"Combustion engine with one or more ""squish"" spaces between the piston and the cylinder head"

The combustion engine forms "squish" spaces between the piston and the cylinder head and has additional guide means in the combustion chamber which create a rotational flow in the combustion chamber. The floor of the combustion chamber is formed by a trough-shaped recess in the piston head, so that it forms a "squish" space extending over the complete width of the combustion chamber. In the area between the valves, a further, central "squish" space extends which, in conjunction with the wall of the cylinder head which is situated above it, forms a further "squish" space flow which reinforces the lateral "squish" space flow. In this way the ignition timing can be further retarded and the temperature peak reduced together with an additional reduction in emissions of oxides of nitrogen. A very weak mixture with an excess of air of 30% or more can be ignited which likewise maintains a low burning temperature thus producing less nitrous oxide. The emission of carbon monoxide, as a result of the weak mixture, is also low, and the hydrocarbon emissions are minimal due to the total combustion by means of rotation of gases in the combustion chambers. Test results show a reduction in fuel consumption between 15% and 20% when compared with current engines.

BACKGROUND OF THE INVENTION 
Systems and procedures are proposed for the detoxification of exhaust gas 
coupled with low fuel consumption which bring into play, in the case of 
the Otto motor, a weak mixture in rotation, in which, by means of this 
rotation the mixture rapidly reaches the spark plug thus ensuring better 
ignition and proper combustion. Very weak mixtures with a composition of 
Lambda 1.3 or less are therefore necessary so that not only the hydro 
carbons and carbon monoxide but also nitrogen content of the exhaust are 
very low. 
A proposal from Ford and others is that, in the area of the inlet valves, 
by means of swirl-creating fittings, a spiral flow is created which 
continues in the combustion chamber up to the point of ignition. In the 
case of the continually-changing operating conditions of revolutions and 
performance, this system does not ensure correct ignition because the 
rotation cannot definitely be maintained in the compression cycle to the 
point of ignition and possibly breaks down before then so that the swirl 
is not maintained until the point of ignition. 
As is known in DE 27 51 993 11, the "squish" space between the piston head 
and the corresponding wall of the cylinder head is so formed that near the 
top dead centre position of the piston at least one "squish" space flow is 
created in parallel to one wall of the combustion chamber so that this 
"squish" space flow in conjunction with the guide means arranged inside 
the combustion chamber results in a rotational flow. The spark plug is 
fitted in the area of the rotational flow so that even a very weak 
air-fuel mixture is enough for ignition. 
BRIEF SUMMARY OF THE INVENTION 
The invention is based on the technical problem of the further development 
of a combustion engine of the type mentioned in the introduction so that 
despite an even weaker air-fuel mixture, correct ignition an be achieved 
during all operating conditions of the motor. 
To solve this technical problem, the invention is characterized in that in 
the space extending between the valves at least one centre "squish" space 
is arranged, which, in conjunction with the wall of the cylinder head 
situated above it, forms a further squish space flow reinforcing the 
lateral "squish" space flow. 
A feature of the present invention is, therefore, that adjacent to the 
previously-known "squish" space flow, a further central "squish" space 
flow is created which is led directly onto the spark plug. In this way, in 
that the central "squish" space extends at least partially into the space 
between the valves, a greater "squish" path is created for the air-fuel 
mixture by this central "squish" space than as compared to the previously 
known "squish" space flow. The central "squish" space, therefore, 
continues the previously known "squish" space and achieves, in the centre 
of the combustion chamber, a rapid acceleration of the flow so that, seen 
over the width of the combustion chamber, a total of two lateral rotating 
flow vortices are created, in between which a faster rotating flow vortex 
is arranged which is created by the centre "squish" space. The faster 
rotation speed is additionally achieved in that the rotation space and 
path (distance between the leading edge of the "squish" space and the 
spark plug) is smaller than that of the lateral adjacent rotation spaces. 
