WO2007012365A1

WO2007012365A1 - Device for limiting the filling of a tank with fluid

Info

Publication number: WO2007012365A1
Application number: PCT/EP2006/006006
Authority: WO
Inventors: Achille Tomasetto
Original assignee: Tomasetto Achille S.P.A.
Priority date: 2005-07-26
Filing date: 2006-06-22
Publication date: 2007-02-01
Also published as: ITVI20050210A1

Abstract

A device for limiting the filling of a tank with fluid includes a substantially hollow main body, which forms a chamber provided with an inlet and an outlet, the chamber slidingly accommodating a flow blocking valve inside it. The valve is kept in an inactive condition by an elastic means, in which it prevents the flow of the fluid through the inlet. The blocking valve is rigidly coupled to a guiding stem, which interacts with a floater-type actuation means, which is adapted to produce the transition from a filling condition, in which the inlet and the outlet are both open, to a closed condition, in which the blocking valve prevents the flow of the fluid through the outlet. The device also includes a movable abutment means, which is adapted to interrupt the action of the elastic means on the blocking valve during the filling condition.

Description

DEVICE FOR LIMITING THE FILLING OF A TANK WITH FLUID

The present invention relates to a device for limiting the filling of a tank with fluid, particularly suitable to limit filling to no more than 80% of the capacity of tanks installed on motor vehicles that run on liquefied petroleum gas. In LPG-fueled cars, the fuel is stored in one or more tanks manufactured in accordance with regulations such as ECE ONU 67-R01 , the European directive that regulates the subject. A multipurpose valve is applied to the tanks and allows to fill the tank, supplies the engine, indicates the level of fuel present in the tank, and also performs certain safety functions. In order to ensure the safety of the entire system, such multipurpose valve limits the internal pressure of the tank to 27 bars, optionally opens external venting ports in case of fire, and limits filling to no more than 80% of the total capacity of the tank, according to the constraints set by currently applicable standards.

Refueling values higher than the indicated one would entail an increase in the internal pressure of the tank, stressing its structure excessively and compromising the correct operation of the LPG system.

The filling limiting device used by most manufacturers generally bases its operation on the difference in pressure between the inside of the tank and the pump of the filling station and is generally constituted mainly by a valve which can slide within a chamber provided with an inlet, which can be connected to the nozzle of the filling station, and an outlet, which is connected directly to the inside of the tank.

In particular, the valve, which in the normal inactive condition closes the inlet by virtue of the constant and continuous thrust of a spring, is connected to a stem by which it interacts with a rod-and-floater device, which is able to block its sliding during filling, keeping both openings free and accordingly allowing the inflow of gas into the tank.

When 80% of the capacity of the tank is reached, the rod-and-floater device frees the stroke of the stem and consequently of the valve, which under the pressure of the gas that arrives from the nozzle blocks the outlet, overcoming the constant contrast thrust applied by the spring. At this point, filling is stopped, interrupting the action of the nozzle, and the spring returns the valve to the inactive condition described earlier.

The above system has a severe drawback, which becomes evident as the filling limit threshold is reached, i.e., when the flow-rate of the nozzle is reduced, consequently decreasing the difference in pressure between the inside of the tank and the pump of the filling station.

In the condition described above, the constant contrast of the spring against the valve causes difficulties in the operation of the filling limiting device, which is unlikely to be able to operate with a flow-rate of less than 7 liters per minute.

This drawback entails the risk of leading to the total filling of the tank and is worsened in extreme climate conditions, i.e., when the high temperature of the outside environment causes an increase in the pressure of the gas in the tank, further reducing its difference with respect to the pump of the filling station.

The aim of the invention is to solve the problems described above, by providing a device for limiting the filling of a tank with a fluid which can operate even with extremely low flow-rates.

Within the scope of this aim, a particular object of the invention is to provide a device for limiting the filling of a tank with fluid which in particular operates even with flow- rates of less than 2 liters per minute.

Another object of the invention is to provide a device for limiting the filling of a tank with fluid which is simple to manufacture and can be produced at competitive costs.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a device for limiting the filling of a tank with fluid, comprising a substantially hollow main body, which forms a chamber provided with at least one inlet and at least one outlet, said chamber slidingly accommodating a flow blocking valve inside it, said flow bloking valve being kept in an inactive condition by an elastic means, in which said blocking valve prevents the flow of said fluid through said inlet, said blocking valve being rigidly coupled to a guiding stem, which interacts with a floater-type actuation means, which is adapted to produce the transition from a filling condition, in which said inlet and said outlet are both open, to a closed condition, in which said blocking valve prevents the flow of said fluid through said outlet, characterized in that it comprises a movable abutment means adapted to interrupt the action of said elastic means on said blocking valve during said filling condition.

