1. Field
The invention relates to a switching valve for the transmission of fluids, in particular to the filling of gas tanks.
2. Description of the Related Art
Transmitting systems with such switching valves achieve a safe transmission of a fluid from a pressure source to a gas tank, for example in a fuelling system. Therein the simple operability and safety against contamination is of particular importance. Thus, U.S. Pat. No. 6,769,450 describes a valve system in which possible contamination from back flowing gas is prevented by a check valve such that residual quantities in the valve system are discharged by a vent valve in a controlled manner.
Further, WO 98/05898 of the Applicants describes a switching valve in the embodiment of a quick coupling, wherein a housing with a fluid inlet and a fluid outlet as well as several valves are provided in order to ensure a safe seal. These valves are controlled in a certain predetermined order by means of a control lever after connecting the quick coupling, whereby first the outlet valve will be opened, then the collets are closed with further movement of the control lever and finally the inlet valve is opened. Here, the control lever is an eccentric shaft with a sliding sleeve for actuating of the collets engaged with a sealing piston, which also releases the fluid inlet after complete coupling of the quick-connection. Further, a vent valve is provided for enabling pressure equalization before removing the quick-connect coupler even with high pressures without the risk of a backstroke. When closing the valves the exhaust valve works in type of a check valve. Although a safe connection is provided in this way, this coupling still has relative high manufacturing expenditure, in particular by the manual operation via the eccentric shaft.
Thus, the object of the invention is to provide a switching valve of the initially mentioned type that has a compact structure and enables simple handling as well as preventing contamination or a fluid reflux by controlled venting.
The suggested switching valve with slide is suitable in particular for use in filling of gas tanks, whereby a simple and compact construction results since the switching valve with put-on control valve for pressure controlled operation of a pivoting lever is compact and stably formed in order to be integrated in filling systems in a space-saving manner.
The proposed pivoting lever is preferably designed with a leverage, i.e. with different lever lengths, so that a strong operation of the slide is achieved on actuating the valve. The piston of the control valve is preferably connected with the pivoting lever via a bolt, which is particularly arranged at a pivot axis in an intermediate housing. Thus, a sensitive control results, in particular when the piston surface cross sections of the piston are equally formed for the inlet and discharge openings. Further, a simple attachment to the valve housing is achieved, likewise a compact connection with a bypass line for actuating of the pressurized control valve.
Subsequently an embodiment is explained and described by the accompanying drawing. Herein:
The housing part 11a encloses a check valve 25 that is represented in
Further, in the right housing part 11c an inlet valve 45 with an associated valve seat is disposed towards the inlet range 12. The inlet valve 45 is likewise shifted by the pivoting lever 50 and the coupling with the switching slide 27 in axial direction, since the switching slide 27 also shifts a valve slide 47 of the inlet valve 45 from the closed position (shown here) into the open position by the movement of the sealing disc 24 of the vent valve 35 towards the right side in type of a sequence control, so that the fluid inflowing from the inlet range 12 can flow through the hollow valve slide 47 and a passage in the sealing disc 24 as well as via the tubular switching slide 27 to the outlet 13, since check valve 25 is here also pressed into the open position by the filling pressure (of the fuelling system or another pressure source/filling pump).
As mentioned above, the housing 11 (including inlet valve 45, vent valve 35 and check valve 25 inserted therein) bears an intermediate housing 19 onto which the control valve 20 is fitted. In this valve 20 a piston 21 is inserted (and laterally sealed), and urged by a spring 22 to the right position, shown here. The two faces, which are exposed to the respective pressure in the bypass line 15, preferably possess the same dimension, such that the piston 21 can shift with smallest pressure differences between right (inlet) and left (discharge opening) side in a sensitive way. The response threshold pressure is defined by the spring 22. The piston 21 is coupled to the pivoting lever 50 by a bolt 53, so that the control valve 20 can operate the valves 35 and 45 via the slide 27 in a pressure controlled manner.
If the pressure in the inlet range 12 (here right side) is higher than on the outlet side 13, as this is the case on starting and performing a filling operation, then first the piston 21 is moved to the left side here and the slide 27 is moved to the right (by swiveling the pivoting lever 50 in anticlockwise direction). The vent valve 35 is also closed and the inlet valve 45 is pressed into open position. As described above, the fluid then flows through the hollow slide 27, pushes the check valve 25 into open position and flows to the gas tank (to be filled) via the outlet portion 13.
Then, the pressure on the outlet side becomes larger than the inlet pressure on the end of the filling operation (with filled gas tank or shutdown of the filling pump), such that the piston 21 goes back into the starting position, shown here (right stop), whereby the pivoting lever 50 makes the slide 27 to move again to the left, so that the inlet valve 45 becomes closed, but the vent valve 35 will still be open, in order to bleed out the space between inlet valve 45 and check valve 25, likewise closed in the meantime (because of the missing inlet pressure). On this swiveling of the pivoting lever 50 (in the clockwise direction) the switching slide 27 is moved to the left, so that the sealing disc 24 of the vent valve 35 releases from its sealing position. Here, the sealing disc 24 and the switching slide 27 as well as the valve slide 47 slightly separate from each other into axial direction, so that the pressure can diminish itself to a pressure balance area 44, which is formed around the sealing disc 24 as recess-like annular space in a gradation at the housing part 11c.
On opening the vent valve 35 by the switching slide 27, as described above, pressurized fluid “caught” in the switching valve escapes via the pressure balance area 44 to a bleed bore 43 at the housing part 11c, in order to flow into a recycling hose or a tank or into the atmosphere, if the fluid is not dangerous.
As regards the pivoting lever 50 it is pointed out that the lever prolongations on both sides of the pivot axis 52 are different, e.g. here in the ratio 3:1, so that force leverage is achieved. Thus, a strong operation of the slide 27 and the valves coupled thereto is achieved, even with relative small construction of the control valve 20 (and/or diameter of the piston 21). This transmission can be easily changed e.g. by changing the intermediate housing 19 and the pivot axis 52 or extension of the pivoting lever 50 located therein, f. i. for adapting to respective filling pressures. Thus, application of the switching valve 10 with a control valve 20 saddled thereon, is more variable, in particularly when the change, if necessary, is rapidly made by means of screws 60 (cf.
Number | Date | Country | Kind |
---|---|---|---|
20 2006 011 681 U | Jul 2006 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2007/006654 | 7/27/2007 | WO | 00 | 5/6/2009 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2008/012095 | 1/31/2008 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3753447 | Davis et al. | Aug 1973 | A |
5056549 | Bouilloux et al. | Oct 1991 | A |
6769450 | Fretwell | Aug 2004 | B2 |
6926310 | Weh et al. | Aug 2005 | B1 |
Number | Date | Country |
---|---|---|
0351319 | Jan 1990 | EP |
0579355 | Jan 1994 | EP |
1239201 | Sep 2002 | EP |
1321639 | Jun 1973 | GB |
WO 9805898 | Feb 1998 | WO |
WO 0052378 | Sep 2000 | WO |
Number | Date | Country | |
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20090314362 A1 | Dec 2009 | US |