WO1999058832A1

WO1999058832A1 - Combustion chamber for internal combustion engine

Info

Publication number: WO1999058832A1
Application number: PCT/FR1999/001132
Authority: WO
Inventors: Antoine Chassaing
Original assignee: Ete International
Priority date: 1998-05-13
Filing date: 1999-05-12
Publication date: 1999-11-18
Also published as: EP1078153A1; FR2778695A1; FR2778695B1; AU3714099A

Abstract

The invention concerns a combustion chamber for internal combustion engine, comprising a flexible and sealed deformable bag (3) capable of being supplied with a fuel mixture, and a tubular braid or sheath (4) enclosing the deformable bag and capable of being connected to mechanical means (10), for example a crankshaft, recuperating the deformation force of the braid as a result of the combustion of the mixture. The braid (4) has geometric characteristics such that when the deformable bag is inflated it causes an increase in the braid diameter and a decrease in its length, and vice versa. Said combustion chamber advantageously replaces standard heat engine sleeve, piston, cylinder head and connecting rod and can be used for propulsion of road vehicles.

Description

Combustion chamber for internal combustion engine

The invention relates to a combustion chamber for an internal combustion engine, in particular for the propulsion of land vehicles.

Currently, conventional internal combustion engines have at least one combustion chamber formed and delimited by a jacket, a cylinder head and a piston. The variation in volume of said chamber is obtained by sliding the piston in the jacket, which assumes dynamic sealing. In addition, during operation of the engine, the pressures prevailing in the combustion chamber mainly tend to exert a compressive force on the piston, therefore on the connecting rod, which is itself linked to the crankshaft. This therefore requires great mechanical rigidity of the connecting rod.

Furthermore, various types of actuators are known. There is in particular a pneumatic actuator called "Me Kibben muscle" which makes it possible to generate a tensile force from a gas under pressure capable of being introduced into a deformable pocket. However, such an actuator is similar to a pneumatic cylinder and cannot be used as a motor.

The invention essentially aims to provide a combustion chamber, of a new type, suitable for use in particular in an internal combustion engine by eliminating the set (s) of liner, piston, cylinder head and connecting rod of thermal engines classics.

The combustion chamber of the invention essentially comprises a deformable pocket, flexible and sealed, suitable for being supplied by a combustion mixture, as well as a tubular braid enveloping the deformable pocket and suitable for being attached to a mechanical means recovering the forces. of 2 deformation of the braid as a result of the combustion of the mixture.

Thus, the combustion chamber of the invention comprises an assembly constituted by a deformable pocket enveloped by a tubular braid which is also deformable and fed by a combustion mixture. This chamber can thus operate according to the thermodynamic principles of the internal combustion engine.

The deformable pocket preferably has the form of a tubular chamber with a rectilinear axis.

The deformable pocket is advantageously made of an elastomer material resistant to high temperatures, in particular a silicone elastomer.

The tubular braid, which can also be called tubular sheath, preferably has the shape of a tube of variable diameter and length, obtained by a network of wires arranged so that an inflation of the deformable pocket causes a increase in the diameter of the braid and a decrease in its length, and conversely a deflation of the deformable pocket causes a decrease in the diameter of the braid and an increase in its length.

The tubular braid is advantageously composed of intertwined threads or fibers forming similar pantographs and resulting from a braiding, knitting, knitting or similar technique. The threads from which the tubular braid is formed are advantageously synthetic threads, in particular made of aramid.

According to another characteristic of the invention, the tubular braid is connected to a fixed end piece and to a mobile end piece, said mobile end piece being suitable for being attached by mechanical means, in particular to a crankshaft. 3

According to another characteristic of the invention, the deformable pocket is provided with an intake valve and an exhaust valve and it houses an ignition device capable of causing the combustion of the mixture. These two valves can be separate or confused.

It will be understood that the assembly constituted by the deformable pocket, the braid and the ends is the equivalent, for a conventional internal combustion engine, of the assembly constituted by the cylinder head, the jacket, the piston and the connecting rod. The other main engine components, in particular the crankshaft and the carburetion device are not specific to the invention and will therefore not be detailed.

The intake valve, the exhaust valve and any ignition device are advantageously housed in the end pieces attached to the braid.

According to another characteristic of the invention, the combustion chamber houses a core, which makes it possible to reduce the dead volume which is not swept by the normal movement of the deformable pocket. The term “core” is used here to designate one or more mechanical parts, generally of cylindrical shape, gas tight, which are located in the combustion chamber delimited by the deformable pocket. This core may consist of a protuberance of one or both ends, but it may also be linked elastically or telescopically to the two ends at the same time, or in any other way.