Further characteristics and advantages will become better apparent from the description of two preferred but not exclusive embodiments of a device for limiting the filling of a tank with fluid according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a side view of a multipurpose valve device;

Figure 2 is a partially sectional view of the multipurpose valve device of Figure 1 ;

Figure 3 is a partially sectional side view of a device for limiting the filling of a tank with fluid according to the invention;

Figure 4 is a partially sectional front view of a device for limiting the filling of a tank with fluid according to the invention, in the inactive condition;

Figure 5 is a partially sectional side view of the device for limiting the filling of a tank with fluid according to Figure 4; Figure 6 is a partially sectional front view of a device for limiting the filling of a tank with fluid according to the invention, in the filling condition;

Figure 7 is a partially sectional side view of the device for limiting the filling of a tank with fluid of Figure 6;

Figure 8 is a partially sectional front view of a device for limiting the filling of a tank with fluid according to the invention, in the closed condition;

Figure 9 is a partially sectional side view of the device for limiting the filling of a tank with fluid of Figure 8;

Figure 10, like Figure 3, is a partially sectional side view of a further embodiment of a device for limiting the filling of a tank with fluid according to the invention; Figure 1 1 is a partially sectional front view of the embodiment of Figure 10, shown in the inactive condition;

Figure 12 is a partially sectional side view of the device for limiting the filling of a tank with fluid of Figure 1 1 ;

Figure 13 is a partially sectional front view of the embodiment of Figure 10, shown in the filling condition; Figure 14 is a partially sectional side view of the device for limiting the filling of a tank with fluid of Figure 13;

Figure 15 is a partially sectional front view of the embodiment of Figure 10, shown in the closed condition; Figure 16 is a partially sectional side view of the device for limiting the filling of a tank with fluid of Figure 15;

Figure 17 is a perspective view of a detail of the embodiment of the preceding figures.

With reference to Figures 1 to 9, a limiter device for limiting the filling of a tank with fluid, generally designated by the reference numeral 1 , is commonly fitted to multipurpose valve devices 100, which are generally applied to the tanks of cars fueled by liquefied petroleum gas.

The limiter device 1 has a main body, which is substantially hollow and is constituted by two portions 2 and 3, which are joined together detachably and form a chamber 4, which is substantially cylindrical and is provided with an inlet 5, which is connected to an inlet duct 6, and with an outlet 7, which is connected directly to the inside of the tank, which is not shown in the accompanying figures.

The chamber 4 slidingly accommodates a blocking valve 8, which is rigidly coupled to a guiding stem 9, which can slide axially and is guided by a through hole 10 formed in the portion 3 of the main body.

The blocking valve 8 has a transverse cross-section which has a polygonal profile or is in any case such as to leave a gap with respect to the walls of the chamber 4, in order to allow the passage of the gas during the filling condition, in which the inlet 5 and the outlet 7 are both free, as shown in the accompanying Figures 6 and 7. An elastic means, preferably constituted by a helical spring 12 which is associated coaxially with the guiding stem 9, keeps the blocking valve 8 in an inactive condition, shown in Figures 4 and 5, in which the blocking valve 8 prevents the flow of gas through the inlet 5, also by means of a gasket 1 1.

The path of the guiding stem 9 affects a milled pivot 13, which is associated rotatably with the portion 3 of the main body so that the longitudinal axis of the former and the rotation axis of the latter are substantially perpendicular.

The milled pivot 13 is provided with a contoured portion 14, which under the action of a floater-type actuation means produces the transition from the filling condition, described earlier, to a closed condition, in which the blocking valve 8 prevents the flow of gas through the outlet 7, as shown in Figures 8 and 9.

In particular, a floater 16 is connected to the end of a rod 15, which is rigidly coupled, at its opposite end, to the milled pivot 13, which converts the ascending and descending motion of the floater 16 into a rotary motion, conditioning the position of the contoured portion 14, which can limit the axial sliding of the guiding stem 9 in the through hole 10 or allow it completely, respectively in the filling and closure conditions.

According to the invention, a movable abutment means 17 is provided in the limiter device 1 for limiting the filling of a tank with fluid and allows to interrupt the action of the elastic means on the blocking valve 8 during the filling condition.

