ITVI20090008A1 - CONNECTION AND TEMPERATURE SENSOR, CONNECTION KIT BETWEEN TWO HYDRAULIC CIRCUITS INCLUDING SUCH A CONNECTION AND SUCH TEMPERATURE SENSOR AND POWER SUPPLY CIRCUIT FOR LPG PRESSURE REDUCER INCLUDING SUCH A TEMPERATURE CONNECTION AND SUCH TEMPERATURE SENSOR - Google Patents

Description

FITTING AND TEMPERATURE SENSOR, CONNECTION KIT BETWEEN TWO HYDRAULIC CIRCUITS INCLUDING THIS CONNECTION AND THIS TEMPERATURE SENSOR AND SUPPLY CIRCUIT FOR LPG PRESSURE REDUCER INCLUDING THIS CONNECTION AND THIS TEMPERATURE SENSOR.

DESCRIPTION

The present invention relates to a fitting for the connection between two hydraulic circuits, particularly suitable for connecting the supply circuit of a pressure reducer for LPG to the cooling circuit of an internal combustion engine.

The present invention also relates to a temperature sensor for a fluid, which can be associated with the aforementioned fitting.

The invention also comprises a kit for the connection between two hydraulic circuits, comprising the aforementioned fitting and sensor.

The invention also includes a power supply circuit for a pressure reducer for LPG comprising the aforementioned fitting and sensor.

It is known that some internal combustion engines, especially for automotive use, are adapted to allow dual fueling by petrol and LPG (Liquefied Petroleum Gas). These engines have an auxiliary LPG system which includes a pressure reducer to bring the LPG from the pressurized liquid state, in which the LPG is when stored in the tank, in the gaseous state, necessary for its combustion. Due to the lowering of pressure, the LPG undergoes a sudden cooling which must be compensated for by a corresponding heating, in order to allow correct operation of the engine.

Therefore, the pressure reducer is equipped with an LPG heater, fed by a hot fluid generally taken from the engine cooling circuit.

The hot fluid is brought to the reducer through a supply circuit arranged in parallel to the motor circuit, to which it is therefore connected at two points.

The system also requires a fluid temperature sensor, connected to a control unit that switches the power supply from petrol to LPG only when the temperature of the fluid is sufficient to heat the LPG.

Since, generally, the internal combustion engines that equip cars do not provide for LPG supply, the power supply circuit and its components must be added later, making it necessary to modify the engine cooling circuit.

This operation is performed by means of three three-way fittings connected in series along the cooling circuit, two of which are used to connect a corresponding end of the power supply circuit to the cooling circuit itself and the third to connect the temperature sensor.

In particular, each fitting is connected to the cooling circuit by two ways, while the third way is used to connect the power supply circuit or the sensor.

The known technique described above has a first drawback of being rather laborious in that it requires interrupting the cooling circuit of the engine in three different points, corresponding to each fitting.

Furthermore, especially in automotive engines, the available space is very limited and, therefore, the insertion of three fittings along the cooling circuit can be a particularly complex operation.

A further drawback is the fact that each joint between the fittings and the cooling circuit is a potential source of fluid loss and related maintenance costs.

The present invention aims to reduce the extent of the aforementioned drawbacks with respect to the known art.

In particular, it is a first aim of the invention to simplify the connections of the LPG system to the engine cooling circuit.

It is also an object of the invention to reduce the incidence and complexity of maintenance interventions linked to the presence of the power supply circuit.

The aforesaid objects are achieved by a fitting according to claim 1 and by a temperature sensor which can be associated with the aforementioned arrangement, according to claim 10.

The aforesaid objects are also achieved by a connection kit according to claim 11 and by a supply circuit for a pressure reducer for LPG according to claim 13, comprising the aforementioned fitting and temperature sensor.

Other detailed characteristics of the invention are reported in the related dependent claims.

In particular, the fitting of the invention comprises a housing for stably accommodating the temperature sensor in a position of thermal connection with the fluid.

