METHOD FOR VALIDATING AN ENGINE OIL

Abstract

The invention relates to a method for validating an engine oil (1) connected to: - a ventilation circuit (10) comprising a valve (11) configured to be in an open state and a closed state; - a heat transfer circuit (20); a pump (22) configured to circulate a heat transfer fluid in the heat transfer circuit (20). The method comprises the following steps: - a step of starting the engine (1) at a predetermined engine speed; - steps of pumping the heat transfer fluid according to predetermined fluid flow rates by the pump (22) when the valve (11) is in the closed or open state; - a step of comparing a measured engine fouling state (1) after pumping the heat transfer fluid with a predetermined engine fouling state (1), so as to validate the engine oil (1). Figure 1

Description

Title of the invention: METHOD FOR VALIDATING AN ENGINE OIL

[0001] The invention relates to validation tests of an engine oil, the validation attesting to the oil's ability not to foul the engine.

[0002] As described in application FR3028044, a method for validating an engine oil is included. A heat transfer circuit comprises the engine, the circuit being configured to circulate a heat transfer fluid. The heat transfer circuit also includes a heat exchanger. The method comprises a series of test cycles alternating between an engine heating phase and an engine cooling phase.

[0003] However, such a process is not entirely representative of the actual conditions of the engine, the process being limited to a variation of the temperature by a heat transfer circuit to perform a validation of the engine oil, affecting the estimation of the overall fouling of the engine by the engine oil.

[0004] The objective of the invention is to overcome these drawbacks and to propose a more reliable method for validating oil in the engine.

[0005] To achieve this objective, the invention proposes a method for validating an oil in an engine connected to: - an aeration circuit including a valve configured to be in an open or closed state; - a heat transfer circuit comprising a heat exchanger and a pump configured to circulate a heat transfer fluid in the heat transfer circuit according to a predetermined fluid flow rate, the process comprising the following steps for a validation cycle: - a step of starting the engine at a predetermined engine speed value; - a first step of pumping the heat transfer fluid according to a first value of fluid flow predetermined by the pump when the valve is in the closed state; - a second stage of pumping the heat transfer fluid according to a second predetermined fluid flow rate value by the pump when the valve is in the open state; - a step of measuring the engine fouling state by a sensor after the pumping of the heat transfer fluid; - a step of comparing the measured engine fouling state with a predetermined engine fouling state, in order to validate the engine oil.

[0006] Such a process makes it possible to evaluate engine oils and to compare them with each other on their ability not to foul the engine.

[0007] In its general definition, the invention provides for validating engine oil. This includes engine components such as an engine piston, including in particular its top ring groove, top ring groove, bottom ring groove, and oil control ring groove. Thus, the oil validation process also makes it possible to reproduce carbon deposits in the aforementioned components, as well as fouling and wear of the piston rings, with fouling of the oil control ring groove potentially obstructing oil return holes. This also includes other engine components such as valves, spark plugs, and a cylinder head intake port.

[0008] Advantageously, the motor includes a temperature probe configured to measure the temperature of the heat transfer fluid, the process including, for the validation cycle, a step of measuring a temperature value of the heat transfer fluid by the temperature probe.

[0009] Such a probe provides the process with an additional means of measurement, increasing the reliability of the process.

[0010] Advantageously, the heat transfer fluid is pumped according to the first predetermined fluid flow value by the pump when the measured temperature value is greater than a first predetermined temperature value.

[0011] Advantageously, the first predetermined temperature value is between 30°C and 40°C.

[0012] Advantageously, the heat transfer fluid is pumped according to the second predetermined fluid flow value by the pump when the measured temperature value is between the first predetermined temperature value and a second predetermined temperature value.

[0013] Advantageously, the second predetermined temperature value is between -20°C and 0°C.

[0014] The heat transfer fluid has a solidification point value and a boiling point value. The heat transfer fluid is advantageously chosen such that the solidification point value of the heat transfer fluid is lower than the second predetermined temperature value and such that its boiling point value is higher than the first predetermined temperature value.

[0015] Advantageously, the first predetermined fluid flow value is less than the second predetermined fluid flow value.