The movable abutment means 17 comprises a spring guiding slider 18, which is guided slidingly by the guiding stem 9, on which it is fitted coaxially by a through cavity

19, which crosses longitudinally the spring guiding slider 18. The profile of the transverse cross-section of the cavity 19 is substantially complementary to the profile of the transverse cross-section of the guiding stem 9.

A receptacle 24 is formed on the spring guiding slider 18 and partially accommodates the helical spring 12, which abuts, at the opposite end, against a seat 20, which is formed in the portion 3 of the main body at the through hole 10.

The spring guiding slider 18 has a pressure surface 21 , which is substantially flat and is formed at right angles to its longitudinal axis, on the opposite end with respect to the end of the receptacle 24, so as to offer the largest possible pressure surface to the gas during filling.

A calibrated bush 22 is associated with the portion 3 of the main body, coaxially to the longitudinal axis of the chamber 4, and forms an abutment surface 23, on the end related to the blocking valve 8, allowing the blocking valve to rest thereon and form a seal during the closed condition. The internal profile of the transverse cross-section of the calibrated bush 22 is substantially complementary to the outside profile of the transverse cross-section of the spring guiding slider 18, which can thus slide therein with extremely limited play, so as to almost form a seal, during the inactive and closed conditions.

As visible in Figures 10 to 17, in which the device for limiting the filling of a tank with fluid has been generally designated by the reference numeral 1 a, the blocking valve 8, which is rigidly coupled to the guiding stem 9, may also be provided with a circular profile, provided that its transverse cross-section is smaller than the transverse cross- section of the chamber 4.

In particular, the gap between the circular profile of the blocking valve 8 and the walls of the chamber 4, considerably facilitates the flow of the gas during the filling condition, and allows the optional insertion, during construction, of a pusher means, not shown in the figures, which is constituted by a second spring, which abuts at one end against the wall of the chamber 4 related to the inlet 5 and at the opposite end against the abutment surface 23 of the calibrated bush 22, keeping the bush in the correct position. In order to ensure a proper seal during the closed condition, despite the reduced dimensions with respect to the variation described earlier, the blocking valve 8 can be provided with a frustum-shaped portion 25, which is formed on its portion related to the guiding stem 9 and is such as to allow convenient mating with the abutment surface 23.

The spring guiding slider 18 may be provided with multiple wings 26a, 26b, 26c and 26d, which are formed on the pressure surface 21 , as clearly shown in Figure 17.

The wings 26, which during the inactive condition rest against the blocking valve 8, transmitting the action of the helical spring 12 thereto, during the filling condition, while allowing correct and constant flow of gas from the inlet 5 to the outlet 7, also act as a guide for the sliding of the guiding stem 9. In the embodiment shown in Figures 10 to 17, the parts that correspond to the parts that have already been described with reference to the embodiment shown in Figures 1 to 9 have been designated by the same reference numerals.

The operation of the device according to the invention is as follows.

In a normal operation for filling the tank of a car fueled by LPG, with gas, starting from the inactive condition shown in Figures 4 and 5, the inlet duct 6 is connected to the pump of the filling station and the dispensing of the gas begins, leading to the filling condition.

In this last condition, the pressure of the gas pushes against the blocking valve 8, causing it to move away from the inlet 5 with a sliding motion which affects indirectly the guiding stem 9, which stops its stroke, blocking the contoured portion 14 of the milled pivot 13, as shown in Figures 6 and 7.

The gas, which flows through the gap that exists between the polygonal profile of the blocking valve 8 and the internal walls of the chamber 4, encounters the pressure surface 21, against which it applies a pressure which is sufficient to cause the spring guiding slider 18 to slide, causing the compression of the helical spring 12, which in this manner interrupts its pushing action against the blocking valve 8 during the filling condition.

The sliding of the spring guiding slider 18 also allows the gas to flow into the tank through the outlet 7, and as the level of the gas increases, the floater 16 rises, causing a rotation of the milled pivot 13, consequently gradually moving the contoured portion 14.

As shown in Figures 8 and 9, when 80% of the capacity of the tank is reached, the closed condition is attained, when the contoured portion 14 of the milled pivot 13 frees the stroke of the guiding stem 9, which thus allows the blocking valve 8 to rest against the abutment surface 23, interrupting the gas flow without having to overcome the contrast of the helical spring 12 and thus allowing the operation of the device 1 for limiting the filling of a tank with fluid even with flow-rates of the dispensing system of less than 2 liters per minute.

Once the filling of the tank has been interrupted by disconnecting the pump of the filling station from the inlet duct 6, the helical spring 12 returns the blocking valve 8 to the initial inactive condition, by means acting on the spring guiding slider 18.