Consequently, the fitting of the invention allows you to connect one end of the power supply circuit and the temperature sensor to a single point of the cooling circuit.

Therefore, advantageously, the total number of fittings required for the installation of the LPG system is reduced and, therefore, assembly is simplified.

Still advantageously, the installation of a smaller number of fittings requires a more limited space, to the further advantage of ease of assembly.

Furthermore, advantageously, the smaller number of fittings corresponds to a smaller number of junctions with the main circuit, limiting the possibility of leaks and the relative maintenance with respect to the circuits obtained with known fittings.

The aforementioned purposes and advantages, together with others that will be better highlighted below, will be understood during the description of some preferred embodiments of the invention, given as an indication but not of limitation with reference to the attached drawing tables, in which:

fig. 1 represents a connection and a sensor according to the invention, in axonometric view;

- fig. 2 represents the fitting and the sensor of fig. 1, partially sectioned view;

figs. 3 and 4 represent two executive variants of the connection of the invention;

fig. 5 schematically represents a power supply circuit according to the invention.

The connection of the invention is illustrated in fig. 1, where it is indicated as a whole with 1.

It is observed that the fitting comprises three ways indicated with 2, 3 and 4, preferably but not necessarily arranged according to a "T". Two ways 2, 3 of the fitting 1 are intended for connection to a main hydraulic circuit in which a fluid flows, while the third way 4 is connected to a secondary circuit to put it in communication with the main circuit.

Preferably, the main circuit is a cooling circuit of an internal combustion engine, while the secondary circuit is a supply circuit of a pressure reducer for LPG.

A possible LPG fuel system is shown in fig. 5 and indicated therein as a whole with 18.

The engine 15 is cooled by the fluid which circulates in the cooling circuit 13, which comprises a radiator 17.

There is also a power supply circuit 14 of the pressure reducer 16 for LPG, connected to the cooling circuit 13 by means of two fittings 1.

The flow of LPG along the circuit 19 (indicated in broken lines) is controlled by means of a valve 20, whose opening or closing is controlled by a control unit (not shown) based on the temperature of the cooling fluid, which is detected from a temperature sensor 8.

It is clear that the aforementioned system 18 is reported for purely illustrative purposes, since the invention can be applied to any LPG system, also made according to a scheme different from the one described above, as long as it provides a secondary circuit 14 connected to the main circuit 13.

In executive variants of the invention, not shown, the fitting can include more than three ways, for example to connect more than one secondary circuit 14 or other devices to the main circuit 13.

Preferably and as can be seen in fig. 1, each way 2, 3, 4 has an end with an increased diameter to facilitate coupling with rubber pipes, of the type commonly used for example in the cooling circuits of internal combustion engines.

According to the invention, the fitting 1 comprises a housing 5 shaped to stably accommodate the temperature sensor 8, in a position of thermal connection with the fluid flowing in the hydraulic circuits 13, 14 and, therefore, in the fitting 1 which connects them.

Preferably and as seen in figs. 1 and 2, the temperature sensor 8 comprises a shaped body 9 adapted to be stably coupled to the aforementioned housing 5, in a position of thermal connection with the fluid.

Preferably, the shaped body 9 comprises removable means for coupling to the housing 5 for, advantageously, being able to replace it in case of failure.

In particular, the aforementioned coupling means comprise a thread on the side surface 9a, which can be screwed to a corresponding internal threaded surface 7 of the housing 5.

Obviously, executive variants of the invention can provide various removable coupling means such as, for example, a bayonet coupling.

In the cases just mentioned, the shaped body 9 is preferably distinct from the sensitive body of the sensor 8 and is glued to it by means of a known type of heat conducting adhesive.

According to a further variant of the invention, not shown, the sensor 8 is directly glued to the housing 5, by means of heat-conducting adhesives of the same type mentioned above.

In this case, preferably, the housing 5 is equipped with a thread at the end, to facilitate the adhesion of the glue to the housing 5 itself.