[0016] Advantageously, the process comprises between 700 and 1000 validation cycles.

[0017] This allows the duration of the validation process to be adapted according to the type of engine.

[0018] The invention also relates to a computer program comprising program code instructions for executing the steps of the process defined as above, when the program is running on a computer.

[0019] The invention further relates to a test bench comprising an electronic control unit including means for acquisition, processing by software instructions stored in a memory as well as control means required for the implementation of the computer program defined as above.

[0020] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig. 1] schematically illustrates a motor connected to a ventilation circuit and a heat transfer circuit according to an embodiment of the invention; - [Fig.2] illustrates a flowchart representing the steps of the process of validating an engine oil, illustrated in [Fig.1], according to an embodiment of the invention.

[0021] Figure [Fig.1] illustrates a motor 1 connected to a ventilation circuit 10 and a heat transfer circuit 20.

[0022] The engine 1 is lubricated by an oil. For example, at least one piston of the engine is lubricated by the oil.

[0023] The ventilation circuit 10 includes a valve 11 configured to be in an open or closed state. In practice, the valve 11 is a solenoid valve configured to be in the open state upon a first command and in the closed state upon a second command. The solenoid valve receives a sequence of commands including the first command and the second command.

[0024] The motor 1 includes an air inlet and an air outlet, not shown in [Fig. 1]. The ventilation circuit 10 also includes an air inlet and an air outlet, not shown in [Fig. 1]. The air outlet of the motor 1 is connected to the air inlet of the ventilation circuit 10. The air inlet of the motor 1 is connected to the air outlet of the ventilation circuit 10.

[0025] Generally, the engine 1 also includes an injection or carburetor and a combustion chamber, not illustrated in [Fig.1], the injection or carburetor being configured to inject fuel into the combustion chamber.

[0026] The motor 1 advantageously includes a temperature probe configured to measure a temperature value of the heat transfer fluid.

[0027] It is understood that the aeration circuit includes an air pump configured to circulate air in the aeration circuit 10 from the air inlet of the aeration circuit 10 to the air outlet of the aeration circuit 10.

[0028] The heat transfer circuit 20 includes a heat exchanger 21 and a pump 22. The pump 22 is configured to circulate a heat transfer fluid in the heat transfer circuit 20 according to a predetermined fluid flow rate value.

[0029] For example, the heat transfer fluid is either water or an antifreeze mixture, typically a mixture of water and ethylene glycol or propylene glycol.

[0030] According to the invention, a test bench, not illustrated in [Fig.1], comprising an electronic control unit including means for acquisition, processing by software instructions stored in a memory and control means electrically connected to the motor 1.

[0031] Figure 2 illustrates a flowchart of a process for validating engine oil 1, the steps of the process for a validation cycle being described below according to one embodiment.

[0032] The validation cycle preferably lasts between 30 min and 90 min, the process comprising between 700 and 1000 validation cycles.

[0033] In a start-up step E0, the engine 1 is started up to a predetermined engine speed value.

[0034] In practice, in a first operating mode, the predetermined engine speed is approximately between 700 rpm and 3500 rpm. In a second operating mode, the predetermined engine speed is approximately 0 rpm. When the engine is in the first operating mode, the engine oil 1 is heated, but its temperature does not exceed approximately 115°C.

[0035] Advantageously, the process includes, before the validation cycle, a break-in stage of the engine, typically the engine 1 being oiled and put into the first regime.

[0036] Advantageously, in a measurement step E'0, a temperature value of the heat transfer fluid is measured by the temperature probe.

[0037] In a pumping step El, the pump 22 pumps heat transfer fluid according to a first predetermined fluid flow rate value when the valve is in the closed state.

[0038] The first predetermined fluid flow value is preferably between 80 L / min and 100 L / min.

[0039] Advantageously, in the pumping step El, the heat transfer fluid is pumped according to the first predetermined fluid flow value by the pump 22, the heat transfer fluid is pumped when the measured temperature value is greater than a first predetermined temperature value.

[0040] The first predetermined temperature value is preferably between 30°C and 40°C.

[0041] Preferably, in the pumping step E1, the motor 1 is in the first speed.

