EP0615948A2 - Filling valve for a filling machine - Google Patents

Abstract

The aim is to improve the design and to simplify the control of the valve. This is achieved in that a first spring (18) is provided in a filling valve (1) for filling containers (28) under counterpressure, which stretches the gas pipe (15) around the valve closing body (8) at a distance from one another, the gas pipe bears against an upper stop (22) of the valve closing body and a second spring (25) with a greater pre-tension than that of the first spring (18) is present and the gas tube is brought into its lower end position by the first spring when the control cam (13) is turned downwards , wherein the valve body (8) remains in the closed position and can be moved into the open position by the action of the switching cam (13) on the second spring (25) against the force of the first spring (18). <IMAGE>

Description

The invention relates to a filling valve for a container filling machine, in particular for filling drinks into containers such as bottles, cans and the like under counterpressure, the filling valve being a gas pipe which can be raised and lowered within a valve closing body and a centering bell which can be raised and lowered independently of this for sealing the container mouth from the ambient atmosphere and the control movement of the valve or the movable valve parts can be initiated at least partially by a rotary pinion which can be actuated outside the boiler receiving the filling valves and has switching cams.

Such a filling valve is known for example from DE-OS 2 126 113. This is a valve for filling beverage cans, the liquid to be filled being under pressure and a corresponding counterpressure also being built up in the can to be filled. For this purpose, the can is preloaded with the pressure prevailing in the boiler and, after the pressure has been equalized, the actual filling valve is opened so that the liquid in the boiler can flow into the can using the geodetic gradient. The liquid rises during the filling process to the lower opening of the return gas pipe, whereupon the further filling process stops automatically because no return gas exchange from the container or the can can take place back into the boiler. This is followed by the pressure relief of the can, which is then removed from the filling valve and closed. A centering bell is provided to seal the can on the filling element a differential pressure chamber works, with which the tulip seal is pressed against the container mouth during the filling process. In this known can filling valve, the gas pipe is movably guided within the filling valve body. However, it has a rigid connection to the centering bell, so that the gas pipe end always protrudes a certain distance above the lower edge of the centering bell according to the desired filling height. Accordingly, the lifting movement of the centering tulip must be designed to be larger by at least this protruding gas pipe piece, so that a certain amount of space remains between the tulip or the gas pipe bottom edge and the top of the box during the insertion of the box under the centering bell or under the filling element. This leads to an undesirable large relief volume.

In another known from DE-OS 37 25 609 can fill valve, which also works with a differential pressure chamber, it has already been proposed to store the gas pipe independently of the up and down movable centering bell, so that only a small stroke to lower the centering bell is required. With this valve, the gas pipe is finally lowered into the lower position by opening the closing body, which can also be lowered downwards. This means that when the filling valve closes, the gas pipe is also raised by the amount of the closing stroke, thereby triggering a subsequent change in the final filling level due to the after-running liquid. The gas pipe is controlled by a piston-cylinder arrangement and the movement of the filling valve body is carried out by a fork of a pinion control which can be controlled from the outside.

Based on this known filling valve, the invention has for its object to achieve an improvement in the design and a simplified control of the valve while avoiding a piston-cylinder arrangement.

This object is achieved in a filling valve of the type mentioned in that a first spring is provided which stretches the gas pipe and the valve closing body from one another at a distance, the gas pipe abutting an upper stop of the valve closing body in that a second spring with a stronger spring is on the valve closing body Bias is present than that of the first spring and that when the switch cam is turned downward, the gas pipe is released and brought into its lower end position by the first spring, the valve closing body remaining in the closed position and by the action of the switch cam on the second spring against the force of the first spring can be brought into the open position.

In an independent embodiment of the invention it is further proposed that the valve closing body is held in the closed position by the internal pressure of the boiler acting on a sealing body of the gas pipe via a stop connection which acts against the force of a spring by means of the gas pipe.

It has proven to be advantageous that when the second spring is relieved, the first spring exerts the closing movement of the valve closing body while the gas pipe is still in the lower stop position.

It is also proposed that with a lifting movement of the switching cam, this against the lower end face of a sealing body or at another stop of the gas pipe and can move the sealing body against the inner end face of the ring bowl.

Further features of the invention emerge from the remaining subclaims.

Compared to the prior art, the filling valve according to the invention has significant advantages in the course of the control processes. This means that there is no need to individually control the valves if the container is missing, since the valve closing body cannot be opened if the container is missing. Furthermore, the predetermined upper and lower stops give exact positions of the individual parts of the filling valve individually as well as to one another. Furthermore, a substantially improved cleaning of the entire filling valve in the circulation system can be carried out by switching off a piston-cylinder arrangement. In addition, the springs required for control are arranged above the boiler filling level.

