Process for converting diesel thermal vehicles to a dual-fuel gas version with a restricted mode

Abstract

Method for converting diesel thermal vehicles to a dual-fuel gas version with a restricted mode. The invention relates to the field of converting thermal vehicles to a dual-fuel gas version in the case of diesel engine vehicles. It comprises the addition in the passenger compartment of a fuel selection switch either in 100% diesel mode or in mode with a proportion of gaseous fuel in indirect injection into the intake and a proportion of diesel fuel in proportions depending on the operating conditions, and in 100% diesel mode the engine power is restricted by at least 20% so as to reduce emissions regardless of the choice made by the user of the vehicle. Figure to be published with the abstract: Fig. 1.

Description

Title of the invention: Method for converting diesel thermal vehicles to a dual-fuel gas version with a restricted mode

[0001] FIELD OF THE INVENTION TO WHICH THE INVENTION RELATES

[0002] The invention relates to the field of conversions of thermal vehicles to a dual-fuel gas version.

[0003] This involves the conversion of a thermal vehicle, a fleet of thermal vehicles, or a fleet of thermal vehicles, vehicles originally equipped with a thermal engine by a dual-fuel gas engine and the optimization of all-mode emissions. PREVIOUS ART

[0004] It is common to convert thermal vehicles to dual-fuel gas, including for older gasoline vehicles operating with indirect gasoline injection.

[0005] In this context, the dual-fuel gas operating mode can be 100% gas, but depending on the embodiments, once a temperature of the engine, and in particular of its cooling water, is reached, the gas is vaporized.

[0006] In the context of gasoline engines with direct injection in each cylinder, it is conventional to keep around 15% of gasoline not for physicochemical considerations but to cool the injectors which in the absence of the original fuel would heat up and deteriorate.

[0007] In the context of diesel engines, in the absence of spark plugs, a direct injection of a minimum of diesel is necessary to initiate the combustion of the two fuels, namely the original diesel fuel and the gas.

[0008] In fact, in these three contexts, it is conventional to have inside the passenger compartment an operating mode switch allowing the engine to be operated either solely with the original fuel or with a 100% gaseous fuel in the context of indirect injection engines or with simultaneous injection without mixing of the original fuel in direct injection and the gaseous fuel in indirect injection in proportions depending on the operating conditions.

[0009] Since the gaseous fuel produces fewer emissions during its combustion than the original fuel, the operating mode with indirect gas injection is the one which produces the least emissions.

[0010] On the other hand, due to the presence of the switch available to the user, he can choose either by constraint, for example when the gas tank is empty, or by a personal, non-ecological choice, to drive only with the original fuel without any gas injection.

[0011] This is all the more damaging in the case of a diesel engine which has more emissions than a petrol version.

[0012] BRIEF DESCRIPTION OF THE INVENTION

[0013] The method for converting vehicles comprising a diesel thermal engine to a dual-fuel gas version according to the invention relates to diesel thermal engines and consists at least in the addition of a second tank with its feed neck and its gas filling orifice in addition to the original tank with its feed neck and its filling orifice with the original fuel, consists at least in the addition of an injection system with its own electronic computer and its injectors for the gas in addition to the original injection system with the original electronic injection computer and its injectors for the original fuel, as well as the addition in the passenger compartment of a fuel selection switch either in 100% diesel mode or in mode with a proportion of gaseous fuel in indirect injection in the intake and a proportion of diesel fuel in proportions depending on the operating conditions,and that in 100% diesel mode the engine power is restricted by at least 20% in order to reduce emissions regardless of the choice made by the vehicle user.

[0014] Advantageously in terms of power, the reduction in power is obtained by the gas calculator which intercepts at least one input signal from the original fuel calculator when the switch is in 100% diesel mode.

[0015] Advantageously, the same interception device by the gas calculator is used to inject a greater quantity of gas than that permitted by the quantity of excess air available in the intake line not used by the combustion of the diesel when the engine is operating at nominal speed.

[0016] Advantageously, the input signal intercepted when the injection system is of the common rail type, is the injection pressure signal common to all the injectors measured by a pressure sensor.

[0017] Advantageously, the intercepted input signal is at least one accelerator pedal position signal.

[0018] Advantageously, the percentage of proportion of diesel injected less in gas injection mode is greater than the percentage of power restriction in 100% diesel mode.

[0019] Advantageously, the percentage of gas proportion injected in gas injection mode is at least 10% greater than the percentage of power restriction in 100% diesel mode.

[0020] Advantageously, it is possible to regain the full power of the engine in 100% diesel mode by connecting a specific diagnostic tool for the duration of an initial calibration.

[0021] Advantageously, in this configuration critical parameters such as temperature or knocking are measured and acceptable thresholds of these same critical parameters are defined in gas injection compared to the values ​​supported in 100% diesel mode.

[0022] Advantageously, by removing the fuse from the entire gas system, starting of the engine is inhibited so that the vehicle can no longer be started and thus the full power of the engine cannot be used in 100% diesel mode.

