FR2620770A3 - METHOD FOR TRANSFORMING A DIESEL CYCLE ENGINE TO AN OTTO CYCLE ENGINE POWERED BY G.P.L. GAS, AND THE MOTOR THUS OBTAINED - Google Patents

Abstract

The invention relates to a diesel cycle engine supplied with G.P.L. for forklift trucks or the like, obtained by converting a similar Diesel cycle engine, by modifying the head of the pistons so as to obtain a compression ratio suitable for the new fuel, by removing the injection pump 18, injectors 22, glow plugs 24, filters 12, 14 and diesel tank 2 and addition of an LPG gas tank 4, a solenoid valve 26, a filter 16, a vaporizer-reducer 28, a mixer 30, an ignition distributor 32, an HT coil 40, an electronic ignition 42 spark plugs 44. The engine obtained by this transformation is very advantageous by virtue of its robustness and the economy of its use.

Description

Process for converting a diesel engine into a cycle engine

  The present invention refers to the process of converting a diesel cycle engine into an Otto cycle engine powered by G.P.L gas. and the engine thus obtained, particularly suitable for use in transport and / or lifting means and in generators. It is known that among the various sources of atmospheric pollution, one which is certainly not negligible is represented by the exhaust gases of the engines of vehicles in general. This disadvantage is particularly felt in closed and poorly ventilated premises such as barracks or low-rise buildings in which normally operate means of transport and / or lifting or generating sets powered by

Diesel engines.

  It is also known that the large quantity of unburned hydrocarbons (HC) that is released into the atmosphere by diesel engines that are not perfectly regulated or that have been operating for a long time is one of the causes respiratory diseases, which are often of severe form and are contracted by staff who

  presence of this type of air pollution.

  Among the various methods proposed and known in the present art for the solution of the problem mentioned above, it is necessary to recall the use of the forklift powered by motors.

  electric motors as well as by internal combustion engines.

  These electric trolleys certainly have the significant advantage of not being pollutants, but at the same time the disadvantage of having only very low lifting ranges or low speeds of displacement which make them uneconomical in

  large offices or offices.

  Devices are also known which are inserted into the exhaust pipe of the internal combustion engine and which exert a

  filtration action on the exhaust gas.

  However, such devices greatly reduce the performance of the vehicle in which they are mounted, apart from the

they are very expensive.

  The present invention proposes to eliminate or reduce the disadvantages and disadvantages created for the environment by internal combustion engines, in particular those with a diesel cycle, by proposing a process for converting said diesel cycle engines into combustion engines. Otto cycle fueled with LPG gas (liquefied petroleum gas). The use of gas G.P.L. (liquefied petroleum gas) is particularly suitable because of its low hydrocarbon content

  unburned residuals and its relatively low acquisition cost.

  Consequently, the internal combustion engines with a Diesel cycle and transformed into an Otto cycle and supplied with gas G.P.L. can be used advantageously in premises where low air pollution is required due to the presence of personnel

  working in the room which is itself slightly ventilated.

  At the same time, the use of said transformed motor results in a significant saving without undergoing power losses, which is the case however when using forklifts

  powered by electric motors, as indicated above.

  A last, and not the least, characteristic of the present invention consists in the extreme simplicity of the transformation into the very high robustness of the motor thus obtained.

  as can be better understood from reading the description that

  follows. Therefore, a first object of the present invention is to propose a method for transforming a diesel cycle engine into an Otto cycle engine powered by LPG gas, characterized in that it comprises the following phases: A - Removal the diesel fuel injection pump; B - Removal of the tank containing the diesel fuel; C - Removal of the diesel fuel pump; D - Removal of diesel filters; E Removal of diesel fuel lines; F - Removal of diesel injectors inside the combustion chambers; G Removal of diesel glow plugs mounted in the precombers of combustion; H - Increasing the volume of the combustion chamber by removing material on the piston head to reduce the compression ratio; I - Modification of the pre-chamber of combustion by closing the glow plug seat; L - Installation of an ignition distributor; M - Mounting of a high-voltage transformer (H.T. coil); N - Assembly of an electronic pulse generator (electronic ignition) connected to the coil H.T .; 0 - Assembly of a pressure tank adapted to contain the gas

G.P.L .;

  P - Installation of a solenoid valve for the interruption or restoration of the gas flow G.P.L .; Q - Installation of a G.P. L Gas Vapor Reducer; R - Assembly of a mixer for the correct formation of the mixture of air and gas; S - Installation of a filter for gas filtration G.P.L .;

  T - Installation of gas supply pipes G.P.L ..

