EP1395490B1 - Dosing device in a tube filling machine - Google Patents

Abstract

The invention relates to a dosing device in a tube filling machine, comprising a dosing chamber in a housing, said chamber having an inlet and an outlet for the medium which is to be dosed. At least one adjustable dosing piston whose volume in the dosing chamber is adjustable is provided in addition to a control bushing which is rotationably mounted in the housing, having at least one connecting channel which joins the inlet or the outlet to the dosing chamber when the control bushing is in a predetermined rotated position. The control bushing has a conical section which is sealingly arranged on a complementary conical section of the dosing chamber and which can be raised therefrom, in addition to an axial through hole in which the at least one dosing piston is displaceably guided. At least one section of the dosing chamber is disposed on the side next to the wider end of the conical section of the control bushing, so that the conical sections are pushed against each other when the pressure in the dosing chamber is increased as a result of movement of the dosing piston.

Description

The invention relates to a tube filling machine with a metering device, with a trained in a housing Dosing chamber having an inlet opening and an outlet opening for a medium to be metered, at least one adjustable metering piston, by means of which the volume of Dosage chamber is changeable, and one rotatable in the housing mounted control sleeve, the at least one connecting channel has, in a predetermined rotational position of the Control sleeve the inlet opening or the outlet opening with the metering chamber connects, wherein the control sleeve has a conical Section having a complementary conical Section of the housing sealingly applied and of this is liftable.

A tube filling machine is used to fill tubes with a tube predetermined, metered amount of a product or Filling medium and usually has one as an endless belt or chain formed conveying device, which a variety of recordings for one tube each. The empty one Tubes are in a feed station in the recordings used the conveyor and then go through several Workstations, which are in particular to a filling station and a downstream sealing station is. In the filling station, the tubes are filled via a filling tube, via a metering device to a filling medium storage connected, filled. The filled tube will then transported to the closure station, in the the upper tube end is closed.

A metering device of known construction (DE 36 36 804 C1) has a housing, which has an inlet opening with the Füllmediumspeicher and via an outlet opening with the Filling tube is connected. In the housing is a control sleeve rotatably mounted, formed in the interior of a metering chamber is that has an access opening depending on from the rotational position of the control sleeve optionally with the inlet or the outlet opening is connected. Within the control sleeve is a metering piston slidably mounted, the a predetermined amount of the filling medium when closed Outlet opening through the inlet opening therethrough suck into the dosing chamber and then closed Slide the inlet opening through the outlet opening and thereby can bring in the tube to be filled. The Intermittent opening and closing of the inlet and Outlet opening is effected by turning the control sleeve.

The control sleeve is via ring seals against the housing sealed and also has a conical Section on, attached to a complementary conical section of the housing is applied. At its one axial end the control sleeve is closed and with an adjusting device connected by means of which it is axially adjustable, so that the two conical sections come out of investment.

When changing the amount of filling medium to be dispensed should, it is usually necessary, the dosing replace, but laborious and therefore costly is, especially the tube filling machine in this Time stands still. However, it is even more complicated if at the tube filling machine after filling a first filling medium a change to another filling medium take place should, since it is necessary for hygienic reasons, the Filling unit and thus the metering completely from residues of the first filling medium. While earlier the dosing device from the tube filling machine completely removed and cleaned by an operator was, while the cleanliness to be achieved by the Quality of the work of the operator was dependent DE 36 36 801 C1 provided by the control sleeve Adjust the adjusting device axially so far that the Housing, the control sleeve and the metering piston from the normal Working position brought into a cleaning position in which they get free from each other and those with whom dosing filling medium coming into contact seals exposed. By introducing a cleaning fluid The components and the seals can then be left over from residues clean the previously filled filling medium. However, that is space required for the adjustment very much great and it has also been shown that the seals by the cleaning process a high wear subject to frequent replacement, which is time consuming and expensive.

Furthermore, a machine according to the preamble of claim 1 known from US-A-4667709.

The invention is based on the object, a tube filling machine with a metering device of the type mentioned to create a compact Construction has and in a simple way a product change allows.

This object is achieved with a tube filling machine with a metering device solved the type mentioned, the characteristic Features of claim 1.

