[0001] This invention concerns a new high efficiency alternating endothermic engine based
on a new thermodynamic cycle as well as eventual transformation of existing engines.
[0002] As is well known, current endothermic engines transform thermal energy into work
through pressure.
[0003] However, these engines have the disadvantage of involving detonation and dissociation
and therefore of requiring the presence of oxidation inhibitors in the fuel (antidetonants
in OTTO cycle engines).
[0004] Detonation is harmful in that, as an instantaneous combustion (foreseen in the ideal
OTTO cycle), it occurs at the wrong moment since it affords maximum pressure in the
instant in which the piston is at zero velocity, with the connecting rod perpendicular
to the crank arm of the drive shaft, and thus the engine moment is zero.
[0005] Dissociation occurs in the engine to create very rapidly alternating dissociations
and reassociations as long as the specific dissociation temperature of the reagents
is maintained. By continuing until the exhaust valve is opened, this leads to incomplete
combustion since some of these reagents escape still unburned.
[0006] Oxidation inhibitors allow a higher compression ratio to be used, but slow down combustion
velocity and cause atmospheric pollution, for the OTTO cycle.
[0007] The aim of this patent is the elimination of the disadvantages described above so
as to obtain an engine with high energy efficiency and considerable reduction of harmful
exhaust gases.
[0008] This goal is achieved by keeping the combustion chamber volume constant for the period
required for complete combustion of the operating fluid. In this way, higher maximum
pressure is achieved for a pre-established and calculable period so as to obtain a
more elevated tangential component and thus a higher engine torque for the same heat
absorption and fuel consumption as in current engines.
[0009] According to this invention the engine consists of a piston or other suitable device
advancing with pre-established. and calculable movement as a function of the type
and the required performance. This movement occurs through crank mechanisms, cams,
rockers or the like positioned or controlled by any type of kinematic chain.
[0010] In this way the invention tends to consider detonation as useful rather than harmful
in that occurring after the Maximum Dead Point (M.D.P.), it does not shove the piston
but rather pushes it without the characteristic spark knock. With the use of suitable
devices, this may even lead to spontaneous ignition of suitably prepared fuel mixtures.
[0011] In fact, by causing combustion after the M.D.P. and interrupting the dissociations-reassociations
equilibrium until the temperature is lowered (the increased pressure compensates),
combustion is completed within favourable limits.
[0012] This is achieved by injecting at the most favourable moment during the dissociation
equilibrium a measured quantity of incombustible liquid (water, for example). In vaporizing,
this then lowers the temperature in the combustion chamber and also allows the cooling
equipment to be reduced or eliminated.
[0013] A preferred but non-limiting variant of this invention, which may be realized in
one or more cylinders, is schematized in enclosed drawings figures 1 and 2.
[0014]
Figure 1 shows a vertical section of a two cycle supercharged variant of the engine
with controlled ignition, composed of two coupled cylindrical elements each showing
two diameters.
Figure 2 shows two variants of the new theoretical thermodynamic cycle, one for controlled
ignition (solid line) and one for spontaneous ignition (dashed line).
[0015] With regard to the details of figure 1, each element of the engine is composed of
a cylinder with two diameters 15 and 16 separated by a diaphragm with a tight stuffing
box 5 designed to protect the engine crank mechanism 10 with connecting rod 12 from
contamination of the coolant and to seal pistons 1 and 2 in their phases of aspiration
and compression of the scavaging air. In piston 2's descending phase, this is followed
by piston 3, connected through connecting rod 13 to crank arm 11, leading to a crank
mechanism approximately 90° out of phase with that of 10. In this way, the volume
of combustion chamber 19 is kept nearly constant up to approximately 40° from the
M.D.P., where ignition and the onset of combustion occur through spark plug 8. The
controlled ignition may be anticipated or retarded as in current engines, or the same
effect may be achieved by regulating the air intake in the spontaneous ignition variants.
Soon after, at the corrent moment, liquid is injected from 9 and in vapourizing lowers
the temperature, limits dissociation-reassociation and causes the pressure to increase,
using the temperature of the exhaust gases and cylinder walls as well. Contemporaneously,
piston 1 sealed with diaphragm 5 begins aspiration through port or valves 18.