  Another object of the present invention is to provide a motor powered with G.P.L gas. according to the method of transformation described above and comprising: - a monobloc carrying inside a crankshaft and associated connecting rods operating between said crankshaft and the pistons; - the distribution organs; - a cylinder head; characterized in that it further comprises: - a reservoir adapted to contain the gas G.P.L. under pressure and a level indicator device of the liquid gas contained therein; a series of liquid gas supply lines connected to the various devices constituting the elements of the transformation; - a solenoid valve connected in series in the gas supply line G.P.L. and capable of alternately interrupting or restoring the flow of gas to the following devices; a filter also mounted in series in the gas supply pipe G. P.L. for filtering this gas; - a liquid gas vaporizer by a heating action of the latter, performing at the same time a pressure regulating action so as to provide downstream devices according to optimal values; - a gas-air mixer mounted in series in the suction pipe, causing inside a gas diffusion chamber a turbulence of this gas to obtain an optimal mixture of gas-air; - an ignition distributor actuated by a shaft connected to the distribution members; - a high voltage transformer (H.T. coil) connected to the ignition distributor; an electronic ignition capable of supplying precise and high power current pulses to the H.T. coil so as to obtain a new increase in the high voltage itself; a plurality of spark plugs of the air-gas mixture according to a

  quantity corresponding to the number of cylinders.

  A preferred embodiment of the invention will now be described, by way of example and not limitation, with reference to the accompanying drawings in which: FIG. 1 is a diagrammatic representation of all the components of an apparatus for supplying and injecting a diesel cycle engine; FIG. 2 is a schematic representation of the elements necessary for the conversion of a diesel cycle engine of FIG. 1 in a Otto cycle engine fed with gas G.P.L. according to the invention; FIG. 3 is a side view of a Diesel cycle engine converted into an Otto cycle engine and fed with G.P.L gas. according to the invention; FIG. 4 is a side view of the portion opposite that of FIG. 3, of a diesel cycle engine converted into an Otto cycle engine and supplied with G.P.L gas. according to the invention; FIG. 5 is a plan view of a gas mixer G.P.L. according to the invention; FIG. 6 is a sectional view along line VIVI of the mixer

of gas G.P.L. of FIG. 5.

  The process of converting a diesel engine into an Otto cycle engine fed with G.P.L. is implemented substantially by the successive phases that start by removing the diesel engine to transform the injection pump, the diesel fuel pump, the diesel filters, the tubes

  diesel fuel, injectors and spark plugs.

  In this first phase of removal of the devices mentioned above follows a second phase of modification of the pistons which are removed by mechanical work part of the material of their head in order to form a semi-spherical cavity to reduce the rate

  existing compression in the diesel engine.

  Then, during a third phase, the prechamber of explosion is modified by closing the glow plug seats of glow plugs. After the withdrawal and modification phases mentioned above, there is a phase which involves the addition and assembly of new devices, making the engine being processed capable of operating with LPG gas, and consisting of: the mounting of an ignition distributor set on a rotary shaft, previously used to drive the injection pump in rotation, an HV coil, an electronic pulse generator - or electronic ignition -, a tank to contain LPG gas, a solenoid valve, a

  filter and vaporizer and gas regulator G.P.L ..

  During a final phase, the installation of an air-gas mixer using an air filter, and the suction manifold of the

engine being transformed.

  The process of converting a diesel engine into an Otto cycle engine fed with G.P.L. according to the invention can be

  considered finished with this last phase.