Fig. 1

zeigt das Füllventil in geschlossener Position,

Fig. 2

zeigt das Füllventil in geöffneter Position und eine Variante des Füllventils mit Zuleitungen für Sterilisationsmaßnahmen.

The invention is explained in more detail below on the basis of exemplary embodiments illustrated in the drawings:

Fig. 1

shows the filling valve in the closed position,

Fig. 2

shows the filling valve in the open position and a variant of the filling valve with supply lines for sterilization measures.

According to the exemplary embodiment shown in FIG. 1, filling valves 1 are arranged in a circular order on an annular bowl 2 of a rotating filling machine (not shown further). The filling valve 1 consists of a lower housing 3, on which a centering bell with a pressure seal 4 can be raised and lowered. At the same time, the housing 3 receives a flushing valve 5, which can be opened one or more times by control tracks 6 in accordance with the desired procedure. At the lower end of the housing 3 there is the actual valve seat 7, against which the valve closing body 8 with its seal 9 rests when the filling valve is closed. The valve closing body 8 has a tubular extension 10 which extends into the upper space 11 of the ring bowl 2 and can be moved into the open position by means of a pressure sleeve 12 and a control cam 13 of a control pinion 14 which can be placed thereon. The gas pipe 15 is arranged inside the valve closing body 8 and in the extension 10. This has a thickening 16 in its central region, which can also be provided as a plastic bushing for guiding the extension 10. The lower end 17 of a first spring 18 is supported on this thickening 16. The upper end of this spring 18 rests on an inner ring 19 of the extension 10 of the valve closing body 8. In this way, the valve closing body 8 and the gas pipe 15 are braced against each other. The spring 18 also supports the contact pressure effect due to the difference in area between the gas pipe body and valve closing body 8 after prestressing the container. In this way, the valve closing body 8 remains in the closed position even when the biasing valve 24 is open. When the extension 10 is mutually preloaded of the valve closing body 8 with the gas pipe 15, webs 21 rest on appropriately designed webs 22 of the extension 10. As a result, the valve closing body 8 is held in the closed position.

At the end of the gas pipe 15 a sealing body 23 is arranged, which is brought into the upper position by the control cam 13 of the control pinion 14 and is held by the boiler overpressure.

When the gas pipe 15 is in the upper position, a direct connection to the preload valve 24 is simultaneously established. In this closed position of the filling valve 1, the pressure sleeve 12 is also held in the upper position by a second spring 25 with a greater pre-tension than that of the first spring 18, a projection 26 abutting a stop 27 of the extension 10 of the valve closing body 8.

How the filling valve works

To fill the pressurized liquid, a container 28 is first moved through feed stars or the like under the ring bowl and the filling valve 1 located in the inlet area. Immediately afterwards, the centering bell 4 with its contact seal is lowered onto the mouth of the container 28 by guide rollers and cam tracks (not shown). As soon as the sealing has taken place, the actual filling process can be started. For this purpose, the biasing valve 24 is first actuated by the control track 36, so that a short circuit with the boiler gas or a separate fresh gas, the purging process is initiated with the purge valve 5 open. If this is considered necessary, a corresponding evacuation of the container interior or a corresponding disinfection, steam sterilization or the like can also be carried out. As soon as the various preparatory and / or sterilizing measures of the interior of the container have been completed, the actual prestressing of the interior of the container takes place to the internal pressure prevailing in the filling machine tank. For this purpose, a pressure equalization is first carried out in the container 28 when the biasing valve 24 is open and the flushing valve 5 is closed, and the rotary pinion 14 is actuated by moving against a control track, as a result of which the air tube 15 is moved downward by the biasing of the inner spring 18. After driving a short distance, the lower ends of the webs 21 then come against a stop 30 of the housing 3, as a result of which the lower end position of the gas pipe 15 is reached. This position can be seen in particular from FIG. 2. By further actuation of the rotary pinion 14, the switching cam 13 reaches the upper end face of the pressure sleeve 12, which then acts on the outer spring 25 and, contrary to the inner spring 18, causes the filling valve to open immediately because the outer spring 25 is more pretensioned than the inner one Has spring 18. As shown in FIG. 2, the gas pipe end 31 is in its lower position, which is also responsible for determining the fill level in the container 28. The switching cam 13 still performs a slight overstroke and remains in this position. The liquid in the ring bowl 2 now flows under the influence of geodesic gradient in the container 28 and reaches the lower end face 31 of the gas pipe 15, whereby a further gas exchange is no longer possible and in this way the final filling level is reached. Subsequently, the switching cam 13 of the rotary pinion 14 is moved up again, whereby the closing process for the valve closing body 8 is automatically initiated when the pressure sleeve 12 is relieved by the inner spring 18. Here, the pressure sleeve 12 moves with its stop edge against the stop ring 27, so that the outer spring 25 becomes ineffective and the inner spring 18 exerts the closing process of the valve closing body 8 when the gas pipe 15 is still in the lower stop position. After a short idle stroke, the upper region of the switching cam 13 lies against the lower end face of the sealing body 23 and thus also moves the gas pipe 15 to the stop 22 of the extension 10 of the valve closing body 8 and thus into the upper stop position. Here, the seal 32 lies against the inner end face of the interior of the boiler and at the same time creates a connection to the preload valve 24. By opening the flushing valve 5, the interior of the container above the liquid level is then relieved and the filled container is removed from the filling machine after the centering bell 4 has been raised. According to the exemplary embodiment shown in FIG. 2, there is a further annular chamber 33 with supply lines 34 above the actual ring vessel 2, which can be used, for example, to store a sterilizing agent, for example sterile air, steam or the like, and a direct connection to the gas pipe 15 through the supply lines 34 has, which can be appropriately controlled by special control valves 35.