[0042] In a pumping step E2, the pump 22 pumps heat transfer fluid according to a second predetermined fluid flow rate value when the valve is in the open state.

[0043] The second predetermined flow rate value is preferably between 100 L / min and 120 L / min.

[0044] By way of example, the air temperature at the engine air intake is approximately 22°C, generally between 17°C and 27°C, while the air temperature at the engine air outlet is approximately 27°C, generally between 22°C and 32°C.

[0045] Advantageously, in the second pumping stage E2, the heat transfer fluid is pumped according to the second predetermined fluid flow value by the pump 22, the heat transfer fluid is pumped when the measured temperature value is greater than a second predetermined temperature value.

[0046] The second predetermined temperature value is preferably between -20°C and 0°C.

[0047] Preferably, in the pumping step E2, the motor 1 is in the second regime.

[0048] In a measurement step E3, the fouling state of the engine 1 is measured by a sensor after pumping the heat transfer fluid.

[0049] For example, the engine fouling level is measured, for instance, with a dynamometer on engine 1. In other cases, the sensor is configured to analyze the oil composition, particularly the presence of particles in the oil, or to measure the flow rate of the heat transfer fluid, or to analyze engine emissions, or to measure the pressure of the heat transfer fluid. In still other cases, the sensor is configured to measure a gas flow rate, particularly the crankcase gas of engine 1, also called "blow-by" gas, indicating the fouling level of engine 1.

[0050] In a comparison step E4, the measured fouling state of engine 1 is compared with a predetermined fouling state of engine 1, so as to validate the oil of engine 1. Thus, when the measured fouling state of engine 1 is lower than that of the predetermined fouling state of engine 1, the ability of the oil not to foul the engine is validated.

Claims

Demands

1. A method for validating an oil in an engine (1) connected to: - a ventilation circuit (10) comprising a valve (11) configured to be in an open or closed state; - a heat transfer circuit (20) comprising a heat exchanger (21) and a pump (22) configured to circulate a heat transfer fluid in the heat transfer circuit (20) according to a predetermined fluid flow rate value, the method comprising the following steps for a validation cycle: - a step of starting the engine (1) to a predetermined engine speed value (E0); - a step of pumping the heat transfer fluid according to a first predetermined fluid flow rate value by the pump (22) when the valve (11) is in the closed state; - a pumping step (E2) of the heat transfer fluid according to a second predetermined fluid flow value by the pump (22) when the valve (11) is in the open state;- a measurement step (E3) of the engine fouling state (1) by a sensor after pumping the heat transfer fluid; - a comparison step (E4) of the measured engine fouling state (1) against a predetermined engine fouling state (1), in order to validate the engine oil (1).

2. Method according to claim 1, characterized in that the motor (1) comprises a temperature probe configured to measure the temperature of the heat transfer fluid, the method comprising, for the validation cycle, a measurement step (E'O) of a temperature value of the heat transfer fluid by the temperature probe.

3. Method according to claim 2, characterized in that the heat transfer fluid is pumped according to the first predetermined fluid flow value by the pump (22) when the measured temperature value is greater than a first predetermined temperature value.

4. Method according to claim 3, characterized in that the first predetermined temperature value is between 30°C and 40°C.

5. A method according to any one of claims 2 to 4, characterized in that the heat transfer fluid is pumped according to the second predetermined fluid flow rate value by the pump (22) when the measured temperature value is between the first predetermined temperature value and a second predetermined temperature value.

6. Method according to claim 5, characterized in that the second predetermined temperature value is between -20°C and 0°C.

7. A method according to any one of claims 1 to 6, characterized in that the first predetermined fluid flow value is less than the second predetermined fluid flow value.

8. A method according to any one of claims 1 to 7, characterized in that the method comprises between 700 validation cycles and 1000 validation cycles.

9. Computer program comprising program code instructions for carrying out the steps of the process according to any one of claims 1 to 8, when the program is running on a computer.

10. Test bench comprising an electronic control unit including means for acquisition, processing by software instructions stored in memory and control means required for the implementation of the computer program according to claim 9.

Images