing tank. Upstream of the sub-step E14, that is to say imperatively before the start of the pumps 41, 42, it is possible to open manual bleed screws 111 positioned on local high points, such as for example on the engine 11.

[0062] In other words, - the draining step E2 comprises a suction of the heat transfer fluid generating a pressure lower than atmospheric pressure in the conduits of the second assembly 20, and / or - the filling step E3 comprises a pressurized injection of a new heat transfer fluid into the second set 20 of conduits, and / or - the thermal system 1 comprises at least one pump 41, 42 and the step E4 of evacuating gas bubbles contained in the thermal system 1 comprises putting the new fluid into circulation by actuating the at least one pump 41, 42.

[0063] In addition or alternatively, the filling step E3 comprises a pressurized injection of the new heat transfer fluid into the second set 50 of conduits.

[0064] In addition or alternatively, the thermal system 1 comprises at least one pump 41, 42 and the step of evacuating gas bubbles contained in the thermal system comprises circulating the new fluid by actuating the at least one pump.

[0065] Further, in one embodiment, the radiator comprises a bleed screw, and the degassing substep comprises evacuating gas bubbles by opening the bleed screw.

[0066] Finally, the maintenance method and the maintenance device according to the invention have several advantages.

[0067] Firstly, the maintenance method and the maintenance device according to the invention allow time to be saved on tasks of filling the cooling circuit in the factory. Indeed, the thermal system according to the invention comprises only a single jar, which reduces the filling time in the factory compared to thermal systems comprising two or more jars. The filling tasks can also be carried out with a single filling machine, whereas for cooling circuits comprising several jars, it was sometimes necessary to invest in several machines to save time on the filling phase.

[0068] In addition, the maintenance method and the maintenance device according to the invention allow for savings in after-sales maintenance time. Indeed, thanks to the optimal position of the cooling circuit reservoir in the system, the reservoir directly supplying the two water pumps, the time required for a technician to fill the cooling circuit is reduced. In addition, a mode of circulation of the coolant, corresponding to the first circulation previously described, has been designed to facilitate the degassing of the cooling circuit after filling carried out during a maintenance visit to the motor vehicle. This mode makes it possible to degas all the components of the cooling circuit at the same time via the reservoir mounted in parallel with the radiator.The time required to degas the cooling circuit is significantly reduced, which helps reduce the TCO (for the acronym "Total Cost of Ownership") of the vehicle, i.e. reducing the overall cost of vehicle ownership.

Claims

1.

2. Claims Method for maintaining a thermal system (1) for a motor vehicle (100), the thermal system (1) comprising • a first set (10) comprising components including - an electric motor (11), - a battery (12), - a thermal resistance (14), - a cooler (13) connected to an air conditioning circuit of a passenger compartment of the motor vehicle, - a radiator (15), • a second assembly (20) comprising conduits for a heat transfer fluid, connecting the components of the first assembly, and a third assembly (30) comprising at least one solenoid valve, and in particular at most three solenoid valves, connected to conduits of the second assembly (20), the thermal system (1) implementing a first circulation (101) of heat transfer fluid through said conduits in a first series circuit connecting together all the components of the first assembly (10) when the solenoid valve(s) of the third assembly are all in the rest state, the maintenance method being characterized in that it comprises - a first step (El) of implementation of the first circulation (101), then - a second step (E2) of draining a heat transfer fluid circulating in the second set of conduits (20) of the thermal system (1), then - a third step (E3) of filling the second set (20) of conduits of the thermal system (1) with a new heat transfer fluid, then - a fourth step (E4) of evacuating gas bubbles contained in the second set (20) of conduits of the thermal system (1). Maintenance method according to the preceding claim, characterized in that the first step (El) comprises placing each solenoid valve of the third assembly (30) in a rest state, the third assembly (30) consisting of - a single solenoid valve (31) with at least seven ways, or - two solenoid valves (32, 33), including a four-way solenoid valve (32), and a three-way solenoid valve (33), or - three three-way solenoid valves (35, 36, 37).

3. Maintenance method according to one of the preceding claims, characterized in that the emptying step (E2) comprises pressurizing air generating a forced evacuation of a heat transfer fluid remaining in the conduits of the second assembly (20), and / or in that the filling step (E3) comprises a pressurized injection of a new heat transfer fluid into the conduits of the second assembly (20), and / or in that the thermal system (1) comprises at least one pump (41, 42) and the fourth step (E4) of evacuating gas bubbles contained in the thermal system (1) comprises a circulation of the new heat transfer fluid by actuation of the at least one pump (41, 42).

4. Maintenance method according to one of the preceding claims, at least one component (11) of the first assembly (10) comprising a bleed screw (111), characterized in that the fourth step (E4) of evacuating gas bubbles contained in the thermal system (1) comprises evacuating gas bubbles by opening the bleed screw (111).

5. Maintenance method according to one of the preceding claims, characterized in that the thermal system (1) comprises a single degassing jar (50), and / or in that the degassing jar (50) is a circulating type jar and / or in that the degassing jar (50) and the radiator (15) are arranged on parallel circuit portions by said conduits, and / or in that an altitude of the degassing jar (50) is greater than an altitude of each component of the first assembly (10).

6. Device (2) for maintaining a thermal system (1) for a motor vehicle (100), the thermal system (1) comprising • a first assembly (10) comprising components including - an electric motor (11), - a battery (12), - a thermal resistor (14),

7. - a cooler (13) connected to an air conditioning circuit of a passenger compartment of the motor vehicle, - a radiator (15), • a second assembly (20) comprising conduits for a heat transfer fluid, connecting the components of the first assembly, and a third assembly (30) comprising at least one solenoid valve, and in particular at most three solenoid valves, connected to conduits of the second assembly (20), the thermal system (1) implementing a first circulation (101) of heat transfer fluid through said conduits in a first series circuit connecting together the components of the first assembly (10) when the solenoid valve(s) of the third assembly are all in the rest state, the device being characterized in that it comprises hardware and / or software elements implementing the method according to one of claims 1 to 5, in particular a tool (60) equipped with a vacuum pump capable of sucking air present in the conduits of the second assembly (20). Motor vehicle (100) equipped with a maintenance device (2) according to claim 6.