In particular when sterilizing agents are supplied at elevated temperatures, the annular chamber can be arranged at a certain distance from the annular bowl (2) by insulating means in order to exclude heat transfer to the latter or the filling material.

In the absence of a can, there is no pressure build-up below the filling valve, as a result of which the contact pressure of the seal 23 is fully retained, since the interior has atmospheric pressure in the open gas pipe bore. As a result, the web 21 remains firmly in contact with the stop 22 and the filling valve is closed.

Although the pinion pivots in the open position and thus exerts a force on the sleeve 12 and the spring 25, the valve body remains in the closed position due to the pressure difference between the internal pressure of the boiler and the external pressure. A special control for the rotary pinion 14 is thereby omitted.

Claims (11)

Filling valve for a container filling machine, in particular for filling beverages in containers such as bottles, cans and the like, under counterpressure, the filling valve comprising a gas pipe which can be raised and lowered within a valve closing body and a centering bell which can be raised and lowered independently of this for sealing the container mouth from the Has ambient atmosphere and the control movements of the valve or the movable valve parts can be introduced at least partially from a rotary pinion with switching cams which can be controlled outside the boiler receiving the filling valves, characterized in that a first spring (18) is provided, which the gas pipe (15) and the Valve closing body (8) spans from each other at a distance, the gas pipe (15) abutting an upper stop (22) of the valve closing body (8), that on the valve closing body (8) a second spring (25) with a greater pre-tension than that of the first spring ( 18) is present and that at dev rotation of the switch cam (13) the gas pipe (15) is released and brought into its lower end position by the first spring, the valve closing body (8) remaining in the closed position and by the action of the switch cam (13) on the second spring (25) against the Force of the first spring (18) can be brought into the open position. Filling valve according to the preamble claim 1, characterized in that the valve closing body (8) by the internal pressure of the boiler acting on a sealing body (23) of the gas pipe (15) via a stop connection (21, 22) effective against the force of a spring (18) by means of the Gas pipe (15) is held in the closed position. Filling valve according to claim 1, characterized in that when the second spring (25) is relieved, the first spring (18) exerts the closing movement of the valve closing body (8) while the gas pipe (15) is still in the lower stop position. Filling valve according to claim 1 or 2, characterized in that when the switching cam (13) is moved, it can be placed against the lower end face of a sealing body (23) or against another stop of the gas pipe (15), and the sealing body (23) against the inner end of the boiler (2) moves. Filling valve according to claim 1 or 2, characterized in that the sealing body (23) of the gas pipe (15) is held in the upper position after relieving the gas space of the container by the internal pressure of the boiler. Filling valve according to claim 1 or 2, characterized in that there is a connection to the biasing valve with the upper stop position of the sealing body. Filling valve according to the preceding claims, characterized in that the prestressing of the container interior can be initiated when a flushing valve (5) is closed. Filling valve according to the preceding claims, characterized in that the valve closing body (8) is spring-closing and can be brought into the open position by rotating the switching cam (13). Filling valve according to the preceding claims, characterized in that the gas pipe (15) can be connected in the upper stop position to the feed line (34) of an annular chamber for sterilizing agents (33). Filling valve according to claim 9, characterized in that the sterilization ring chamber (33) is designed as part of the ring bowl (2). Filling valve according to claim 9, characterized in that the sterilizing ring chamber (33) is held at a distance from the ring bowl (2) by insulating means.

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