By means of the differing speeds of rotation in the area of the spark plug 
in comparison to the neighbouring areas, the combustion process is, among 
others, accelerated in this way in that the flow vortices have differing 
speeds of rotation and the central vortex rotates faster than the 
neighbouring outer ones. In this way the slower rotating vortices to the 
left and right of the spark plug are laterally met by the faster vortices 
already ignited by the spark plug, in which the central vortex can be 
defined as an ignition jet which penetrates into the lateral slower 
vortices, swirling them so that they quickly and intensively mix with the 
ignition jet and burn through. 
This achieves the advantage in that the combustion process even in the 
outer vortices takes place quicker because of the differing pressure 
ratios. 
By means of the technical teaching according to the invention it is 
therefore possible to retard the point of ignition in comparison with 
current layouts which, in combination with the use of a weak air-fuel 
mixture, brings about an even further reduction of the emission of oxides 
of nitrogen. 
In a first embodiment example of the present invention, it is provided that 
the central "squish" space is formed by a wedge-shaped guide projection on 
the piston head. It is preferred here that this guide protection continues 
the slope of the lateral mating "squish" spaces so that, seen over the 
width of the combustion chamber, a smooth transfer from the "squish" 
spaces into the combustion chamber is ensured. 
In a further embodiment example of the present invention it is provided 
that a central "squish" space of a differing slope mates with the outer 
"squish" spaces, so that the vortices created by the outer long "squish" 
spaces are led at an angle over the centre "squish" space and subsequently 
flow into the combustion chamber. 
Further features of the invention are the subject of the remaining 
sub-claims. 
The subject matter of the present invention is defined by the Patent Claims 
individually and in combination. 
In the following, by means of drawings illustrating several embodiment 
examples, the invention is further explained. In this way further 
essential features and advantages of the invention arise from the drawings 
and their descriptions.

DETAILED DESCRIPTION 
In a cylinder (1) a piston (2) is arranged, and in the cylinder head (5) an 
inlet valve (6) and an outlet valve (7) are fitted. The combustion chamber 
(8) formed in the piston head (15) is formed by a trough-shaped recess 
(22) in the piston head (15) whereas the opposing side is formed by the 
slope (9) of the wall of the cylinder head (5). The cylinder head (5) has, 
on the inner side wall, a guide curve (4) which always passes over the 
trough-shaped recess(22) in the piston head (15). One side wall of the 
recess (22) is formed by a further guide surface (20) which itself, again, 
always passes over the upper wall of the cylinder head (5), so that they 
form together a trough-shaped combustion chamber (8) in which a rotating 
flow of the mixture is created as described in the following manner. 
On one side of the firing chamber the piston (2) is formed with a slope 
(10) in the upwards direction which lies opposite to a parallel slope (9) 
of the cylinder head (5). These two opposing slopes (9)(10) form a 
"squish" space (25) whose opening is directed obliquely upwards in the 
combustion chamber so that the "squish" space flow (29) out of the 
"squish" space (25) runs roughly parallel to the undersides of the valves 
(6)(7) and to the upper wall of the cylinder head (5). 
The "squish" space flow (29), after sweeping over the underside of the 
valves (6)(7) is diverted by the guide curve (4) and combines itself there 
with a smaller "squish" space flow from a "squish" space (13) formed on 
the right side wall of the cylinder which is likewise formed from the 
corresponding surfaces of the piston (2) and the cylinder (1). 
This flow is directed in arrow direction (23)(Ref. FIG. 3) to the recess 
(22) in the piston head (15) and is diverted there in the direction of 
arrow (12) so that it flows along the floor of the recess (22). 
This fast-rotating flow along the floor of the recess (22) is diverted by 
the guide surface (20) of the guide projection (16) and is again always 
diverted in the direction of the cylinder head (5). 
In the combustion chamber (8) a fast-rotating flow in the direction of 
arrows (11)(12) is achieved. 
In accordance with the invention, in the intermediate space between the 
valves a further guide projection (17) is arranged which is likewise 
provided with a slope (9) similar to that of the "squish" space (25) below 
it. 
