DE1010342B - Three-way drain cock with automatic bleeding, especially for fuels - Google Patents

Description

GERMAN

The invention relates to a three-way drain cock with automatic ventilation, in particular for fuels. Three-way drain cocks for fuels are already known in many versions. The known constructions have, mostly conical or cylindrical Chicks open and have the switch positions "closed", "open" and "reserve". The vent of such a Drain cock is made by having a Vent noJir from the chick room a little over the The maximum level of the fuel protrudes. The purpose of the vent line is to remove fuel vapors or air bubbles that form in the drain line located between the tap and the carburetor, dissipate. The venting is very important as a progressive bubble formation prevents the flow of the fuel can hinder and sometimes even completely prevent it. Used for gasoline engines or two-stroke engines the fuel supply from the fuel tank to the carburetor by means of gravity running of the fuel then results in an imperfect Venting the inflow line will cause a low fuel combustion which will damage the piston and Cylinders. The well-known, apparently unfounded, engine stall is almost always due to the fact that the fuel supply was temporarily cut off by the formation of bubbles.

Attempts have already been made to solve the problem of venting by means of a special shape of the drain cock to solve. However, the known drain cocks have too high a flow rate in the Chicks, which made it difficult and difficult for the air bubbles to rise. In the inventive Hahn, the flow rate in the chick is deliberately kept lower, especially but what is achieved is that the downwardly flowing fuel and the upwardly rising bubbles Separate them at the chick entrance in such a way that the gas or air passes freely can escape above.

This object of the invention is achieved in that the passage in the chick in section transverse to the chick axis is limited by two convexly curved contours, of which in each of the two open positions one merges into one contour of the derivation without a kink, the other also into one contour of the Ventilation line, whereby the passage has a larger cross-section at every point than the supply lines.

Experiments have shown that a liquid is passed over a convex cylindrical jacket-shaped surface is due to the adhesion of this surface via the '-.rch gravity and flow reaction Path length follows. Furthermore, the flow at this point is largely laminar Character.

Three-way drain cock
with automatic ventilation,
especially for fuels

Applicant:

Ernst Heinkel Aktiengesellschaft,
Stuttgart-Zuff enhaus en,
Hellmuth-Hirth-Strasse

Horst Speer, Stuttgart-Feuerbach,
has been named as the inventor

Fig. 1 shows in section a three-way drain cock according to the invention in the "closed" position;

Fig. 2 shows the same tap in section in the "open" position, and

Fig. 3 shows the tap in section in the "reserve" position.

In the plug hole 1 of the three-way drain cock 2 there is the plug 3, the passage opening 4 of which is delimited by the plug walls 5, its contour protrudes convexly into the chick space 4. The chick space 1 is through the fuel supply line 6 connected to the fuel tank (not shown). The fuel drain line 7 leads from the chick space to the carburetor (not shown). Furthermore, the fuel supply line 8 (to the reserve tank, not shown) and the vent pipe 9 connected to the chickweed.

The mode of operation of this arrangement is shown in FIGS. Fig. 2 shows the. Three-way drain cock in the "open" position, d. H. with connection of the fuel tank to the carburettor. The fuel moves through the fuel supply pipe 6 into the plug chamber 4 and is here over the curved Area 5 headed. Following this area, the fuel flows off through the fuel drain pipe 7. the Flow is held by surface 5 on the right (relative to the aspect of the drawing) and has a laminar character when exiting the chick. The cross section of the chick opening is greater than the sum of the cross-sections

■ r 709 548/243

of the respectively connected lines 6, 7, so that the Flow velocity and thus the flow pressure in the plug when the liquid enters the Chick is severely degraded. As a result of this arrangement, the air bubbles can pass through unhindered the chick upwards, escape, because of the greatly reduced flow pressure there hold by the left side (aspect of the drawing). '

Since the edges of the plug opening lie exactly on the inlet openings of the pipeline 6, 7, 9, there is the possibility of congestion or turbulence.

Fig. 3 shows the same process when the reserve tank is connected to the carburetor is.

Claims (1)

-Patent claim: Three-way drain cock, with automatic venting, in particular reserve gasoline valve, characterized in that the passage in the plug in the Section transverse to the chick axis is bounded by two convexly curved contours, of which in each of the two open positions merges into the one contour of the derivative without a kink, the others also into one contour of the vent line, the passage being larger at each point Has cross-section than the supply lines. Considered publications:
German Patent Nos. 217 525, 457 574, 054; French patents nos. 786 419, 971 176. 1 sheet of drawings . © 709 548/243 6.57