In the metering device is the seal between the control sleeve and the housing alone or at least predominantly by the sealing attachment of the conical Sections of these components achieved. In this way can be a reliable and durable seal between the control sleeve and the housing achieve by the both conical sections are stretched against each other. So that the two conical sections in abutment get rid of each other, only needs the Control sleeve axially displaced by a small amount, whereby a gap is formed between the conical sections is flushed out with a cleaning fluid can be. Subsequently, the control sleeve is again in shifted opposite direction, so that the two conical Portions of the control sleeve and the housing again sealing contact. This way you can special on elastic plastic seals are dispensed with, thereby also the risk of excessive wear and tear the necessity of the seal change no longer exists is.

A particularly compact design of the metering device is achieved in that the control sleeve has an axial through hole in which the at least one metering piston slidably guided. The dosing piston is with a Piston section in the axial through-hole below tight fit and thus sealed taken, so that Again, no special plastic seals necessary are.

The metering chamber is at least partially on the wider end of the conical portion of the control sleeve facing Page trained. If that is in the dosing chamber located filling medium by means of the metering piston through the Outlet opening into the filling nozzle and thus the tube is pressed in, the pressure in the metering chamber increases at. This pressure is used according to the invention that the two conical sections of the control sleeve and the housing be stretched or pressed against each other, causing on the one hand the sealing effect between the housing and the Control sleeve is guaranteed and what else on the other hand too a higher dosing accuracy for low-viscosity products leads.

Particularly good sealing properties can be achieved if the housing and / or the control sleeve and / or the metering piston consist of a ceramic material.

In development of the invention are two coaxial dosing provided, of which a first metering piston than in the axial through bore of the control sleeve guided Ring piston is formed, in turn, an axial bore in which a second metering piston slidably is guided.

This embodiment brings with it the significant advantage itself that the amount of over the outlet opening of the dosing to the tube promoted filling medium in a simple Can be changed without replacing the metering piston. If the two coaxial dosing as a unit will be moved to a relatively large amount Promoted filling medium. If the outer, annular in cross-section however, the first metering piston stops, and only the inner second metering piston is adjusted, becomes a conveyed much smaller amount of filling medium. alternative However, it is also possible, the inner second metering let stand and only the outer annular to adjust the first metering piston, which in turn another amount of filling medium is conveyed, the preferably larger and in particular twice as large as the funded alone by the inner second metering Amount of filling medium is. Preferably, each metering piston a separate drive, especially in the form of a Servo motor assigned.

In development of the invention it is provided that in the axial through bore of the control sleeve a rinsing chamber enlarged diameter is formed, in which a piston portion the first metering piston can be received under play is, and that the rinsing chamber via at least one feed opening a rinsing liquid can be supplied. In the cleaning position the annular first metering piston is so far within the axial through bore of the control sleeve Move that his piston section freely in the washing chamber lies. The inner second metering piston stops and protrudes due to the displacement of the first metering piston free from this forth, so that when introducing a Rinsing fluid and the inner second dosing piston cleaned can be.

If the control sleeve is moved axially, get the both conical sections disengaged and between the Housing and the control sleeve is formed a gap, for cleaning the dosing with a rinsing liquid can be flushed through. The rinsing liquid is preferably introduced in a separate feed opening, in the foot area of the conical section of the housing in this is formed.

In one possible embodiment of the invention, there is an end the control sleeve in the metering chamber and the connecting channel, by means of which a connection between the Dosing chamber and the inlet opening or the outlet opening can be made, then can be structurally easier Form of a frontally opening axial groove.

Although a connecting channel or an axial groove is sufficient, to either the inlet opening or the outlet opening with To connect the dosing, it is to achieve as possible short and fast adjusting movements of the control sleeve useful, at least two connecting channels or axial grooves to be provided, which are arranged so that in no position, both the inlet opening and the inlet opening connected to the dosing chamber.

Preferably, the conical portion of the control sleeve formed on the projecting into the metering axial end, wherein also the axial grooves in the conical section the control sleeve are provided.

Figur 1

einen Vertikalschnitt durch eine erfindungsgemäße Dosiervorrichtung in der Ausgangsstellung,

Figur 2

eine Aufsicht auf die Dosiervorrichtung gemäß Fig. 1 bei abgenommenem Deckel,

Figur 3

die Dosiervorrichtung gemäß Fig. 1 am Ende des Ansaugtaktes,

Figur 4

eine Aufsicht auf die Dosiervorrichtung gemäß Fig. 3 bei abgenommenem Deckel,

Figur 5

die Dosiervorrichtung gemäß Fig. 1 am Ende des Fördertaktes,

Figur 6

eine Aufsicht auf die Dosiervorrichtung gemäß Fig. 5 bei abgenommenem Deckel,

Figur 7

die Dosiervorrichtung gemäß Fig. 1 am Ende des Ansaugtaktes bei einer ersten alternativen Betriebsweise,

Figur 8

die Dosiervorrichtung gemäß Fig. 1 am Ende des Ansaugtaktes bei einer zweiten alternativen Betriebsweise und

Figur 9

die Dosiervorrichtung gemäß Fig. 1 in der Reinigungsstellung.