In accordance with FIG. 3 the mixture is then rapidly accelerated through 
the "squish" space (25) and is directed over the valves (6) (7) in the 
form of lateral "squish" space flows toward the spark plug (14). 
In the central area of the combustion chamber these "squish" space flows 
reach the additional central "squish" space (26) formed by the guide 
projection (17) and are there further accelerated so that in the middle of 
the combustion chamber (8) a "squish" space flow (30) of higher speed 
arises which is directed into the spark plug in the intermediate space 
between the valves (6)(7). 
In the central area of the combustion chamber (8) therefore, a rotating 
"squish" space (30) is created which impinges at high speed on the 
opposingly arranged spark plug (14) and is directed in the direction of 
arrow (25) on the guide curve (4) of the cylinder head wall (3). 
An improved effect is achieved if the spark plug (14) is arranged in a 
chamber (24) into the cylinder head wall (3) which is recessed relative to 
the combustion chamber (8). The direction of the chamber (24) must be so 
arranged that the ignition jet (18) emerging from the chamber (24) is 
introduced approximately parallel to the "squish" space flow (30) flowing 
past in the direction of arrow (23). 
This is achieved in the embodiment example shown in FIG. 3 in that the 
upper edge (19) of the chamber (24) lies approximately parallel to 
"squish" space flow (30) flowing past in arrow direction (23) thus 
ensuring a rapid through-ignition of the mixture. 
FIG. 5 shows a front face view of the piston head illustrating the central 
guide projection (17). 
It is seen here that the flow vortices (31) flowing from both lateral 
"squish" spaces (25) are rotating whereas the "squish" space flow formed 
by the central "squish" space (26) forms a fasterrotating vortex which 
impinges, as described, on the spark plug (14) opposite to it. 
It is preferred here that the central guide projection (17) extends in the 
form of a wedge into the intermediate space (21) between the valves 
(6)(7). In accordance with FIG. 5, the guide projection (17) has a central 
face (28) joining onto the sides of which, at an angle, are wedge faces 
(27) which always pass over the guide projection (16) joining on to the 
sides of it. 
In FIGS. 4 and 6, in a further embodiment example, another combustion 
chamber is shown in which the outer "squish" spaces (45) form an angle 
relative to the central "squish" space (46). The outer "squish" spaces 
(45) here form outer "squish" space flows (39) which, as described, rotate 
slower than the central "squish" space flow (40) created by the "squish" 
space (46). 
In accordance with FIG. 6 a central guide projection (37) again extends 
into the intermediate space between the valves (6)(7) which always passes 
over the guide projection (36) joining it on the sides. 
In the embodiment example shown in FIGS. 7 to 9 the index numbers are the 
same as those in FIGS. 1 to 3 for the same parts. The views are also 
mainly the same as those shown in FIGS. 1 to 3. A differentiating feature 
of this embodiment example is that the trough-shaped recess (22) in the 
piston head (15) is dispensed with. The piston head (15) is flat in the 
area of the combustion chamber (8) and forms, for example, one plane with 
the right "squish" space (13). In accordance with the description of FIGS. 
1 to 3 the previously-described features and advantages are achieved again 
by the creation of a central "squish" space flow (30) which is laterally 
limited by the "squish" space flow (29). 
By means of the inventive technical teaching it is therefore possible to 
retard the ignition timing thus reducing the temperature peaks and, 
additionally, the oxides of nitrogen content of the exhaust. Temperature 
and nitrogen content of the exhuast are low as the very weak air fuel 
mixture already has an air excess of 30% or more which maintains a low 
burning temperature thus producing less oxides of nitrogen. The carbon 
monoxide is, as a result of the weak air fuel mixture, low and the 
hydrocarbons in the exhaust are minimal due to the total combustion by 
means of rotation. Test results show a reduction in combustion of between 
15 and 20% compared with current engines. 
The design is simple and economic and requires no expensive electronic or 
similar control.