DEVICE FOR THE CONTROL OF THE VACUUM

Abstract: The invention refers to a device to regulate the dosage of fuel, to be used in engine feeding systems by suction of the fuel. The device is to be set in the main conduit of air, overlays the diffuser (7) and involves a set of laminar elements (1) displayed in a radial way according to a common plan, being the fastening of its peripheral extremities achieved by means of its insertion in a double ring (2) which bears a central shutter through narrow radial extensions (6). The ring is fixed to a supporting base with saliences (4) to overcome the spaces between the laminar elements and reenterings (5) to allow its flexure. The flexure of the laminar elements is performed through a calculated progression according to a proper gradient resulting into the formation of in-between spaces (3). Countering the increase of the speed of the current of air, a calculated increase in the area of the sections of the in-between spaces, allow to obtain the regulation of a value of vacuum in the area surrounding the diffuser, vacuum which, in its turn, will determine a debt of fuel proportional to the volume of the current of air in such a way that a correct dosage of the mixture air/fuel in the whole range of rotation of the engine is achieved.

Description: DESCRIPTION DEVICE FOR THE CONTROL OF THE VACUUM Technical domain This invention concerns complementary arrangements to regulate the dosage of fuel, applied to engine feeding systems by suction of the fuel, in order to obtain a air/fuel ratio of the mixture which will fulfill the conditions for a correct performance of the engines in the whole range of regimes of rotation. If we regulate a carburettor of a simple construction to the correct relation of mixture for a maximum number of rotations, this mixture will be too poor in what the low regimes are concerned. On the contrary, if we choose a relation of mixture suitable for low regimes, this mixture will be too rich for the maximum number of rotations. Previous technique To minimize these inconvenients, arrangements of complementary regulation included in the carburettors have been idealized and these could shortly and in a generic way be specified in the following types according to the description of Dante Giacosa in his book "Endothermic Engines", Ed. Omega, Barcelona, 14th edition, pages 370/3: - Compensating gauge carburettors (Zenith) where the action of the main gauge, regulated to the suitable dosage in a maximum of rotations, is corrected through a secondary or compensator gauge which enriches the mixture in low regimes. Carburettors of suplementary air (Krebs-Pallas) where the mixture dosed to low regimes is impoverished to the high regimes through the aspiration of suplementary air, by means of conduits placed under the diffuser. Carburettors of antagonistic air (Solex-Weber) where the mixture, also regulated to low regimes is impoverished in the high regimes by means of air that, required by the same depression, acts antagonistically to the fuel. Carburettors of double conduits of air where the main flow of air is subdivided by two conduits of aspiration, acting, one of them, to the low regimes of rotation and the two of them together to the high regimes. However the referred arrangements of complementary regulation depend on the actions of movement which use routes of fuel and air in suplementary conduits - mechanical elements, as springs and small levers. These actions involve an appreciable inertia which prevents or delays the timely and strict adjustment in order to obtain a well balanced dosage in all the extent of rotation regimes. Adding to these difficulties, such complementary arrangements are performed integrating them in the carburettors which increases the complexity of its construction. Explanation of the invention The aim of the invention is to solve these problems by means of a device which regulates the vacuum and which acts directly and immediatly in the main current of air. The active laminar elements which constitute the essential point of the device have a very weak inertia and this characteristic allows them to react in an almost instantaneous way to the changes of the regime of rotation by flexing variably according to the changes of speed in the main current of air. From the variation of the amplitude of the bending of the laminar elements results the formation between them of an in- between space aimed at the passage of the current of air, whose area is of variable size according to the variation of speed of the current of air and according to the resistence to the flexure selected for the laminar elements. An important advantage of the invention stays in the possibility of mutual adjustment of the mencioned variables in such a way that, from it, it results, in the space of the conduit that surrounds the diffuser of fuel, the regulation of a certain value of vacuum which, in association with a proper value of the gauge which gives fuel to the diffuser allows to obtain a correct dosage in the whole range of rotation with special incidence to the high regimes. Another important advantage is the fact that each device and each carburettor constitute independent units simplifying its modulation and allowing a functional construction of accurate exactitude. One of the ways by which the invention can be build up is found next, in detail, with a reference to the drawings which only represent one way of making it. Figure 1 displays a view of the device whose laminar elements (1) are keeping a flat form because they have not been pushed yet by the current of air to some angle of flexure. Figure 2 displays a cross-section of the device inserted in the entrance of the main current of air, overlaying the diffuser, and also shows the curvilinear shape of each support (5) which shapes the flexure of each laminar element. Figure 3 displays a view of the device where the laminar elements are totally fleeted allowing the formation of an in- between space with its maximum value of the area (3) . Figure 4 displays a cross-section the profile of the central shutter (6), the complete bend of the laminar elements together with the profile of the respective supports and shows the in-between space for the the passage of the current of air corresponding to the maximum rotation. As one can notice from the drawings, an example of the device according to the present invention is constituted by a set of laminar elements (1) displayed in a radial form following one only plan, being the fastening of its peripheral extremities done by means of its insertion in a double ring (2) which also bears a shutter in central position (6) through narrow radial extensions. Each laminar element is constituted by a small retangle of steel blade with a thickness and corresponding resistance to the flexure calculated in such a way that it can be fleeted in its maximum curvature when pressed by the current of air at its maximum speed. The set of the laminar elements is fixed to a bearing base, having, this one, saliences (4) and recesses (5) the saliences being for the purpose of closing the radial spaces which were left free between the laminar elements and the recesses having a depth surface profiled with a modelled curvature which allows the progressive settling of the elements according to a gradient of flexure calculated for a range of rotations. The central shutter (6) is an element with a static position whose profile is modelled in order to contribute, together with the gradient of the flexure of the laminar, elements to the formation of the in-between spaces of progressive area. When the rotation is minimum, the strenght of the current of air do not allow enough pressure to fleet the laminar elements (figures 1 and 2) . As the engine rotation increases, also increases the the strenght of the current of air and consequently increases the flexure of the laminar elements resulting from this an increase of the in-between area too (figures 3 and 4) . This increase of the in-between area following a calculated progression according to an adequate gradient, countering to the increase of the speed of the air, determines the regularization of a vacuum value in the area surrounding the diffuser, this value of vacuum, on its turn, determining a flow of fuel which is proportional to the volume of the current of the air and so equivalent to a correct dosage of the mixture air/fuel. The use of this invention to engine feeding systems by suction of the fuel will prevent the excess of consumption mainly in the high regimes of rotation, preventing consequently major pollution of the environment.