Such a core is directly exposed to the flame resulting from combustion. By occupying at least part of the dead volume of the deformable chamber, it makes it possible to significantly increase the volumetric ratio of the combustion chamber.

The invention also relates to an internal combustion engine comprising at least one combustion chamber as defined above. 4

It also relates to a land vehicle wheel incorporating a plurality of combustion chambers as defined above, arranged in a specific arrangement, in particular a radial star arrangement. Thus, several combustion chambers according to the invention can be integrated into at least one wheel of a land vehicle, and reduce the size of the engine.

In the detailed description which follows, given solely by way of example, reference is made to the appended drawings, in which:

- Figure 1 is a schematic representation of a combustion chamber according to the invention;

- Figures 2 to 6 illustrate different successive phases of operation of a combustion chamber according to the invention; and

- Figure 7 is a plan view of a land vehicle wheel incorporating a plurality of combustion chambers according to the invention, in a radial star arrangement.

Firstly, reference is made to FIG. 1 which shows a combustion chamber 9 comprising a deformable pocket 3 produced from a flexible tube made of silicone elastomer, which acts as an air chamber, while resisting high temperatures. This deformable pocket is wrapped in a deformable braid 4 of chemical textile fibers, in particular of the aramid type. This pocket is terminated at its two ends respectively by a fixed tip 1 and a movable tip 2 linked to the braid. The movable end piece 2 is suitable for being attached to mechanical means, in the example a crankshaft 10 (shown diagrammatically).

In the fixed nozzle 1 is housed an intake valve 6 to allow the introduction into the deformable pocket 3 of a combustion mixture (air and fuel) capable of being ignited by a spark triggered by a spark plug 7 housed in the deformable pocket 3 and carried by the fixed tip 1. 5

The tubular braid 4 is a tube of variable diameter and length obtained by a network of threads or fibers intertwined so as to form similar pantographs. Such a network is advantageously obtained by a braiding, knitting, knitting or similar technique. It makes it possible to produce a deformable pocket endowed with particular geometric properties, namely that swelling of the deformable pocket (caused by admission of a combustion mixture) causes an increase in the diameter of the braid and a decrease in its length. Conversely, deflation of the deformable pocket causes a decrease in the diameter of the braid and an increase in its length. The crankshaft 10 is thus driven in rotation by the deformations of the braid, that is to say by the variations of its axial length.

The deformable pocket 3 advantageously houses a core 5 (shown diagrammatically in FIG. 1) making it possible to reduce the dead volume not swept by the normal movement of the deformable pocket.

We will now describe, with reference to Figures 2 to 6, the operation of this combustion chamber in the case of operation with a four-stroke cycle, the combustion mixture being composed of air and LPG (liquefied petroleum gas ). LPG is a mixture of butane and propane whose combustion is very polluting.

In the embodiment of FIGS. 2 to 6, the combustion chamber comprises a single intake and exhaust valve 6, but it could be two separate valves as in the case of FIG. 1.

In FIGS. 2 to 6, the fixed end piece 1 is articulated on a support 11, while the mobile end piece 2 is articulated on a crankshaft 10. The bottom dead center and the bottom point are indicated by the references PMB and TDC respectively dead top of the combustion chamber. 6

The intake phase (Figure 2) is the first stage of the engine. The inlet valve 6 is open and the deformable pocket 3 increases in volume, allowing fresh gases (air), as indicated by arrow A, to penetrate, and fuel (LPG), as indicated by arrow G. So that the fresh gas enters the deformable pocket 3, it may be necessary to send them under pressure or to place the deformable pocket and the braid in an enclosure under low pressure. During this phase, we go from top dead center to bottom dead center and the chamber sucks the air-LPG mixture.

In the compression phase (Figure 3), which constitutes the second stroke of the engine, we pass from bottom dead center to top dead center. The volume of the deformable pocket 3 decreases, the valves 6 and 8 being closed, so that the pressure increases. The chamber thus compresses the air-LPG mixture. When the volume of the deformable pocket is close to its minimum (Figure 4), the spark of the spark plug 7 triggers the combustion of the air-LPG mixture. The gases contained in the chamber are brought to high temperature and the chamber exerts an extremely vigorous traction.

The next phase or expansion phase (Figure 5) constitutes the third stage of the engine. The valve is closed and the burnt gases expand in the combustion chamber. It follows that the volume of the deformable pocket increases and that the pressure of the burnt gases at high temperature generates a large tensile force on the crankshaft 10 via the movable end piece 2 and the braid 4. This is thus passed from top dead center to bottom dead center.