[0023] Advantageously, the connection between the starter control and the starter excitation is intercepted by a relay.

[0024] Advantageously, the relay is powered by an output of the gas calculator.

[0025] Advantageously, the output of the calculator is not a specific output of the calculator but a supply voltage of 5 volts or 12 volts of at least one element of the LPG system, element with a connector of at least 3 ways which are the ground, the power supply and a connection specific to the element.

[0026] Advantageously, the element is an LPG level sensor in the gas tank. Brief description of the drawings

[0027] Other characteristics and advantages of the invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the attached drawing.

[0028] [Fig-1] shows an embodiment of a conversion of a vehicle to dual gas fuel, in particular with the addition of a second tank with its feed chute and its gas filling orifice and the addition of an injection system with its own electronic computer and its injectors for the gas.

[0029] [Fig.2] shows an embodiment of the inhibition of the starter when the fuse of the system is removed, with a relay intercepting the connection between the ignition key and the starter excitation, the relay itself being kept energized using the power output of the GAS computer to an element of the gas system comprising a three-way connection (ground, signal, power supply). DETAILED DESCRIPTION OF THE INVENTION

[0030] The method for converting vehicles (V) comprising a diesel thermal engine (M) to a dual-fuel gas version with emissions according to the invention relates to diesel thermal engines and consists at least in the addition of a second tank (R2) with its feed neck and its filling orifice (02) with gas in addition to the original tank (RI) with its feed neck and its filling orifice (01) with the original fuel, consists at least in the addition of an injection system with its own electronic computer (C2) and its injectors (12) for the gas in addition to the original injection system with the original electronic injection computer (Cl) and its injectors (II) for the original fuel,as well as the addition in the passenger compartment of a fuel selection switch either in 100% diesel mode or in mode with a proportion of gaseous fuel in indirect injection into the intake and a proportion of diesel fuel in proportions depending on the operating conditions, and that in 100% diesel mode the engine power is restricted by at least 20% so as to reduce emissions regardless of the choice made by the user of the vehicle.

[0031] [Fig.l] illustrates the classic implementation of the conversion of a thermal engine vehicle by a dual-fuel gas version consisting at least of the addition of a second tank (R2) with its feed neck and its filling orifice (02) with gas in addition to the original tank (RI) with its feed neck and its filling orifice (01) with the original fuel and the addition of an injection system with its own electronic computer (C2) and its injectors (12) for the gas in addition to the original injection system with the original electronic injection computer (Cl) and its injectors (II) for the original fuel.

[0032] Advantageously, a multi-valve (PV) is associated with the gas tank (R2) in particular to provide a safety valve function.

[0033] Conventionally, a vapor-reducer (VD) is added which allows the liquid LPG from the gas tank (R2) to be converted into gas for the gas injectors (12) as well as in the case of low-temperature natural gas. To this end, the vapor-reducer (VD) uses the heat from the engine by intercepting the engine cooling circuit via water pipes (CE).

[0034] Advantageously in terms of power, the reduction in power is obtained by the gas calculator (C2) which intercepts at least one input signal from the original fuel calculator (Cl) when the switch is in 100% diesel mode.

[0035] The input signal of the original fuel calculator is intercepted to become an input of the gas calculator (C2) which generates an output signal to the intercepted input of the original fuel calculator (Cl).

[0036] Advantageously, the same interception device by the gas calculator (C2) is used to reduce the quantity of diesel injected by the original calculator (Cl) to inject by the gas calculator (C2) a greater quantity of gas than that authorized by the quantity of excess air available in the intake line not used by the combustion of the diesel when the engine is operating at nominal speed.

[0037] Advantageously, the input signal intercepted when the injection system is of the common rail type, is the injection pressure signal common to all the injectors measured by a pressure sensor.

[0038] Advantageously, the intercepted input signal is at least one accelerator pedal position signal.

[0039] There are redundant accelerator pedal position sensors, i.e. with two deliberately different signals, for example one signal increasing as a function of the angle and a second signal decreasing.

[0040] In this configuration, it is necessary to intercept the two signals in parallel.

[0041] Advantageously, the percentage of proportion of diesel injected less in gas injection mode is greater than the percentage of power restriction in 100% diesel mode.

[0042] Advantageously, the percentage of gas proportion injected in gas injection mode is at least 10% greater than the percentage of power restriction in 100% diesel mode.

[0043] Advantageously, it is possible to regain the full power of the engine in 100% diesel mode by connecting a specific diagnostic tool for the duration of an initial calibration.

[0044] Advantageously, in this configuration critical parameters such as temperature or knocking are measured and acceptable thresholds of these same critical parameters are defined in gas injection compared to the values ​​supported in 100% diesel mode.

[0045] Advantageously, by removing the fuse (F) from the entire gas system, starting of the engine is inhibited so that it is no longer possible to start the vehicle (V) and thus to not be able to exploit the full power of the engine in 100% diesel mode.