Further details and features of the invention will become apparent from the following description of an embodiment with reference to the drawings. Show it:

FIG. 1

a vertical section through a dosing device according to the invention in the starting position,

FIG. 2

a plan view of the metering device of FIG. 1 with the cover removed,

FIG. 3

the metering device according to FIG. 1 at the end of the intake stroke,

FIG. 4

a plan view of the metering device according to FIG. 3 with the cover removed,

FIG. 5

the metering device according to FIG. 1 at the end of the delivery cycle,

FIG. 6

a plan view of the metering device according to FIG. 5 with the cover removed,

FIG. 7

1 at the end of the intake stroke in a first alternative mode of operation,

FIG. 8

the metering device according to FIG. 1 at the end of the intake stroke in a second alternative mode of operation and

FIG. 9

the metering device according to FIG. 1 in the cleaning position.

1 comprises a metering device 10 in a tube filling machine a housing 11 which is not closer to one shown carrier 17 is held. In the housing 11 is an axial bore 12 formed in the upper area of the housing 11 is continuously flared. This conically enlarged portion 12 a of the axial bore 12th defines in its interior a metering chamber 13, the the upper end of the housing 12 by a lid 16 sealing is closed.

In the central region of the conical section 12a is in the housing 11 is formed a radial inlet opening 14, by a filling medium in the metering chamber 13 can be introduced is as indicated by the arrow M. Diametrically opposed to the inlet opening 14 is in the housing 11 a radial Outlet opening 15 is formed through which the filling medium from the metering chamber 18 to a not shown Fülldüse is herausdrückbar, as indicated by the arrow F in FIG. 5 is indicated. In the lower part of the conical section 12a, i. in the transition between the axial bore 12th and its conical portion 12 a is in the housing 11 a formed radial bore 11 a, which is connected to a not shown Stock of flushing liquid is connected.

In the axial bore 12 of the housing 11 is a control sleeve 18 inserted, with a lower circular cylindrical section sits in close fitting in the axial bore 12 and at the upper end a flared portion 18a having the same pitch angle as the conical Section 12a of the axial bore 12 has. Between the upper end side of the conical portion 18a of the control sleeve 18 and the lid 16, the metering chamber 13 is formed.

1 shows the control sleeve 18 in its lower position, in the conical section 18a sealing it to the conical Section 12a of the axial bore 12 is present. In the conical Section 18 a of the control sleeve 18 are two at the upper end opening axial grooves 18b and 18c (see Fig. 2) are formed, which in width substantially the width of the inlet opening 14 and the outlet opening 15 and up to their foot area extend. The two axial grooves 18b and 18c are in the circumferential direction the control sleeve by an angle of about 135 ° added. When the control sleeve 18 in the in Fig. 1 and 2 shown position in which the axial groove 18b, a connection between the inlet port 14 and the Dosing chamber 13 produces, is also the connection between the metering chamber 13 and the outlet port 15 is interrupted. When the control sleeve 18 from that shown in Fig. 2 Position at an angle of approx. 45 ° clockwise is rotated, thereby the connection between the inlet opening 14 and the metering chamber 13 is interrupted and instead the connection between the dosing chamber 13 and the outlet opening 15 made.

In the control sleeve 18 is a central axial through hole 18d formed in the lower portion of the control sleeve 18 to a washing chamber 18e larger diameter is extended. The rinsing chamber 18e is via a radial feed opening 21 to the supply of flushing liquid, not shown connected.

In the axial through hole 18 d of the control sleeve 18 is a first metering piston 19 used slidably, the has an annular cross-section and at its upper End has a piston portion 19 a, which under close Fit in the axial through hole 18d of the control sleeve 18 is sitting. Below the piston portion 19 a are the Dimensions of the first metering 19 reduced. The metering piston 19 penetrates at the lower end of the control sleeve 18 at a bore 18f and is guided by this.