  As has been said in the preamble, the invention also applies to the engine obtained according to the transformation method described above. Referring to Figs. 1, 2, 3 and 4, the transformation of a

  Diesel cycle engine in an Otto cycle engine powered by gas G.P.L.

  is carried out essentially by replacing the diesel fuel tank 2 with a tank capable of containing G.P.L gas. and further comprising

  Level 6 indicator of the liquid gas contained in the latter.

  The diesel fuel supply lines 8 are then eliminated by replacing them with new supply lines 10

G.P.L gas

  After the previous operation, the diesel filters 12 are eliminated

  and 14 and replaced by a G.P.L gas filter. 16.

  Continuing the transformation, it eliminates the injection pump 18, the feed pump 20, the injectors 22 and the glow plugs 24 by replacing these devices by a solenoid valve 26 which interrupts or restores the gas flow G.P.L. from the tank, with a vaporizer and regulator 28 provided for the regulation of the gas pressure G.P.L. and to optionally vaporize a portion of the gas still in the liquid state and present in the supply line and convey this gas to a mixer -7

gas-air 30 described later.

  In addition to the added elements that have been described above to convert a Diesel cycle engine into an Otto cycle engine, it is also necessary to add an ignition device for the gas.

G.P.L ..

  This electrical device comprises an ignition distributor 32 set on a shaft 34 connected to the distribution group (not shown) and which transmits priority rotation to the pump

Injection 18

  The ignition distributor 32 is attached to a flange 36 which is

  connected on its side to the monoblock 38 shown in FIG. 3.

  The ignition device further comprises an HT coil 40 and a pulse generator 42 (electronic ignition) adapted to raise the voltage applied to the coil HT to obtain a better output voltage and therefore a higher power of the coil. arc between

candle electrodes 44.

  The ignition device further comprises a number of

  candles 44 corresponding to the number of cylinders of the engine.

  In essence, the components of the original diesel engine that do not undergo modifications are the monoblock inside which a crankshaft rotates, the connecting rods connected to it, the

  distribution organs and the cylinder head.

  These organs have not been described because they are known to

the skilled person.

  Two lines 46, 46 'derived from the hydraulic cooling circuit of the engine and connected to the vaporization and control device facilitate the transition from the liquid state to the gaseous state

  G.P.L. fuel by the heat brought by this derivation.

  A switch 48 connected to the positive pole of a battery (not shown) interrupts or enables the operation of the device.

ignition cited above.

  In order to obtain a high efficiency of the engine which is the subject of the present invention, it is necessary to reduce the compression ratio by increasing the volume of the combustion chamber in order to

to obtain an optimal value.

  This modification consists of the removal of material parts from the head of each of the pistons 50 to give them a shape.

  spherical geometry shown in FIG. 2.

  A last modification provides that the threaded seats of the glow plugs 24 of FIG. 1 are closed by screwing a

  bolt 52 shown in FIG. 2.

  To be able to adapt the spark plugs 44 to the seats of the injectors 22, there is provided a shell 54 having a stop shoulder, an internal thread and an external thread. This shell 54 is screwed into the seat of the injector to the shoulder

  stop and screw inside the spark plug 44.

  A gas-air mixer shown in Figs. 5 and 6 is essentially constituted by a metal body 56 inside which is mounted a butterfly valve 58 and a ring 60 for the diffusion of the

G.P.L gas

  The butterfly valve 58 is controlled by a lever 62 connected with its

  side to the accelerator pedal (not shown).

  G.P.L. gas from the vaporizer-regulator 28 is routed through line 64 of FIG. 2 attached to the connector 66 to a groove 68 formed in the outer periphery of a ring 60 adapted to render

  optimal distribution of the gas inside the mixer 30.

  A plurality of holes 69 arranged obliquely to the radii of the inner circumference of the ring 60 constitute a turbulence chamber capable of obtaining an optimum mixture between the air sucked by the engine and the gas G.P.L. sent inside the mixer

by the aforementioned holes 68.

  The regulation in the case of a low speed rotation of the engine, is obtained by a mixture flow passing through a narrow slot 70 provided between the butterfly valve 58 in the closed position

  and a small blind duct 72 disposed within the mixer 30.