[0046] According to an illustrated embodiment [Fig.2], the connection (L) between the starter control usually by the ignition key (CC) and the excitation of the starter (D) is intercepted by a relay (R). This relay (R) is powered for example by the supply voltage (AG) of the LPG system directly connected via the fuse (F) to the positive terminal (P) of the battery (B), so if the fuse (F) of the LPG system is removed, the relay (R) is no longer powered and the vehicle (V) cannot start.

[0047] Advantageously, the relay (R) is not directly powered by the power supply (AG) of the LPG system protected by the fuse (F) but by an output of the computer (C2), which will make it possible to stop the current consumption when the computer (C2) goes into standby, unlike the direct power supply (AG) after the fuse (F).

[0048] Advantageously, this output is not a specific output of the computer but a supply voltage of 5 volts or 12 volts of at least one element (E) of the LPG system, element (E) with a connector of at least 3 ways (C3V) which are the ground (G), the power supply (V) and a specific connection (S) to the element (E). For example, this may be the user interface in the passenger compartment, a pressure sensor, a temperature sensor or a LPG level sensor in the tank.

[0049] Advantageously, the element (E) is an LPG level sensor in the gas tank (R2). Industrial application

[0050] In terms of industrial application, the process concerns the conversion of diesel thermal vehicles with an optimization of the percentage of gas compared to the original fuel.

[0051] The present invention is in no way limited to the embodiments described and shown, but those skilled in the art will be able to make any variation in accordance with its spirit for implementations adapted to each specific context.

Claims

Claims

1. Method for converting vehicles (V) comprising a diesel thermal engine (M) to a dual-fuel gas version, characterized in that it relates to diesel thermal engines and consists at least in the addition of a second tank (R2) with its feed neck and its filling orifice (02) for gas in addition to the original tank (RI) with its feed neck and its filling orifice (01) for the original fuel, consists at least in the addition of an injection system with its own electronic computer (C2) and its injectors (12) for the gas in addition to the original injection system with the original electronic injection computer (Cl) and its injectors (II) for the original fuel,as well as the addition in the passenger compartment of a fuel selection switch either in 100% diesel mode or in mode with a proportion of gaseous fuel in indirect injection into the intake and a proportion of diesel fuel in proportions depending on the operating conditions, and that in 100% diesel mode the engine power is restricted by at least 20% so as to reduce emissions regardless of the choice made by the user of the vehicle.,

2. Method according to claim 1 characterized in that the reduction in power is obtained by the gas calculator (C2) which intercepts at least one input signal from the original fuel calculator (Cl) when the switch is in 100% diesel mode.

3. Method according to claim 2 characterized in that the same interception device by the gas calculator (C2) is used to reduce the quantity of diesel injected by the original calculator (Cl) to inject by the gas calculator (C2) a greater quantity of gas than that authorized by the quantity of excess air available in the intake line not used by the combustion of the diesel when the engine is operating at nominal.

4. Method according to any one of claims 2 to 3 characterized in that the injection system is of the common rail type and that the intercepted input signal is the injection pressure signal common to all the injectors measured by a pressure sensor.

5. Method according to any one of claims 2 to 3 characterized in that the intercepted input signal is at least one accelerator pedal position signal.

6. Method according to any one of claims 1 to 5 characterized in that the percentage of proportion of diesel injected less in mode with gas injection is greater than the percentage of power restriction in 100% diesel mode.

7. Method according to any one of claims 1 to 6, characterized in that the percentage of proportion of gas injected in gas injection mode is at least 10% greater than the percentage of power restriction in 100% diesel mode.

8. Method according to any one of claims 1 to 7, characterized in that it is possible to regain the full power of the engine in 100% diesel mode by connecting a specific diagnostic tool for the duration of an initial calibration.

9. Method according to claim 8 characterized in that in this configuration critical parameters such as temperature or knocking are measured and acceptable thresholds of these same critical parameters are defined in gas injection compared to the values ​​supported in 100% diesel mode.

10. Method according to any one of claims 1 to 9, characterized in that by removing the fuse from the entire gas system, starting of the engine is inhibited so that the vehicle can no longer be started and thus the full power of the engine cannot be used in 100% diesel mode.

11. Method according to claim 10, characterized in that the connection (L) between the starter control and the starter excitation is intercepted by a relay (R).

12. Method according to claim 11, characterized in that the relay (R) is supplied by an output of the gas calculator (C2).

13. Method according to claim 12, characterized in that the output of the calculator is not a specific output of the calculator but a supply voltage of 5 volts or 12 volts of at least one element (E) of the LPG system, element (E) with a connector of at least 3 ways (C3V) which are the ground (G), the power supply (V) and a specific connection (S) to the element (E).

14. Method according to claim 13, characterized in that the element (E) is an LPG level sensor in the gas tank (R2).

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