In the first metering piston 19 is a central axial bore 19b formed of constant cross-section, in which a second Dosing piston 20 is slidably disposed. The second Metering piston 20 has an upper piston portion 20a, the tight fit and sealed in the axial bore 19b of the first metering piston 19 is seated. At the bottom the piston portion 20 a of the second metering piston 20 joins a piston rod portion 20 b, which is a lower guide and cover plate 22 of the first metering piston 19 penetrates sealing and is guided by this. The axial bore 19b of the first metering piston 19 has its lower end a feed opening 23, also at the supply of flushing liquid is connected.

The first metering piston 19 can either together with the second metering piston 20 as a unit in the axial bore 18d the control sleeve 18 are moved, but it is also possible, each of the metering pistons 19 and 20 regardless of to adjust the other dosing piston.

The following is the operation of the metering device as well as their possible operating modes exemplified become:

Figs. 1 and 2 show the starting position of a dosing. Here are the two metering 19th and 20 with their piston portions 19a and 20a respectively in FIG an upper end position and the control sleeve 18 is so within the housing 11 is set that the inlet opening 14 via the axial groove 18b with the metering chamber 13 in connection stands. The connection between the metering chamber 13 and the outlet opening 15 is interrupted. Starting from this Position the two metering 19 and 20 as a unit within the axial bore 18d of the control sleeve 18 after adjusted down, whereby the volume of the metering 13th is increased (see Fig. 3). The thereby adjusting Vacuum sucks the filling medium through the inlet opening 14th and the axial groove 18b in the metering chamber 13. When the metering 19 and 20 have reached their lower end position, the control sleeve 18 is rotated by 45 °, whereby the Connection between the inlet port 14 and the metering chamber 13 is interrupted and instead a connection made between the metering chamber 13 and the outlet port 15 is (see Fig. 6). Thereupon the two become Dosierkolben 19 and 20 together adjusted upwards, whereby the volume of the metering chamber 13 again reduced is, which causes the filling medium from the metering chamber 13 via the axial groove 18 c through the outlet opening 15th is pushed out. The resulting pressure increase within the metering chamber 13 also acts on the control sleeve 18 and push it down so that the conical section 18a of the control sleeve 18 against the conical section 12 of the axial bore 12 of the housing 11 is pressed becomes, whereby the sealing effect is reinforced. At the end the stroke of the metering piston 19 and 20 are these again in its upper end position (see Fig. 5), whereby the conveying process is finished. The control sleeve 18 is then again rotated by 45 ° in the opposite direction, so that again the Starting position shown in FIG. 1 is reached, from the one new dosing can be started.

When the amount of the through the two metering 19 and 20 metered filling medium is too large, the dosing 19 and 20 are also adjusted independently. One first example of this is shown in FIG. outgoing from the initial position shown in FIG. 1, in which the metering chamber 13 via the axial groove 18 b with the inlet opening 14th is connected, now not both dosing 19th and 20, but the inner second metering piston 20 stops and only the annular outer first metering piston 19 is adjusted down, so that also Pumped fluid through the inlet port 14 and the axial groove 18 b is sucked into the metering chamber 13, however, is the Volume increase of the metering chamber 13 is lower, so that also the sucked filling medium quantity is reduced.

By turning the control sleeve 18 and returning the outer annular first metering piston 19 in the starting position can be located in the metering chamber 13 filling medium pushed out through the axial groove 18 c and the outlet port 19 become.

Fig. 8 shows an alternative mode of operation in which the outer annular first metering piston 19 stops while only the inner second metering piston 20 for sucking the Filled medium in the metering chamber 13 down becomes. The volume increase of the dosing chamber achieved thereby 13 is even lower than the previously explained Example in which only the outer first metering piston 19 adjusted is dosed so that an even smaller amount of filling medium becomes. Again, after rotation of the control sleeve 18 pushed out the filling medium from the metering chamber 13, by the second metering piston 20 in its upper initial position is reset.