The next phase or exhaust phase (Figure 6) constitutes the fourth stroke of the engine. The valve opens, while the volume of the deformable pocket decreases expelling the burnt gases (arrow B). We thus pass from bottom dead center to top dead center.

This constitutes an engine operating in a four-stroke cycle. However, it is possible to plan 7 other variants and in particular to add "dead times", in which engine revolutions are made without admitting fuel or combustion. This improves scanning and cooling, thanks to valve control means, not linked to the crankshaft.

It is also possible to envisage a device for sweeping the burnt gases operating simultaneously with the introduction of fresh gases, in order to produce a two-stroke engine.

It will be understood that the combustion chamber of the invention offers various advantages compared to conventional combustion chambers.

The deformable pocket can be completely waterproof, thus eliminating any dynamic sealing.

The constituent parts of such a chamber can be made of light materials such as polymers, which makes it possible to obtain a very low weight / displacement ratio.

All the force is transmitted to the crankshaft by the braid, which only works in traction, which eliminates the problems of stiffness of the connecting rods, which work in compression.

The combustion chamber can be produced without machining and almost without metals by mass production methods such as injection or extrusion, resulting in particularly economical production.

The deformable pocket being made of flexible materials, the "sounding board" effect of conventional motors is greatly reduced.

During combustion and expansion, the hot gases are almost in contact only with the deformable pocket made of flexible materials. These materials, especially elastomers, have a low thermal conductivity compared to that 8 of metals. This allows, from a thermodynamic point of view, a more "adiabatic" expansion, therefore a better engine efficiency.

Reference is now made to FIG. 7 which shows a wheel 12 integrating a plurality of combustion chambers 9 according to the invention, in the example eleven in number, in a radial star arrangement. The wheel 12 has a hollow rim 13 to which is attached one of the ends of each of the deformable pockets, on the intake-ignition side. The other end of each of the deformable pockets is connected to an eccentric rotor 14 rotating at the same speed as the wheel (whose direction of rotation is indicated by the arrow R) but along an offset axis and to which the other end is attached of each deformable pocket, on the exhaust side.

The phases of the combustion chambers are shifted successively. In FIG. 7, Pi designates the compression phase, P2 the combustion phase, P3 the expansion phase and P4 the scanning phase.

This constitutes a plurality of heat engines inseparable from the wheel. The deformable pockets rotate with it around a fixed crankshaft which serves as a hub and which is linked to the chassis of the vehicle.

Of course, the invention is not limited to the embodiments described above by way of example and extends to other variants.

Claims

claims

1. Combustion chamber for internal combustion engine, characterized in that it comprises a deformable pocket (3) flexible and waterproof suitable for being supplied by a combustion mixture, as well as a tubular braid (4) enveloping the deformable pocket and suitable for being attached to a mechanical means (10) recovering the deformation forces of the braid as a result of the combustion of the mixture.

2. Combustion chamber according to claim 1, characterized in that the deformable pocket (3) has the shape of a tubular chamber with a rectilinear axis.

3. Combustion chamber according to one of claims 1 and 2, characterized in that the deformable pocket (3) is made of an elastomeric material resistant to high temperatures, in particular a silicone elastomer.

4. Combustion chamber according to one of claims 1 to 3, characterized in that the tubular braid (4) has the shape of a tube of variable diameter and length obtained by a network of wires arranged so that swelling of the deformable pocket causes an increase in the diameter of the braid and a decrease in its length, and conversely a deflation of the deformable pocket causes a decrease in the diameter of the braid and an increase in its length.

5. Combustion chamber according to one of claims 1 to 4, characterized in that the tubular braid (4) is composed of intertwined threads forming similar pantographs and resulting from a technique of braiding, stitching, knitting or the like .

6. Combustion chamber according to one of claims 1 to 5, characterized in that the tubular braid (4) is connected to a fixed end piece (1) and to a mobile end piece (2), 10 said movable tip being adapted to be attached to mechanical means (10).

7. Combustion chamber according to one of claims 1 to 6, characterized in that the deformable pocket (3) is provided with an intake valve (6) and an exhaust valve (8) and housing an ignition device (7) capable of causing the combustion of the mixture.

8. Combustion chamber according to one of claims 1 to 7, characterized in that it houses a core (5).

9. Internal combustion engine comprising at least one combustion chamber (9) according to one of claims 1 to 8.

10. Land vehicle wheel incorporating a plurality of combustion chamber (9) according to one of claims 1 to

8, arranged in a radial arrangement.