  A small passage of the air-gas mixture creates a slight depression in the aforementioned blind duct 72, the latter which is connected by a connection 74 and a tube 76 to the vaporizer-regulator 28 acting on the latter by causing it to discharge a small amount of gas. which is enough to

keep the engine rotating.

  The invention is not limited to the embodiment specifically described and illustrated and is subject to modifications.

  and variants within the limits of his inventive idea.

- 10 -

Claims (7)

  1. Process for converting a diesel cycle engine into an Otto cycle engine powered by LPG gas, characterized in that it comprises the following phases: A - Removal of the diesel fuel injection pump (18) ; B - Removal of the tank (2) containing the diesel fuel; C Removal of the diesel fuel pump (20); D - Removal of diesel filters (12, 14); E - Removal of diesel fuel lines (8); F - Removal of the diesel injectors (22) inside the combustion chambers; G - Removal of the diesel glow plugs (24) mounted in the combustion chambers; H - increasing the volume of the combustion chamber by removing material on the piston head (50) to reduce the compression ratio; I Modification of the combustion chamber by closing the screw seat of the glow plugs (24); L - mounting an ignition distributor (32); M - Mounting a high voltage transformer (H.T. coil) (40); N - Assembly of an electronic pulse generator (electronic ignition) connected to the coil H.T .; 0 - Assembly of a pressure tank adapted to contain the gas G.P.L .;   P - Installation of a solenoid valve (26) for the interruption or re-establishment of the gas flow G.P.L .; Q - Installation of a vaporizer vaporizer (28) G.P.L gas; R - assembly of a mixer (30) for the correct formation of the mixture of air and gas; S - Installation of a filter (16) for gas filtration G.P.L .; T - Installation of gas supply lines (10, 64, 76) G.P.L .. - he -   2. Engine powered by gas G.P.L. according to the method of transformation described above and comprising: - a monobloc (38) carrying inside a crankshaft and associated connecting rods operating between said crankshaft and the pistons (50);   - the distribution organs; - a cylinder head; characterized in that it further comprises: - a reservoir (4) adapted to contain the gas G.P.L. under pressure and an indicator device (6) for the level of the liquid gas contained therein; - a series of supply lines (10, 64, 76) of the liquid gas connected to the various devices constituting the elements of the transformation; - a solenoid valve (26) connected in series in the gas supply line G.P.L. and capable of alternately interrupting or restoring the flow of gas to the following devices; a filter (16) also mounted in series in the gas supply line G.P.L. for filtering this gas; - a liquid gas vaporizer by a heating action of the latter, performing at the same time a pressure regulating action so as to provide downstream devices according to optimal values; - a gas-air mixer (30) connected in series in the suction pipe, causing inside a gas diffusion chamber a turbulence of this gas to obtain an optimal mixture of gas-air; - an ignition distributor (32) actuated by a shaft (34) connected to the dispensing members; - a high voltage transformer (40) (H.T. coil) connected to the ignition distributor (32); an electronic ignition (42) capable of supplying precise and high power current pulses to the H.T. coil (40) so as to obtain a new increase in the high voltage itself; 2620 7 70 - 12 -   a plurality of spark plugs of the air-gas mixture according to a   quantity corresponding to the number of cylinders.   3. Otto cycle engine fed with gas G.P.L. according to claim 2, characterized in that the head of said pistons (50) is spherical in shape.   4. Otto cycle engine fed with gas G.P.L. according to claim 2, characterized in that the threaded seats of the   reheating candles (24) are closed by a bolt (52).   5. Otto cycle engine fed with gas G.P.L. according to claim 2, characterized in that it is provided for the adaptation of said spark plugs (44) in the seats of said injectors (22) a threaded ferrule (54) comprising a stop shoulder. 6. Otto cycle engine fed with gas G.P.L. according to claim 2, characterized in that the distribution of gas G.P.L. inside the mixer (30) is obtained by a plurality of holes (69) arranged obliquely to the radii on the periphery internal ring (60).   7. Otto cycle engine fed with gas G.P.L. according to claim 2, characterized in that in said ring (60) is provided a circular groove (68) disposed in the outer circumference of said ring, said groove being adapted to a homogeneous distribution of G.P.L. gas