When changing the filling medium to be metered must Dosing device 10 are cleaned. For this purpose let the components in a so-called cleaning position method, which is shown in Fig. 9. For one thing the outer first metering piston 19 within the axial Through hole 18 d of the control sleeve 18 as far down method, that its piston portion 19 a free in the washing chamber 18e of the control sleeve 18 is arranged. The piston section 20a of the inner second metering piston 20 is completely upward from the axial bore 19b of the first Dosing piston 19 and is free within the axial Through hole 18 d of the control sleeve 18. This is pushed upwards by a small amount relative to the housing 11, causing her conical section 18a of the plant with the conical portion 12a of the axial bore 12 of the housing 11 is released. Through the feed opening 21 is cleaning or rinsing liquid is introduced into the rinsing chamber 18e, as indicated by the arrow C1, the piston portion 19 a of the outer first metering piston 19 flows around and thereby cleans. In addition, through the feed opening 23 in the axial bore 19b of the first metering piston 19 cleaning or rinsing liquid introduced, as indicated by the arrow C2, the axial bore 19b flows through and exits at the top and then the exposed piston portion 20a of the inner second metering piston 20 lapped.

By the axial adjustment of the control sleeve 18 relative to the housing 11 is between the conical portion 12 a of Axial bore 12 of the housing 11 and the conical section 18a of the control sleeve 18, an annular gap formed at its lower end communicates with the opening 11a, introduced by the cleaning or rinsing liquid becomes as shown by the arrow C3. additionally can also through the inlet port 14 cleaning and rinsing fluid be introduced (arrow C4). The named in Way introduced cleaning and rinsing liquid can be discharged through the outlet port 15, for example, as indicated by the arrow C5.

After completion of the cleaning process, the outer first Dosierkolben 19 within the control sleeve 18 upwards proceed until its piston portion 19a sealing under close Fit in the axial through hole 18d of the control sleeve 18 is arranged. An adjustment of the control sleeve 18 in the axial direction brings back the two conical Sections 12a and 18a in sealing contact, so that then again reached the initial position shown in Fig. 1 is.

Claims (9)

1. Tube filling machine with a dosing device, comprising a dosing chamber (13) which is formed in a housing (11) and having an inlet opening (14) and an outlet opening (15) for a medium to be dosed, with at least one adjustable dosing piston (19, 20) with which the volume of the dosing chamber (13) can be changed, and a control sleeve (18) which is rotatably disposed in the housing (11) and which has at least one connecting channel (18b, 18c) to connect the inlet opening (14) or the outlet opening (15) to the dosing chamber (13) at respective predetermined rotated positions of the control sleeve (18), wherein the control sleeve (18) has a conical section (18a) which can be sealingly disposed on a complementary conical section (12a) of the housing (11) and be lifted therefrom, with at least one section of the dosing chamber (13) being formed on the side facing the wider end of the conical section (18a) of the control sleeve (18), wherein the conical sections (12a, 18a) can be clamped against each other when the pressure in the dosing chamber (13) increases in response to motion of the dosing piston (19, 20), characterized in that the control sleeve (18) has an axial bore (18d) and two coaxial dosing pistons (19, 20) are provided one (19) of which is formed as an annular piston which is displaceably guided in the axial bore (18d) of the control sleeve (18) and has an axial bore (19b) in which a second dosing piston (20) is displaceably guided.
2. Dosing device according to claim 1, characterized in that the two dosing pistons (19, 20) can be adjusted as a unit or independently of each other.
3. Dosing device according to claim 1 or 2, characterized in that each dosing piston (19, 20) has its own drive in the form of a servomotor.
4. Dosing device according to any one of the claims 1 through 3, characterized in that a rinsing chamber (18e) with enlarged diameter is formed in the axial opening (18d) of the control sleeve (18), in which a piston section (19a) of the first dosing piston (19) can be received with play, wherein the rinsing chamber (18e) can be supplied with rinsing liquid through at least one supply opening (21).
5. Dosing device according to any one of the claims 1 through 4, characterized in that rinsing liquid can be introduced through at least one supply opening (11a) of the housing (11) into a space formed between the housing (11) and the control sleeve (18) when the conical section (18a) is lifted.
6. Dosing device according to any one of the claims 1 through 5, characterized in that the housing (11) and/or the control sleeve (18) and/or the dosing pistons (19, 20) are made from ceramic material.
7. Dosing device according to any one of the claims 1 through 6, characterized in that the connecting channel is formed by an axial groove (18b, 18c).
8. Dosing device according to claim 7, characterized in that at least two axial grooves (18b, 18c) are provided through which the inlet opening (14) or the outlet opening (15) can be connected to the dosing chamber (13).
9. Dosing device according to claim 7 or 8, characterized in that the axial grooves (18b, 18c) are formed in the conical section (18a) of the control sleeve (18).

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