The device for limiting the filling of a tank with fluid shown in Figures 10 to 17 has an operation which is similar to what has been described with reference to Figures 1 to 9, except that during the closed condition the blocking valve 8 prevents the gas from flowing through the outlet 7, resting its frustum-shaped portion 25 against the internal edge of the abutment surface, as shown in Figures 15 and 16. In practice it has been found that the device for limiting the filling of a tank with fluid according to the invention fully achieves the intended aim and objects, being simple and economic and ensuring its correct operation even with extremely low flow-rates of the nozzle and in particular even with flow-rates of less than 2 liters per minute. This application claims the priority of Italian Patent Application No.

VI2005A000210, filed on 26 July 2005, the subject matter of which is incorporated herein for reference.

The device for limiting the filling of a tank with fluid thus conceived is susceptible of numerous modifications and variations, within the scope of the appended claims. All the details may be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to requirements and to the state of the art.

Claims

1. A device for limiting the filling of a tank with fluid, comprising a substantially hollow main body, which forms a chamber provided with at least one inlet and at least one outlet, said chamber slidingly accommodating a flow blocking valve inside it, said flow blocking valve being kept in an inactive condition by an elastic means, in which said blocking valve prevents the flow of said fluid through said inlet, said blocking valve being rigidly coupled to a guiding stem, which interacts with a floater-type actuation means, which is adapted to produce the transition from a filling condition, in which said inlet and said outlet are both open, to a closed condition, in which said blocking valve prevents the flow of said fluid through said outlet, characterized in that it comprises a movable abutment means adapted to interrupt the action of said elastic means on said blocking valve during said filling condition.

2. The device for limiting the filling of a tank with fluid according to claim 1 , characterized in that said movable abutment means comprises at least one spring guiding slider, which is slidingly guided by said guiding stem, with respect to which it is coaxial.

3. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said spring guiding slider comprises a through cavity, which is formed centrally along the longitudinal axis.

4. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that the profile of the transverse cross-section of said through cavity is substantially complementary to the profile of the transverse cross- section of said guiding stem.

5. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said elastic means comprises a helical spring, which is coaxially associated with said guiding stem and abuts against said spring guiding slider and against a seat formed inside said chamber.

6. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said spring guiding slider comprises a receptacle that partially accommodates said helical spring.

7. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said spring guiding slider comprises a pressure surface, which is formed on the end that lies opposite the end related to said receptacle.

8. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said pressure surface is substantially flat and transverse with respect to said through cavity and with respect to the longitudinal axis of said spring guiding slider.

9. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said spring guiding slider comprises multiple wings, formed with a longitudinal extension at said pressure surface.

10. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that it comprises a calibrated bush associated with said main body, inside said chamber and coaxially with respect to said stem.

11. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said calibrated bush comprises an abutment surface, which is formed on the portion related to said blocking valve and forms a seal against the portion of said blocking valve related to said stem during said closed condition.

12. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that the internal profile of the transverse cross- section of said calibrated bush is substantially complementary to the external profile of the transverse cross-section of said spring guiding slider, said spring guiding slider substantially forming a seal against said calibrated bush during said inactive condition.

13. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that it comprises a pressure means which makes said calibrated bush adhere to said main body.

14. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said pressure means comprises at least one second spring, which is inserted inside said chamber and abuts against said chamber and against said abutment surface.

15. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said blocking valve comprises at least one gasket, which is associated with the portion of said blocking valve which lies opposite said stem.

16. The device for limiting the. filling of a tank with fluid according to one or more of the preceding claims, characterized in that the profile of the transverse cross-section of said blocking valve allows the passage of said fluid from said inlet to said outlet during said filling condition.

17. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that the profile of the transverse cross-section of said blocking valve is polygonal.

18. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that the profile of the transverse cross-section of said blocking valve is circular and is narrower than the profile of the transverse cross- section of said chamber.

19. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said blocking valve comprises at least one frustum-shaped portion, which is formed on said portion related to said stem and may be associated with said abutment surface.

20. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said floater-type actuation means comprises a milled pivot, which is rotatably associated with said main body.

21. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that the rotation axis of said milled pivot affects the longitudinal axis of said stem, said two axes being substantially mutually transverse.

22. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said milled pivot comprises a contoured portion, which interferes with said stem and is suitable to produce the transition from said filling condition to said closed condition.

23. The device for limiting the filling of a tank with fluid according to one or more of the preceding claims, characterized in that said floater-type actuation means comprises a rod, which is connected at one end to a floater and is rigidly coupled, at the opposite end, to said milled pivot.