Advantageously, the direct gluing mentioned above avoids having to realize the aforementioned coupling means on the shaped body 9, thus reducing the cost of execution of the sensor 8. Furthermore, advantageously, the direct gluing allows to improve the thermal contact between the sensor 8 and housing 5, increasing the accuracy and speed of temperature measurement.

As can be seen in fig. 2, the housing 5 is preferably a blind hole 6 open to the outside of the fitting 1, so as to be able to insert and remove the temperature sensor 8.

The hole 6 is delimited by a bottom 6a which separates it from the ports 2, 3, 4 of the fitting 1, so that there is no communication between the hole 6 and the area of the fitting 1 in which the fluid flows.

The blind hole 6 allows the sensor 8 to be coupled to the fitting 1 without the need for sealing means against fluid leakage, advantageously making assembly easier,

Moreover, advantageously, the blind hole 6 simplifies the maintenance of the sensor 8, since it makes it possible to remove it without causing the loss of the fluid contained within the circuit.

Preferably, the bottom 6a of the blind hole 6 has a surface conjugated to an abutment surface 10 of the sensor 8 to advantageously allow an optimal thermal contact between the sensor 8 and the fitting 1 in correspondence with the aforesaid surfaces. Therefore, advantageously, the measurement of the temperature is more precise and faster, allowing a more prompt response of the sensor 8.

Preferably, the surface of the bottom 6a and the corresponding abutment surface 10 of the shaped body 9 of the sensor 8 are conical or frusto-conical, to the advantage of the simplicity of construction of the bottom 6a and of the contact area, which is more extensive than, for example , in the case of flat surfaces.

Furthermore, advantageously, the conical or truncated cone shape of the bottom 6a allows you to compensate for any alignment defects between the hole 6 and the sensor 8, while still ensuring a minimum contact area. However, it is clear that, in executive variants of the invention not shown, the aforementioned surfaces can have any shapes.

Since the heat transmission between the fluid and the temperature sensor 8 occurs by conduction through the walls of the fitting 1 and of the relative housing 5, the fitting 1 is preferably made of a heat-conducting material, in particular brass or another metal material. of equivalent thermal conductivity.

As far as the shape of the fitting 1 is concerned, the axes of the hole 6 and of the three ways 2, 3, 4 are preferably converging at one point to advantageously make the fitting 1 more compact.

Fig. 3 represents an executive variant of the connection of the invention, indicated with 11, in which the axis of the hole 6 is aligned with the axis of one of the ways of the connection 11.

In a further variant embodiment of the invention, shown in fig. 4 and indicated by 12, the axis of the hole 6 is parallel to the axis of one of the vias, preferably of the via 4 used for connecting the secondary circuit.

Advantageously, this variant allows the secondary circuit and the temperature sensor 8 to be connected by operating on the same side of the fitting 11, facilitating assembly when the available space is very limited.

It is however evident that these further two variants 11 and 12 have the same advantages described above for the first variant of the fitting 1.

The present invention also relates to a kit for the connection between two hydraulic circuits, in particular between the cooling circuit 13 of an internal combustion engine 15 and the supply circuit 14 of a pressure reducer 16 for LPG, schematically represented in fig. 5.

According to the invention, the aforementioned connection kit comprises a fitting 1, 11, 12 of the types described above, with two ways 2, 3 connectable to the main circuit 13 and the third way 4 connectable to the secondary circuit 14, and a temperature sensor 8 which can be stably coupled to the housing 5 of this fitting 1, 11, 12, in a position of thermal connection with the cooling fluid.

Advantageously, the aforementioned connection kit facilitates the modification of the cooling circuit of the engine 15 to adapt it to the LPG supply.

In fact, the kit allows you to use a single fitting 1 to connect both the temperature sensor 8 and one end of the power supply circuit 14 of the pressure reducer 16 to the cooling circuit 13, while two fittings are required in the known art.

Finally, the present invention relates to a supply circuit 14 of a pressure reducer 16 for LPG, schematically represented in fig. 5.

According to the invention, the power supply circuit 14 comprises a fitting 1 and a temperature sensor 8, which can be coupled stably to each other according to what has been described above.

