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US 5,178,331 AGranted
Device for atomization of fluids
AssigneeRobert Bosch GmbH
InventorWillibald Schuerz
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AssigneeRobert Bosch GmbH
InventorWillibald Schuerz
Estimating the term…
A known device for the atomization of liquids for injection valves including upper and lower fluid entry levels by which a tangential entry of air is provided into a space located below the injection valve in the direction of flow by which the generally occurring unevenness of distribution of fuel to different cylinders of an internal combustion engine is to be improved. The entry of the fluid from the upper and lower levels are oppositely oriented at the individual levels and thus produce two opposing swirl flows. The device is particularly suitable for injection valves for internal combustion engines.
A device for the atomization of fuel for an internal combustion engine ejected by an injection valve, said device includes a cylindrical passage (14) having a uniform diameter with a fuel inlet opening (29) and a fuel outlet opening (28) coaxial to an axis of the cylindrical passage and upper and lower compressed air swirl passages (17 and 18) situated one above the other axially, each of said upper and lower compressed air swirl passages have a compressed air outlet between said fuel inlet and said fuel outlet openings and in communication with the cylindrical passage and a compressed air inlet, said fuel is ejected through said cylindrical passage from said fuel inlet opening to said fuel outlet opening and said upper and lower swirl passages extend in opposite directions so that a first fluid swirl flow is produced by the upper swirl passages opposite to a second fluid swirl flow produced by the lower swirl passages and the first and second fluid swirl flow passes out through said compressed air outlets to act upon the fuel flow through said cylindrical passage, said upper swirl passage includes at least one upper slit (15) which tapers from an outer larger end to a smaller inner end which opens tangentially into an upper annular channel (23) and said lower swirl passage includes at least one lower slit (16) which tapers from an outer larger end to a smaller inner end which opens into a lower annular channel (24) in such a manner that said second fluid swirl flow (18) is produced in the lower annular channel (24) and swirls in a direction of flow which is in an opposite direction to said first fluid swirl flow (17) produced in the upper annular channel (23).
A device for the atomization of fuel for an internal combustion engine ejected by an injection valve, said device includes a cylindrical passage (14) downstream of said injection valve coaxial therewith, an upper annular chamber (23) and a lower annular chamber (24) situated one above the other, at least one upper slit (15) which opens tangentially into said upper annular chamber;
A device for atomization of fuel for an internal combustion engine ejected by an injection valve, said device includes a cylindrical passage (14) downstream of said injection valve coaxial therewith, an upper annular chamber (23) and a lower annular chamber (24) situated one above the other, at least one upper slit (15) which opens tangentially into said upper annular chamber, at least one lower slit (16) which opens tangentially into said lower annular chamber (24) in a direction opposite from that of said at least one upper slit (15), said at least one upper slit tapers from a larger outer end to a smaller inner end which connects with said upper annular chamber 23 said at least one lower slit (16) tapers from a larger outer end to a smaller inner end which connects with said lower annular chamber (24), said upper annular chamber (23) includes an annular portion that tapers toward the axis of said cylindrical passage (14) and connects with said cylindrical passage (14), and said lower annular chamber includes an annular portion that tapers toward the axis of said cylindrical passage (14) and connects with said annular passage (14) whereby said at least one upper and lower slit (15, 16), said upper and lower annular chambers (23, 24), and said upper and lower annular tapered portions of said upper and lower annular chambers form upper and lower swirl passages in which the swirl in said upper and lower swirl passages are in opposite directions surrounding said cylindrical passage and which act upon a fuel flow through said cylindrical passage (14).
Dependencies are inferred from the claim text.
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Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel:…
Injectors peculiar thereto: injectors with air chambers, e.g. communicating with atmosphere for aerating the nozzles
Supplying combustion engines in general with combustible mixtures or constituents thereof
Term ended 27 Feb 2011 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The invention is directed to a device for the atomization of liquids such as for internal engines. The invention is therefore in the sphere of the atomization of liquids by means of compressed air produced independently or by a use of the suction in the manifold of internal combustion engines. The liquids used are particularly fuels to be mixed for combustible mixtures for internal combustion engines with external mixture production. Compressed air or suction in the manifold have up to now been used to atomize fuels in such a manner that the air expanded at an annular slot seizes at high velocity the fuel jet emanating from the opening of the injection valve. The great difference in velocity between the air and fuel leads to atomization.
This type of atomization is however disadvantageous in that fine droplets resulting from the atomization process are accelerated to high velocities in the air flow so that they are in part no longer able to follow a change of direction of the flow of the intake air. The droplets impinge against the wall of the manifold and contribute to the formation of a film on the wall. Only very small tolerances are permissible fir the excentricity of entry of the fuel into the air flow. Excessive manufacturing tolerances in this area lead to deviation sideways of the atomized fuel jet in consequence of which there results in the case of centralized injection an increase in the unevenness of fuel distribution between the individual cylinders of a multi-cylinder engine. A fuel injection device for internal combustion engines is also already known in which the opening of an injection valve is directed into an auxiliary air nozzle whereby the fuel and the air are mixed by swirling in a swirl chamber formed therein. The air entry into the interior space of the auxiliary air nozzle is in this case tangential.
The device for atomization of liquids has an advantage that due to the low exit velocity from the device of the droplets of liquid, these are able to follow the changes of direction of the intake air. The unevenness of distribution of fuel between the individual cylinders of a multi-cylinder internal combustion engine can thereby for instance in the case of centralized injection be effectively reduced particularly in the full power range. The quantity of liquid forming a film on the wall is also reduced, which has a positive effect on the smooth running of internal combustion engines. The atomized jet of liquid emanating from the device has a very good jet symmetry so that there is no unevenness of distribution. In particular no deviation sideways of the liquid jet. This is of particular importance in internal combustion engines.
FIG. 1 shows a sectional representation of a centralized injection unit in accordance with the invention as related to a fuel injection valve;
FIG. 2 is a detail of the atomization device shown in of FIG. 1 in accordance with the invention;
FIG. 3 is a section along the line A--A of FIG. 2;
The device will be explained with regard to a centralized injection unit, but its application is not limited to such a centralized injection unit. Nor is the invention limited to the atomization of fuel, but any liquid which must be atomized can be used with the present invention.
The centralized fuel injection device 11 in accordance with FIG. 1 is shown in combination with an injection valve 1 and is fitted directly on the manifold and supplies finely dispersed fuel to the motor. In addition to the injection valve 1, a pressure regulator 2 connected to the injection valve through a duct 7 and a throttle valve housing 9 with a throttle valve 10 is shown.
An intermediate ring 6 is provided between the throttle valve housing 9 and upper housing 8 which positions the injection valve in place. The intermediate ring 6 encompasses the atomizing device 11 in accordance with the invention to which there lead two air ducts 30, 31. This device 11 in accordance with the invention is shown in more detail in FIG. 2.