[0016] At the end of its descending phase, piston 2 covers the exhaust 7 and intake 6 ports,
leading to wash out with previously compressed air.
[0017] In its ascending phase, piston 2 (which is joined to piston 1 via rod 14) covers
ports 6 and 7. Liquid or gaseous fuel is then injected through injector 4, compression
occurs and the cycle is repeated.
[0018] The wash out operation is greatly facilitated in the engine with two coupled cylinders
at 180°, as in figure 1, and air feed is likewise favoured. The above-mentioned coupling
of the two cylindrical elements is effected through exhaust ports 17 and 7 for compressed
air.
[0019] The diagram in figure 2 illustrates the thermodynamic cycle of the controlled ignition
engine: 1-2, aspiration; 2-3, compression; 3-4, maintenance of the achieved pressure;
4-5, instantaneous combustion; 5-6, continuation of combustion; 6-7, expansion; 7-2-1,
discharge.
[0020] The above refers to a theoretical cycle of a four cycle supercharged engine. Of course,
this invention covers application in current normally aspirated engines as well.
[0021] Figure 2 also shows the spontaneous ignition possible using suitable fuels, in the
dashed line variant 3-3'-5.
[0022] Of course, while the principle of this invention remains the same, the forms of realization
and the particulars of construction may vary widely from that described and illustrated
here, without however going beyond the bounds of this invention.
1. Alternating endothermic engine with new thermodynamic cycle characterized in that
combustion chamber volume is kept constant for the period required for complete combustion
of the operating fluid and that a higher maximum pressure is achieved for a pre-established
and calculable period so as to obtain a more elevated tangential component and thus
a higher engine torque for the same heat absorption and fuel consumption as in current
engines, with striking reduction of dangerous emissions.
2. Engine according to claim 1, characterized in that detonation occurs after the
Maximum Dead Point (M.D.P.) to render it useful rather than harmful since the piston
is not shoved but rather pushed without the characteristic spark knock; with suitable
devices, this may even allow spontaneous ignition of suitably prepared fuel mixtures.
3. Alternating endothermic engine according to claims 1 and 2, characterized in that
a measured quantity of an incombustible like water is injected at the most opportune
moment during combustion to lower the temperature in the combustion chamber, leading
to the possibility of reducing or eliminating the cooling equipment.
4. Alternating endothermic engine according to claims 1, 2 and 3, characterized in
that each element consists of a cylinder with two diameters 15 and 16 separated by
a diaphragm with a tight stuffing box 5 designed to protect engine crank mechanism
10 with connecting rod 12 from contamination of the coolant and to seal pistons 1
and 2 in their phases of aspiration and compression of the scavaging air; in piston
2's descending phase, this is followed by piston 3 connected through connecting rod
13 to crank arm 11, leading to a crank mechanism approximately 90° out of phase with
that of 10 so that the volume of combustion chamber 19 is kept nearly constant up
to approximately 40° from the M.D.P., where ignition and the onset of combustion occur
via spark plug 8; soon after liquid is injected from 9 at the opportune moment which
vapourizes and lowers the temperature to limit dissociation-reassociation and increase
the pressure, using the temperature of the exhaust gases and cylinder walls as well;
contemporaneously piston 1 sealed with diaphragm 5 begins aspiration through port
or valves 18; at the end of the descending phase, piston 2 (joined to piston 1 via
rod 14) covers ports 6 and 7, liquid or gaseous fuel is injected through injector
4, compression occurs and the cycle is repeated.
5. Alternating endothermic engine according to claims 1, 2, 3 and 4, characterized
in that controlled ignition may be anticipated or retarded as in current engines or
the same effect may be achieved by regulating air intake in the spontaneous ignition
variants.
6. Alternating endothermic engine with controlled ignition characterized by the following
thermodynamic cycle: 1-2, aspiration; 2-3, compression; 3-4, maintenance of the achieved
pressure; 4-5, instantaneous combustion; 5-6, continuation of combustion; 6-7, expansion;
7-2-1, discharge.
7. Alternating endothermic engine according to claim 1, characterized by spontaneous
ignition, with suitable fuels, according to the thermodynamic cycle shown by dashed
line 3-3'-5. The entire invention is substantially as described and illustrated and
has the specified aims.