The circuit 14 can be connected to a cooling circuit 13 of an internal combustion engine 15 by means of the aforementioned connection 1, as described above, and by means of a further three-way connection which can be of a known type or made according to the invention. .

From what has been said so far, it is understood that the fitting and the temperature sensor described above achieve the intended purposes.

In particular, the housing provided on the fitting allows the temperature sensor to be mounted directly on the fitting itself, without having to use an additional fitting, so as to simplify the connection of the power supply circuit of an LPG reducer to the engine cooling circuit.

Furthermore, the possibility of using two fittings instead of three, as in the case of the known art, limits the possibility of leaks in the circuit and, therefore, reduces maintenance interventions.

Evidently, a connection kit and a power supply circuit including the fitting and the temperature sensor of the invention also achieve the intended purposes.

During the execution phase, further modifications or variations may be made to the fitting and to the temperature sensor of the invention which, although not described and not represented in the drawings, should they fall within the scope of the following claims, they must all be considered protected by the present document. patent.

Claims (13)

CLAIMS 1) Fitting (1; 11; 12) with at least three ways (2, 3, 4) connectable to a hydraulic circuit (13, 14) for the passage of a fluid characterized by the fact that it comprises a housing (5) suitable for a temperature sensor (8) stably in a position of thermal connection with said fluid. 2) Fitting (1; 11; 12) according to claim 1) characterized by the fact that said housing (5) is a blind hole (6) facing outwards of said fitting (1; 11; 12) and delimited by a bottom (6a) which separates said blind hole (6) from said channels (2, 3, 4). 3) Fitting (1; 11; 12) according to claim 2) characterized by the fact that the surface of said bottom (6a) is conjugated to an abutment surface (10) of said sensor (8). 4) Fitting (1; 11; 12) according to claim 3) characterized in that said bottom (6a) has a conical or truncated cone shape. 5) Fitting (1; 11; 12) according to any one of claims 2) to 4) characterized in that said hole (6) has an internal threaded surface (7) for screwing said sensor (8). 6) Fitting (1; 11) according to any one of claims 2) to 5) characterized in that the axes of said hole (6) and of said three ways (2, 3, 4) converge at one point. 7) Fitting (12) according to any one of claims 2) to 5) characterized by the fact that the axis of said hole (6) is flanked by the axis of at least one of said ways (4). 8) Fitting (1; 11; 12) according to any one of the preceding claims, characterized in that it is made of a heat-conducting material. 9) Fitting (1; 11; 12) according to claim 8) characterized by the fact that said heat-conducting material is brass. 10) Temperature sensor (8) characterized by the fact of comprising a shaped body (9) able to couple stably to the housing (5) of a fitting (1; 11; 12) according to any one of claims 1) to 9) , in a position of thermal connection with the fluid circulating in said fitting (1; 11; 12). 11) Kit for the connection between two hydraulic circuits (13, 14), comprising a fitting (1; 11; 12) according to any one of claims 1) to 9), which has two ways (2, 3) that can be connected to a first of said circuits (12) and at least a third way (4) connectable to the second of said circuits (13), and a temperature sensor (8) which can be coupled stably to the housing (5) of said connector (1; 11; 12) ), in a position of thermal connection with a fluid circulating in said circuits (12, 13). 12) Kit according to claim 11) characterized by the fact that said first circuit (13) belongs to an internal combustion engine (15) and said second circuit (14) is a supply circuit for a pressure reducer (16) for LPG . 13) Supply circuit (14) of a pressure reducer (16) for LPG, said circuit (14) comprising a fitting (1; 11; 12) according to any one of claims 1) to 9), which has a (4) connected to said supply circuit (14) and at least two other ways (2, 3) which can be connected to a hydraulic circuit (13) of an internal combustion engine (15), and a temperature sensor (8) which can be stably coupled to the housing (5) of said fitting (1; 11; 12), in a position of thermal connection with a fluid circulating in said hydraulic circuit (13). By assignment.