The present invention relates to a non-return valve with resilient reeds or tongues for the feeding of internal-combustion engines, which is formed as a single body with a flange for mounting on the engine, with a connection duct which can be connected to the device feeding the fresh mixture to the engine, and with means for the pressure outlet downstream of the valve and for supplying lubricant to the engine.
It is known in the art that automatic non-return valves used for the feeding of internal-combustion engines are positioned between the equipment for feeding the engine and the part of the latter designed for intake of the charge itself. This equipment consists of the cylinder head, in the case of a four-stroke cycle, and the cylinder or the pump housing, in the case of engines with a two-stroke cycle.
These automatic non-return valves are able to increase the performance of the engines since they prevent the losses of fresh charge from the engine due to the unfavourable conditions of the pressure waves existing in the intake duct.
It is known that the technical evolution of engines, associated with the demand for increasingly better performance, with the need for a reduction in atmospheric pollution and with the need to include new engine components, has resulted in an increase in the number of separate parts, such as, for example, pressure outlets for operation of the fuel shut-off valve, seats for fuel injectors, seats for lubricant injectors, seats for supplying the idle air, pressure outlets for the petrol diaphragm pumps, means for guiding the flow of the fresh charge through the reed valve and the like, which are contained in the engine feed devices.
These component parts must therefore be mounted separately with obvious loss of time and increase in costs.
The technical problem which is posed, therefore, is that of providing an automatic non-return valve which may be mounted between the devices feeding the mixture to the engine and the engine itself, which consists of a small number of parts and is provided initially with all the components mounted individually in the feed system, and which can be inserted in the engine as a single body by means of a few rapid assembly operations.
These technical problems are solved according to the present invention by a non-return valve with resilient reeds or tongues for the feeding of internal-combustion engines, characterized in that it comprises, in a single body, a flange for mounting on the engine, a connection element which can be connected to the device feeding the fresh mixture to the engine, mounting means for a pressure outlet downstream of the valve, means for mounting a supply of lubricant to the engine, a seat for housing means for supplying air for adjustment of the engine idles speed and a seat for housing a fuel injector.
Further details may be obtained from the following description of a non-limiting example of embodiment of the invention, provided with reference to the accompanying drawings, in which:
As shown in Figures 1 and 2, a non-return reed valve, according to the invention, for internal-combustion engines, comprises a valve body 1 which is made preferably of metallic material or a plastic composite and can be connected to the internal-combustion engine (not shown) by means of the flange 2 which is integrally joined to the valve body itself.
A sealing element 9 which may have the shape shown in the drawings or have a flat shape is arranged around the flange 2.
The valve body 1 comprises, moreover, a series of apertures 4 (Fig. 2) which can be closed by means of resilient reeds or tongues 5 which are fixed to the valve body 1 by means of screws 6, opening of which is limited by by an abutment element 7; sealing gaskets 8 for the resilient reeds or tongues 5 are also provided in the region of said apertures.
The valve body 1 is provided with a connection element 3 which can be connected to the device (not shown) for feeding the internal-combustion engine, by means of a sleeve 17.
Said element 3 has internal zones 18 and 19 forming connection zones for the flow of the fresh mixture through the valve.
The elastomer used for the manufacture of the connection element 3 is used for providing the uniform jointing of the sections for the flow of fresh mixture through the whole valve and in particular the jointing in the internal zones 18 and 19 of the valve body 1.
The said connection element 3 contains a rubber-mounting pipe 10 for the pressure outlet downstream of the reed valve for operating, for example, a diaphragm pump for the fuel or for operating the fuel shut-off valve, and a rubber-mounting pipe 11 for injecting the lubricating oil into the engine.
The rubber-mounting pipes 10 and 11 are generally made of metal and the seat 13 for the fuel injector may be made of metal or a plastic composite.
The connection element 3 may also have, formed in it, a seat 12 for mounting a device supplying the air for adjustment of the engine idle speed.
Fig. 3 shows an embodiment of the valve according to the invention, comprising a seat 13a for mounting a support piece 13 inside which a fuel injector 14 is inserted.
Figure 4 shows a variation of the element for fixing the connection part 3 onto the engine feed device: said fixing element is formed as a flange 15, on which flange 15 the sealing elements 16 are formed.
The elastomer used for manufacture of the connection element 3 may be used also for manufacture of the sealing element 16 on the flange 15; alternatively, and in order to obtain a reduction in costs, it is nevertheless possible to manufacture the sealing element 16 alone using an elastomer with superior characteristics compared to those of the elastomer used for the connection element 3.
Figs. 5 and 6 show two variations of embodiment of the valve according to the invention which envisage a flow guiding insert 20 which has a suitable shape and is designed to optimize the flow of fresh charge through the valve body.
In the two embodiments shown, the flow guiding element 20 is respectively formed with its larger dimension positioned parallel to the plane of symmetry of the cusp of the valve (Fig. 5) or with its larger dimension positioned perpendicularly with respect to the said plane of symmetry (Fig. 6).
It is envisaged, however, that said flow guiding element may be oriented in different angular positions with respect to said plane of symmetry.
It is therefore obvious how, as a result of the single-body valve according to invention, it is possible to manufacture the valve itself and the engine intake duct as one piece which can be easily installed, and how this single piece is designed to house all the elements necessary for operation of the engine, integrated in the valve body, thereby avoiding the separate assembly operations necessary for the corresponding parts known in the art.
In addition to this, owing to the use of elastomer materials, the section of the intake duct connecting the valve and engine may be manufactured in a precise manner, at a low cost and with the desired shape.