Claims: CLAIMS 1. Device to regulate the vacuum to be applied in engine feeding systems by suction of the fuel, characterized by being constituted by a set of laminar elements (1) , placed in a radial way according to a common plan, being the peripheral extremities fastened by means of its insertion in a double ring (2) which bears the central shutter (6) through narrow radial extensions. 2. Device to regulate the vacuum, according to claim 1, characterized by the fact that the ring which fastens the laminar elements is fixed in a bearing base with saliences (4) and recesses (5) aimed the saliences to overcome the radial spaces which were left free between the laminar elements, and the recesses aimed to allow its free flexure. 3. Device to regulate the vacuum, according to claim 1, characterized by the fact that each laminar element is constituted by a small rectangle of steel blade, calculated with a thickness and corresponding resistance to the flexure, in such a way that it can be fleeted in its maximum curvature when pressed by the current of air at its maximum speed. 4. Device to regulate the vacuum, according to claim 2, characterized by the fact that each recess has a curvilinear profile which models the gradient of flexure of each laminar element while giving it support. 5. Device to regulate the vacuum, according to claims 3 and 4, characterized by the fact that the flexure of the laminar elements is done according to a calculated progression resulting from this gradual flexure the formation of in- between spaces (3) where the area of the respective sections varies according a certain gradient, proportional to the volume of the current of air. 6. Device to regulate the vacuum, according to claim 1, characterized by the fact that the central shutter has a profile in accordance with the gradient calculated for the variation of the formation of the in-between spaces. 7. Device to regulate the vacuum, according to claims 5 and 6, characterized by the fact that countering to each increase of the speed of the current of air, a calculated increase of the area of the sections of the in-between spaces allow to obtain a regularization of a value of vacuum in the area that surrounds the diffuser (7), vacuum that in its turn determines a debt of fuel proportional to the volume of the current of air in such a way that a correct dosage of the mixture air/fuel in the whole range of rotation of the engine is achieved.

Inventors: BAPTISTA FERNANDO AUGUSTO, PEREIRA DIAS BAPTISTA JOAO MAN, BAPTISTA, FERNANDO, AUGUSTO, PEREIRA DIAS BAPTISTA, JOAO, MANUEL
Applicants: BAPTISTA FERNANDO AUGUSTO, PEREIRA DIAS BAPTISTA JOAO MAN, BAPTISTA, FERNANDO, AUGUSTO, PEREIRA DIAS BAPTISTA, JOAO, MANUEL
Application year: 1995
Main classification: F02M9
IPC codes: F02M9